Showing papers in "Iete Journal of Research in 2012"
TL;DR: In this article, a fuzzy-based closed-loop controller is applied to obtain a robust controller for blood glucose regulation in type I diabetes mellitus patients, which provides the possibility of more accurate control of blood glucose level in the patient in spite of uncertainty in model parameters and measurement noise.
Abstract: In this paper, fuzzy-based closed-loop controller is applied to obtain a robust controller for blood glucose regulation in type I diabetes mellitus patients. The control technique incorporates expert knowledge about treatment of disease by using Mamdani-type fuzzy logic controller to robustly stabilize the blood glucose concentration in normoglycemic level. Controller performance is considered in terms of its ability to reject the multiple meals, on an averaged nonlinear patient model. Robustness of the controller is tested over a group of patients with model parameter varying considerably from the average model. The controller provides the possibility of more accurate control of blood glucose level in the patient in spite of uncertainty in model parameters and measurement noise. The proposed controller has showed superiority over other classical control techniques. A comparative study is presented with well-known conventional H∞ control technique. Simulation results show the superiority of the pr...
19 citations
TL;DR: In this article, the authors demonstrate the feasibility of constructing end-fire arrays with good performance for forward and rear vision applications in airborne radar applications for forward-and rear-vision applications.
Abstract: Planar end-fire arrays can be used in airborne radar applications for forward and rear vision. The purpose of this work is to demonstrate the viability of constructing end-fire arrays with good ban...
15 citations
TL;DR: In this paper, the adaptive minimum mean squared error (MMSE) equalizer scheme was proposed to suppress the inter-symbol interference induced by optical multipath dispersion in a non-directed line-of-sight (LOS) model using white light emitting diode illumination.
Abstract: Multipath dispersion results from optical signals passing through more than one path. In this paper, we investigate a non-directed line of sight (LOS) model using white light emitting diode illumination. Typically in such a link, the optical signals are modeled as a reflection component and a directed LOS component over optical wireless (OW) channels. However, inter-symbol interference (ISI) induced by multipath dispersion critically influences the performance of OW communications. In this paper, we propose the adaptive minimum mean squared error (MMSE) equalizer scheme to suppress the multipath ISI, since this scheme can minimize the mean square error (MSE) between the desired equalizer output and the actual equalizer output. We compared the following two algorithms: Least mean square and recursive least square. Our computer simulations demonstrated that visible light communication using an adaptive MMSE equalizer can alleviate the serious effects of optical multipath dispersion.
13 citations
TL;DR: A new automatic personalized document summarization using pseudo relevance feedback (PRF) and semantic features to extract meaningful sentences from retrieval documents in the Internet to reduce the semantic gap between the low level of summarizing search results and the high level of user's perception.
Abstract: This document proposes a new algorithm for Motion Estimation using the Kalman Filter. The algorithm predicts the motion vectors for the next frame by using the motion vectors of the current frame. The new algorithm is compared with the already existing search algorithms such as Exhaustive search, Three-Step Search, and Four-Step Search and show that the prediction using the Kalman Filter leads to reduction in the computational complexity.
13 citations
TL;DR: In this paper, the authors proposed a third-order recursive wideband digital integrator and differentiator, which is obtained by interpolating two digital integration techniques, the Schneider-Kaneshige-Groutage (SKG) rule and the Trapezoidal rule.
Abstract: Novel designs of third-order recursive wideband digital integrator and differentiator are presented. The integrator is obtained by interpolating two digital integration techniques, the Schneider-Kaneshige-Groutage (SKG) rule and the Trapezoidal rule. The differentiator is obtained by inverting the transfer function of the designed integrator after necessary modifications. The proposed integrator and differentiator approximate their ideal counterparts with absolute magnitude errors less than 0.02 and 0.14, respectively, over the entire frequency spectrum. Their performance compares favorably with existing integrators and differentiators.
12 citations
TL;DR: A low power, low-phase noise, high tuning range, and fully integrated inductorless RC-VCO (voltage-controlled oscillator) for OC-48 application is designed and simulated in standard 0.18 µm CMOS technology as discussed by the authors.
Abstract: A low-power, low-phase noise, high tuning range, and fully integrated inductorless RC-VCO (voltage-controlled oscillator) for OC-48 application is designed and simulated in standard 0.18 µm CMOS technology. The proposed inductorless RC-VCO has a simulated phase noise of -141 dBc/Hz at 1 MHz offset from the carrier frequency of 2.4 GHz, with a bias current of 605 µA and voltage headroom of 1.8 V. It has 50% tuning range at 2.4 GHz of operating frequency and consumes 1.09 mW of power. This RC-VCO shows a figure of merit performance of -208.2 dBc/Hz at the desired frequency.
12 citations
TL;DR: The ITEM algorithm was applied to the speaker verification problem using NIST 2001, 2002, 2004, and 2006 speaker recognition evaluation corpora and MFCC with delta, energy, and zero-crossing features and showed an improvement of the equal error rate over the classical EM approach.
Abstract: Gaussian Mixture Model (GMM)-based speaker models yield very good performance in text.independent speaker verification systems. GMMs use expectation maximization (EM) as an optimization procedure to train speaker models. This paper proposes the information theoretic expectation maximization (ITEM) with improved convergence rates to train the speaker models. The approach amounts to information theoretic (IT) since it uses the parzen density estimation and Kullback.Leibler (KL) divergence measure. EM encounters the problem of convergence thus to enhance the convergence rates of EM, an IT procedure is incorporated. The proposed ITEM algorithm adapts means, covariances, and weights, like the conventional EM algorithm; however, this process is not conducted directly on feature vectors but on a smaller set of centroids derived by the IT procedure, which simultaneously minimizes the divergence between the Parzen estimates of the feature vector's distribution within a given class and the centroids distribution within the same class. The ITEM algorithm was applied to the speaker verification problem using NIST 2001, 2002, 2004, and 2006 speaker recognition evaluation corpora and MFCC with delta, energy, and zero-crossing features. The results showed an improvement of the equal error rate over the classical EM approach. The ITEM method also showed higher convergence rates compare with the EM method.
11 citations
TL;DR: Development and implementation of multilevel inverter (MLI)-based active power Alter (APF) using DSP of dSPACE is presented and experimental results of prototype model are presented under different loading conditions to investigate the steady-state and transient performance of the APF.
Abstract: This paper presents the development and implementation of multilevel inverter (MLI)-based active power Alter (APF) using DSP of dSPACE. Implementation of MLI for APF in high-voltage system eliminates use of bulky and high-cost transformer to connect APF. This algorithm, to generate switching signal of devices, is developed in MATLAB SIMULINK. The reference signals of APF are generated by using instantaneous reactive power (p-q) theory. Carrier phase-shifted pulse width modulation (CPS-PWM) scheme is implemented to generate switching signals which reduces the individual device switching frequency. Experimental results of prototype model are presented under different loading conditions to investigate the steady-state and transient performance of the APF.
10 citations
TL;DR: FECG is extracted from the maternal electrocardiogram using adaptive neuro-fuzzy inference systems and undecimated wavelet transform (UWT) is proposed and Experimental results show that the UWT produce better results than DWT, as the MSE of DWT is higher than the UWG.
Abstract: The Fetal electrocardiogram (FECG) signal reflects the electrical activity of the fetal heart. Fetal heart monitoring yields vital information about the fetus health and can support medical decision making in critical situations. In this paper, FECG is extracted from the maternal electrocardiogram using adaptive neuro-fuzzy inference systems and undecimated wavelet transform (UWT) is proposed. The performance of the proposed system is compared with the standard discrete wavelet transform (DWT). For numerical evaluation, the mean square error (MSE) between de-noised FECG signal and original FECG signal is used. Experimental results show that the UWT produce better results than DWT, as the MSE of DWT is higher than the UWT.
10 citations
TL;DR: In this paper, an RF model is presented and verified against extensive Y-parameter measurements, which were carried out on a long channel Lateral double-diffusion MOS device.
Abstract: The High-Voltage MOSFET is used in a wide variety of applications covering from power systems up to RF-IC. Compact models that describe the high-frequency behavior of the device are required to predict high-frequency operation and switching capabilities of these elements in HV state-of-the-art systems. In this paper, an RF model is presented and verified against extensive Y-parameter measurements, which were carried out on a long channel Lateral double-Diffusion MOS device. Assessment of the model with measurements confirms the validity of this approach.
9 citations
TL;DR: Chaos-based encryption may offer new quality in secure data transmission as mentioned in this paper, however, a recently proposed Chaotic Key-Based Algorithm (CKBA) has been shown to be unavoidably susceptible to chosen/known plainte...
Abstract: Chaos-based encryption may offer new quality in secure data transmission. A recently proposed Chaotic Key-Based Algorithm (CKBA) has been shown to be unavoidably susceptible to chosen/known plainte...
TL;DR: In this article, a scheme to correct the frequency offset by using wavelength division-adaptive interference cancellation (WD-AIC) was proposed to reduce the negative effects of inter-carrier interference and common phase error (CPE).
Abstract: This paper studies the performance degradation caused by optical Doppler shift in light-emitting diode-based visible light communication systems, which integrate orthogonal frequency division multiplexing (OFDM). Through theoretical analysis and computer simulations, we can observe that frequency offset plays a significant role in the OFDM performance deterioration due to inter-carrier interference (ICI) and common phase error (CPE). Therefore, a scheme to correct the frequency offset by using wavelength division-adaptive interference cancellation (WD-AIC) was proposed. The main approach is to assign an estimated sub-carrier after every two adjacent sub-carriers to reduce the negative effects of both ICI and CPE. Finally, the simulation results declare that our proposed WD-AIC is indeed effective against the high degree of frequency offset.
TL;DR: In this paper, a coaxial type cavity has been proposed to meet the specified design parameters, such as the quality factor, shunt impedance, etc., with the help of the simulation tool.
Abstract: This article presents the computer-aided design of the intermediate and input/output cavities of a multi-beam klystron (MBK) working in the J-band frequency range. A coaxial type cavity has been proposed to meet the specified design parameters. The state of the art electromagnetic simulation tool Computer Simulation Technology microwave studio has been used for the design and optimization of the cavity. Different cavity parameters such as the quality factor, shunt impedance, etc. have been estimated with the help of the simulation tool. For the input/output cavities, the issue of symmetric coupling has been studied and a rectangular-shaped central conductor has been proposed to achieve the desired coupling.
TL;DR: In this article, the effect of SAF on source current, reference current produced, individual harmonic content of source current and phase lag compensation is analyzed using PSim 6.0 Software.
Abstract: The paper presents detailed explanation of the design of single-phase shunt active power Alter (SAF) and its control circuit. “Compensating (reference) current” required to eliminate harmonics from load is produced by current subtraction method. “Hysteresis band” control topology is used to produce trigger signals required by inverter for producing “reference current.” Power circuit is designed with three loads. Single phase inverter with dc source acting as SAF is connected to power circuit. To analyze the effect of SAF on power distribution system, simulation is done using PSim 6.0 Software. During simulation, variation is done in harmonic content of load and phase lag is created. Simulation is done for different load conditions and the results obtained are displayed in this paper. Paper presents the effect of SAF on source current, reference current produced, individual harmonic content of source current, and phase lag compensation. Analysis is done for different power parameters from results o...
TL;DR: In this paper, the use of reactance functions for frequency transformation of a normalized low-pass filter (NLPF) to a multiple passband filter (MPBF) is presented.
Abstract: It is shown that the use of reactance functions for frequency transformation of a normalized low-pass filter (NLPF) to a multiple passband filter (MPBF) is straightforward and simpler than the methods using repeated low-pass to band-pass transformation or a combination of such transformations. The method gives the band edges of the MPBF corresponding to the positive and negative cutoff frequencies of the NLPF unambiguously. The transformation function is found explicitly in terms of the band edges of the MPBF and the NLPF elements are converted to those of the MPBF with ease. Furthermore, the center frequencies of the passbands are also found with ease. Dual and triple passband filters are considered for illustrating the use of the method.
TL;DR: A radial basis function neural network (RBFNN) has been designed and implemented for recognizing paraphrases and it has been observed that the RBFNN recognizer consistently outperforms the SVM recognizer with respect to accuracy and that the best performance was achieved when a combination of lexical, syntactic, and semantic features were used.
Abstract: Paraphrasing is the restatement of a given text using alternate words. Recognition of paraphrases is vital in applications such as question answering, information extraction, and multi-document summarization. Lexical, syntactic, and semantic features of text can be used either individually or in combinations for recognizing paraphrases. Several machine-learning classifiers such as support vector machines (SVM), nearest neighbour method, and decision trees have been used for paraphrase recognition with SVM recognizers being the most popular ones. This paper explores the applicability of neural networks for paraphrase recognition. A radial basis function neural network (RBFNN) has been designed and implemented for recognizing paraphrases. Experiments have been carried out on the Microsoft research paraphrase corpus. From the results of the experiments, it has been observed that the RBFNN recognizer consistently outperforms the SVM recognizer with respect to accuracy and that the best performance was...
TL;DR: In this article, the authors investigated the quality-factor (Q-factor) deterioration due to individual effects of stimulated Raman scattering, cross-phase modulation, and four-wave mixing and their collective impact on system Q-factor in presence of amplified spontaneous emission noise for various ITU-T compliant fibers.
Abstract: This paper investigates the Quality-factor (Q-factor) deterioration due to individual effects of stimulated Raman scattering, cross-phase modulation, and four-wave mixing and their collective impact on system Q-factor in presence of amplified spontaneous emission noise for various ITU-T compliant fibers (G.652, G. 652D, G. 653, G. 654, and G.655), considering the optical frequency grid based on ITU-T Recommendation G.692. The results obtained through the developed mathematical model show very clearly that the performance of G.653 fiber is worst compared to other fiber types, thus justifying the preferred use of fibers with high dispersion and effective area values (G.652, G.652D, G.654, and G.655) over G.653 in view of combating the deleterious effects of nonlinearities. The results suggest that with the use of a fiber having low dispersion and effective area values, it may not be possible to obtain the desired error rate of 10−9 (Q=6). The simulation results make it evident that deterioration due...
TL;DR: The analysis on ASR performance while using both narrowband and wideband speech coding standards and using different sampling and bit rates in the practical systems is presented.
Abstract: Usage of Automatic Speech Recognition (ASR) systems is increasing day-by-day for voice centric applications in mobile handheld and Voice over Internet Protocol (VoIP) devices. The necessity is also increasing to find out the ASR performance under different network impediments. Among them, speech and audio coding standards is the one, which affects the ASR performance greatly, when, using them with different sampling and bit rates in the practical systems. Another common impediment which influences the ASR accuracy is the bit errors in the wireless networks and packet drop conditions in the VoIP networks. ASR performance with some of the speech coding standards under noise conditions for the wireless networks is reported in the literature. However, each study is reporting the ASR performance for few narrowband codecs with different speech databases and different ASR toolkits like RAPHEL, HTK, SPHINX, etc. In this paper, the analysis on ASR performance while using both narrowband and wideband speech...
TL;DR: In this article, the shape reconstruction of a perfectly conducting cylinder buried in a half-space by measured transverse magnetic scattered field and the modified particle swarm optimization (MPSO) was studied.
Abstract: In this paper, the shape reconstruction of a perfectly conducting cylinder buried in a half-space by measured transverse magnetic scattered field and the modified particle swarm optimization (MPSO). Assume that a conducting cylinder of unknown shape is buried in one half-space and scatters the field incident from another half-space where the scattered filed is measured. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. The inverse problem is resolved by an optimization approach, and the global searching scheme PSO is then employed to search the parameter space. Two algorithms: the PSO and the MPSO have been examined. Both techniques have been tested in the case of simulated measurements contaminated by additive Gaussian noise. Numerical results demonstrate that even when the initial guess is far away from the exact one, the two algorithms can both obtain good recon...
TL;DR: A novel idea is proposed that combines properties of continuous phase modulation and pulse position modulation techniques and takes into account the Rayleigh nature of body area channel to present a novel modulation format for BANs.
Abstract: Population of the world is growing at rapid pace. It is becoming difficult to provide healthcare facilities to people in highly populous countries like China and India. One way to solve this problem is the development of medical infrastructure in the form of wireless Body Area Networks. The body area networks (BANs) tend to provide medical monitoring for patients. Prime concern in the BANs is the communication, which needs to be energy and bandwidth efficient. The paper presents a novel modulation format for BANs. We propose a novel idea that combines properties of continuous phase modulation and pulse position modulation techniques. The new modulation technique takes into account the Rayleigh nature of body area channel. Apart from being power efficient, the technique does not require large bandwidth.
TL;DR: In this article, the authors investigated the impact of the parasitic resistances in the contiguous zones of the Double-gate MOSFET (DG-MOSFet) and derived a two-dimensional model in analytical closed form by using conformal mapping technique.
Abstract: In this work, we investigate the impact of the parasitic resistances in the contiguous zones of the Double-gate MOSFET (DG-MOSFET). Since the channel length is scaled down to 20 nm, the parasitic source/drain resistances get more important and cannot be neglected. To calculate these resistances in such devices, a two-dimensional model in analytical closed form has been derived by using the conformal mapping technique. The model is able to predict the parasitic resistances for DG-MOSFETs as well as for devices with raised source drain (RSD) structures and/or wrapped contacts. The influence of source/drain geometries on the access resistances is accurately described. A bias dependency is obtained by introducing a field-dependent approach. At last, the results from the model are compared with the parasitic source/drain resistances determined from TCAD device simulation software.
TL;DR: In this article, a dual-mode rectangular-matched feed was proposed to cancel the unwanted high cross-polarization generated by the offset parabolic reflector antenna, which is very much suitable for monopulse tracking radar.
Abstract: This paper presents the design and the experimental results of a dual-mode rectangular-matched feed. This type of feed cancels the unwanted high cross-polarization generated by the offset parabolic reflector antenna. In order to design this feed, higher order TE11 mode has been added in correct amplitude and phase with the fundamental TE01 mode in a rectangular structure. The proposed feed was then used as a primary feed to illuminate a linearly polarized offset parabolic reflector antenna. Through experimental results, it is verified that such a feed suppresses the undesired high cross-polarization introduced by the offset geometry of an offset reflector antenna. This kind of feed is very much suitable for monopulse tracking radar.
TL;DR: Numerical results show that the proposed robustification offers improved performance over Huber’s minimax detector and outperforms the DPSK decorrelating detector, particularly when the channel is highly impulsive.
Abstract: In this article, we deal with the problem of robust code division multiple access (CDMA) signal detection in a chaotic communication system transmitting across a Non-gaussian fading channel. Since the performance of robust multiuser detector depends on the selection of M-estimator and the spreading sequences, a new influence function is used to derive an improved robust detector for the problem of data detection in CDMA impulsive fading channels using chaotic spreading. Numerical results show that the proposed robustification offers improved performance over Huber’s minimax detector and outperforms the DPSK decorrelating detector, particularly when the channel is highly impulsive.
TL;DR: The proposed probabilistic neural network (PNN) technique is based on well-established statistical principles rather than heuristic approaches that are adopted in the multi-layer perceptrons and results appear promising and easily realizable in the industries.
Abstract: In this paper, an intelligent technique for detecting the turn fault and supply voltage unbalances in an induction machine is proposed under varying load conditions. The proposed probabilistic neural network (PNN) technique is based on well-established statistical principles rather than heuristic approaches that are adopted in the multi-layer perceptrons. The PNN is derived from the Bayes decision strategy and nonparametric kernel-based estimators of probability density functions. The machine model is developed for inter-turn short circuit fault and it is compared with its a priori models for its robustness in detecting the fault at incipient stages under various operating conditions of the machine. This algorithm is proposed for first time and training, testing, and validation results using the method appear promising and easily realizable in the industries.
TL;DR: In this paper, the authors used impulse radar for through-the-wall imaging (TWI) and back projection algorithm was used to retrieve the B-scan signal and the peak signal to noise ratio was observed to be −3.79 dB.
Abstract: Through-the-wall imaging (TWI) is an emerging area of research and development which is very much useful in urban warfare situations. Ultra-wide band range radar is the best suitable for this application where this range of signals has the capability of penetrating through the materials but still can provide better resolution. The incorporation of signal processing techniques on the raw data will give better representation of the scanned scene. The paper uses impulse radar for TWI, and back projection algorithm is used to retrieve the B-scan signal. A constant gain of factor 100 is used to increase the echo strength. Singular value decomposition is used to reduce the clutter from the B-scan signal and the peak signal to noise ratio is observed to be −3.79 dB.
TL;DR: In this article, a methodology is proposed to extend aging simulation to a more complex behavior, and indeed implementable into a commercial software environment (in the case Eldo UDRM by Mentor Graphics).
Abstract: Usually, aging models implemented in design kits are able to accurately describe parameter degradation only if kinetics during constant voltage stress is relatively simple; a methodology is proposed to extend aging simulation to a more complex behavior, and indeed implementable into a commercial software environment (in the case Eldo UDRM by Mentor Graphics). The methodology is applied to describe Ron drift of a 40 V Nch MOS transistor.
TL;DR: In this paper, a subtractive method is proposed for the optimization of NiCr thin film resistor (TFR) in steady of a method of depositing the bottom metal layer from the semi-additive method.
Abstract: In this paper, a subtractive method is proposed for the optimization of NiCr thin film resistor (TFR) in steady of a method of depositing the bottom metal layer from the semi-additive method. The variations of the maximum sheet resistances in the optimized NiCr TFR are within 2.88% and the 3-sigma variation is around 0.87%, which are much higher accurate than the previous fabricated TFRs demonstrated in the lately published papers. The proposed manufacturing process is an optimal solution for manufacturing the NiCr TFRs in the advanced integrated passive devices (IPDs) process on the semi-insulating-GaAs substrate that require stringent size and volumetric efficiency.
TL;DR: An optimum configuration of SLs is proposed by estimating its Geometric Dilution of Precision (GDOP) value and improvement in GDOP due to augmentation of SL-based navigation system with geostationary satellite(s) is investigated.
Abstract: A Global Positioning Sysem (GPS)-independent, stratolite (SL)-based navigation system is introduced and an optimum configuration of SLs is proposed by estimating its Geometric Dilution of Precision (GDOP) value. Improvement in GDOP due to augmentation of SL-based navigation system with geostationary satellite(s) is investigated. For this purpose, GDOP is estimated for various geometries of SLs/geostationary satellites. Furthermore, effect on DOP due to augmentation of SLs with GPS is examined. When a constellation of four SLs is augmented with GPS over Hyderabad region of India, GDOP is improved to 3.25 (max) from 4.45 (max).
TL;DR: In this paper, the authors investigated CMOS circuits with Self-Bias Transistors (SBTs) connected between the pull-up/down network and the supply rails and extended the analyses by studying both static and dynamic power and also propagation delay for combinational as well as sequential circuits.
Abstract: Power dissipation and propagation delay are contradicting factors in the design of VLSI CMOS circuits. This paper investigates CMOS circuits with Self-Bias Transistors (SBTs) connected between the pull-up/down network and the supply rails. Previous research on circuits with SBTs shows substantial reduction in leakage power of combinational circuits. We extend the analyses by studying both static and dynamic power and also propagation delay for combinational as well as sequential circuits. Transistor-level dual-Vt technique is employed for combinational circuits with SBTs to achieve a good power and delay trade-off by selecting different transistors in the circuit to have different Vt. Extensive HSPICE simulations were performed with 0.18 μm CMOS technology. Results show that on average, a 45% reduction in static power and 17% reduction in dynamic power can be achieved by employing SBTs in combinational CMOS circuits. Similar results for sequential CMOS circuits are also included. Simulation result...
TL;DR: In this paper, the authors used the chi-square test to validate the data and findings and identified the outer race fault (ORF) in an induction machine at different load conditions.
Abstract: Induction machines are employed as prime movers in several applications in the present day industries. The major contributors of faults in an Induction machine are the bearings. The Incipient Bearing Failure defines the fault at an early stage and is a potential danger to the catastrophic failure of the electrical machine. One of the common faults found in bearings is the Outer Race Fault (ORF). The aim of this paper is to identify ORF in the induction machine at different load conditions. The vibration data is acquired and analysis is done by computing the statistical parameters, probability density function, and the cumulative distribution function. Finally, the chi-square test is used to validate the data and findings.