• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.581-587
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• 2013

Among different linear motors, single-sided linear induction motors have been widely used in industry due to their simplicity and low construction cost. However, these types of motors suffer from low efficiency and power factor. In this paper, an effective procedure is proposed to design single-sided linear induction motors. The designed motor is simulated in MATLAB software in order to investigate the effect of design parameters on the performance of the machine. Regarding the obtained results, the Genetic Algorithm is employed to optimize the design considering product of efficiency and power factor as objective function. The results show significant improvement of the performance. Finally, experimental results and 2D finite element method is used to validate the model parameters and the optimization results.

• 한국조명전기설비학회지:조명전기설비
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• 제6권3호
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• pp.57-62
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• 1992

In this paper, the reasonable design standard of Demand Factor for large office buildings is introduced that was made by the statistical way considering actual conditions, such as investigated electrical equipment capacity, electrical power consumption, etc. The results are as follows. 1) It is shown that th saving of electrical equipment investment, the decrease of power loss, the improvement of facilities utilization and the decrease of electrical power rates can be contributed by the application of the design standard. 2) The effect of reduction is showed to confirm the practical use of the proposed reference Demand Factor, and also, it is believed that this proposed reference Demand Factor will be useful in electrical equipment operation and planning.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권1호
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• pp.24-29
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• 2004

A new low cost hybrid active filter for thyristor-controlled rectifier load is presented to overcome the high cost problem of the active or the other hybrid active filters. The proposed hybrid active filter which consists of tuned (5th and 7th harmonics) LC passive filters, power factor improvement(PFI) capacitor bank, and active filter compensates power factor as well as harmonic currents. Since most of harmonic currents are filtered by the passive filter and most of reactive power is compensated by the PFI capacitor bank, the power rating of active filter can be minimized, resulting in cost minimization of the proposed hybrid active filter. A 300kVA hybrid active filter system is implemented and tested using 1MVA thyristor rectifier load to verify the operation and performance.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(C)
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• pp.354-357
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• 2011

Support Vector Machine (SVM)은 주어진 데이터 중에서 각 클래스를 잘 표현하는 Support Vector (SV)를 계산함으로써 새로운 데이터를 분류하는 알고리즘이다. SVM은 전체 데이터 분포를 고려하지 않기 때문에 잘못된 데이터에 의해 분류가 잘못될 가능성이 적다. 하지만, SV가 잘못되었을 경우에는 정확도가 감소하게 되는 문제점이 있다. 본 논문에서는 SV가 잘못 주어진 데이터일 가능성을 고려, 아웃라이어 검출 알고리즘인 Local Outlier Factor (LOF) 알고리즘을 이용해 주어진 데이터 중 잘못된 데이터를 제거함으로써 SVM의 분류 정확도를 높이는 알고리즘을 제안하였다. 추가적으로, Incremental LOF를 이용해 새로운 데이터 중 판단하기 어려운 데이터를 제거함으로써 SVM의 정확도를 보다 향상시켰다. 제안된 방법은 두 개의 클래스를 가진 데이터에 대해서 실험하였다.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.203-210
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• 2003

A simulation study was carried to analyze the vehicle fuel consumption on component basis. Experiments was also carried out to identify the simulation results, under FTP-75 Hot Phase driving conditions. and arbitrary driving conditions. A good quantitative agreement was obtained. Based on the simulation, fuel energy was used in pumping loss(3.7%), electric power generation(0.7%), engine friction(12.7%), engine inertia(0.7%), torque converter loss(4.6%), drivetrain friction(0.6%), road-load(9.2%), and vehicle inertia(13.4%) under FTP-75 Hot Phase driving conditions. Using simulation program, the effects of capacity factor and idle speed on fuel consumption were estimated. A increment of capacity factor of torque converter resulted in fuel consumption improvement under FTP-75 Hot Phase driving conditions. Effect of a decrement of idle speed on fuel consumption was negligible under the identical driving conditions.

• 반도체디스플레이기술학회지
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• 제15권4호
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• pp.79-85
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• 2016

For long life time and high efficiency, not necessary in improvement of LED chip structure, but also improve heat radiation for decrease heat in LED chip. In this study, efficiency decline factor has been investigated in LED lamp as study heat characteristic, luminance flux and heat resistance. When LED lamp temperature was increased, about 7% loss of luminance flux. In consequence of temperature analysis, width of fin was the most important factor of heat radiation. As a result, secure the enough heat path is very important factor of LED lamp design.

• 무역상무연구
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• 제70권
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• pp.21-38
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• 2016

The trend of payment terms of an international trade has been changed from letter of credit to open account. In this regard factoring has come out to support SMEs in terms of financing on a without recourse basis. However, factoring is in Korea is not workable softly due mainly to legal system affecting smooth assignment of receivables. Therefore this study suggest the following solutions : Korean Civil Law shall be modified to protect factor's position as a right creditor to debtor and protect factor's position when perfection among several creditors are incurred. However, formal modification to this end would not be easy in short run and it is suggested that a special law be established in case a commercial receivable assignment both domestic and internationally happens between seller and factor.

• 전기학회논문지P
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• 제57권1호
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• pp.36-40
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• 2008

Most of the low-voltage feeder are designed with approximately balanced and connected at the three phase four wire systems. However, Most of the power distribution systems' load which is composed of single or three phase are unbalanced by generating load unbalance. Unbalanced current will draw a highly unbalanced voltage. The power factor of an induction motor at rated operation is between 25 and 90%, depending on the size and speed of the motor. However, many induction motors operate below the nominal rating, resulting in poor power factor. This condition needs power factor improvement. Addition of power capacitor at the motor terminal may draw to stress due to voltage unbalance. This paper presents operation characteristics on steady states of a three-phase induction motor under unbalanced voltages with power capacitor. The existence of voltage unbalance have an effect on stress of power capacitor.

• 한국기계가공학회지
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• 제7권1호
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• pp.22-31
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• 2008

The operating window method is a novel approach in quality improvement. But it has not received deserved attention in academic research. If a critical factor for competing failure modes can be identified, the probability of failure can be reduced by widening the operating window of this factor. Traditional SN ratio for the operating window advocated by Taguchi has a critical shortcoming, which has been derived under the assumption that failure rates are determined by the operating window factor only. A new metric for robustness is given for the operating window method, which has relaxed the restrictive assumption of Taguchi's SN ratio. And procedures for determining optimal conditions based on the new metric is presented. The effectiveness of the proposed approach over the traditional practice is tested with the aid of a wave soldering process.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.1001-1008
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• 2001

This paper presents a new camera calibration algorithm for ill-conditioned cases in which the camera plane is nearly parallel to a set of non-coplanar calibration boards. for the ill-conditioned case, most of existing calibration approaches such as Tsais radial-alignment-constraint method cannot be applied. Recently, for the ill-conditioned coplanar calibration Lee&Lee[16] proposed an iterative algorithm based on the least square method. The non-coplanar calibration algorithm presented in this paper is an iterative two-stage procedure with extends the previous coplanar calibration algorithm. Through the first stage, camera, position and orientation parameters as well as one radial distortion factor are determined optimally for a given data of the scale factor and the focal length. In the second stage, the scale factor and the focal length are locally optimized. This process is repeated until any improvement cannot be expected any more Computational results are provided to show the performance of the algorithm developed.