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In this paper, we investigated rotor iron loss of interior permanent magnet synchronous machine (IPMSM), which has distributed armature windings. In order to study the iron loss with the effect of slot-pole combination, two machines for high-speed operation such as electric vehicle were designed. One is fractional slot winding and the other is conventional one. In the analysis, we developed a new iron loss model of electrical machines for high-speed operation. The calculated iron loss was compared with the experimental data. It was clarified that the proposed method can estimate iron loss effectively at high-speed operation. Based on this newly proposed method, we analyzed iron loss of the two machines according to their driving conditions. From the analysis results, it was shown that rotor iron loss of machine employing fractional slot-winding is definitely large at load condition. In addition, it is interesting that the ratio (rotor iron loss/stator iron loss) becomes larger as the speed of the machines increase if the number of slot per pole is fractional. Index Terms--Distributed armature winding, electric vehicle, fractional slot per pole, high-speed, iron loss, interior permanent magnet synchronous machine.

The present study proposes a new neuronal electrical source model to simulate electroencephalography (EEG) forward signals more effectively. Contrary to the conventional methods which used a presumed activation function at cortical patches or point dipolar sources, the proposed model reflects electrophysiological facts and introduces probability concept, resulting in more plausible and readily controllable artificial EEG waveforms. Index Terms--Artificial electroencephalography (EEG) waveform, electrophysiology, EEG, neuronal electrical source model.

In this paper, the fast moving least square reproducing kernel method (FMLSRKM) for solving the axisymmetric Laplace problem is proposed. To maximize the advantages of FMLSRKM, a point collocation scheme is used. The accuracy of the proposed method is verified by applying it to a test electrostatic model with analytic solution, and the electric potential distribution in the arc region of a gas circuit breaker is also analyzed as a practical application. Index Terms--Axisymmetric, fast moving least square reproducing kernel method (FMLSRKM), gas circuit breaker, mesh- free.

Optimal design of the direct-driven PM wind generator, coupled with finite element analysis and genetic algorithm, has been performed to maximize the annual energy production over the whole wind speed characterized by the statistical model of wind speed distribution. Particularly, the parallel computing via internet web service has been applied to loose excessive computing times for optimization. Index Terms--Annual energy production (AEP), genetic algorithm (GA), parallel computing, permanent magnet (PM) wind generator.

In the present paper, an improved particle swarm optimization (PSO) algorithm for multimodal function optimization is proposed. The new algorithm, named auto-tuning multigrouped PSO (AT-MGPSO) algorithm mimics natural phenomena in ecosystem such as territorial dispute between different group members and immigration of weak groups, resulting in automatic determination of the size of each group's territory and robust convergence. The usefulness of the proposed algorithm is verified by the application to a specially designed test function and a practical electromagnetic optimization problem. Index Terms--Electromagnetic optimization problems, multi-grouped particle swarm optimization (MGPSO), multimodal function optimization, particle swarm optimization (PSO).

An analysis and design methodology of the B(sub 14) rotary ultrasonic motor (RUSM) using a numerical method, three-dimensional finite element method along with an analytic method is discussed. The methodology incorporated the contact mechanism, with nonlinearity due to heat generation was not considered in the analysis of the B(sub 14) RUSM.

This paper proposes a new parametric source model to precisely estimate brain electrical source distribution from electroencephalogram (EEG) or magnetoencephalogram recordings. In the proposed approach, only four free parameters need to be evaluated for each anatomically constrained area source to express both spatial locations and extensions of brain electrical activities on cortical surface. The feasibility of the proposed model is verified through the applications to realistic EEG simulations and epilepsy patient's data. Index Terms--Anatomically constrained area source (ACAS), electroencephalography (EEG), functional brain source imaging, magnetoencephalography (MEG).

This paper is a report of an investigation of the relationship between the condition number of a leadfield matrix of magnetoencephalography and source reconstruction accuracy. We suggest the use of the condition number as a promising a pr/or/accuracy estimator of a neuromagnetic inverse problem (NIP) since various simulation studies demonstrated that the reconstructed source distribution has the wider region and contains more spurious sources if a leadfield matrix has the higher condition number. The simulation results also verified that the accuracy estimator based upon the condition number can explain well-known phenomena of NIP, which suggests a potential application of the proposed concept. Index Terms--Condition number, leadfield matrix, magnetoencephalography (MEG).

In this paper, a new hybrid approach to reconstruct more accurate brain functional source images from electroencephalography is proposed. The proposed approach combines extended source model and focal underdetermined system solution algorithm. Feasibility studies with realistic simulation data and the epilepsy patient's data demonstrate that continuous, as well as focalized, brain electrical source images can be reconstructed utilizing the proposed approach. Index Terms--Brain functional source image, cortical source imaging, electroencephalography (EEG), focal underdetermined system solution (FOCUSS), linear inverse problem.

This paper describes a proposal for a new source space model called the multilevel source space model for the efficient and precise estimation of brain electrical activities. Unlike conventional source models, the proposed one generates both high- and low-resolution brain models which represent gray matter of a human cerebral cortex. The model can then be used to estimate brain electrical sources in a multiresolutive way. The usefulness of the proposed model has been verified using realistic simulations with real brain noise and anatomy. Index Terms--Gray matter, inverse problem, multiresolution, source space model.

In this paper, an improved magnetoencephalography (MEG) source reconstruction technique considering anatomical connectivity of cortical sources is proposed. The anatomical connectivity information was taken into account by calculating three-dimensional geodesic distance between neighboring sources, and then the resultant inverse solutions were compared with those of other cases: 1) inverse estimate without connectivity information; 2) use of Euclidean distance instead of geodesic distance. The proposed technique was applied to realistic simulations for a real brain anatomy, and the results showed that estimated sources can be smoother and more accurate by using the anatomical connectivity information. Index Terms--Anatomical connectivity, magnetoencephalography (MEG) source reconstruction, Wiener estimation, 3-D geodesic distance.

This paper investigates the origins of localization errors when cortically distributed source approach is applied to magnetoencephalography (MEG) and electroencephalography (EEG) focal source reconstruction problems. It was revealed from simulations that the errors mainly stem from 1) asymmetric distribution of crosstalk and 2) large noises at some time slices. To enhance the localization accuracy, a new algorithm named cortical surface scanning (CSS) method is presented. The proposed algorithm was applied to realistic simulations and more accurate and robust source estimates could be obtained. Index Terms--Electroencephalography (EEG), focal brain source localization, inverse problem, magnetoencephalography (MEG).

In this paper, a new algorithm for the multimodal function optimization is proposed, based on the particle swarm optimization (PSO). A new method, named the multigrouped particle swarm optimization (MGPSO), keeps basic concepts of the PSO, and, thus, shows a more straightforward convergence compared to conventional hybrid type approaches. Moreover, the MGPSO has a unique advantage in that one can search N superior peaks of a multimodal function when the number of groups is N. The usefulness of the proposed algorithm was verified by the application to various case studies, including a practical electromagnetic optimization problem. Index Terms--Electromagnetic optimization problems, multigrouped particle swarm optimization (MGPSO), multimodal function optimization, particle swarm optimization (PSO).

Computer simulation is performed in a whole breaking period except the region of current zero of gas circuit breaker. The Euler equation is solved using the finite volume fluid in cell method. In order to consider the effects of arc, electric field intensity and radiation transport are calculated using the finite element method and the method of partial characteristics, respectively. Also, the quantity and the electrical conductivity of ablated nozzle vapor are calculated, and its effects are investigated through computer simulation. Improved simulation results are obtained and compared with the experimental one. Index Terms--Ablation, arc discharges, gas circuit breakers (GCB), S[F.sub.6].

Optimal design process of multilayer buried magnet synchronous machine combined with mechanical and thermal analysis is presented in this paper. Fast stress and thermal analysis method using electromagnetic analysis information is explained in detail. Through the optimization result and comparison with experimental data, the validity of proposed method is verified. Index Terms--Fast stress analysis, fast thermal analysis, multilayer buried magnet synchronous machine, optimal design.

In this paper, an adaptive frequency sampling technique is applied to the moment method for the analysis of microstrip filters and patch antennae. The analysis of microstrip low-pass filter and patch antenna in the frequency domain has been usually done with uniform frequency step. An adaptive frequency sampling technique can significantly reduce the time taken for the analysis through the frequency range without reducing the accuracy of the results. Index Terms--Adaptive sampling, method of moments, microwave devices, planar structures.

The direct (d)- and quadrature (q)-axis inductance characteristics of the interior permanent-magnet synchronous motor (IPMSM) are presented, with an emphasis on the cross-coupling effects. Nonlinear variation of phase inductance is investigated, according to the rotor position on entire stator current excitations. We also propose a new analytical method, called the fixed permeability method (FPM). We applied this method (FPM) to steel-cored permanent-magnet linear synchronous motors for large powered linear motional applications. Experimental data were found to corroborate the findings obtained by the FPM method. We also used FPM to analyze magnetic saturation characteristics of the prototype IPMSM, and compared the air-gap flux density and d- and q-axis inductance with the conventional finite element analysis results. Index Terms--Cross-magnetization effect, finite-element method (FEM), inductance, interior permanent-magnet synchronous motor (IPMSM), magnetic saturation.

This paper proposes a novel approach to enhancing results of magnetoencephalography cortical source imaging. The proposed approach utilizes bell-shaped functions defined on an inflated cortical surface, which has one-to-one correspondence with original tessellated cortical surface. The coefficients of the functions are then determined using sensitivity analysis with conjugate gradient updating scheme. Applications of the approach to a simulation study and a practical experiment have resulted in more stable and smoother brain source distribution, compared to conventional linear inverse approach. Index Terms--Brain surface inflation, cortical source imaging, inverse problem, magnetoencephalography (MEG).

The successful numerical analysis of breaking performance of gas circuit breaker (GCB) depends not only on the electric field analysis, but also on the properties of the insulating medium. S[F.sub.6] cannot be assumed to act as an ideal gas due to its imperfect thermodynamic properties. The cold flow simulation considering the real gas properties of S[F.sub.6] is presented in this paper and the dielectric breakdown of gas circuit breaker based on the simulation is also presented with the experimental data. Index Terms--Breaking performance, gas circuit breaker (GCB), S[F.sub.6].

This paper describes the methodology considering the parallel effects for the analysis of stress and thermal problem coupled with the electromagnetic field problem of multilayer buried magnet synchronous machine with a wide speed range. Fast analysis methodology using conventional finite element method information is proposed in the design process. The validity of these methods is verified by comparing their results with the conventional and experimental data Index Terms--Bridge, center-post, heat transfer coefficient, multilayer buried magnet synchronous machine.

Left-handed material (LHM) exhibiting negative permittivity and negative permeability in certain band has dispersive medium property varying with frequency. The effective permittivity and permeability function of this material have a similar form of Lorentz material model. Piecewise linear recursive convolution (PLRC) technique for finite difference time domain (FDTD) method is applied to simulate the propagation characteristic of LHM effectively. Modified anisotropic perfectly matched layer (APML) is proposed for absorbing boundary condition of LHM. The simulation results show narrow pass band in the stop band where LHMs have double negative properties. Index Terms--Anisotropic perfectly matched layer (APML), dispersive medium, double negative (DNG), finite difference time domain (FDTD), left-handed material (LHM), metamaterial, piecewise linear recursive convolution (PLRC), split ring resonator (SRR).

In this paper, an efficient method for the three-dimensional (3-D) computation of steady-state skin effect problems in current-carrying conductors is presented. It is assumed that the total current is composed of the source current and eddy current, and source current density is proportional to the precalculated electric field intensity. The additional variable is the proportional coefficient which is constant for one conductor. To calculate the magnetic vector potential and the proportional coefficient, the iterative procedure is employed. The proposed method requires much less computational resource and can be easily implemented in the existing 3-D finite element code with slight modification. The method is validated by comparison to known solutions of slot-embedded model and applied to the analysis of current distribution in the GIS conductors. Index Terms--Current-carrying conductor, eddy current, iterative method, skin effect.

In this paper, a novel algorithm for multimodal function optimization is proposed, based on the concept of evolution strategy. A new concept, named restricted evolution, shows more improved characteristics than conventional approaches that have been used for multimodal function optimization. The efficiency and usefulness of the proposed method will be verified by the application to various cases including practical optimization problems. Index Terms--Evolution strategy (ES), multimodal function optimization, restricted evolution.

In this paper, an improved technique for multiresolutive reconstruction of magnetoencephalography source distribution is proposed. Using the proposed technique, focal source distribution with higher energy density can be reconstructed. Moreover, the proposed approach is very easy to implement compared with conventional ones. The usefulness of the proposed technique is verified using a cortical patch test for a realistic brain model. Index Terms--Inverse problem, magnetoencephalography, multiresolutive technique, sensitivity analysis.

Size optimization of steel-cored permanent magnet linear synchronous motor (PMLSM) using auto-tuning niching genetic algorithm (GA) is executed for realizing rapid and smooth driving on the short reciprocating trajectory. Particularly, the dynamic constraints are newly proposed and applied for considering the running conditions of PMLSM. Furthermore the optimally designed one is manufactured, and experimented for comparing the results with the calculated ones. Index Terms--Auto-tuning niching genetic algorithm (GA), dynamic constraints, steel-cored PMLSM.

A multidipole searching technique using a moving dipole concept is proposed for magnetoencephalography (MEG source localization. The proposed method can be a promising method to resolve a critical disadvantage of conventional equivalent current dipole (ECD) method--the number of current dipoles should be given a priori. From several simulation results, the accuracy and effectiveness of the method will be verified. Index Terms--Equivalent current dipole (ECD) method, in verse problems, magnetoencephalography (MEG), multidipole searching technique.

This paper proposes a hybrid genetic algorithm (GA) for electromagnetic topology optimization. A two-dimensional (2-D) encoding technique, which considers the geometrical topology, is first applied to electromagnetics. Then, a 2-D geographic crossover is used as the crossover operator. A novel local optimization algorithm, called the on/off sensitivity method, hybridized with the 2-D encoded GA, improves the convergence characteristics. The algorithm was verified by applying it to various case studies, and the results are presented herein. Index Terms--Genetic algorithm (GA), geographic crossover, local optimization, topology optimization, two-dimensional (2-D) encoding.

An inversion scheme for piezoelectric transformers is described and discussed.

The force equation of a synchronous permanent-magnet planar motor (SPMPM) was investigated. The flux density distribution of a two-dimensional (2-D) magnet array for a SPMPM was obtained by solving the equations of the scalar magnetic potential. The expressions of the force and back-EMF constant were derived and examined. Using these expressions, the conditions for normal operation of the SPMPM were found and the optimal design was determined in order to maximize the force of the SPMPM. Index Terms--Back-EMF, force constant, permanent magnet, planar motor.

This paper proposes a numerical algorithm that reconstructs the complex permittivity profile of unknown scatterers by the design sensitivity analysis (DSA) and topology optimization technique. By introducing the DSA and adjoint-variable method, the derivatives of the error function with respect to the complex permittivity variables can be calculated, and the material property in each cell can be changed simultaneously using sensitivity information. The steepest descent method is used as an optimization technique. The proposed method is validated by applying it to reconstructions of unknown two-dimensional scatterers that are illuminated by T[M.sup.z] with a Gaussian-pulsed plane wave. Index Terms--Design sensitivity analysis (DSA), finite-difference time-domain (FDTD) methods, inverse problems, topology optimization.

A small, single-sided synchronous linear motor with superconducting primary coils is described. A module of the proposed motor has been constructed and tested.

A 200-kJ superconducting magnetic energy storage (SMES) coil that relies on high-temperature superconductive (HTS) wire has been designed and optimized. A pilot system is sceduled to be tested in 2004.

Practical techniques for optimizing the coil shape of deflection yoke are proposed. An accurate and practical winding modeler is developed. Volume integral equation method is used for field calculation. A two-step optimization procedure is performed by using 1 + 1 evolution strategy. The first step is for dimensional optimization, while the second performs the pin-position optimization. The optimization processes suitable for the deflection yoke are developed and various techniques are applied to reduce computational time for the optimization. Index Terms--Deflection yoke, evolution strategy, shape optimization, volume integral equation method.

Among several niching methods, the restricted competition selection (RCS) method searches almost all the location of multiple solutions in the search space. This paper proposes a neo-niching method using the RCS method combined with pattern search method to reduce the calculation time. Through application to the numerical examples and optimal design of interior permanent magnet synchronous motor, it is verified that the proposed method searches the peaks fast and is appropriate for the design of electric machines. Index Terms--Genetic algorithm, interior permanent magnet synchronous motor, niching method, pattern search method, restricted competition selection.