• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1409-1415
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• 2010

A linear induction motor have advantages for reducing mechanical frictions and noises because it has thrust force by induced torque instead of friction force between rail and wheels. An it has additional advantage for reducing volume of bogie frame for light rail transit. The small volume causes the cost of construction down. Recently, researches of linear induction motor for thrust force of the light rail transit have been actively studied. For the rail transit, vehicle is running as follow accelerating and constant speed, finally decelerating speed passing local stops between stations. The light rail transit have only these three patterns of operating. Thus, design of that has different design specifications from others. In this paper, the linear induction motor for the light rail transit was designed considering the goal speed, accelerating time, and accelerating distance for approaching the goal speed. The designed motor was proved that it could meet the requirement of accelerating performance by2-dimensional finite element method and mechanical dynamics equation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.381-385
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• 2009

This paper describes performance characteristics of a centrifugal fan having a different volute casing. The centrifugal fan has a backward blade type, and is used in a refuse collecting system. The flow characteristics inside the components are analyzed by three-dimensional Navier-Stokes analysis, and also compared to the results by experiments. Distributions of pressure and efficiency obtained by numerical simulation has a good agreement with the experimental results. Throughout the numerical simulation of the centrifugal fan, a fan efficiency is increased by decreasing local losses in the blade passage. It is found that the fan efficiency is enhanced by decreasing the distance between the shroud of a impeller and casing. Detailed flow analysis is also analyzed and discussed using the results obtained by numerical simulation.

• Journal of Korean Society for Quality Management
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• v.22 no.2
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• pp.79-88
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• 1994

Delay has influenced customer satisfaction while using a telephone. It has been ranked second after transmission impairments in annoyance to customers. Therefore, it is important to analyze its behavior not only to increase the quality of service for the customers, but to provide its information to network planners and administrators and to designers of equipment and systems. In this paper, we consider a log-normal model as a candidate for describing the statistical behavior of the post dialling delay, i.e., the time to connect a call to the telephone network after dialling. Based on the real data, the log-normalness of the post dialling delays are convinced for the long distance calls, but not supported for the local calls. Uses of graphical plotting paper and statistical test of fit art discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1071-1078
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• 2006

Three buffalo populations viz. Bhadawari, Tarai and local buffaloes of Kerala were genotyped using 24 heterologous polymorphic microsatellite loci. A total of 140 alleles were observed with an average observed heterozygosity of 0.63. All the loci were neutral and 18 out of the 24 loci were in Hardy Weinberg Equilibrium. The $F_{IS}$ values (estimate of inbreeding) for 16 loci in all the three populations were negative. This indicated lack of population structure in the three populations. The effective number of immigrants was 5.88 per generation between the Tarai and Bhadawari populations which was quite high suggesting substantial gene flow. The genetic distances revealed closeness between the Tarai and Bhadawari populations which was expected from geographical contiguity. The FST values were not significantly different from zero showing no population differentiation. The Correspondence Analysis based on the allelic frequency data clustered the majority of the Tarai and Bhadawari individuals as an admixture.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.125-131
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• 2000

The local heat/mass transfer coefficients for arrays of impinging circular air jets on a plane surface are determined by means of the naphthalene sublimation method. Spent fluid makes a crossflow in the confined space. The crossflow reduces heat/mass transfer at the small gap distance between the jet plate and impingement surface because of reentrainment of the spent fluid. The present study suggests a new exhaust system having effusion holes in the impinging jet plate. The spent air flow out after impingement just through effusion holes located in the upper plate. This system increases heat/mass transfer coefficients and uniformity for small gap distances$(H/d{\leq}2)$

• Journal of Power Electronics
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• v.8 no.4
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• pp.325-331
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• 2008

Power system perturbations are due to many reasons; one of the most common perturbation causes is switching off/on the power capacitors. This paper monitors and discusses the overvoltages which appear on local and remote capacitor connected buses in power systems. Using the Fast Fourier Transfer (FFT), the total harmonic content of voltages and currents waveforms is also estimated at all buses. The power factor during different cases of switching modes "off/on" is monitored. The monitoring technique tackles not only the longitudinal long distance mutual effects of switching power capacitors between different buses but also evaluates the overvoltage durations. A relative long term monitoring is implemented using the Matlab/Simulink environment to show severity assessments in different switching modes on the transformers' voltages and currents' waveforms.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.285-288
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• 2000

본 논문에서는 다중 에이전트(multi-agent) 환경에서 에이전트들의 행동을 효율적으로 조정 (coordination)하기 위해 강화 학습(reinforcement learning)을 이용하였다. 제안된 방법은 각 에이전트가 목표(goal)와의 거리 관계(distance relationship)와 인접 에이전트들과의 공간 관계(spatial relationship)를 이용하였다. 그러므로 각 에이전트는 다른 에이전트와 충돌(collision) 현상이 발생하지 않으면서, 최적의 다음 상태를 선택할 수 있다. 또한, 상태 공간으로부터 입력되는 강화 값이 0과 1 사이의 값을 갖기 때문에 각 에이전트가 선택한 (상태, 행동) 쌍이 얼마나 좋은가를 나타낼 수 있다. 제안된 방법을 먹이 포획 문제(prey pursuit problem)에 적용한 결과 지역 제어(local control)나. 분산 제어(distributed control) 전략을 이용한 방법보다 여러 에이전트들의 행동을 효율적으로 조정할 수 있었으며, 매우 빠르게 먹이를 포획할 수 있음을 알 수 있었다.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.79-86
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• 2012

In the two-band excitation (TBE) model, maximum voiced frequency (MVF) is the most important feature of the excitation parameter because the synthetic speech quality depends on MVF. Thus, this paper proposes an enhanced MVF estimation scheme based on the peak picking method. In the proposed scheme, the local peak and the peak lobe are picked from the spectrum of a linear predictive residual signal. The normalized distance between neighboring peak lobes is calculated and utilized as a feature to estimate MVF. Experimental results of both objective and subjective tests show that the proposed scheme improves synthetic speech quality compared with that of the conventional one.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.143-149
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• 2012

MANET is a network that is a very useful application to build network environment in difficult situation to build network infrastructure. But, nodes that configures MANET have difficulties in data retrieval owing to resources which aren't enough and mobility. Therefore, caching scheme is required to improve accessibility and availability for frequently accessed data. In this paper, we proposed a technique that utilize mobility prediction of nodes to retrieve quickly desired information and improve data availability. Mobility prediction of modes is performed through distance calculation using location information. We used technique which global cluster table and local member table is managed by cluster head to reduce data consistency and query latency time. We compared COCA and CacheData and experimented to confirm performance of proposed scheme in this paper and efficiency of the proposed technique through experience was confirmed.

• Journal of Biomedical Engineering Research
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• v.8 no.1
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• pp.81-86
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• 1987

An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.