A survey of various numerical techniques to solve operator equations in electromagnetics

The objective of this paper is to survey many of the popular methods utilized in solving numerical problems arising in electromagnetics. Historically, the matrix methods have been quite popular. One of the primary objectives of this paper is to introduce a new class of iterative methods, which have advantages over the classical matrix methods in the sense that a given problem may be solved to a prespecified degree of accuracy. Also, these iterative methods (particularly conjugate gradient methods) converge to the solution in a finite number of steps irrespective of the initial starting guess. Numerical examples have been presented to illustrate the principles.     

Model-based ideal testing of hardware description language (HDL) programs

Software and Systems Modeling - An ideal test is supposed to show not only the presence of bugs but also their absence. Based on the Fundamental Test Theory of Goodenough and Gerhart (IEEE Trans...     

Comparison of cefpodoxime proxetil release and antimicrobial activity from tablet formulations: complexation with hydroxypropyl-β-cyclodextrin in the presence of water soluble polymer

This study aims to prove the complexation of cefpodoxime proxetil (CP) by hydroxypropyl-β-cyclodextrin (HP-β-CD) in the presence of sodium carboxymethyl cellulose (Na CMC), and makes a comparison of commercial tablets by dissolution and antimicrobial activity studies. The CP--HP-β-CD complex was prepared by kneading method and characterized by SEM, FTIR and DSC. The solubility method was used to investigate the effect of HP-β-CD and Na CMC on the solubility of CP. The complex tablets were prepared using direct compression method. Dissolution studies were performed with complex tablets and commercial tablets in pH 1.2, 4.5, 6.8 and 7.4 buffer solutions. It was observed that complexation occurred in all formulations, and HP-β-CD is able to increase CP solubility and dissolution rate of CP was improved from complex tablets, when compared with commercial tablets. Furthermore, the antimicrobial activity studies revealed that the CP--HP-β-CD complex and complex tablets were shown to have more effective antimicrobial activity than commercial tablets. It is evident from the results that complexation with HP-β-CD in the presence of Na CMC is feasible way to prepare a more efficient tablet formulation with improved dissolution and antimicrobial activity.     

Ensuring location diversity in privacy-preserving spatio-temporal data publishing

The rise of mobile technologies in the last decade has led to vast amounts of location information generated by individuals. From the knowledge discovery point of view, these data are quite valuable, but the inherent personal information in the data raises privacy concerns. There exists many algorithms in the literature to satisfy the privacy requirements of individuals, by generalizing, perturbing, and suppressing their data. Current techniques that try to ensure a level of indistinguishability between trajectories in a dataset are direct applications of \(k\) -anonymity, thus suffer from the shortcomings of \(k\) -anonymity such as the lack of diversity in sensitive regions. Moreover, these techniques fail to incorporate some common background knowledge, an adversary might have such as the underlying map, the traffic density, and the anonymization algorithm itself. We propose a new privacy metric \(p\) -confidentiality that ensures location diversity by bounding the probability of a user visiting a sensitive location with the \(p\) input parameter. We perform our probabilistic analysis based on the background knowledge of the adversary. Instead of grouping the trajectories, we anonymize the underlying map, that is, we group nodes (points of interest) to create obfuscation areas around sensitive locations. The groups are formed in such a way that the parts of trajectories entering the groups, coupled with the adversary background, do not increase the adversary’s belief in violating the \(p\) -confidentiality. We then use the map anonymization as a model to anonymize the trajectories. We prove that our algorithm is resistant to reverse-engineering attacks when the statistics required for map anonymization is publicly available. We empirically evaluate the performance of our algorithm and show that location diversity can be satisfied effectively.     

Speed control of SR motor by self-tuning fuzzy PI controller with artificial neural network

In this work, the dynamic model, flux-current-rotor position and torque-current-rotor position values of the switched reluctance motor (SRM) are obtained in MATLAB/Simulink. Motor control speed is achieved by self-tuning fuzzy PI (Proportional Integral) controller with artificial neural network tuning (NSTFPI). Performance of NSTFPI controller is compared with performance of fuzzy logic (FL) and fuzzy logic PI (FLPI) controllers in respect of rise time, settling time, overshoot and steady state error.     

Design and development of a self-microemulsifying drug delivery system of olmesartan medoxomil for enhanced bioavailability

Olmesartan medoxomil (OM) is a hydrophobic antihypertensive drug with low bioavailability (26%) and is known to have adverse effects such as celiac disease and enteropathy. The purpose of this study was to develop SMEDDS to increase bioavailability and decrease potential side effects of OM. Hydrophilic lipophilic balance was calculated by testing solubility of OM in different oils, surfactants, and cosurfactants to obtain the most suitable combination of SMEDDS. Pseudoternary phase diagram was used to select the better oil/water formulation of SMEDDS. After a test for 3-month stability, dissolution tests and parallel artificial membrane permeability assay (PAMPA) were conducted to investigate drug solubility and permeability. Biodistribution of fluorescent marked SMEDDS was observed by using in vivo imaging system. The pharmacodynamics of the drug were determined by measuring blood pressure from tails of rats. At the end of the experiment, intestines were examined for adverse effects of OM. Compared with tablet formulation according to the dissolution study, SMEDDS formulation showed 1.67 times improvement in solubility of OM. PAMPA studies suggested a much faster permeability rate for OM SMEDDS compared to the suspension form. Labeled SMEDDS gave 3.96 times stronger fluorescent emission than control dye administered mice in in vivo imaging system (IVIS^®) studies, indicating an increased bioavailability. Treating effect of SMEDDS was 3.1 times more efficient compared to suspension in hypertensive rats. It caused neither celiac-like enteropathy nor diarrhea, during 21-day noninvasive blood pressure system (NIBP) assay. Our results suggest that SMEEDS formulation improves dissolution and oral bioavailability of OM while reducing its adverse effects.     

Influence of deposition potential on the electrodeposited Ternary CoFeCu films

Ternary CoFeCu films, relating their magnetic and magnetoresistance properties with film composition, surface morphology and the corresponding crystal structure, were investigated in terms of different deposition potentials in electrodeposition. The films were grown on polycrystalline titanium substrates. The potentials were obtained from cyclic voltammetry and the current–time transients were also recorded to control the growth of proper films. From the structural analysis by X-ray diffraction, all films had a face-centred cubic structure and the calculated grain size increased with increasing deposition potential. The film compositions by energy dispersive X-ray spectroscopy revealed that the Co, Fe and Cu contents varied and the scanning electron microscope images disclosed that the film morphologies changed as the deposition potential changed. The saturation magnetization was high and coercivity was low at high deposition potential. The easy axis of magnetization was parallel to the film plane for all films. All films showed anisotropic magnetic resistance and their magnitudes were between 3.2 and 3.8 %. The variations in magnetic and magnetoresistive properties related to the microstructure were attributed to the variation of the film contents caused by deposition potential.     

UHF RF Front-End Circuits in 0.35-μm Silicon on Insulator (SOI) CMOS

In this work, design and measurement results of UHF RF frontend circuits to be used in low-IF and subsampling receiver architectures are presented. We report on three low noise amplifiers (LNA) (i) single-ended (ii) differential (iii) high-gain differential and a double-balanced mixer all implemented in 0.35-μ m SOI (Silicon on Insulator) CMOS technology of Honeywell. These circuits are considered as candidate low-power building blocks to be used in the two fully-integrated receiver chips targeted for deep space communications. Characteristics of square spiral inductors with high quality (Q) factors (as high as 10.8) in SOI CMOS are reported. Single-ended and fully-differential LNA's provide gains of 17.5 dB and 18.74 dB at 435 MHz, respectively. Noise figure of the single-ended LNA is 2.91 dB while the differential LNA's noise figure is 3.25 dB. These results were obtained for the power dissipations of 12.5 mW and 16.5 mW from a 2.5-V supply for the single-ended and differential LNA's, respectively. High-gain low-power differential LNA provides a small-signal gain of 45.6 dB with a noise figure of 2.4 dB at 435 MHz. Total power dissipation of the high gain LNA is 28 mW from a 3.3-V supply. The double-balanced mixer provides a conversion gain of 5.5 dB with a noise figure of 13 dB at 2 MHz IF. The power dissipation of the mixer is 11.5 mW from a 2.5-V supply. The measured responses and the power dissipations of the building blocks meet the requirements of the communications system. The die areas occupied by the single-ended LNA, differential LNA, high-gain LNA and the mixer are 0.6 mm × 1.4 mm, 1 mm × 1.4 mm, 1.4 mm × 1.2 mm and 0.6 mm × 0.9 mm, respectively. Ertan Zencir received the B.Sc. and M.S. degrees in electrical and electronics engineering from Middle East Technical University, Ankara, Turkey, and Ph.D. degree in electrical engineering from Syracuse University, Syracuse, NY in 1995, 1997, and 2003, respectively. He joined the Electrical Engineering and Computer Science Department of University of Wisconsin-Milwaukee as an Assistant Professor in August 2004. 2003). His current research focuses on RFIC and transceiver design for wireless communications. Douglas Te-Hsin Huang was born in Chia-yi Taiwan. He received the B.S. degree in electrical engineering from National Taiwan Ocean University, Kee-lung, Taiwan in 1993, and the M.S. and Ph.D. degrees in electrical engineering from Syracuse University, Syracuse, New York, in 2001 and 2003, respectively. In 2004, he joined Skyworks Solutions Inc., where he is currently an RFIC Design Engineer. His research deals mainly with low-power, infrastructure, analog RFIC, and microwave integrated circuit designs. Besides microwave and semiconductor engineering, Dr. Huang has broad interest in art, music, and philosophy. Ahmet Tekin received his B.S. degree in Electrical Engineering from Bogazici University, Istanbul, Turkey in 2002 and MS degree in Electrical engineering form North Carolina A&T State University, Greensboro, NC. He is currently working towards his PhD degree at University of California, Santa Cruz, CA. He was a Research Assistant at RF Microelectronic Laboratory, North Carolina A&T State University, from 2002 to 2004. He worked on the design of low power UHF transceiver circuits for space applications. He is currently a Research Assistant at Bio-mimetic Microelectronic Systems Laboratory, University of California at Santa Cruz, working on implantable very low power UHF frequency transceiver for a body sensor network. Numan S. Dogan received the B.Sc. degree from Karadeniz Technical University, Trabzon, Turkey, in 1975, the M.Sc. degree from Polytechnic University, New York, in 1979, and the PhD degree from the University of Michigan, Ann Arbor, in 1986, all in electrical engineering. Since 1998, he has been with the Electrical and Computer Engineering Department, North Carolina A&T State University, Greensboro, North Carolina, where he is an Associate Professor. He was a Visiting Faculty Researcher at Air Force Research Laboratory (AFRL), Eglin Air Force Base, Florida, in 1998, and General Electric Corporate Research and Development Laboratory, Schenectady, New York, in 1999. His earlier research interests included microwave and millimeter-wave solid-state devices and circuits, high-temperature electronics, and silicon micromachining. His recent research interests include RF CMOS Integrated Circuits and low-power Medical Implant Communication Systems (MICS) transceivers. Currently he serves as the Chair of the IEEE Central North Carolina Section. In April 2004, he organized “a walking robot competition” for High School Students. He enjoys hiking to Alpine Lakes in the Pacific Northwest and fishing. Ercument Arvas (M'85–SM'89) received the B.S. and M.S. degrees from METU, Ankara, Turkey, in 1976 and 1979, respectively, and the Ph.D. degree from Syracuse University, Syracuse, New York, in 1983, all in Electrical Engineering. Between 1984 and fall of 1987, he was with the Electrical Engineering Department of Rochester Institute of Technology, Rochester, New York. He joined the Electrical Engineering and Computer Science Department of Syracuse University in 1987, where he is currently a Professor. His research interests include numerical electromagnetics, antennas, and microwave circuits and devices.     

节能降耗 绿色威特

自从京都协议书在1997年重新修订过后，环保越来越被人们所重视。如何合理利用珍贵的能源资源将是全人类今后几十年甚至几代人所要面临的艰巨挑战。工程机械领域的节能将在环境平衡表上留下深深的烙印。这不仅包括热绝缘、取暖、空调、灯光等要素，而且包括了电梯，因为电梯至少占楼宇耗电的3％～8％。由于人口的增加以及全球城市化的影响，全世界至少有850万部电梯在运行，而且每年至少要新装45万部电梯。因此电梯的节能越来越受到人们的重视。