Electrical and Electronics Engineering publications abstract of: 11-2017 sorted by title, page: 2

» A Simplified Finite-Element Model of Hybrid Excitation Synchronous Machines With Radial/Axial Flux Paths via Magnetic Equivalent Circuit
Abstract:
In this paper, a novel modeling method for hybrid excitation synchronous machines (HESMs) with radial/axial flux paths via magnetic equivalent circuit (MEC) is proposed. 3-D finite-element analysis (FEA) is essential when analyzing a machine with radial/axial flux paths due to the asymmetry in the axial direction. However, 3-D FEA is computationally expensive and time-consuming, especially during the preliminary design stage. The proposed modeling method is analyzed and validated based on an HESM with magnetic shunting rotor. The fundamental structure and working principle of the HESM with magnetic shunting rotor are introduced. On the basis of 3-D structure, an MEC considering saturation and leakage flux distribution is built and illustrated, as well as field analysis is performed. A 2-D equivalent finite-element model via MEC is built and illustrated. A prototype HESM with magnetic shunting rotor has been designed by the proposed modeling method and developed for experimental verification. With the proposed modeling method, the computational efficiency is significantly improved in the design stage. The proposed modeling method is verified by the good agreement between the predicted and measured results.
Autors: Ye Liu;Zhuoran Zhang;Weiwei Geng;Jincai Li;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Simplified Model for the Retrieval of Precipitable Water Vapor From GPS Signal
Abstract:
In this paper, a simplified latitude and day-of-year (DoY)-based model is proposed for the retrieval of precipitable water vapor (PWV) from global positioning system (GPS) signal. Conventionally, PWV, the total amount of water in a vertical column of a unit cross-sectional area, is estimated from the GPS signal delay and a dimensionless conversion factor PI. This PI value is found to rely on a water vapor weighted mean temperature (Tm) value which varies widely across the day, month, and year for different regions. It is, therefore, both time specific and site specific. Analysis of the PI value and its effect on the retrieved PWV from the data obtained for tropical, subtropical, and temperate regions show that although the PI value is time and site specific, the change in the median value of PI for different years is minimal and is dependent only on factors like the latitude coordinates of the particular site and the DoY. Therefore, using the data obtained from 174 different sites, a latitude-coordinate and DoY-based PI value model for the retrieval of PWV is proposed in this paper. The proposed model has been successfully validated using data from different databases: the International GNSS Service Global Positioning System National Aeronautics and Space Administration (IGS GPS NASA) database, the International GNSS Service Global Positioning System Global Geodetic Observing System (IGS GPS GGOS) database, and the very-long-baseline interferometry (VLBI) database. Results show strong agreement between PWV values calculated using the proposed model and those calculated using the temperature dependent models with 99%, 98%, and 93% of error within ±1 mm for IGS GPS NASA, IGS GPS GGOS, and VLBI databases, respectively. Moreover, the proposed model allows for the ease of PWV retrieval, which is useful in meteorological studies and also applicable in satellite communi- ations.
Autors: Shilpa Manandhar;Yee Hui Lee;Yu Song Meng;Jin Teong Ong;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6245 - 6253
Publisher: IEEE
 
» A Single-Channel EOG-Based Speller
Abstract:
Electrooculography (EOG) signals, which can be used to infer the intentions of a user based on eye movements, are widely used in human–computer interface (HCI) systems. Most existing EOG-based HCI systems incorporate a limited number of commands because they generally associate different commands with a few different types of eye movements, such as looking up, down, left, or right. This paper presents a novel single-channel EOG-based HCI that allows users to spell asynchronously by only blinking. Forty buttons corresponding to 40 characters displayed to the user via a graphical user interface are intensified in a random order. To select a button, the user must blink his/her eyes in synchrony as the target button is flashed. Two data processing procedures, specifically support vector machine (SVM) classification and waveform detection, are combined to detect eye blinks. During detection, we simultaneously feed the feature vectors extracted from the ongoing EOG signal into the SVM classification and waveform detection modules. Decisions are made based on the results of the SVM classification and waveform detection. Three online experiments were conducted with eight healthy subjects. We achieved an average accuracy of 94.4% and a response time of 4.14 s for selecting a character in synchronous mode, as well as an average accuracy of 93.43% and a false positive rate of 0.03/min in the idle state in asynchronous mode. The experimental results, therefore, demonstrated the effectiveness of this single-channel EOG-based speller.
Autors: Shenghong He;Yuanqing Li;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Nov 2017, volume: 25, issue:11, pages: 1978 - 1987
Publisher: IEEE
 
» A Single-Crystal Mössbauer Study of Spin Reorientations in the Multi-Ferroic HoFeO3
Abstract:
57Fe Mössbauer spectroscopy on single crystal slices has been used to study the spin reorientation transition that occurs in HoFeO3 for K. We also prepared a powder sample for comparison and confirmed that the results were consistent between the two data sets. By using thin polished slices cut perpendicular to the three orthorhombic axes we have been able to follow --axis reorientation in detail and confirm that moments also tip toward the −axis by ~ 20° before returning closer to the −plane. We also show that the moments are never fully parallel or perpendicular to any of the three orthorhombic axes; a consequence of the mixed ferro-/antiferro-magnetic structure adopted by HoFeO3.
Autors: D. H. Ryan;Quentin Stoyel;Larissa Veryha;Kai Xu;Wei Ren;Shixun Cao;Zahra Yamani;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Soft Four Degree-of-Freedom Load Cell Based on the Hall Effect
Abstract:
This paper presents the design of a soft four degree-of-freedom load cell that is robust and light-weight and can be integrated into robotic applications. The sensor measures three axes of force and a single axis of torque about the central axis. The sensor is comprised of a magnet suspended within an elastomer above two three-axis Hall effect sensors. As a load is applied, the magnet is displaced within the elastomer that results in changes in the magnetic flux density at the locations of the two Hall effect sensors. Experimental measurements of magnetic flux density within the area of interest were used to formulate analytical expressions to relate magnet field strength to the position of the magnet. The displacement and orientation measurements combined with the material properties of the elastomer are used to calibrate and calculate the applied load. The ability to measure the three degrees-of-freedom force and axial torque was evaluated with combined loading applied by a robotic arm. The decoupled results show the four degree-of-freedom load cell can distinguish three axes of force and one axis of torque with 6.9% average error for normal force, 4.3% and 2.6% average error for shear force in the - and -axes, respectively. There was 8.6% average error for the torque.
Autors: Qiandong Nie;Frank C. Sup;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7355 - 7363
Publisher: IEEE
 
» A Soft-5/6 Modulation Code With Iterative ITI Subtraction Scheme in Multireader TDMR Systems
Abstract:
The huge growth of the consumer electronic industry is driving the need for achieving ultrahigh areal storage densities. 2-D magnetic recording is a promising high-density storage technology where the shingled writing technique is employed for increasing the track per inch (TPI) and achieving higher areal densities. Nevertheless, high TPI causes a reader to cover higher number of tracks, which leads to the intertrack interference (ITI); hence the system performance is severely deteriorated. Therefore, we first propose the soft-5/6 modulation code together with iterative ITI subtraction scheme. Here, the soft information encoding and decoding schemes operate based on Boolean logic circuit for using in the iterative system. Furthermore, we also propose to move the upper and lower readers closer to the center reader to avoid the ITI effect from their outer tracks, which will then be performed together with ITI subtraction scheme. Moreover, this proposed reading technique is also applied together with the soft-4/5 modulation code. The simulation results show that the proposed systems are superior to the conventional system, especially at high user density.
Autors: Kotchakorn Pituso;Chanon Warisarn;Damrongsak Tongsomporn;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Sparse Linear Model and Significance Test for Individual Consumption Prediction
Abstract:
Accurate prediction of user consumption is a key part not only in understanding consumer flexibility and behavior patterns, but in the design of robust and efficient energy saving programs as well. Existing prediction methods usually have high relative errors that can be larger than 30% and have difficulties accounting for heterogeneity between individual users. In this paper, we propose a method to improve prediction accuracy of individual users by adaptively exploring sparsity in historical data and leveraging predictive relationship between different users. Sparsity is captured by popular least absolute shrinkage and selection estimator, while user selection is formulated as an optimal hypothesis testing problem and solved via a covariance test. Using real-world data from PG&E, we provide extensive simulation validation of the proposed method against well-known techniques such as support vector machine, principle component analysis combined with linear regression, and random forest. The results demonstrate that our proposed methods are operationally efficient because of linear nature, and achieve optimal prediction performance.
Autors: Pan Li;Baosen Zhang;Yang Weng;Ram Rajagopal;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4489 - 4500
Publisher: IEEE
 
» A Spatial Modulation With Space-Phase Constellation for Spatially Correlated Channels
Abstract:
We design a spatial modulation (SM) scheme for spatially correlated channels under the constraints of a single radio frequency chain transmitter and open-loop transmission. To alleviate the performance degradation of the conventional SM in highly correlated channels, the proposed SM scheme adopts the antenna grouping and a new space-phase constellation, which is designed by considering the phase-only constraint and received symbol distance in fully correlated channels. In the simulation results, the proposed scheme achieves about 2.5-dB gain at bit error rate of compared with the conventional SM in highly correlated channels.
Autors: Yongjin Ahn;Hoondong Noh;Chungyong Lee;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2396 - 2399
Publisher: IEEE
 
» A Study of the Effect of RRAM Reliability Soft Errors on the Performance of RRAM-Based Neuromorphic Systems
Abstract:
Resistive RAM (RRAM) device has been extensively used as a scalable nonvolatile memory cell in neuromorphic systems due to its several advantages, including its small size and low-power requirements. However, resulting from the stochastic nature of the oxygen vacancies, the RRAM device suffers from reliability soft errors. In this paper, we provide for the first time a modeling framework to compute the effect of those soft errors on the system accuracy. Applying the proposed technique on a case-study system used to recognize the MNIST data set, our simulation results show that the system accuracy can degrade from 91.6% to 43% due to the RRAM reliability soft errors. To overcome this loss in the system performance, various possible adjustments to the parameters of the neuron pulses are analyzed. Furthermore, in this paper, two methodologies are proposed for automatically detecting and fixing the degradation in the system accuracy caused by the RRAM reliability soft errors. Using the suggested methodologies, the system accuracy of our case-study system can be restored back from 43% to 91.6% with small increase in the training cycle duration and with as small as 0.1% increment in the energy consumption of the system.
Autors: Amr M. S. Tosson;Shimeng Yu;Mohab H. Anis;Lan Wei;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3125 - 3137
Publisher: IEEE
 
» A Study of Wind Direction Effects on Sea Surface Specular Scattering for GNSS-R Applications
Abstract:
A modeling study investigating the influence of wind direction on spaceborne global navigation satellite system reflectometry (GNSS-R) near-specular observations of the sea surface is reported. The study first focuses on a purely specular geometry under plane wave incidence, for which it is shown using the theorem of reciprocity and reflection symmetry that up-down wind variations are identically zero. It is also shown that “single-scattering” approximations of rough surface scattering predict no variations with wind direction of any kind for a purely specular geometry, while higher order approximations (such as the second-order small-slope approximation) can predict up/cross wind differences. Examples of these variations are reported and found to be small. Because the delay doppler maps (DDMs) measured in GNSS-R include some nonspecular contributions even for “specular” portions of the DDM, the second part of the study performs an examination of near-specular DDM variations with wind direction using the widely used geometrical optics approximation of surface scattering for a surface described with the non-Gaussian Cox–Munk slope probability density function. Variations with wind direction of the normalized radar cross section (NRCS) mapped onto the surface are examined, and again, it is shown that these variations are small for surface portions contributing to the near-specular portion of the DDM. In addition, it is shown that the dependencies of the bistatic NRCS on wind direction are such that differing portions of the surface “glistening zone” have differing phase shifts in their dependence on wind direction, causing the wind dependencies of the final near-specular DDM to be negligible. The final results of the study suggest that any wind direction dependence in spaceborne GNSS-R should be sought only in portions of the DDM away f- om the specular region. These results provide information to guide analyses of the wind direction information available in current GNSS-R missions such as TDS-1 and Cyclone Global Navigation Satellite System.
Autors: Jeonghwan Park;Joel T. Johnson;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4677 - 4685
Publisher: IEEE
 
» A Study on Analytical Methods of FEM-Based Edge Heating System
Abstract:
This paper focuses on analytical methods of a finite-element method (FEM)-based edge heating system. The edge heating system plays a role in maintaining the temperature in the hot rolling process of carbon steel. Carbon steel moves along the production line and maintains the temperature by the edge heating system in the process. Power-of-the-edge heating system is transmitted to carbon steel during the process. Eddy currents are generated in carbon steel by Faraday’s law of electromagnetic induction, and eddy current loss serves as a heat source to increase the temperature. Thus, there is a need for accurate electromagnetic-field analysis and thermal analysis because the eddy current path generated in carbon steel greatly affects the heat distribution in carbon steel. This multiphysics analysis requires high reliability. Accordingly, this paper presents a coupling analysis method using an FEM-based coordinate mapping method as a more accurate analytical method. This paper also established an analytical approach to the edge heating system using the ductility analytical method of this coordinate mapping method.
Autors: Geochul Jeong;Youngmin Yang;Jae-Nam Bae;Ju Lee;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Study on Lunar Regolith Quantitative Random Model and Lunar Penetrating Radar Parameter Inversion
Abstract:
Lunar penetrating radar (LPR) is an important way to evaluate the geological structure of the subsurface of the moon. The Chang’E-3 has utilized LPR, which is equipped on the lunar rover named Yutu, to obtain the shallow lunar regolith structure in Mare Imbrium. The previous result provides a unique opportunity to map the subsurface structure and vertical distribution of the lunar regolith with high resolution. In order to evaluate the LPR data, the study of lunar regolith media is of great significance for understanding the material composition of the lunar regolith structure. In this letter, we focus on the lunar regolith quantitative random model and parameter inversion with LPR synthetic data. First, based on the Apollo drilling core data, we build the lunar regolith quantitative random model with clipped Gaussian random field theory. It can be used to model the discrete-valued random field with a given correlation structure. Then, we combine radar wave impedance and stochastic inversion methods to carry out LPR data inversion and parameter estimation. The results mostly provide reliable information on the lunar regolith layer structure and local details with high resolution. This letter presents a further research strategy for lunar probe and deep-space detection with LPR.
Autors: Jing Li;Zhaofa Zeng;Cai Liu;Nan Huai;Kun Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1953 - 1957
Publisher: IEEE
 
» A Study on Optimal BAR in Array Head Reading
Abstract:
Two-dimensional magnetic recording (TDMR), which combines shingled magnetic recording (SMR) with 2-D signal processing attracts attention from the hard disk drive industry. SMR is a magnetic recording system in order to increase the track density by writing tracks without the guard band. Therefore, the influences of writing and reading intertrack interferences (ITIs) deteriorate the quality of reproducing waveforms. Additionally, degradation of track due to overwriting and crosstalk from the adjacent tracks due to the width of reader sensitivity. The equalization using 2-D finite impulse response filter for the waveforms from three adjacent tracks is proposed as a method to reduce the influence of reading ITIs. In this paper, we evaluate the bit aspect ratio (BAR) in TDMR read/write channel under a specification of 4 Tb/in2 using bit error rate of the low-density parity-check (LDPC) coding and iterative decoding system obtained by computer simulation. The results show that the suitable BAR in array head reading is 2.0.
Autors: T. Kondoh;Y. Nakamura;M. Nishikawa;H. Osawa;Y. Okamoto;Y. Kanai;H. Muraoka;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Study on Relationship Between Recording Pattern and Decoding Reliability in SMR
Abstract:
The shingled magnetic recording (SMR) system is influenced by not only jitter-like medium noise from adjacent bits in the down-track direction but also intertrack interference (ITI) from the adjacent tracks. In this paper, we investigate the relationship between the recording pattern and the decoding reliability by classifying the log-likelihood ratio at the a posteriori probability decoder output according to the recording patterns under an SMR R–W channel specification of 4 Tb/in2 by computer simulation. The result shows that the decoding reliability for the recording pattern “010” heavily affected by transition jitter is the lowest and little improved even if the influence of ITI is mitigated by a 2-D finite-impulse response filter.
Autors: R. Suzutou;Y. Nakamura;M. Nishikawa;H. Osawa;Y. Okamoto;Y. Kanai;H. Muraoka;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» A Study on the Multi-Channel TMS Device
Abstract:
Transcranial magnetic stimulation (TMS) is a painless, non-invasive brain nerve stimulation technique, which has been a common diagnosis and treatment method for psychiatry and neurology in recent years. Compared with traditional single-channel magnetic stimulation coil, multi-channel coil array can achieve multi-point synchronous stimulation, scanning stimulation, and flexible switching of various stimulation patterns. Therefore, it has a great development prospect. However, the multi-channel TMS device is still in experimental stage due to the complexity of the drive circuit and the electromagnetic coupling between the coils. Aiming at these two difficulties, this paper developed a novel multi-channel TMS device. By using two closely linked coils with opposite rounded direction to replace one coil, the complexity of the drive circuit can be greatly reduced. Then, the experiment was taken to study the effect of electromagnetic coupling on pulse current in different stimulation patterns. The results show that the coupling coefficient between the adjacent coils limits the minimum amplitude ratio of the auxiliary current to main current. Therefore, the measure of reducing the coupling coefficient was studied in detail. Adding a 6.5 cm-high and 1 mm-thick copper plate in the middle of the adjacent coils was proven to be effective by simulation and experiment.
Autors: Jiangtao Li;Hui Cao;Zheng Zhao;Minjun Zheng;Yuhao Liu;Jiaxin He;Yi Sun;Ziyuan Ren;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 5
Publisher: IEEE
 
» A Switched-Capacitor-Controlled Digital-Current Modulated Class-E Transmitter
Abstract:
An envelope elimination and restoration transmitter that comprises a class-E power amplifier (PA) and a digitally controlled current digital-to-analog converter (DAC) modulator are presented. A switched-capacitor DAC is designed to control an open-loop transconductor that operates as a current modulator, modulating the amplitude of the current supplied to a class-E PA. Such a topology allows for increased filtering of the quantization noise that is problematic in most digital PAs (DPA). The system measurements yield a peak output power and system efficiency (SE) of 22.5 dBm and 23.6%, respectively. When applying a local thermal equilibrium signal, the measured error vector magnitude is 3.72% and the adjacent channel leakage ratio is −30.2 dBc, while outputting 18.1 dBm at 10.6% SE.
Autors: Wen Yuan;Jeffrey S. Walling;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3218 - 3226
Publisher: IEEE
 
» A Systematic Approach for Variable Selection With Random Forests: Achieving Stable Variable Importance Values
Abstract:
Random Forests variable importance measures are often used to rank variables by their relevance to a classification problem and subsequently reduce the number of model inputs in high-dimensional data sets, thus increasing computational efficiency. However, as a result of the way that training data and predictor variables are randomly selected for use in constructing each tree and splitting each node, it is also well known that if too few trees are generated, variable importance rankings tend to differ between model runs. In this letter, we characterize the effect of the number of trees (ntree) and class separability on the stability of variable importance rankings and develop a systematic approach to define the number of model runs and/or trees required to achieve stability in variable importance measures. Results demonstrate that both a large ntree for a single model run, or averaged values across multiple model runs with fewer trees, are sufficient for achieving stable mean importance values. While the latter is far more computationally efficient, both the methods tend to lead to the same ranking of variables. Moreover, the optimal number of model runs differs depending on the separability of classes. Recommendations are made to users regarding how to determine the number of model runs and/or trees that are required to achieve stable variable importance rankings.
Autors: Amir Behnamian;Koreen Millard;Sarah N. Banks;Lori White;Murray Richardson;Jon Pasher;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1988 - 1992
Publisher: IEEE
 
» A Temperature Compensated Triple-Path PLL With $K_{mathrm {VCO}}$ Non-Linearity Desensitization Capable of Operating at 77 K
Abstract:
A novel triple-path PLL (TPPLL) is presented to compensate the VCO frequency drift caused by the large temperature variations meanwhile maintaining a stable bandwidth and good jitter performance. The proposed PLL architecture splits the VCO tuning loop into three paths as the proportional, the integral, and the temperature compensation (TC) path, respectively. The feed-forward TC path with a large VCO gain but a small bandwidth is adopted to realize the compensation for the VCO frequency temperature drift in a closed-loop manner without affecting the high-frequency performance of the VCO. The fixed control voltage on the proportional path and limited control-voltage variation on the integral path desensitize the VCO gain () non-linearity and stabilizes the loop bandwidth over large temperature range. The small VCO gain on the proportional and integral paths contributes to low phase noise and spurs. In addition, the different gain settings for the separate proportional and integral paths work as a capacitor multiplier, leading to saving on the silicon area of the loop filter. A prototype TPPLL at 2.56 GHz using a 65-nm CMOS process has been implemented and measured. The core circuits occupy an area of 0.08 mm2, and consume 8.5 mW. The silicon measurement results show that this PLL can continuously work (without calibration) when the temperature changes from 300 K down to 77 K, and has a frequency drift reduction by 99%, while keeping good jitter performance across the entire temperature range.
Autors: Tianwei Liu;Xiaoran Wang;Rui Wang;Guoying Wu;Tao Zhang;Ping Gui;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2835 - 2843
Publisher: IEEE
 
» A Thin-Film, a-IGZO, 128b SRAM and LPROM Matrix With Integrated Periphery on Flexible Foil
Abstract:
A fast, 128-b implementation of both SRAM and LPROM with integrated periphery in a thin-film amorphous indium–gallium–zinc oxide technology is reported. The SRAM block can be read in 265 /byte and written in 110 /byte, consumes 12.3 mW, and has an area of 11.9 mm2. Furthermore, after power down, an SRAM memory state retention time of 83 s is shown. The LPROM can be read in 40 /b, consumes 4.50 mW, and has an area of 3.75 mm2. The SRAM enables fast volatile RAM memory for thin-film microprocessors, while the LPROM can be used to store the identification code for state-of-the-art thin-film RFID tags.
Autors: Florian De Roose;Kris Myny;Marc Ameys;Jan-Laurens P. J. van der Steen;Joris Maas;Joris de Riet;Jan Genoe;Wim Dehaene;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 3095 - 3103
Publisher: IEEE
 
» A Third-Order MASH $Sigma Delta $ Modulator Using Passive Integrators
Abstract:
This paper presents a MASH using only passive integrators and simple differential pairs as low-gain blocks. Instead of high-gain power hungry op-amps it uses more processing gain from the comparator (1-bit quantizer) as a part of the loop gain. The proposed approach allows the design of a continuous-time, 2–1 MASH in a 65-nm CMOS technology occupying an area of just 0.027 mm2. Measurement results show that the modulator achieves a peak SNR/SNDR of 76/72.2 dB and a DR of 77 dB for an input signal bandwidth of 10 MHz, while dissipating 1.57 mW with 1 V supply. The proposed achieves a Walden figures of merit (FoM) of 23.6 fJ/level and a Schreier FOM of 170 dB.
Autors: Błażej Nowacki;Nuno Paulino;João Goes;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2871 - 2883
Publisher: IEEE
 
» A Truncated Prediction Framework for Streaming Over Erasure Channels
Abstract:
We propose a new coding technique for sequential transmission of a stream of Gauss–Markov sources over erasure channels under a zero decoding delay constraint. Our proposed scheme is a combination (hybrid) of predictive coding with truncated memory, and quantization-and-binning. We study the optimality of our proposed scheme using an information theoretic model. In our setup, the encoder observes a stream of source vectors that are spatially independent and identically distributed (i.i.d.) and temporally sampled from a first-order stationary Gauss–Markov process. The channel introduces an erasure burst of a certain maximum length , starting at an arbitrary time, not known to the transmitter. The reconstruction of each source vector at the destination must be with zero delay and satisfy a quadratic distortion constraint with an average distortion of . The decoder is not required to reconstruct those source vectors that belong to the period spanning the erasure burst and a recovery window of length following it. We study the minimum compression rate in this setup. As our main result, we establish upper and lower bounds on the compression rate. The upper bound (achievability) is based on our hybrid scheme. It achieves significant gains over baseline schemes such as (leaky) predictive coding, memoryless binning, a separation-based scheme, and a group of pictures-based scheme. The lower bound is established by observing connection to a network source coding problem. The bounds simplify in the high resolution regime, where we provide explicit expressions whenever possible, and identify conditions when the proposed scheme is cl- se to optimal. We finally discuss the interplay between the parameters of our burst erasure channel and the statistical channel models and explain how the bounds in the former model can be used to derive insights into the simulation results involving the latter. In particular, our proposed scheme outperforms the baseline schemes over the i.i.d. erasure channel and the Gilbert–Elliott channel, and achieves performance close to a lower bound in some regimes.
Autors: Farrokh Etezadi;Ashish Khisti;Jun Chen;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7322 - 7351
Publisher: IEEE
 
» A Tunable 5–7 GHz Distributed Active Quasi-Circulator With 18-dBm Output Power in CMOS SOI
Abstract:
Circulators and quasi-circulators (QCs) have a tradeoff between maximum isolation and bandwidth. We present a tunable distributed active circuit to achieve high isolation over a wide frequency range. The reported QC provides more than 40-dB suppression between transmit (TX) output signal at the antenna and TX leakage into the receive (RX) port over a tuning range of 5.3–7.3 GHz in small-signal operation. Large-signal TX-RX suppression is optimized across power level. The TX output achieves peak power of 18 dBm and 12% power-added efficiency at 6.3 GHz. The QC is designed in a high-resistivity 45-nm CMOS silicon-on-insulator process and occupies an area of .
Autors: Kelvin Fang;James F. Buckwalter;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 998 - 1000
Publisher: IEEE
 
» A Unified Approach for Modeling Fading Channels Using Infinitely Divisible Distributions
Abstract:
This paper proposes to unify fading distributions by modeling the instantaneous SNR as an infinitely divisible random variable, which is a known class of random variables from the probability theory literature. A random variable is said to be infinitely divisible if it can be written as a sum of independent and identically distributed random variables for each . The proposed unification subsumes several classes of multipath and shadowing fading distributions previously proposed in the wireless communication literature. We show that infinitely divisible random variables have many useful mathematical properties that are applied in the performance analysis of wireless systems. Specific applications include diversity analysis and partial ordering of fading distributions.
Autors: Adithya Rajan;Cihan Tepedelenlioğlu;Ruochen Zeng;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10194 - 10206
Publisher: IEEE
 
» A Variance Distribution Model of Surface EMG Signals Based on Inverse Gamma Distribution
Abstract:
Objective: This paper describes the formulation of a surface electromyogram (EMG) model capable of representing the variance distribution of EMG signals. Methods: In the model, EMG signals are handled based on a Gaussian white noise process with a mean of zero for each variance value. EMG signal variance is taken as a random variable that follows inverse gamma distribution, allowing the representation of noise superimposed onto this variance. Variance distribution estimation based on marginal likelihood maximization is also outlined in this paper. The procedure can be approximated using rectified and smoothed EMG signals, thereby allowing the determination of distribution parameters in real time at low computational cost. Results: A simulation experiment was performed to evaluate the accuracy of distribution estimation using artificially generated EMG signals, with results demonstrating that the proposed model's accuracy is higher than that of maximum-likelihood-based estimation. Analysis of variance distribution using real EMG data also suggested a relationship between variance distribution and signal-dependent noise. Conclusion: The study reported here was conducted to examine the performance of a proposed surface EMG model capable of representing variance distribution and a related distribution parameter estimation method. Experiments using artificial and real EMG data demonstrated the validity of the model. Significance: Variance distribution estimated using the proposed model exhibits potential in the estimation of muscle force.
Autors: Hideaki Hayashi;Akira Furui;Yuichi Kurita;Toshio Tsuji;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Nov 2017, volume: 64, issue:11, pages: 2672 - 2681
Publisher: IEEE
 
» A Vector Flow Imaging Method for Portable Ultrasound Using Synthetic Aperture Sequential Beamforming
Abstract:
This paper presents a vector flow imaging method for the integration of quantitative blood flow imaging in portable ultrasound systems. The method combines directional transverse oscillation (TO) and synthetic aperture sequential beamforming to yield continuous velocity estimation in the whole imaging region. Six focused emissions are used to create a high-resolution image (HRI), and a dual-stage beamforming approach is used to lower the data throughput between the probe and the processing unit. The transmit/receive focal points are laterally separated to obtain a TO in the HRI that allows for the velocity estimation along the lateral and axial directions using a phase-shift estimator. The performance of the method was investigated with constant flow measurements in a flow rig system using the SARUS scanner and a 4.1-MHz linear array. A sequence was designed with interleaved B-mode and flow emissions to obtain continuous data acquisition. A parametric study was carried out to evaluate the effect of critical parameters. The vessel was placed at depths from 20 to 40 mm, with beam-to-flow angles of 65°, 75°, and 90°. For the lateral velocities at 20 mm, a bias between −5% and −6.2% was obtained, and the standard deviation (SD) was between 6% and 9.6%. The axial bias was lower than 1% with an SD around 2%. The mean estimated angles were 66.70° ± 2.86°, 72.65° ± 2.48°, and 89.13° ± 0.79° for the three cases. A proof-of-concept demonstration of the real-time processing and wireless transmission was tested in a commercial tablet obtaining a frame rate of 27 frames/s and a data rate of 14 MB/s. An in vivo measurement of a common carotid artery of a healthy volunteer was finally performed to show the potential of the method in a realistic setting. The relative SD averaged over a cardiac cycle was 4.33%.
Autors: Tommaso Di Ianni;Carlos Armando Villagómez Hoyos;Caroline Ewertsen;Thomas Kim Kjeldsen;Jesper Mosegaard;Michael Bachmann Nielsen;Jørgen Arendt Jensen;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Nov 2017, volume: 64, issue:11, pages: 1655 - 1665
Publisher: IEEE
 
» A Very Fast Trace-Driven Simulation Platform for Chip-Multiprocessors Architectural Explorations
Abstract:
Simulation is the main tool for computer architects and parallel application developers for developing new architectures and parallel algorithms on many-core machines. Simulating a many-core architecture represent a challenge to software simulators even with parallelization of these SW on multi-cores. Field Programmable Gate Arrays offer an excellent implementation platform due to inherent parallelism. Existing FPGA-based simulators however, are mostly execution-driven which consumes too many FPGA resources. Hence, they still trade-off accuracy with simulation speed as SW simulators do. In this work, an application-level trace-driven FPGA-based many-core simulator is presented. A parameterized Verilog template was developed that can generate any number of simulator tiles. The input trace has an architecturally agnostic format that is directly interpreted by the FPGA-based timing model to re-construct the execution events of the original application with accurate timing. This allows fitting a large number of simulation tiles on a single FPGA without sacrificing simulation speed or accuracy. Experimental results show that the simulator's average accuracy is ∼14 percent with simulation speeds ranging from 100’s of MIPs to over 2,200 MIPS for a 16-core target architecture. Hence, with accuracy similar to SW simulators, its speed is higher than all other FPGA-based simulators.
Autors: Muhammad E. S. Elrabaa;Ayman Hroub;Muhamed F. Mudawar;Amran Al-Aghbari;Mohammed Al-Asli;Ahmad Khayyat;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3033 - 3045
Publisher: IEEE
 
» A Vessel Detection Method Using Compact-Array HF Radar
Abstract:
A compact-array high-frequency surface wave radar equipped with two crossed-loop/monopole receiving antennas has been established for vessel detection. Using two compact antennas of the same design, this system can obtain two extremely similar sets of radar range-Doppler spectra over the same period. To detect vessel targets efficiently, the spectra of two antennas are enhanced by performing a principle component analysis. A wavelet-based approach is then applied to suppress clutter and reduce noise. The signal-to-noise ratios and signal-to-clutter ratios of the echoes are thus improved. Finally, an adaptive threshold is used to extract targets. The real radar data detection results are compared with Automatic Identification System data as well as those from the conventional ordered-statistic constant false alarm rate method. The feasibility and the validity of method proposed here are thus demonstrated.
Autors: Bo Lu;Biyang Wen;Yingwei Tian;Ruokun Wang;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 2017 - 2021
Publisher: IEEE
 
» A Wavelet-Based AFM Fast Imaging Method With Self-Tuning Scanning Frequency
Abstract:
Due to its numerous advantages, atomic force microscopy (AFM) has been widely utilized in various fields, such as nanotechnology, nanomanipulation, bioscience, etc. However, when considering the increasing requirements from different applications, low scanning speed is one of the most challenging drawbacks which prevents further applications of an AFM system. Based on this observation, this paper proposes a novel wavelet-based AFM fast imaging method with an intelligent adjustment mechanism for scanning frequency over different parts of detected samples, which is especially efficient when scanning biological samples with sparse features. More specifically, a sample is first skipped through quickly with forward scan, during which wavelet analysis is implemented for the collected data to distinguish interesting areas from uninteresting ones, based on which, the sample is then reversely scanned with varying frequencies to obtain trusty information to generate an accurate image for its surface. That is, the proposed fast AFM imaging method carefully scans the identified interesting areas at comparatively low frequency, while skipping through the uninteresting ones quickly with much higher speed, so as to reduce scanning time and simultaneously enhance imaging performance. Performance analysis demonstrates that, due to its unique ability of intelligent tuning for scanning speeds, the designed wavelet-based AFM scanning method maximally increases the imaging speed by ten times. In addition, both simulation and experimental results also verify the good performance of the proposed method. The designed imaging method is finally utilized to scan some biological samples, with collected results further exhibiting its promising prospect.
Autors: Yinan Wu;Yongchun Fang;Xiao Ren;Han Lu;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 1088 - 1098
Publisher: IEEE
 
» A Wideband All-Digital CMOS RF Transmitter on HDI Interposers With High Power and Efficiency
Abstract:
This paper demonstrates a wideband CMOS all-digital polar transmitter with flip-chip connection to three high-density-interconnection PCB interposers. The interposers are designed to extract power from a CMOS open-drain inverse Class-D power amplifier core. For a wide frequency range from 0.7 to 3.5 GHz, continuous-wave output power higher than 25.5 dBm and drain efficiency (DE) above 40% are demonstrated. The low-band package achieves a peak power of 29.2 dBm at 1.1 GHz with DE of 60%, the mid-band package outputs 28.8 dBm at 1.5 GHz with DE of 56%, and the high-band package generates 26 dBm at 3 GHz with DE of 49%. The amplitude modulation (AM) is achieved by digitally modulating the switch conductance of the inverse Class-D core, and the on-chip phase modulation is achieved by digitally weighing the in-phase and quadrature bias currents in the IQ mixer. Detailed modulation tests, involving 64 quadrature amplitude modulation (QAM) and 20-MHz WLAN and LTE signals, exhibit excellent power and efficiency at 0.6, 1.2, 1.8, 2.4, 3, and 3.6 GHz. The associated specifications on spectral masks and error vector magnitudes are satisfied.
Autors: Nai-Chung Kuo;Bonjern Yang;Angie Wang;Lingkai Kong;Charles Wu;Vason P. Srini;Elad Alon;Borivoje Nikolić;Ali M. Niknejad;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4724 - 4743
Publisher: IEEE
 
» Absorptive Frequency-Selective Reflection and Transmission Structures
Abstract:
Tailoring methodology is proposed in this communication to achieve an arbitrary frequency response within a wide absorption band. An ultrawideband (UWB) absorber utilizing multiple resonances in the unit cell of 3-D frequency-selective structure is utilized as the textile for the proposed designs. Two types are proposed: one is absorptive frequency-selective reflection structure (AFSR) and the other is absorptive frequency-selective transmission structure (AFST). These structures have reflection/transmission band within a wide absorption band. Two prototypes are designed, fabricated, and measured to validate the proposed methodology. The first one is an UWB absorber with 155.7% absorption bandwidth from 1.8 to 14.4 GHz with structure’s thickness of at the lowest absorption frequency. The second one is an AFST with wide absorption bands at both sides of its transmission window. It exhibits 54% and 76% for the lower and upper absorption bands, respectively, with 1 dB insertion loss in the transmission window. A good agreement is achieved between simulation and measured results.
Autors: Ahmed Abdelmottaleb Omar;Zhongxiang Shen;Hao Huang;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6173 - 6178
Publisher: IEEE
 
» Accelerating Decision Tree Based Traffic Classification on FPGA and Multicore Platforms
Abstract:
Machine learning (ML) algorithms have been shown to be effective in classifying a broad range of applications in the Internet traffic. In this paper, we propose algorithms and architectures to realize online traffic classification using flow level features. First, we develop a traffic classifier based on C4.5 decision tree algorithm and Entropy-MDL (Minimum Description Length) discretization algorithm. It achieves an overall accuracy of 97.92 percent for classifying eight major applications. Next we propose approaches to accelerate the classifier on FPGA (Field Programmable Gate Array) and multicore platforms. We optimize the original classifier by merging it with discretization. Our implementation of this optimized decision tree achieves 7500+ Million Classifications Per Second (MCPS) on a state-of-the-art FPGA platform and 75-150 MCPS on two state-of-the-art multicore platforms. We also propose a divide and conquer approach to handle imbalanced decision trees. Our implementation of the divide-and-conquer approach achieves 10,000+ MCPS on a state-of-the-art FPGA platform and 130-340 MCPS on two state-of-the-art multicore platforms. We conduct extensive experiments on both platforms for various application scenarios to compare the two approaches.
Autors: Da Tong;Yun Rock Qu;Viktor K. Prasanna;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3046 - 3059
Publisher: IEEE
 
» Accessible Software Verification with Dafny
Abstract:
Dafny is a formal-verification system that takes a language-based approach. Its programming language includes the necessary specification and proof facilities. The idea is to provide developers with an immersive experience that feels like programming but encourages thinking about program correctness every step of the way.
Autors: K. Rustan M. Leino;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 94 - 97
Publisher: IEEE
 
» Accurate De-Embedding and Measurement of Spin-Torque Oscillators
Abstract:
We present a method for accurately de-embedding the electrical effects of the bias and measurement electrode structure used for spin-torque oscillator (STO) measurements. We propose a simple, but very accurate, method that requires only one additional test structure per STO wafer. We show that the effects of the electrode structure, including phase shift over frequency and insertion loss, can be removed, providing an accurate measurement of the true STO parameters. Our method is verified using 24 STOs across four different wafers each containing 140 STOs.
Autors: M. Abbasi;B. Wang;S. Tamaru;H. Kubota;A. Fukushima;D. S. Ricketts;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Accurate Floating-Point Argument Calculation for Sine-Fitting Algorithms
Abstract:
In this paper, accurate argument calculation for sine-fitting algorithms is investigated, assuming floating-point (FP) arithmetic. An easy-to-implement incremental calculation technique is suggested. In order to decrease error propagation, the algorithm is complemented with an advanced summation technique. Theoretical and numerical analyses on computational demand are performed to highlight that incremental argument calculation outperforms the method proposed in former research. Furthermore, an algorithm is implemented to mitigate the effect of imprecise representation of frequency on FP arithmetic. Monte Carlo analyses are carried out to demonstrate the accuracy of the suggested algorithms. Results show that phase information can be evaluated precisely even with single-precision FP arithmetic, applying incremental argument calculation. By this means, the cost of equipment that is needed to perform sine fitting can be reduced significantly. Finally, possible application areas are shown to demonstrate the applicability of the suggested solutions in the state-of-art measurement procedures.
Autors: Balázs Renczes;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2988 - 2996
Publisher: IEEE
 
» Achievable Rates of Full-Duplex Massive MIMO Relay Systems Over Rician Fading Channels
Abstract:
We analytically study the achievable rates of full-duplex massive multiple-input multiple-output (MIMO) relay systems over Rician fading channels. The decode-and-forward protocol is adopted at the relay station, where the channel state information (CSI) is assumed to be imperfect. We demonstrate that the system bottleneck, self-interference (SI), can be significantly canceled by zero-forcing (ZF) processing at the relay station, which is equipped with massive receive and transmit arrays. Because no active SI cancellation is deployed at the relay station, there is no need for SI channel estimation. We derive an approximate closed-form achievable rate expression for ZF processing with statistical CSI. When the number of antennas of the transmit and receive arrays at the relay station is sufficiently large, the transmit powers of each source and the relay station can be significantly scaled down proportionally to the number of antennas. Since Rayleigh fading is a special case of Rician fading, the results in this paper hold for Rayleigh fading channels. The theoretical analysis is verified by the numerical results.
Autors: Siyuan Wang;Yi Liu;Wei Zhang;Hailin Zhang;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9825 - 9837
Publisher: IEEE
 
» Achieving Content-Oriented Anonymity with CRISP
Abstract:
As a popular realization of Information-Centric Network (ICN), Named Data Networking (NDN) greatly improves the efficiency of Internet content-distribution. A feature of NDN is that it improves privacy, as no addresses are needed for either the content consumer or publisher. However, NDN packets contain content names, and hence a well-motivated adversary can still deduce what content the user is requesting once it can link the packets and users. How to provide privacy in NDN, given its unique data retrieval mode, is an open problem. In this paper, we explore a specific content-oriented anonymity model called content-user unlinkability, which breaks the relationship between the content and the requesting user. We argue that achieving content-user unlinkability efficiently is a non-trivial task, since existing tunnel-based approaches will largely dismiss content caching of NDN, resulting in large content retrieval delay. To this end, we propose CRISP, namely Cooperative Random IntereSt P ropagation. In CRISP, routers cooperate to form full-meshed groups, within which content requests are randomly propagated before they are forwarded to content producers. We show CRISP can achieve probable content-user unlinkability with probabilistic models. Extensive simulations demonstrate that CRISP outperforms existing solutions including ANDANA and Crowds, in terms of both content retrieval latency and data throughput.
Autors: Peng Zhang;Qi Li;Patrick P. C. Lee;
Appeared in: IEEE Transactions on Dependable and Secure Computing
Publication date: Nov 2017, volume: 14, issue:6, pages: 578 - 590
Publisher: IEEE
 
» Achieving Full Secure Degrees-of-Freedom for the MISO Wiretap Channel With an Unknown Eavesdropper
Abstract:
In this paper, we study the achievable secure degrees-of-freedom (sdof) for the multiple-input single-output (MISO) wiretap channel with an unknown eavesdropper. It is assumed that the eavesdropper’s (Eve’s) channel state information (CSI) is unknown to the transmitter (Alice) and legitimate receiver (Bob). Recent studies have shown that the achievable sdof in the sense of strong secrecy is zero when Eve’s number of antennas is equal to or more than Bob’s number of antennas, which is the scenario considered in this paper. To this end, we propose a novel precoding technique and a coding strategy that together achieve full sdof in the sense of strong secrecy without knowing Eve’s CSI and without using artificial noise. The proposed precoding method uses the CSI of the Alice-Bob channel in a nonlinear fashion, which makes the transmitted symbols undecodable at Eve. The proposed coding scheme is based on the channel resolvability concept and ensures strong secrecy. Achieving full sdof with an unknown Eve’s CSI is significant, because it is contrary to what is believed about the achievable sdof for the MISO wiretap channel in the sense of strong secrecy. We also show that the proposed scheme achieves near Alice-Bob’s channel capacity in the sense of strong secrecy with a probability approaching one at finite signal-to-noise ratio.
Autors: Mohaned Chraiti;Ali Ghrayeb;Chadi Assi;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7066 - 7079
Publisher: IEEE
 
» Achieving High Availability in Heterogeneous Cellular Networks via Spectrum Aggregation
Abstract:
The exponential growth in data traffic and dramatic capacity demand in fifth generation (5G) have inspired the move from traditional single-tier cellular networks toward heterogeneous cellular networks (HCNs). To face the coming trend in 5G, the high availability requirement in new applications needs to be satisfied to achieve low latency service. Usually, these applications require an availability of six nines or even higher. In this paper, we present a tractable multitier multiband availability model for spectrum aggregation-based HCNs. We first derive a closed-form expression for the availability of spectrum aggregation-based HCNs using the signal-to-interference-plus-noise model. By doing so, we formulate two optimization problems, one is to maximize the average availability, and the other one is to minimize the average power consumption. These two optimization problems are both nonconvex problems, which are challenging to solve. To cope with them, we propose to apply genetic algorithm for the joint user equipment (UE) association, subcarrier assignment, and power allocation problem. Our results show that the average availability in spectrum aggregation-based HCNs improves with decreasing number of UEs, as well as increasing power budget ratio. We also show that increasing the maximum number of aggregated subcarriers decreases the average power consumption, but cannot guarantee the substantial improvement of average availability.
Autors: Jie Jia;Yansha Deng;Jian Chen;Abdol Hamid Aghvami;Arumugam Nallanathan;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10156 - 10169
Publisher: IEEE
 
» Achieving Theoretical Limit of SFDR in Pipelined ADCs
Abstract:
In pipelined analog-to-digital converters (ADCs), the spurious free dynamic range (SFDR) and signal-to-noise ratio depend strongly on the precision with which the interstage gain and capacitor mismatch terms are estimated using digital calibration techniques. This paper introduces a dithering-based calibration technique, which facilitates accurate estimation of the interstage gain and capacitor mismatch term with minimal hardware overhead, thus realizing pipelined ADCs that achieve the theoretical maximum SFDR. The proposed technique is validated both at system level using MATLAB and then at circuit level. A prototype 12-bit pipelined ADC operating at 500 MHz was designed in 55-nm global foundry LP-CMOS process. The prototype 12-bit ADC realized with op amp that have open-loop gains as low as 54 dB, but linearity ≈100 dB achieves an SFDR of 100.13 dB when calibrated using the proposed technique.
Autors: Vineeth Sarma;Chithira Ravi;Bibhu Datta Sahoo;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3175 - 3185
Publisher: IEEE
 
» Active Disturbance Rejection Control for Uncertain Nonaffine-in-Control Nonlinear Systems
Abstract:
In this technical note, the active disturbance rejection control (ADRC) is generalized to uncertain nonaffine-in-control nonlinear systems. The proposed controller incorporates both an extended state observer (ESO) as well as a dynamic inversion. The ESO is designed to estimate system state and total uncertainty, which includes the uncertain internal dynamics and the external disturbance, and is nonaffine-in-control. Based on the output of the ESO, the dynamic inversion is used to deal with the nonaffine-in-control problem. The proposed control has a multi-time-scale structure, in which the ESO is the fastest time scale; the dynamic inversion is the second; and the considered nonlinear system is the slowest. The practical convergence of the resulting closed-loop system is obtained. An example is presented to illustrate the efficiency of the proposed method.
Autors: Maopeng Ran;Qing Wang;Chaoyang Dong;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5830 - 5836
Publisher: IEEE
 
» Active Eight-Path Filter and LNA With Wide Channel Bandwidth and Center Frequency Tunability
Abstract:
This paper presents a differential eight-path bandpass filter with tunable center frequency and bandwidth. Fully differential Miller compensated Butterworth Gm-C biquads are used to implement the active low-pass filters required in the structure of the eight-path filter. The −3-dB bandwidth of each Gm-C filter can be tuned from 2.5 to 51 MHz by means of six digital bits. The center frequency of the eight-path filter can be tuned from 100 MHz to 2 GHz by varying the frequency of the 12.5% duty cycle clocks applied to the gates of the switches in the filter. A wideband low-noise amplifier (LNA) is designed to precede the eight-path filter and acts as an active single-to-differential converter while providing a moderate voltage gain to compensate for the noise produced by the eight-path filter. The LNA has a noise canceling common-gate common-source with 20 dB of gain and a noise figure (NF) of 1.8 dB. The filter and LNA are designed and fabricated in 180-nm CMOS process. The circuit operates in 100 MHz to 2 GHz frequency range, achieving a voltage gain of 19 dB and a total NF of 3.3 dB. The achieved out-of-band input third-order intercept point of the circuit is +23 dBm, and the power consumption of the filter is approximately 32.3 mW, while the LNA consumes 16.5 mW.
Autors: Baktash Behmanesh;Seyed Mojtaba Atarodi;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4715 - 4723
Publisher: IEEE
 
» Activity Maximization by Effective Information Diffusion in Social Networks
Abstract:
In a social network, even about the same information the excitement between different users are different. If we want to spread a piece of new information and maximize the expected total amount of excitement, which seed users should we choose? This problem indeed is substantially different from the renowned influence maximization problem and cannot be tackled using the existing approaches. In this paper, motivated by the demand in a few interesting applications, we model the novel problem of activity maximization, and tackle the problem systematically. We first analyze the complexity and the approximability of the problem. We develop an upper bound and a lower bound that are submodular so that the Sandwich framework can be applied. We then devise a polling-based randomized algorithm that guarantees a data dependent approximation factor. Our experiments on four real data sets clearly verify the effectiveness and scalability of our method, as well as the advantage of our method against the other heuristic methods.
Autors: Zhefeng Wang;Yu Yang;Jian Pei;Lingyang Chu;Enhong Chen;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2374 - 2387
Publisher: IEEE
 
» Adaptable Blockchain-Based Systems: A Case Study for Product Traceability
Abstract:
Traceability allows tracking products through all stages of a supply chain, which is crucial for product quality control. To provide accountability and forensic information, traceability information must be secured. This is challenging because traceability systems often must adapt to changes in regulations and to customized traceability inspection processes. OriginChain is a real-world traceability system using a blockchain. Blockchains are an emerging data storage technology that enables new forms of decentralized architectures. Components can agree on their shared states without trusting a central integration point. OriginChain’s architecture provides transparent tamper-proof traceability information, automates regulatory compliance checking, and enables system adaptability.
Autors: Qinghua Lu;Xiwei Xu;
Appeared in: IEEE Software
Publication date: Nov 2017, volume: 34, issue:6, pages: 21 - 27
Publisher: IEEE
 
» Adaptive 3D Face Reconstruction from Unconstrained Photo Collections
Abstract:
Given a photo collection of “unconstrained” face images of one individual captured under a variety of unknown pose, expression, and illumination conditions, this paper presents a method for reconstructing a 3D face surface model of the individual along with albedo information. Unlike prior work on face reconstruction that requires large photo collections, we formulate an approach to adapt to photo collections with a high diversity in both the number of images and the image quality. To achieve this, we incorporate prior knowledge about face shape by fitting a 3D morphable model to form a personalized template, following by using a novel photometric stereo formulation to complete the fine details, under a coarse-to-fine scheme. Our scheme incorporates a structural similarity-based local selection step to help identify a common expression for reconstruction while discarding occluded portions of faces. The evaluation of reconstruction performance is through a novel quality measure, in the absence of ground truth 3D scans. Superior large-scale experimental results are reported on synthetic, Internet, and personal photo collections.
Autors: Joseph Roth;Yiying Tong;Xiaoming Liu;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2127 - 2141
Publisher: IEEE
 
» Adaptive Asymptotic Tracking Control of Uncertain Time-Driven Switched Linear Systems
Abstract:
This technical note establishes a novel result for adaptive asymptotic tracking control of uncertain switched linear systems. The result exploits a recently proposed stability condition for switched systems. In particular, a time-varying positive definite Lyapunov function is used to develop a novel piecewise continuous model-reference adaptive law and a dwell-time switching law. In contrast with previous research, where asymptotic tracking was possible only in the presence of a common Lyapunov function for the reference models, in this work asymptotic tracking is shown in a more general setting. Additionally, in the presence of persistence of excitation, the controller parameter estimation errors will converge to zero asymptotically. The main contribution of this work consists in establishing a symmetry between adaptive control of classical non-switched linear systems and adaptive control of switched linear systems. A practical example with an electro-hydraulic system is adopted to illustrate the results.
Autors: Shuai Yuan;Bart De Schutter;Simone Baldi;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5802 - 5807
Publisher: IEEE
 
» Adaptive Bus Encoding for Transition Reduction on Off-Chip Buses With Dynamically Varying Switching Characteristics
Abstract:
This paper presents an adaptive encoding framework for the reduction of transition activity in high-capacitance off-chip data buses, since power dissipation associated with those buses can be significant for high-speed communication. The technique relies on the observation of data characteristics over fixed window sizes and formation of cluster with bit lines having highly correlated switching patterns. The proposed method utilizes redundancy in space and time to prevent loss of information while retrieving data. We present analytical and experimental analyses, which demonstrate the activity reduction of our encoding scheme for various data. The extra power cost due to the encoder and decoder circuitry along with redundancy is offset due to reduced number of off-chip transitions.
Autors: Sumantra Sarkar;Ayan Biswas;Anindya Sundar Dhar;Rahul M. Rao;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3057 - 3066
Publisher: IEEE
 
» Adaptive Compensation of Traction System Actuator Failures for High-Speed Trains
Abstract:
In this paper, an adaptive failure compensation problem is addressed for high-speed trains with longitudinal dynamics and traction system actuator failures. Considered the time-varying parameters of the train motion dynamics caused by time-varying friction characteristics, a new piecewise constant model is introduced to describe the longitudinal dynamics with variable parameters. For both the healthy piecewise constant system and the system with actuator failures, the adaptive controller structure and conditions are derived to achieve the plant-model matching. The adaptive laws are designed to update the adaptive controller parameters, in the presence of the system piecewise constant parameters and actuator failure parameters which are unknown. Based on Lyapunov functions, the closed-loop stability and asymptotic state tracking are proved. Simulation results on a high-speed train model are presented to illustrate the performance of the developed adaptive actuator failure compensation control scheme.
Autors: Zehui Mao;Gang Tao;Bin Jiang;Xing-Gang Yan;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Nov 2017, volume: 18, issue:11, pages: 2950 - 2963
Publisher: IEEE
 
» Adaptive Digitization and Variable Channel Coding for Enhancement of Compressed Digital Mobile Fronthaul in PAM-4 Optical Links
Abstract:
The standardization and development of LTE-A and 5G introduced advanced wireless technologies including multiple-input multiple-output and carrier aggregation, which require multiple wireless carriers to be delivered to and from each remote radio head. The common public radio interface (CPRI) as the mainstream standard in mobile fronthaul (MFH) with on-off-keying-based optical links cannot fulfill the capacity and efficiency requirement. Instead, using compressed CPRI in a high-speed pulse-amplitude-modulation-4 (PAM-4) link is actively researched and demonstrated. In this paper, we propose and demonstrate adaptive digitization and channel coding based on these compression and capacity boosting technologies. Depending on the optical link condition, the digitization bits and channel coding rates can be adaptively and dynamically changed to achieve the lowest error vector magnitude (EVM) of wireless carriers. By separating digitization bits into high bits and low bits, the coding overhead can be different between groups, while still keeping the same bit rate per wireless carrier. Based on the existing digital MFH infrastructure, the proposed scheme can significantly improve the capacity and sensitivity in the PAM-4-based compressed digital MFH. Capacity gains from 30% to 68%, sensitivity improvement of 2-9 dB, and significant EVM improvements are demonstrated experimentally, comparing with other compressed CPRI MFH solutions.
Autors: Feng Lu;Mu Xu;Lin Cheng;Jing Wang;Shuyi Shen;Hyung Joon Cho;Gee-Kung Chang;
Appeared in: Journal of Lightwave Technology
Publication date: Nov 2017, volume: 35, issue:21, pages: 4714 - 4720
Publisher: IEEE
 
» Adaptive Finite-Time Stabilization of a Class of Uncertain Nonlinear Systems via Logic-Based Switchings
Abstract:
In this paper, global adaptive finite-time stabilization is investigated by logic-based switching control for a class of uncertain nonlinear systems with the powers of positive odd rational numbers. Parametric uncertainties entering the state equations nonlinearly can be fast time-varying or jumping at unknown time instants, and the control coefficient appearing in the control channel can be unknown. The bounds of the parametric uncertainties and the unknown control coefficient are not required to know a priori. Our proposed controller is a switching-type one, in which a nonlinear controller with two parameters to be tuned is first designed by adding a power integrator, and then a switching mechanism is proposed to tune the parameters online to finite-time stabilize the system. An example is provided to demonstrate the effectiveness of the proposed result.
Autors: Jun Fu;Ruicheng Ma;Tianyou Chai;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5998 - 6003
Publisher: IEEE
 
» Adaptive Multiresolution Energy Consumption Prediction for Electric Vehicles
Abstract:
This paper introduces an adaptive multiresolution framework for electric vehicle (EV) energy consumption estimation with real-time capability. Three key parameters, namely powertrain efficiency, wind speed, and rolling resistance, are adaptively estimated using a two-step nonlinear iterative algorithm. Based on this algorithm, a multichannel framework for high-resolution powertrain efficiency estimation is introduced. Employing the “connected vehicles” concept, more reliable trip level energy estimates are achieved by sharing sensed environmental information. In addition, state-of-charge aware energy cost prediction methods of different accuracy and complexity are introduced to combat range anxiety and reduce computational complexity during times of high energy reserves. A variety of detailed simulations illustrate the introduced concept and its benefits for future EV systems.
Autors: Zonggen Yi;Peter H. Bauer;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10515 - 10525
Publisher: IEEE
 
» Adaptive Multiuser Scheduling for Simultaneous Wireless Information and Power Transfer in a Multicell Environment
Abstract:
Simultaneous wireless information and power transfer (SWIPT) is a promising technique to transmit information and harvest energy at the same time. In this paper, we investigate multiuser scheduling criteria in a multiuser SWIPT system taking into account co-channel interference in a multicell environment, where each transmitter operate independently. We propose an -adaptive scheduling scheme, which is able to adjust a scheduling criterion between maximizing achievable rate and maximizing harvested energy of the scheduled device by adjusting factor. Employing a power splitting receiver, we derive closed-form analytical results including cumulative distribution function (CDF) of the harvested energy, CDF of the achievable rate, average harvested energy, and average achievable rate. We also investigate the effect of adjustable factor in the proposed scheduling scheme and multiuser diversity in terms of the CDF of the harvested energy, the CDF of the achievable rate, and rate-energy tradeoff, compared with two conventional scheduling schemes: random scheduling and max-SNR scheduling. Our analytical results provide insightful information for designing multiuser scheduling criteria considering co-channel interference in the SWIPT systems.
Autors: Inkyu Bang;Su Min Kim;Dan Keun Sung;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Nov 2017, volume: 16, issue:11, pages: 7460 - 7474
Publisher: IEEE
 
» Adaptive Optimal Control for Large-Scale Nonlinear Systems
Abstract:
In this paper, we present an adaptive optimal control approach applicable to a wide class of large-scale nonlinear systems. The proposed approach avoids the so-called loss-of-stabilizability problem and the problem of poor transient performance that are typically associated with adaptive control designs. Moreover, it does not require the system model to be in a certain parameterized form, and most importantly, it is able to efficiently handle systems of large dimensions. Theoretical analysis establishes that the proposed methodology guarantees stability and exponential convergence to state trajectories that can be made as close as desired to the optimal ones. A numerical example demonstrates the capability of the proposed approach to overcome loss-of-stabilizability problems. Moreover, simulation experiments for energy-efficient climate control performed on a ten-office building demonstrate the effectiveness of the proposed approach in large-scale nonlinear applications.
Autors: Iakovos Michailidis;Simone Baldi;Elias B. Kosmatopoulos;Petros A. Ioannou;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 5567 - 5577
Publisher: IEEE
 
» Adaptive RF Front-Ends Using Electrical-Balance Duplexers and Tuned SAW Resonators
Abstract:
This paper proposes an adaptive RF front-end (RFFE) architecture that uses an electrical-balance duplexer (EBD) and tuned surface acoustic wave (SAW) resonators to enable adaptive dual-frequency isolation suited for LTE’s frequency-division duplex (FDD) mode of operation. Alternatively, in the in-band full-duplex (IBFD) mode, the EBD cancels the in-band TX self-interference directly at RF for increased channel capacity. Furthermore, the EBD’s balance network is optimized to reduce the TX insertion loss (IL) below the nominal 3-dB limit in the FDD mode. A 0.18- SOI CMOS prototype implements the EBD, low-noise amplifier, and SAW-tuning capacitor banks. The chip is mounted to a module substrate together with the SAWs and matching components. The RFFE achieves >50-dB dual-frequency isolation and 2.6–3.4-dB TX IL in FDD mode, has +58/+42-dBm TX/RX-path IIP3 for an increased IBFD-link budget and handles up to +27.5-dBm TX power in both modes.
Autors: Barend van Liempd;Akshay Visweswaran;Saneaki Ariumi;Shinya Hitomi;Piet Wambacq;Jan Craninckx;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Nov 2017, volume: 65, issue:11, pages: 4621 - 4628
Publisher: IEEE
 
» Adaptive Secure Transmission for RF-EH Untrusted Relaying with Alien Eavesdropping
Abstract:
An adaptive cooperative scheme is proposed to improve the security of a wireless-powered relay network. A source node sends data to a destination node in the presence of an amplify-and-forward untrusted relay node and an alien eavesdropper where both are assumed to attempt to decode the source’s information signal. The source uses a fraction of its transmit power to send a jamming signal to keep its information confidential. To save energy, the energy-harvesting relay node transmits with the minimum power level that ensures secure transmissions. We derive a closed-form upper bound on the system’s secrecy outage probability. The proposed cooperative scheme is more efficient than the conventional scheme, where once the relay has accumulated sufficient energy, it assists the source’s information transmission.
Autors: Asma Mabrouk;Ahmed El Shafie;Kamel Tourki;Naofal Al-Dhahir;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2516 - 2519
Publisher: IEEE
 
» Adaptive Spur Cancellation Technique in All-Digital Phase-Locked Loops
Abstract:
The phenomenon of periodic phase errors (also known as spurs) in phase-locked loops (PLLs) is widely acknowledged and is responsible for posing considerable challenge on development of miniaturized wireless communication devices. The common approach employed today for spur mitigation calls for a digital notch filter within the receive chain, while there is no similar digital scheme for the transmit chain. In addition, this notch filter is not perfect and usually degrades the overall receiver sensitivity. This brief puts forward a novel idea, which is to cancel the spurs inside the PLL such that the local oscillator signal and consequently TX and RX antenna ports become spur-free. The technique is based on a least-mean squares algorithm that features a self-learning capability. The method has been silicon proven in a digital PLL of a transceiver radio test chip realized in a standard nanoscale CMOS technology.
Autors: Rotem Avivi;Michael Kerner;Evgeny Shumaker;Giuseppe Li Puma;Tami Sela;Lidor Sofer;Gil Horovitz;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Nov 2017, volume: 64, issue:11, pages: 1292 - 1296
Publisher: IEEE
 
» Adaptive Time Taps of STAP Under Channel Mismatch for GNSS Antenna Arrays
Abstract:
Although antenna arrays can effectively suppress interference and maintain the navigation signal integrity, interference suppression performance is limited by channel mismatch. However, a space-time adaptive processor (STAP) can reduce channel mismatch by introducing time taps within each element, which will further suppress the interference and improve the performance. However, interference suppression depends significantly on the number of time taps. This paper presents a proportion differentiation (PD) algorithm for the adaptive control of time taps based on the antenna arrays output power is presented. The effectiveness of the proposed algorithm is verified through simulations and measured data. The STAP with adaptive time taps has achieved excellent performance for interference suppression performance without increasing the computational load.
Autors: Zukun Lu;Junwei Nie;Feiqiang Chen;Huaming Chen;Gang Ou;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2813 - 2824
Publisher: IEEE
 
» Additive Manufacturing of Bonded Nd–Fe–B—Effect of Process Parameters on Magnetic Properties
Abstract:
Isotropic-bonded magnets were fabricated by powder bed fusion additive manufacturing (AM) using a feedstock composed of polymeric binder polyamide 12 (PA-12) and a near stoichiometric Nd2Fe14B atomized nanocrystalline powder. The AM equipment constructed for that purpose uses a computer-controlled laser beam to melt the binder and build the parts layer by layer. Three process parameters were evaluated: layer thickness (LT), hatch spacing (HS), and laser power (LP). For the evaluation of magnetic properties, cylindrical samples with diameter and height of 10 mm were produced and measured in a hysteresisgraph. For a feedstock, based on a 34% volumetric fraction of PA-12, the highest density value achieved was 3.6 g/cm3, resulting in a remanence of 0.3 T. These relatively low values for remanence are due to the isotropic characteristic of the powder, the binder fraction, and the interparticle porosity not being completely eliminated. Results indicate that LT affects densification more significantly than LP and HS. Consequently, remanence follows the same trend. Coercivity has not been affected much by optimized process parameters, since the values of original atomized powder of around 700 kA/m remained practically the same. The overall conclusion shows encouraging results to explore this alternative AM technique to produce net shape permanent magnets.
Autors: A. B. Baldissera;P. Pavez;P. A. P. Wendhausen;C. H. Ahrens;J. M. Mascheroni;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» Advancing Nonvolatile Computing With Nonvolatile NCFET Latches and Flip-Flops
Abstract:
Nonvolatile computing has been proven to be effective in dealing with power supply outages for on-chip check-pointing in emerging energy-harvesting Internet-of-Things applications. It also plays an important role in power-gating to cut off leakage power for higher energy efficiency. However, existing on-chip state backup solutions for D flip–flop (DFF) have a bottleneck of significant energy and/or latency penalties which limit the overall energy efficiency and computing progress. Meanwhile, these solutions rely on external control that limits compatibility and increases system complexity. This paper proposes an approach to fundamentally advancing the nonvolatile computing paradigm by intrinsically nonvolatile area-efficient latches and flip–flops designs using negative capacitance FET. These designs consume fJ-level energy and ns-level intrinsic latency for a backup plus restore operation, e.g., 2.4 fJ in energy and 1.1 ns in time for one proposed nonvolatile DFF with a supply power of 0.80 V.
Autors: Xueqing Li;Sumitha George;Kaisheng Ma;Wei-Yu Tsai;Ahmedullah Aziz;John Sampson;Sumeet Kumar Gupta;Meng-Fan Chang;Yongpan Liu;Suman Datta;Vijaykrishnan Narayanan;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Nov 2017, volume: 64, issue:11, pages: 2907 - 2919
Publisher: IEEE
 
» Affinely Adjustable Robust Model for Multiperiod Production Planning Under Uncertainty
Abstract:
Demand forecasting is an important factor in production planning, but future demand is not easy to forecast in practice. We consider a multiperiod, multiproduct production planning problem under demand uncertainty with constrains for raw materials, manufacturing capacity, and inventory. Under the assumption that probability distribution of demand is not available, two types of robust optimization models are proposed. First, a robust counterpart is developed to determine the here-and-now decision. Next, an affinely adjustable robust counterpart is developed to determine the wait-and-see decisions by approximating a robust solution with a linear decision rule. The robust models find an optimal solution that is always feasible and less sensitive against all realized demand within a given uncertainty set, in order to minimize production, procurement, inventory, and lost sales costs even in the worst case. Numerical studies demonstrated that, without knowing probability distribution of future demand, the affinely adjustable robust counterpart approach could outperform the robust counterpart and deterministic model in terms of the average cost, the standard deviation of the realized cost, and the worst-case scenario cost. The proposed method is much better than the others, especially when penalty cost due to lost sales is high and unknown demand is left skewed.
Autors: Byung Soo Kim;Byung Do Chung;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 505 - 514
Publisher: IEEE
 
» aHDFS: An Erasure-Coded Data Archival System for Hadoop Clusters
Abstract:
In this paper, we propose an erasure-coded data archival system called aHDFS for Hadoop clusters, where codes are employed to archive data replicas in the Hadoop distributed file system or HDFS. We develop two archival strategies (i.e., aHDFS-Grouping and aHDFS-Pipeline) in aHDFS to speed up the data archival process. aHDFS-Grouping - a MapReduce-based data archiving scheme - keeps each mapper’s intermediate output Key-Value pairs in a local key-value store. With the local store in place, aHDFS-Grouping merges all the intermediate key-value pairs with the same key into one single key-value pair, followed by shuffling the single Key-Value pair to reducers to generate final parity blocks. aHDFS-Pipeline forms a data archival pipeline using multiple data node in a Hadoop cluster. aHDFS-Pipeline delivers the merged single key-value pair to a subsequent node’s local key-value store. Last node in the pipeline is responsible for outputting parity blocks. We implement aHDFS in a real-world Hadoop cluster. The experimental results show that aHDFS-Grouping and aHDFS-Pipeline speed up Baseline’s shuffle and reduce phases by a factor of 10 and 5, respectively. When block size is larger than 32 MB, aHDFS improves the performance of HDFS-RAID and HDFS-EC by approximately 31.8 and 15.7 percent, respectively.
Autors: Yuanqi Chen;Yi Zhou;Shubbhi Taneja;Xiao Qin;Jianzhong Huang;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Nov 2017, volume: 28, issue:11, pages: 3060 - 3073
Publisher: IEEE
 
» Airborne DInSAR Results Using Time-Domain Backprojection Algorithm: A Case Study Over the Slumgullion Landslide in Colorado With Validation Using Spaceborne SAR, Airborne LiDAR, and Ground-Based Observations
Abstract:
The major impediment to accurate airborne repeat-pass differential synthetic aperture radar (SAR) interferometry (DInSAR) is compensating for aircraft motion caused by air turbulence. Various motion compensation (MoCo) procedures have been used in the airborne DInSAR processing to acquire reliable deformation mapping. In this paper, we present the use of time-domain backprojection (BP) algorithm for SAR focusing in an airborne DInSAR survey: No MoCo procedure is needed because the BP algorithm is inherently able to compensate for platform motion. In this study, we present the results of a pilot study aimed at demonstrating the feasibility of deformation mapping with an airborne SAR system based on the monitoring of the Slumgullion landslide in Colorado, USA between July 3 and 10 of 2015. The employed airborne SAR system is an Artemis SlimSAR that is a compact, modular, and multi-frequency radar system. Airborne light detection and ranging and global navigation satellite system (GNSS) observations, as well as spaceborne DInSAR results using COSMO-SkyMed (CSK) images, were used to verify the performance of the airborne SAR system. The surface velocities of the landslide derived from the airborne DInSAR observations showed good agreement with the GNSS and spaceborne DInSAR estimates. A three-dimensional deformation map of the Slumgullion landslide was also generated, which displayed distinct correlation between the landslide motion and topographic variation. This study shows that an inexpensive airborne L-band DInSAR system has the potential to measure centimeter level deformation with flexible temporal and spatial baselines.
Autors: Ning Cao;Hyongki Lee;Evan Zaugg;Ramesh Shrestha;William Carter;Craig Glennie;Guoquan Wang;Zhong Lu;Juan Carlos Fernandez-Diaz;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Nov 2017, volume: 10, issue:11, pages: 4987 - 5000
Publisher: IEEE
 
» Albert Einstein - refrigerator technician? [Resources_History]
Abstract:
Albert Einstein is a legend for his breakthroughs in theoretical physics, but sometimes even the most abstract theorists have a practical side. In collaboration with other scientists and technologists throughout his career, Einstein also filed patents and promoted practical inventions that included a refrigerator, a hearing aid, and a camera.
Autors: Mark Anderson;
Appeared in: IEEE Spectrum
Publication date: Nov 2017, volume: 54, issue:11, pages: 19 - 19
Publisher: IEEE
 
» All-Digital Time-Mode Direct-Form All-Pole Biquadratic Filter Realization
Abstract:
In this brief, the design of time-mode signal processing (TMSP) circuits having an all-digital advantage is introduced and experimental data covering all necessary aspects of operation such as frequency response are presented. TMSP building blocks were used to design two second-order filter prototypes having Butterworth and Chebychev I responses demonstrating peak signal-to-noise-plus-distortion values of 47 dB and 37 dB, respectively, making it a good candidate for data conversion applications.
Autors: Moataz Abdelfattah;Gordon W. Roberts;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Nov 2017, volume: 64, issue:11, pages: 1262 - 1266
Publisher: IEEE
 
» Alternative Scheduling Decisions for Multipath TCP
Abstract:
In this letter, we discuss the impact of packet scheduling decisions on the performance of Multipath Transmission Control Protocol (MPTCP) flows. We propose, implement, and evaluate three alternative schedulers, namely, Highest Sending Rate (HSR), Largest Window Space (LWS) and Lowest Time/Space (LTS). We evaluate and compare them to the current MPTCP’s scheduler, Lowest Latency (LL), in an experimental environment. To analyze the performance of the multipath throughput improvement of these schedulers, we conducted a vast set of 40 different experiments that combine homogeneous and heterogeneous link parameterizations, considering packet loss rate, delay, and transmission rate. Experimental results showed that the proposed alternatives achieved a higher performance than LL in most of the experiments, allowing better alternatives for improving multipath throughput with paths under loss, delay, and varied transmission rates.
Autors: Bruno Y. L. Kimura;Demetrius C. S. F. Lima;Antonio A. F. Loureiro;
Appeared in: IEEE Communications Letters
Publication date: Nov 2017, volume: 21, issue:11, pages: 2412 - 2415
Publisher: IEEE
 
» Amplifying the Randomness of Weak Sources Correlated With Devices
Abstract:
The problem of device-independent randomness amplification against no-signaling adversaries has so far been studied under the assumption that the weak source of randomness is uncorrelated with the (quantum) devices used in the amplification procedure. In this paper, we relax this assumption, and reconsider the original protocol of Colbeck and Renner using a Santha-Vazirani (SV) source. To do so, we introduce an SV-like condition for devices, namely that any string of SV source bits remains weakly random conditioned upon any other bit string from the same SV source and the outputs obtained when this further string is input into the devices. Assuming this condition, we show that a quantum device using a singlet state to violate the chained Bell inequalities leads to full randomness in the asymptotic scenario of a large number of settings, for a restricted set of SV sources (with ). We also study a device-independent protocol that allows for correlations between the sequence of boxes used in the protocol and the SV source bits used to choose the particular box from whose output the randomness is obtained. Assuming the SV-like condition for devices, we show that the honest parties can achieve amplification of the weak source, for the parameter range , against a class of attacks given as a mixture of product box sequences, made of extremal no-signaling boxes, with additional symmetry conditions. Composable security proof against this class of attacks is provided.
Autors: Hanna Wojewódka;Fernando G. S. L. Brandão;Andrzej Grudka;Karol Horodecki;Michał Horodecki;Paweł Horodecki;Marcin Pawłowski;Ravishankar Ramanathan;Maciej Stankiewicz;
Appeared in: IEEE Transactions on Information Theory
Publication date: Nov 2017, volume: 63, issue:11, pages: 7592 - 7611
Publisher: IEEE
 
» An 80-mVpp Linear-Input Range, 1.6- $text{G}Omega $ Input Impedance, Low-Power Chopper Amplifier for Closed-Loop Neural Recording That Is Tolerant to 650-mVpp Common-Mode Interference
Abstract:
Closed-loop neuromodulation is essential for the advance of neuroscience and for administering therapy in patients suffering from drug-resistant neurological conditions. Neural stimulation generates large differential and common-mode (CM) artifacts at the recording sites, which easily saturate traditional recording front ends. This paper presents a neural recording chopper amplifier capable of handling in-band 80-mVpp differential artifacts and 650-mVpp CM artifacts while preserving the accompanying small neural signals. New techniques have been proposed that introduce immunity to CM interference, increase the input impedance of the chopper amplifier to 1.6 , and increase the maximum realizable resistance of duty-cycled resistors (DCR) to 90 . These techniques enable our recording front-end to achieve a dynamic range of 74 dB (200 Hz–5 kHz) and 81 dB (1–200 Hz). Implemented in a 40-nm CMOS process, the prototype occupies an area of 0.069 mm2/channel, and consumes 2.8 from a 1.2-V supply. The input-referred noise is 5.3 (200 Hz–5 kHz) and 1.8 (1–200Hz). The total harmonic distortion for a 40-mV input at 1 kHz is −76 dB. This work improves the input impedance by 5.3 for chopped- front-ends, linear-input range by 2, maximum resistance of DCR by 32, and tolerance to CM interferers by 6.5, while maintaining comparable power and noise performance.
Autors: Hariprasad Chandrakumar;Dejan Marković;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Nov 2017, volume: 52, issue:11, pages: 2811 - 2828
Publisher: IEEE
 
» An Accurate Two-Step ISAR Cross-Range Scaling Method for Earth-Orbit Target
Abstract:
Inverse synthetic aperture radar (ISAR) cross-range scaling is used to obtain the actual cross-range size of the target, which is essential for space surveillance and automatic target recognition. In this letter, a novel two-step ISAR cross-range scaling method for earth-orbit targets is proposed, which improves the computational efficiency through the use of prior information and achieves high estimation accuracy. An initial rotation velocity (RV) is calculated first using the open two-line element data of the satellite orbit to coarsely achieve a cross-range scaling of the ISAR image with high efficiency. Then, the refined cross-range scaling result is obtained with an accurate RV, which is accomplished by the isolated scatterer extraction and the chirp-rate estimation, wherein the blob detection and the integrated cubic phase function are employed, respectively. The initial RV is used to narrow the search width of the chirp-rate estimation, and the corresponding computational burden is expected to decrease accordingly. Finally, simulations and real-data experiments are performed to verify the effectiveness and the accuracy of the proposed method.
Autors: Yuhan Du;Yicheng Jiang;Wei Zhou;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1893 - 1897
Publisher: IEEE
 
» An Active Interferometric Method for Extreme Impedance On-Wafer Device Measurements
Abstract:
Nano-scale devices and high-power transistors present extreme impedances, which are far removed from the 50- reference impedance of conventional test equipment, resulting in a reduction in the measurement sensitivity as compared with impedances close to the reference impedance. This letter describes a novel method based on active interferometry to increase the measurement sensitivity of a vector network analyzer for measuring such extreme impedances, using only a single coupler. The theory of the method is explained with supporting simulation. An interferometry-based method is demonstrated for the first time with on-wafer measurements, resulting in an improved measurement sensitivity for extreme impedance device characterization of up to 9%.
Autors: Haris Votsi;Chong Li;Peter H. Aaen;Nick M. Ridler;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Nov 2017, volume: 27, issue:11, pages: 1034 - 1036
Publisher: IEEE
 
» An Adaptive Control Architecture for Mitigating Sensor and Actuator Attacks in Cyber-Physical Systems
Abstract:
Recent technological advances in communications and computation have spurred a broad interest in control law architectures involving the monitoring, coordination, integration, and operation of sensing, computing, and communication components that tightly interact with the physical processes that they control. These systems are known as cyber-physical systems and due to their use of open computation and communication platform architectures, controlled cyber-physical systems are vulnerable to adversarial attacks. In this technical note, we propose a novel adaptive control architecture for addressing security and safety in cyber-physical systems. Specifically, we develop an adaptive controller that guarantees uniform ultimate boundedness of the closed-loop dynamical system in the face of adversarial sensor and actuator attacks that are time-varying and partial asymptotic stability when the sensor and actuator attacks are time-invariant. Finally, we provide a numerical example to illustrate the efficacy of the proposed adaptive control architecture.
Autors: Xu Jin;Wassim M. Haddad;Tansel Yucelen;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 6058 - 6064
Publisher: IEEE
 
» An Agile Confidential Transmission Strategy Combining Big Data Driven Cluster and OBF
Abstract:
This paper investigates an agile confidential transmission strategy combining big data driven cluster and opportunistic beamforming (OBF) in the scenario where the same huge content is downloaded simultaneously by many users from the same base station. Instead of a burden from the traditional perspective, big data can be viewed as a resource. With the help of big data, data driven cluster taking into account security issues can be formed. Due to some obvious advantages, physical layer security (PHY-security) techniques as an alternative to the traditional high complexity cryptography-based secrecy methods are employed to achieve confidential transmission. For the purpose of superior secrecy performance, the scheme combining big data driven cluster and OBF, each of which can configure limited communication resources agilely and effectively in a dynamically changing network environment, is proposed. As the number of authorized users increases in the system, not only the channel vectors of cluster heads can tend to match with beamforming vectors with a high probability, but also more authorized users can be added into clusters and attain confidential content. These advantages ensure the combination of these two techniques is an attractive approach to transmit confidential message at a high rate. Based on different demand cases, multiple versions of the scheme combining cluster and OBF are put forward. In order to validate our proposed schemes, numerical simulations are carried out and the results show that a significant performance gain over both the average secrecy sum-capacity and the average number of authorized users accessing the system is achieved.
Autors: Shuai Han;Sai Xu;Weixiao Meng;Cheng Li;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 10259 - 10270
Publisher: IEEE
 
» An Algorithm for the In-Field Calibration of a MEMS IMU
Abstract:
Recently, micro electro-mechanical systems (MEMS) inertial sensors have found their way in various applications. These sensors are fairly low cost and easily available but their measurements are noisy and imprecise, which poses the necessity of calibration. In this paper, we present an approach to calibrate an inertial measurement unit (IMU) comprised of a low-cost tri-axial MEMS accelerometer and a gyroscope. As opposed to existing methods, our method is truly infield as it requires no external equipment and utilizes gravity signal as a stable reference. It only requires the sensor to be placed in approximate orientations, along with the application of simple rotations. This also offers easier and quicker calibration comparatively. We analyzed the method by performing experiments on two different IMUs: an in-house built IMU and a commercially calibrated IMU. We also calibrated the in-house built IMU using an aviation grade rate table for comparison. The results validate the calibration method as a useful low-cost IMU calibration scheme.
Autors: Umar Qureshi;Farid Golnaraghi;
Appeared in: IEEE Sensors Journal
Publication date: Nov 2017, volume: 17, issue:22, pages: 7479 - 7486
Publisher: IEEE
 
» An All-Region I–V Model for 1-D Nanowire MOSFETs
Abstract:
An all-region short-channel MOSFET, model is developed for nanowire semiconductors with 1-D density of states. It is shown that in the quantum capacitance limit, the long-channel saturation current exhibits a (Vgs Vt)3/2 dependence on gate voltage. With the velocity saturation effect implemented in the model, the IdsVgs characteristics of 1-D MOSFETs are compared to those of 2-D MOSFETs at 10-nm channel length. The above threshold model is joined with a subthreshold current model derived from short-channel solutions to form an IV model continuous in all regions.
Autors: Jianzhi Wu;Yuan Taur;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 1062 - 1066
Publisher: IEEE
 
» An Antinoise-Folding Algorithm for the Recovery of Biomedical Signals From Noisy Measurements
Abstract:
Sparse sampling (SS) has shown a significant promise for the recovery of biomedical signals from noisy measurements. In practice, the premeasurement noise, i.e., the noise associated with the unprocessed signal is often ignored. At large compression, a small perturbation in the raw signal may degrade the signal-to-noise ratio by a significant amount due to the noise-folding effect. In this paper, a new antinoise-folding sparse recovery framework is proposed, which is blind-to-noise-statistics, and it does not require any prior warm-up step to select the starting point. The source signal is recovered from the noisy measurements by solving a nonconvex regularization-based constrained minimization problem followed by a data-adaptive Stein's unbiased risk estimate-based denoising process. The constrained problem is linearized by employing the method of majorization-minorization. Furthermore, the sparse recovery analysis of the new algorithm is established. The numerical test results obtained by employing noisy photoplethysmogram data and real-world fetal-electrocardiogram data show the superior performance of the proposed method as compared with various state-of-the-art SS methods.
Autors: Priya Ranjan Muduli;Atindra Kanti Mandal;Anirban Mukherjee;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 2909 - 2916
Publisher: IEEE
 
» An Attitude Jitter Correction Method for Multispectral Parallax Imagery Based on Compressive Sensing
Abstract:
Attitude jitter is a common problem for high-resolution earth-observation satellites and can diminish the geo-positioning and mapping performance of observed images. It is especially necessary to address this problem when high-performance attitude measurements are unavailable. Therefore, an attitude jitter correction method for multispectral parallax imagery that utilizes the compressive-sensing technology is proposed in this letter. In the proposed method, the attitude jitter is estimated from the parallax disparities of different band images, and then the image displacement caused by attitude jitter can be corrected. Using the normalized cross correlation method and compressive-sensing technology, the proposed method can deal with the condition of texture-feature deficiency in the partial image. The multispectral images of the Terra and ZY-3 satellites are used as experimental data to evaluate the proposed method. The registration errors of different bands are greatly reduced in both the cross- and along-track directions, and the experiment results indicate that the proposed method is effective for correcting the attitude jitter of both satellites.
Autors: Jun Chen;Jun-Gang Yang;Wei An;Zhi-Jie Chen;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Nov 2017, volume: 14, issue:11, pages: 1903 - 1907
Publisher: IEEE
 
» An Easy-to-Implement Hysteresis Model Identification Method Based on Support Vector Regression
Abstract:
The classical Preisach hysteresis model and its modifications are time consuming to implement due to the determination of the weight function. Another defect of the Preisach-based model is that it could only be an approximation in the absence of the congruency property. For such reasons, this paper proposes a hysteresis model identification method based on support vector regression which could be a promising alternative in practical applications. Support vector machine is attractive in regression analysis due to its strong generalization capability. A four-stage identification procedure is implemented and key techniques are introduced in detail. The penalty parameter and the kernel parameter are optimized using grid search and cross-validation method. The influences of data scaling and parameter optimization are analyzed. An identified hysteresis model of aluminum nickel cobalt alloy is evaluated and verified with the criteria of mean squared error and identified time.
Autors: Shukuan Zhang;Mingqiao Wang;Ping Zheng;Guangyuan Qiao;Faliang Liu;Lei Gan;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» An Eco-Friendly Means of Biosynthesis of Superparamagnetic Magnetite Nanoparticles via Marine Polymer
Abstract:
A facile, environmental friendly green approach was introduced in this study, which superparamagnetic magnetite nanoparticles (Fe3O4-NPs) have been satisfactorily synthesized. Seaweed Kappaphycus alvarezii (K. alvarezii) extract was employed in this synthesis process, which played a role as bio-stabilizer. The structure and morphology of the synthesized K. alvarezii/Fe3O 4-NPs were analyzed by X-ray diffraction (XRD) and transmission electron microscope. The spherical shape of K. alvarezii/Fe3O4-NPs with an average size of 19.4 nm showed high crystallinity and purity based on the characteristic XRD planes at (220), (311), (400), (422), (511), (440), and (533). The presence of Fe3O4-NPs was identified by Fourier transform infrared, Raman spectroscopy, and energy-dispersive X-ray spectroscopy. The magnetic properties of K. alvarezii /Fe3O4-NPs were studied using vibrating sample magnetometer, which gave a result of 24.85 emu/g. The K. alvarezii/Fe3O4-NPs were very stable, where zeta potential value showed −53.57 mV.
Autors: Yen Pin Yew;Kamyar Shameli;Mikio Miyake;Nurul Bahiyah Bt Ahmad Khairudin;Shaza Eva Bt Mohamad;Hirofumi Hara;Mariam Firdhaus Bt Mad Nordin;Kar Xin Lee;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Nov 2017, volume: 16, issue:6, pages: 1047 - 1052
Publisher: IEEE
 
» An Efficient Robust Solution to the Two-Stage Stochastic Unit Commitment Problem
Abstract:
This paper provides a reformulation of the scenario-based two-stage unit commitment problem under uncertainty that allows finding unit-commitment plans that perform reasonably well both in expectation and for the worst case. The proposed reformulation is based on partitioning the sample space of the uncertain factors by clustering the scenarios that approximate their probability distributions. The degree of conservatism of the resulting unit-commitment plan (that is, how close it is to the one provided by a purely robust or stochastic unit-commitment formulation) is controlled by the number of partitions into which the said sample space is split. To efficiently solve the proposed reformulation of the unit-commitment problem under uncertainty, we develop two alternative parallelization and decomposition schemes that rely on a column-and-constraint generation procedure. Finally, we analyze the quality of the solutions provided by this reformulation for a case study based on the IEEE 14-node power system and test the effectiveness of the proposed parallelization and decomposition solution approaches on the larger IEEE 3-Area RTS-96 power system.
Autors: Ignacio Blanco;Juan M. Morales;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4477 - 4488
Publisher: IEEE
 
» An Electromagnet-Assisted Ferrite Magnet Motor
Abstract:
This paper proposes an electromagnet-assisted ferrite magnet motor (EMaFM) with a double air-gap structure. To confirm the principle and validity of the proposed EMaFM, a prototype machine was designed and fabricated. Moreover, the electromagnetic performance of the prototype machine was simulated using a finite-element analysis (FEA) and was supported by experiments. The proposed EMaFM has field regulation capability while utilizing the ferrite magnets. From the FEA and experimental results, it was found that the torque can be controlled widely by the armature current or field current.
Autors: Tadashi Fukami;Kazuki Motoki;Ryohei Kirihata;Kazuo Shima;Masato Koyama;Takeshi Mori;Masatsugu Nakano;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 4
Publisher: IEEE
 
» An Empirical Evaluation of Techniques for Ranking Semantic Associations
Abstract:
Searching for associations between entities is needed in many domains like national security and bioinformatics. In recent years, it has been facilitated by the emergence of graph-structured semantic data on the Web, which offers structured semantic associations more explicit than those hiding in unstructured text for computers to discover. The increasing volume of semantic data often produces excessively many semantic associations, and requires ranking techniques to identify the more important ones for users. Despite the fruitful theoretical research on innovative ranking techniques, there is a lack of comprehensive empirical evaluation of these techniques. In this article, we carry out an extensive evaluation of eight techniques for ranking semantic associations, including two novel ones we propose. The practical effectiveness of these techniques is assessed based on 1,200 ground-truth rankings created by 30 human experts for real-life semantic associations and the explanations given by the experts. Our findings also suggest a number of directions in improving existing techniques and developing novel techniques for future work.
Autors: Gong Cheng;Fei Shao;Yuzhong Qu;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2388 - 2401
Publisher: IEEE
 
» An Empirical Mode Decomposition Method for Sea Surface Wind Measurements From X-Band Nautical Radar Data
Abstract:
In this paper, sea surface wind direction and speed are obtained from X-band nautical radar images. A data control strategy is proposed to distinguish rain-free and rain-contaminated radar data. The radar data are decomposed by an ensemble empirical mode decomposition method into several intrinsic mode functions (IMFs) and a residual. A normalization scheme is applied to the first IMF to obtain the amplitude modulation (AM) component. Wind direction is determined from the residual for the rain-free and high-wind-speed rain-contaminated data, and from the AM portion of the first IMF for the low-wind-speed rain-contaminated data, based on curve fitting a harmonic function. Wind speed is determined from a combination of the residual and the AM part of the first IMF for both rain-free and rain-contaminated data using a logarithmic relationship. Results employing ship-borne radar and anemometer data collected in a sea trial off the east coast of Canada are presented. The root-mean-square differences for wind direction and speed measurements are 11.5° and 1.31 m/s, respectively, compared with reference values from anemometers.
Autors: Weimin Huang;Xinlong Liu;Eric W. Gill;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6218 - 6227
Publisher: IEEE
 
» An Empirical Study of the Telecommunications Service Industries Using Productivity Decomposition
Abstract:
Telecommunications service industry provides services that transmit voice, data, text, sound, video, and other signals. In the Internet age, the telecommunications service industry has experienced tremendous growth to form an indispensable infrastructure platform for today's global networked economy. In this study, we examine the output performance of telecommunications service industries in 13 Organization of Economic Cooperation and Development countries from 2000 to 2011 using the Malmquist total factor productivity index (MTFPI) as the performance metric and data envelopment analysis as the measurement approach. We further decompose MTFPI into three factors: 1) technical change; 2) pure efficiency change; and 3) scale efficiency change, that represent innovation, catch-up, and demand fluctuation, respectively. The results show that these telecommunications service industries exhibit comparatively strong productivity growth. In addition, through our decomposition analysis, it is found that telecommunications service industry is an innovator skilled at adopting technological advances that turn out to be the key driving force for the observed productivity growth. By contrast, both pure efficiency change and scale efficiency change lead to negative impacts. Based on these findings, we draw and discuss implications for telecommunications service at the country and industry levels, and provide suggestions for practice and future research.
Autors: Benjamin B. M. Shao;Winston T. Lin;Juliana Y. Tsai;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Nov 2017, volume: 64, issue:4, pages: 437 - 449
Publisher: IEEE
 
» An End-to-End Trainable Neural Network for Image-Based Sequence Recognition and Its Application to Scene Text Recognition
Abstract:
Image-based sequence recognition has been a long-standing research topic in computer vision. In this paper, we investigate the problem of scene text recognition, which is among the most important and challenging tasks in image-based sequence recognition. A novel neural network architecture, which integrates feature extraction, sequence modeling and transcription into a unified framework, is proposed. Compared with previous systems for scene text recognition, the proposed architecture possesses four distinctive properties: (1) It is end-to-end trainable, in contrast to most of the existing algorithms whose components are separately trained and tuned. (2) It naturally handles sequences in arbitrary lengths, involving no character segmentation or horizontal scale normalization. (3) It is not confined to any predefined lexicon and achieves remarkable performances in both lexicon-free and lexicon-based scene text recognition tasks. (4) It generates an effective yet much smaller model, which is more practical for real-world application scenarios. The experiments on standard benchmarks, including the IIIT-5K, Street View Text and ICDAR datasets, demonstrate the superiority of the proposed algorithm over the prior arts. Moreover, the proposed algorithm performs well in the task of image-based music score recognition, which evidently verifies the generality of it.
Autors: Baoguang Shi;Xiang Bai;Cong Yao;
Appeared in: IEEE Transactions on Pattern Analysis and Machine Intelligence
Publication date: Nov 2017, volume: 39, issue:11, pages: 2298 - 2304
Publisher: IEEE
 
» An Ensemble Approach to Link Prediction
Abstract:
A network with nodes contains possible links. Even for networks of modest size, it is often difficult to evaluate all pairwise possibilities for links in a meaningful way. Further, even though link prediction is closely related to missing value estimation problems, it is often difficult to use sophisticated models such as latent factor methods because of their computational complexity on large networks. Hence, most known link prediction methods are designed for evaluating the link propensity on a specified subset of links, rather than on the entire networks. In practice, however, it is essential to perform an exhaustive search over the entire networks. In this article, we propose an ensemble enabled approach to scaling up link prediction, by decomposing traditional link prediction problems into subproblems of smaller size. These subproblems are each solved with latent factor models, which can be effectively implemented on networks of modest size. By incorporating with the characteristics of link prediction, the ensemble approach further reduces the sizes of subproblems without sacrificing its prediction accuracy. The ensemble enabled approach has several advantages in terms of performance, and our experimental results demonstrate the effectiveness and scalability of our approach.
Autors: Liang Duan;Shuai Ma;Charu Aggarwal;Tiejun Ma;Jinpeng Huai;
Appeared in: IEEE Transactions on Knowledge and Data Engineering
Publication date: Nov 2017, volume: 29, issue:11, pages: 2402 - 2416
Publisher: IEEE
 
» An Epitaxy Transfer Process for Heterogeneous Integration of Submillimeter-Wave GaAs Schottky Diodes on Silicon Using SU-8
Abstract:
This letter describes a new approach for fabricating quasi-vertical submillimeter-wave GaAs Schottky diodes heterogeneously integrated to high-resistivity silicon substrates. The new method is robust and eliminates previous processing steps that were prone to result in wafer fracture and delamination. Diodes fabricated with the new process and measured in the 325–500 GHz range using on-wafer RF probes exhibits low parasitic capacitance and series resistance, achieving device characteristics comparable to the prior state-of-the-art submillimeter-wave diodes.
Autors: Linli Xie;Souheil Nadri;Naser Alijabbari;Michael E. Cyberey;Matthew F. Bauwens;Arthur W. Lichtenberger;N. Scott Barker;Robert M. Weikle;
Appeared in: IEEE Electron Device Letters
Publication date: Nov 2017, volume: 38, issue:11, pages: 1516 - 1519
Publisher: IEEE
 
» An Equalized Global Graph Model-Based Approach for Multicamera Object Tracking
Abstract:
Nonoverlapping multicamera visual object tracking typically consists of two steps: single-camera object tracking (SCT) and inter-camera object tracking (ICT). Most of tracking methods focus on SCT, which happens in the same scene, while for real surveillance scenes, ICT is needed and single-camera tracking methods cannot work effectively. In this paper, we try to improve the overall multicamera object tracking performance by a global graph model with an improved similarity metric. Our method treats the similarities of single-camera tracking and inter-camera tracking differently and obtains the optimization in a global graph model. The results show that our method can work better even in the condition of poor SCT.
Autors: Weihua Chen;Lijun Cao;Xiaotang Chen;Kaiqi Huang;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Nov 2017, volume: 27, issue:11, pages: 2367 - 2381
Publisher: IEEE
 
» An Equivalent Model of Gas Networks for Dynamic Analysis of Gas-Electricity Systems
Abstract:
The increasing coupling between natural gas and electricity systems by gas-fired generation units brings new challenges to system analysis, such as pressure variations due to consumption perturbations of generation units. The emerging issues require revolutionary modeling and analysis techniques. This paper proposes a novel model to quantify gas pressure variations due to gas-fired power unit ramping and the impact of constraints from natural gas pressure change on ramp rates of gas-fired plants. By utilizing Laplace transform to resolve the governing equations of gas networks, the proposed model can significantly reduce modeling complexity and computational burden. The dynamic behaviors in time scale in s-domain and spatial partial differential equations are transformed into finite difference equations. By introducing the concept of transfer matrices, the relation between states at each node of gas systems can be expressed by transfer parameter matrices. Additionally, a simplified model is introduced to simply the analysis. The explicit expressions of nodal pressure variations in response to demand change are very convenient for analyzing system dynamic performance under disturbances, identifying the most influential factors. The new models are extensively demonstrated on three natural gas networks and benchmarked with traditional simulation approaches. Results illustrate that they produce very close results with the simulation approach, particularly when gas pipelines are long and enter steady states.
Autors: Yongzhi Zhou;Chenghong Gu;Hao Wu;Yonghua Song;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4255 - 4264
Publisher: IEEE
 
» An External Capacitor-Less Ultralow-Dropout Regulator Using a Loop-Gain Stabilizing Technique for High Power-Supply Rejection Over a Wide Range of Load Current
Abstract:
An external capacitor-less ultra low-dropout (LDO) regulator that can continue to provide high power-supply rejection (PSR) over a wide range of the load current is proposed. Using the loop-gain stabilizer (LGS) to fix the dc level of the output voltage of the error amplifier to the optimal value, the LDO can keep maximizing the unity-gain frequency, while the load current changes widely up to 200 mA. Despite the multiple poles in the regulating loop, the stability can easily be obtained due to an intrinsic left-half plane zero, generated by the auxiliary path of the LGS. The proposed LDO was fabricated in a 40-nm CMOS process, and it had an input voltage of 1.1 V. When the dropout voltage was 0.1 V and the load current was 200 mA, the measured PSRs were −60 and −35 dB at 1 and 10 MHz, respectively. Due to the LGS, the dc loop gain was maintained to be high, resulting in good load and line regulations of /mA and 0.75 mV/V, respectively. While the total current consumption of the LDO was , the LGS consumed only . The area was 0.008 mm2 with 4-pF on-chip capacitance for compensation.
Autors: Younghyun Lim;Jeonghyun Lee;Yongsun Lee;Seong-Sik Song;Hong-Teuk Kim;Ockgoo Lee;Jaehyouk Choi;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3006 - 3018
Publisher: IEEE
 
» An Imbalance Compensation Framework for Background Subtraction
Abstract:
Class imbalance refers to the instance where the number of training samples for the majority classes is far more than that of the minority classes (relative imbalance), and the quality of training samples for the minority classes is inferior to that of the majority classes (absolute imbalance), which are further complicated by other imbalance factors, e.g., data overlapping. Video background subtraction aims to classify each pixel into two classes: foreground and background. This paper first reveals that background subtraction is a class imbalance problem, where the foreground and background are the minority and majority classes, respectively. By exploring spatial and temporal correlation inherent in video data, we present an imbalance compensation framework for background subtraction, which consists of two sequential modules, imbalance-compensated bilayer modeling, and imbalance-compensated Bayesian classification. In the first module, spatio-temporal oversampling (SOS) and selective downsampling (SDS) are proposed to compensate the imbalance at data level. SOS attempts to synthesize representative samples appended to the minority sample set, while SDS selectively deletes a number of majority samples in data overlapping areas. The rebalanced samples are then used to learn a bilayer model. In the second module, novel cost functions are proposed to compensate the effect of class imbalance at algorithm level. The cost functions are based on imbalance measurement, and used to construct the prior term in the Bayesian classification scheme. Experiments are conducted on public databases to demonstrate the effectiveness of the proposed method.
Autors: Xiang Zhang;Ce Zhu;Honggang Wu;Zhi Liu;Yuanyuan Xu;
Appeared in: IEEE Transactions on Multimedia
Publication date: Nov 2017, volume: 19, issue:11, pages: 2425 - 2438
Publisher: IEEE
 
» An Improved Criterion for Controllability of Boolean Control Networks
Abstract:
This paper tackles the controllability problem of Boolean control networks (BCNs). By resorting to the semi-tensor product technique and the Warshall algorithm, several improved novel reachability and controllability criteria are obtained for the BCNs. Through constructing a sequence of rigorous Boolean matrices, controllability matrix of the considered BCNs is derived iteratively. It is worth pointing out that the proposed method has lower computational complexity, and thus facilitates the reachability and controllability analysis for BCNs. In addition, the issue concerning controllability of BCNs with undesirable interior states is investigated by checking a set of designated Boolean matrices. Finally, to test the effectiveness of the obtained theoretical results, a genetic network model known as the switch is used as an example for numerical simulation.
Autors: Jinling Liang;Hongwei Chen;James Lam;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Nov 2017, volume: 62, issue:11, pages: 6012 - 6018
Publisher: IEEE
 
» An Improved Displacement Measurement Based on Model Reconstruction for Permanent Magnet Synchronous Motor
Abstract:
Permanent magnet synchronous linear motor (PMSLM) and PM synchronous planar motor are important motion devices in the modern precision industry. Their inherent periodic magnetic fields are highly related to motor position. Correspondingly, the magnetic fields can be utilized to determine their own displacement and replace expensive sensors. However, the measurement result of this strategy seriously depends on magnetic field model (MFM) preciseness. To improve measurement accuracy, a novel MFM with Fourier series is proposed in this paper. First, a high-order theoretical model from theoretical derivation is developed. And the analyses show that even harmonics exist in the magnetic field of motor, which are not included in the theoretical model. This model deviation obviously affects measurement accuracy. Hence, the new MFM is reconstructed based on a high-order theoretical model. Comparative experiments with the three different MFMs are carried out to measure the displacement of the PMSLM. In the experiments, a linear hall sensors array containing eight sensors is self-developed to detect motor magnetic field. The root mean square of displacement measurement errors using a reconstruction model, a high-order theoretical model, and a fundamental model is 4.84, 8.42, and 758 μm, respectively. The experimental results validate that the measurement result of the proposed reconstruction MFM is better than the other two MFMs.
Autors: Shengwu Du;Jinchun Hu;Yu Zhu;Ming Zhang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Nov 2017, volume: 66, issue:11, pages: 3044 - 3051
Publisher: IEEE
 
» An Improved Hybrid Turbo Equalizer for Single Carrier Transmission with Impulsive Noise and ISI
Abstract:
In this paper, we propose an improved hybrid turbo equalizer (TEQ) for single-carrier transmission over multipath channels with symmetric alpha-stable noise. First, a nonlinear myriad filter is adopted for combating the effect of impulsive noise. The noise output of this nonlinear filter is analyzed by an asymptotic statistic method and shown to be asymptotically Gaussian. Then, a matched minimum mean square error based linear TEQ is proposed for further mitigating the effects of the residual impulsive noise and the intersymbol interference caused by multipath fading. In our proposed TEQ design procedure, the instantaneous estimation of the noise variance is exploited to obtain robust TEQ coefficients. Simulation results show that the proposed hybrid TEQ provides geometric signal-to-noise ratio improvements (of up to 4.5 dB) compared to conventional algorithms designed for Gaussian channels.
Autors: Ping Yang;Yong Liang Guan;Xiao Bei Liu;Zilong Liu;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Nov 2017, volume: 66, issue:11, pages: 9852 - 9861
Publisher: IEEE
 
» An Improved Magnetic Circuit Model of a 3-DOF Magnetic Bearing Considering Leakage and Cross-Coupling Effects
Abstract:
This paper presents an improved magnetic circuit (MC) model considering the leakage, cross coupling, and saturation effects for the performance analysis of an integrated 3 degrees of freedom magnetic bearing (3-DOF MB). Compared with the conventional MC model, this paper analyzes the permanent-magnet bias field, radial and axial control current fields together. By using this improved MC model, it reveals the cross-coupling effect between radial and axial directions in such an integrated 3-DOF MB. The stiffnesses of radial force are significantly influenced by the axial control current, while the stiffnesses of the axial force are independent of the radial control current. Its accuracy is verified by the 3-D finite-element method.
Autors: Yunlong Zhong;Lijian Wu;Xiaoyan Huang;Youtong Fang;Jian Zhang;
Appeared in: IEEE Transactions on Magnetics
Publication date: Nov 2017, volume: 53, issue:11, pages: 1 - 6
Publisher: IEEE
 
» An Incentive Framework for Mobile Data Offloading Market Under Price Competition
Abstract:
Mobile data offloading can help the mobile network operator (MNO) cope with the explosive growth of cellular traffic, by delivering mobile traffic through third-party access points. However, the access point owners (APOs) would need proper incentives to participate in data offloading. In this paper, we consider a data offloading market that includes both price-taking and price-setting APOs. We formulate the interactions among the MNO and these two types of APOs as a three-stage Stackelberg game, and study the MNO’s profit maximization problem. Due to a non-convex strategy space, it is in general a non-convex game. Nevertheless, we transform the strategy space into a convex set and prove that a unique subgame perfect equilibrium exists. We further propose iterative algorithms for the MNO and price-setting APOs to obtain the equilibrium. Employing the proposed algorithms, the APOs do not need to obtain full information about the MNO and other APOs. Through numerical studies, we show that the MNO’s profit can increase up to three times comparing with the no-offloading case. Furthermore, our proposed incentive mechanism outperforms an existing algorithm by 18 percent in terms of the MNO’s profit. Results further show that price competition among price-setting APOs drives the equilibrium market prices down.
Autors: Hamed Shah-Mansouri;Vincent W.S. Wong;Jianwei Huang;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Nov 2017, volume: 16, issue:11, pages: 2983 - 2999
Publisher: IEEE
 
» An Intelligent Packing Programming for Space Station Extravehicular Missions
Abstract:
Packing programming for extravehicular missions to the space station is the process of arranging a set of missions into multiple extravehicular activities. It is an interesting combinatorial optimization problem developed from the traditional bin-packing problem. This paper first formulates a practical mathematical model that considers both the constraints of the time window for each extravehicular mission and the spacewalk time per astronaut. An Ant Colony Optimization (ACO) algorithm with a self-adaptation strategy and a new pheromone matrix characterizing the relationship between any two extravehicular missions is then proposed. The simulation results on various independent experiments show that the proposed ACO algorithm is capable of producing optimal packing programming schemes with a success rate of over 90%, which is acceptable for application to real-world problems.
Autors: Yuehe Zhu;Yazhong Luo;Kay Chen Tan;Xin Qiu;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Nov 2017, volume: 12, issue:4, pages: 38 - 47
Publisher: IEEE
 
» An Interactive Robotic Fish Exhibit for Designed Settings in Informal Science Learning
Abstract:
Informal science learning aims to improve public understanding of STEM. Free-choice learners can be engaged in a wide range of experiences, ranging from watching entertaining educational videos to actively participating in hands-on projects. Efforts in informal science learning are often gauged by their ability to elicit interaction, to foster learning, and to influence perceptions of STEM fields. This paper presents the installation of a biomimetic robotic fish controlled by an iDevice application at an informal science learning exhibit. Visitors to the exhibit are offered a unique experience that spans engineering and science, in which they can steer the robotic fish, choosing from three modes of control. Visitor engagement is examined through the lens of the Selinda model of visitor learning, while their behavior is examined using an adapted model of Borun’s framework for behaviors indicative of learning. The evaluation of the efficacy of the exhibit is assessed through a post-experience survey questionnaire, an analysis of the application usage, and a behavior coding study. Data collected on visitor interactions with the exhibit indicate that free-choice learners value the importance of engineering research, and prefer interactive modes. Further, behavior coding results support the ability of the robotic fish platform to capture the visitors’ attention. Findings offer compelling evidence that the exhibit is both highly engaging to visitors and a suitable format for science inquiry.
Autors: Paul Phamduy;Mary Leou;Catherine Milne;Maurizio Porfiri;
Appeared in: IEEE Transactions on Education
Publication date: Nov 2017, volume: 60, issue:4, pages: 273 - 280
Publisher: IEEE
 
» An Interference-Robust Reconfigurable Receiver With Automatic Frequency-Calibrated LNA in 65-nm CMOS
Abstract:
An interference-robust reconfigurable receiver in 65-nm CMOS is presented. The front end is split into a low-band (LB) RF path (0.1–1.5 GHz) and a high-band (HB) RF path (1–5 GHz). By utilizing a harmonic recombination technique, the LB path could reject the third /fifth-order harmonic interferences. A tunable narrowband dual-feedback common-gate low-noise amplifier (LNA) with resonant load provides second-order bandpass filtering to reject the harmonic interferences in the HB path. The RF high-Q bandpass filtering based on the voltage-mode passive mixer and the current-mode low-pass filter in the analog baseband improves the receiver’s resilience to out-of-band interferences. A novel power-detection-based automatic frequency calibration technique is proposed to calibrate the operating frequency of the LNA in the HB path and overcome the effects of process, voltage, and temperature variations. The presented receiver has been implemented in a 65-nm CMOS and consumes 20–76-mW power from 1.2-V power supplies, with a core die area of 5 mm2. The measured results show that the receiver can tolerate −5-dBm interference with 16-dB noise figure (NF) and achieve 95–105-dB maximum conversion gain and 1.7–8-dB NF over 0.1–5 GHz. It also achieves an average harmonic rejection (HR3)/HR5 of 61/68-dB, +7.1/+14.4 dBm in-band/out-of-band input third-order intercept point (OB-IIP3), +71.2-dBm OB-IIP2, and 58.1-dB-image rejection, after the digitally assisted calibrations. The system-level measurements show that the presented receiver achieves 2.1% error vector magnitude (EVM) for 850-MHz Global System for Mobile Communication signals and 5% EVM for band - 2 time division duplexing-local thermal equilibrium (LTE) signals, respectively.
Autors: Xinwang Zhang;Zipeng Chen;Yanqiang Gao;Feng Ma;Jiachen Hao;Guodong Zhu;Baoyong Chi;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Nov 2017, volume: 25, issue:11, pages: 3113 - 3124
Publisher: IEEE
 
» An Interferometric Approach to Cross-Track Clutter Detection in Two-Channel VHF Radar Sounders
Abstract:
Surface cross-track clutter can corrupt both earth and planetary radar sounder (RS) observations preventing definitive interpretation of subsurface features, which are often of primary interest to geologists and planetary scientists. This clutter is usually identified either by manual or automatic techniques that require ancillary information about the topography of the surface, or by using multichannel RS systems with arrays of antennas. However, topographic information is not always available and multichannel systems are generally too massive and costly to mount on satellites for the planetary exploration. In this paper, we propose a novel approach to clutter discrimination that is independent of ancillary information and limits the hardware complexity of the RS system. This approach uses a two-channel RS and exploits cross-channel interferometric phase differences to discriminate the clutter. Our approach includes three main steps: 1) manual feature extraction and theoretical phase-difference estimation; 2) RS interferogram formation; and 3) comparison of theoretical and real phase difference distributions. The proposed method was validated on RS data acquired in Greenland and provides a proof of concept for the surface clutter discrimination using RS data.
Autors: Davide Castelletti;Dustin M. Schroeder;Scott Hensley;Cyril Grima;Gregory Ng;Duncan Young;Yonggyu Gim;Lorenzo Bruzzone;Alina Moussessian;Don D. Blankenship;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Nov 2017, volume: 55, issue:11, pages: 6128 - 6140
Publisher: IEEE
 
» An LQR Controller for Damping of Subsynchronous Interaction in DFIG-Based Wind Farms
Abstract:
This paper presents a linear-quadratic regulator (LQR) for damping of subsynchronous interaction (SSI) in doubly-fed induction generator (DFIG)-based wind farms. The proposed LQR controller employs a full-state observer to estimate all state variables. The output of the LQR is added to control signals of inner current control loops of DFIG converters as supplementary control signals. The supplementary control signals are dynamically limited to avoid saturating the converters and to provide the DFIG with the desired transient response against power system faults. The proposed SSI damping controller is designed for a realistic series compensated wind farm, and its performance is verified using electromagnetic transient (EMT) simulations. The EMT simulations are performed using a detailed DFIG model which includes all nonlinearities and all required transient functions to meet the grid code requirements corresponding to fault-ride-through (FRT). The results show that the proposed SSI controller is able to significantly mitigate the oscillations due to the SSI phenomenon, and to provide excellent transient response against systems faults.
Autors: Mohsen Ghafouri;Ulas Karaagac;Houshang Karimi;Simon Jensen;Jean Mahseredjian;Sherif O. Faried;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4934 - 4942
Publisher: IEEE
 
» An Optically Tunable Cavity-Backed Slot Antenna
Abstract:
There is a growing pressure on antenna designers to provide ever increasing operating bandwidth, efficiency, and flexibility. Emerging communications standards are requiring operation over wide frequency ranges, often with multiple, separated bands of operation. This communication proposes and demonstrates an optically tunable cavity backed slot antenna. Through the incorporation of four silicon bridging pieces and a fiber coupled laser, the operating frequency can be tuned between 4.2 and 6 GHz. Antenna efficiency has been measured and ranges between 36% and 62% depending upon the combination of frequency and tuning state, with the gain taking values between 4.3 and 6.9 dBi. An effective fabrication process for the incorporation of silicon into the antenna has been described, as well as methods for effectively simulating the optically generated conductivity. Simulations and measurements show good agreement, and several proposed improvements are proposed for this novel and flexible tuning technology.
Autors: M. A. Collett;C. D. Gamlath;M. Cryan;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Nov 2017, volume: 65, issue:11, pages: 6134 - 6139
Publisher: IEEE
 
» An Optimal Robust Excitation Controller Design Considering the Uncertainties in the Exciter Parameters
Abstract:
This paper develops a novel framework to design an optimal robust excitation system controller considering the uncertainties in the parameters of the model of the excitation system. The uncertainties may cause the parameter values to vary from their nominal values within a specified upper and lower limit. These uncertainties can have a significant influence on the dynamic characteristics of the power system, that is, the variations in the parameters of the excitation controller model due to the uncertainties in the parameters can cause the system to change from being stable to unstable. It is, therefore, important to design a robust excitation system controller that can ensure that irrespective of the values of the parameters within the boundary of the uncertainties, the power system will not have any variation from its stability. The proposed framework decomposes the uncertainties in the parameters of the excitation system model into two components: matched and unmatched. To eliminate the uncertainties from both components, a linear quadratic regulator problem is constructed to deal with the matched component, while an augmented control is used to cope with the unmatched component. The robustness of the resulting controller is verified using time-domain dynamic stability simulations of a single-machine test system and the IEEE 39-bus New England system.
Autors: Hadi Lomei;Danny Sutanto;Kashem M. Muttaqi;Alireza Alfi;
Appeared in: IEEE Transactions on Power Systems
Publication date: Nov 2017, volume: 32, issue:6, pages: 4171 - 4179
Publisher: IEEE
 

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  2015:   January     February     March     April     May     June     July     August     September     October     November     December    

  2014:   January     February     March     April     May     June     July     August     September     October     November     December    

  2013:   January     February     March     April     May     June     July     August     September     October     November     December    

  2012:   January     February     March     April     May     June     July     August     September     October     November     December    

  2011:   January     February     March     April     May     June     July     August     September     October     November     December    

  2010:   January     February     March     April     May     June     July     August     September     October     November     December    

  2009:   January     February     March     April     May     June     July     August     September     October     November     December    

 
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