Paper Title, Authors, Abstract (Issue 1, Volume 6, 2012)

Pages

Self-Timed Multi-Operand Addition
P. Balasubramanian, D. A. Edwards, W. B. Toms

Abstract: Self-timed addition of multiple data operands is discussed in this paper. Though there are various works in the existing literature targeting dual-operand addition, multiple operand addition has not been exclusively dealt with. In this context, this paper throws light on two important concepts – i) presenting a bit-partitioning scheme that divides input data into groups where additions within the individual groups are carried out in parallel, and ii) proposing novel and efficient (4:2) logic compressor realizations corresponding to weak-indication and robust early output timing regimes. An analysis of the efficiency of addition for a significant case study involving 8 input data, each of size 32-bits, is performed with carry save adders or logic compressors employed for the input field partitions. The simulation results show the proposed early propagative compressor design effectively optimizing the power-delay-area design envelope.
 

Self-Organizing Map Weights and Wavelet Packet Entropy for Speaker Verification
K. Daqrouq, A. Al-Qawasmi, O. Daoud, W. Al-Sawalmeh

Abstract: With the growing trend toward distant security verification systems for telephone banking, biometric security measures and other remote access applications, Automatic Speaker Verification (ASV) has attracted a great attention in recent years. The complexity of ASV system and its verification time depends on the number of feature vector elements. Therefore, in this paper, we concentrate on optimizing dimensionality of feature space by selecting the weights of Self-Organizing Map (WSOM) Neural Network (NNT) for text-independent speaker verification system. This is accomplished by decreasing the number of feature vector elements of individual speaker obtained by using wavelet packet (WP) Shannon, Sure, and log energy in conjunction with energy indices ( 1020 elements) to 64 elements by WSOM. To investigate the performance of the proposed WSOM and wavelet packet entropies (SOMWPE) method, two other verification methods are proposed: Gaussian mixture model based method (GMMWPE) and K-Means clustering based method (KMWPE). The results indicated that a better verification rate for the speaker-speaker system was accomplished by SOMWPE. Better result was achieved (94.34%) in case of the speaker-imposter verification system. In case of white Gaussian noise (AWGN), it was observed that the SOMWPE system is generally more noise-robust than GMMWPE and KMWPE systems.
 

Genetic Algorithms Based Fuzzy Speed Controllers for Indirect Field Oriented Control of Induction Motor Drive
Moulay Rachid Douiri, Mohamed Cherkaoui, Ahmed Essadki

Abstract: In this paper the genetic algorithms is applied to automate and optimize the fuzzy controller design process. To do this, the normalization parameters, membership functions and decision table are converted into binary bit string. This optimization requires a predefined objective function. The task of such a design algorithm is the modification of the existing knowledge and at the same time, the investigation of new feasible structures. The proposed approach in this paper is employed for the speed control of an induction motor drive with indirect field oriented control.
 

DSP Based Simulator for Field Oriented Control of the Surface Permanent Magnet Synchronous Motor Drive
Abdel-Karim Daud, Basim Alsayid, Arafat Zaidan

Abstract: Permanent Magnet Synchronous Motors (PMSM) have wide applications in industry, especially in AC servo drives. Digital Signal Processors (DSP) has greatly enhanced the potential of PMSM servo drive in such applications. Most of controller drives the PMSM by using the field-orientation control mode. This method laid the motor at maximum theoretical performance.
This paper presents the field oriented vector control scheme for permanent magnet synchronous motor (PMSM) drives, where current controller followed by hysteresis comparator is used. The field oriented vector control, that regulates the speed of the PMSM, is provided by a quadrature axis current command developed by the speed controller. The simulation includes all realistic components of the system. This enables the calculation of currents and voltages in different parts of the voltage source inverter (VSI) and motor under transient and steady state conditions. Implementation has been done in MATLAB/Simulink. A study of hysteresis control scheme associated with current controllers has been made. Experimental results of the PMSM control using TMS320F24X DSP board are presented. The speed of the PMSM is successfully controlled in the constant torque region.
Experimental results show that the PMSM exhibits improved speed stability especially in very low speed range. The validity and usefulness of the proposed control scheme are verified through simulation and experimental results.
 

Positioning Error Reduction by the Use of Multiple GPS Terminal
Yuki Odaka, Shinya Takano, Yusuke In, Masakazu Higuchi, and Hitomi Murakami

Abstract: Recently, studies of location identification by mobile phone have been attracting a lot of attention, and it is applied to various applications. Now, when mobile phones have become ubiquitous terminals, many mobile phone GPS terminals may be unevenly distributed within local locations. Our study examines the error characteristics of terminals that are located within a short distance. We used GPS loggers in this experiment because we intended to investigate the change effect of satellites. In this paper, we consider that positioning errors in GPS terminals depend on the difference in the number of satellites used for positioning calculation and the satellite numbers. In addition, we perform theoretical analysis of GPS errors and study the error characteristics of GPS loggers and mobile phone GPS.
 

Contribution to Modification of Graph Cut Method and Its Implementation in the Image Segmentation
I. Zolotova, P. Karch

Abstract: This article presents the implementation of methods to improve Graph cut segmentation. An initialization contour in the form of approximate tracing of the object for segmentation is used for initialization. The proposed modifications are designed to change the value setting of edges in the graph, implementation of iterative method and optimization of efficiency and accuracy. The modifications bring less dependence on user-set constants of Graph cut segmentation and thereby simplify user interaction. The experimental verification of the proposed modifications is tested for the efficiency, accuracy and repeatability of these modifications.
 

On One Approach to Parameters Evaluation of Energy Minimizing Image Restoration Methods
Igor V. Gribkov, Peter P. Koltsov, Nikolay V. Kotovich, Alexander A. Kravchenko, Alexander S. Koutsaev, Andrey S. Osipov, Alexey V. Zakharov

Abstract: We study input parameters of energy methods for image restoration, when a restored image is obtained after minimization of an integral functional. Although such a functional is global, only few pixels in a small neighborhood of any pixel on the initial image can influence on the corresponding pixel on the restored image. Conversely, any pixel on the initial pixel affects some pixels in a neighborhood of the corresponding pixel on the restored image. We call these neighborhoods "influence areas" and propose a technique for their calculation and their visualization on computer screen. The whole testing technique based upon this approach is applied to a couple of known image restoration methods. The parameters of these methods, ensuring their better performance, are found.
 

The Judgment of Document Similarities Orthogonal Transformations and Improvement of the Property
Atraru Matsuzawa, Masakazu Higuchi, Gamba Jonah, Shuji Kawasaki, Hitomi Murakami

Abstract: The objective of this work is to propose a new method to evaluate similarity of documents using Orthogonal transformations and examine its performance experimentally expecting its application to plagiarism detection. The numbers are transformed by the Fourier, Cosine, Haar Wavelet and Hadamard system. As a measure of the similarity of two documents, the correlation of them is used. As a result of the experiment, it turns out that Fourier transformation is effective for certain similar documents presumed to be produced by plagiarism. Therefore we focus on Fourier system. In case single-byte characters and double-byte characters is intermixed there is a problem. That is result of document similarities is low thought documents are similar. Against this problem we propose character-code-conversion. To standardize double-byte characters by character-code-conversion, the precision of judge rise. Furthermore, we decided threshold of each length of sentences.
 

3D Ad-Hoc Sensor Networks Based Localization and Risk Assessment of Buried Landfill Gas Source
Saurav Mitra, Siddhartha P. Duttagupta, Kushal Tuckley, Samsul Ekram

Abstract: Anaerobic decomposition of landfill garbage produces gases like CH4 and H2S at subsurface. These gases diffuse through the foundation and come out to pollute the indoor building environment above. CH4 is highly flammable and causes explosion whereas H2S causes equipment failure and significant pulmonary ailments in human beings over long term exposure. This work focuses on 3D ad-hoc wireless sensor network (WSN) based localization and risk assessment of such a gas source buried at subsurface. Experiments are performed to emulate the gas diffusion process at underground. Experiments also help to determine gas propagation constants over the surface. Higher precision of the threestep maximum likelihood (ML) based source localization method enhances the accuracy of source risk assessment process. Simulation results indicate that the proposed localization algorithms with limited sensor node mobility offer higher accuracy of estimation using lesser network resources. Finally, we propose an analysis for remote source concentration measurement. This help estimate severity of threat possessed by the buried landfill gas source. Also a method is proposed for 3D ad-hoc WSN based source location estimation with obstructed paths for surface gas propagation.
 

Fast Periodic Auto and Cross Correlation Algorithms for an Orthogonal Set of Real-Valued Perfect Sequences from the Huffman Sequence
Takahiro Matsumoto, Hideyuki Torii, Shinya Matsufuji

Abstract: A perfect sequence has the optimal periodic autocorrelation function where all out-of-phase values are zero, and an orthogonal set has orthogonality that the periodic correlation function for any pair of distinct sequences in the set takes zero at the zero shift. The real-valued perfect sequences of period N = 2^n are derived from a real-valued Huffman sequence of length 2^ν + 1 with ν >= n whose out-of-phase aperiodic autocorrelation function takes zero except at the left and right shift-ends. This paper proposes fast periodic auto- and cross-correlation algorithms for an orthogonal set of real-valued perfect sequences of period 2^n. As a result, the number of multiplications and additions can be suppressed on the order N log_2 N.
 

Design of Telemetry and Telecommand Subsystem of a Micro-Satellite Based on Industrial-Level Chips
Jie Liu, Hao Zhang, Wei Zheng, Liuguo Yin

Abstract: Miniaturized satellites characterized with small size, low weight, cheap designs, short development period, and flexible launching way have been recognized as cost effective solutions for universities, Businesses and even individuals to develop satellites. However, the design of highly reliable subsystem based on commercial level or industrial level VLSI chips is the key challenging problem in micro-satellite production. In this paper, a redundant design scheme is proposed for designing the telemetry and telecommand (TTC) subsystem of a micro satellite based on industrial-level VLSI chips, and the reliability of the subsystem with the proposed design scheme is also analyzed. It is shown with analytical results that with redundant design scheme the reliability of a CAN Bus could be effectively improved, and the redundant CAN bus based on low-level VLSI chips could be applied to the TTC subsystem of a micro-satellite.
 

Perceptually Motivated Bayesian Estimators With Generalized Gamma Distribution Under Speech Presence Probability
Atanu Saha, Tetsuya Shimamura

Abstract: In this paper, we propose a family of Bayesian estimators for single channel speech enhancement. The Bayesian estimators, which utilize the cost function of the log-spectral amplitude (LSA) estimator, are based on generalized Gamma distribution under speech presence probability. The cost function obtained from the LSA estimator is weighted by psychoacoustically motivated speech distortion measure to take advantage of the perceptual interpretation. The experimental results show that the proposed estimators provide less residual noise and better speech quality compared to the traditional state-of-the-art estimators.
 

Analog SPICE Implementation of Multi-Frequency Ultrasound System
Imamul Muttakin, Nik Muhamad Arif, Syed Mohd Nooh, Eko Supriyanto

Abstract: The emergence of ultrasound applications raises the need of reliable transducer to comply with that purpose. As polymer material being popular in medical ultrasound, there are chances to combine it with former piezoelectric ceramic material in designing diagnostic transducer to get hybrid characteristics required for multi-frequency application. In this work, SPICE model of ceramic-polymer piezoelectric has been described. Using Leach’s approach, the modeled transducer covers triple peaks resonances. Electro-acoustic circuit simulation level shows that by hybridization, characteristics of both materials are providing a satisfying performance for multi-frequency transducer. With signal conditioner circuit, complete analog system for ultrasound has also been developed. As initial, transducer test for ceramic and polymer model were generated. By filtering and amplifying frequency range from 1 MHz until 10 MHz, the system offers wideband medical ultrasonic acceptance. With -5 to +5 voltage head-room, it gives smooth result of ultrasound signal for medical purposes.
 

Study of Non-Stationary Temperature Fields in Printed Circuit Boards During Separation by Cutting
D. Janacova, H. Charvatova, K. Kolomaznik, V. Vasek, P. Mokrejs, Z. Dvorak, R. Drga

Abstract: Nowadays, growth of electronic waste represents serious global problem. Therefore, ways of its recycling are searched. In the paper we deal with the printed circuit boards recycling. We focused on study of a cutting as an alternative method of conductive ways from plastic board separation as one of stages of the printed circuit board recycling procedure. For this purpose we formulated mathematic model of the cutting process and next we used its analytical solution for its modeling by mathematic software Maple. The obtained results confirm energy intensity of the cutting process.