• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.51-59
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• 2016

This paper presents a method of DCT-based illuminant compensation to enhance the accuracy of face recognition under an illuminant change. The basis of the proposed method is that the illuminant is generally located in low-frequency components in the DCT domain. Therefore, the effect of the illuminant can be compensated by controlling the low-frequency components. Moreover, a directional high-order local pattern descriptor is used to detect robust features in the case of face motion. Experiments confirm the performance of the proposed algorithm got up to 95% when tested using a real database.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.131-141
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• 2007

This paper proposes analysis on new equipment for power quality in electric railway. The proposed equipment consists of series inverter and parallel inverter. Each inverter is connected by capacitor as dc link. This structure can be compensated for active and reactive power in catenary through transformer. We verified the proposed equipment using the PSCAD/EMTDC and the calculation results from the proposed approach are widely described in the paper.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.17-26
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• 2008

In this paper, we propose a distributed multi-view video coding method employing illumination compensation for multi-view video coding. Distributed multi-view video coding (DMVC) methods can be classified either into a temporal or an inter-view interpolation-based ones according to ways to generate side information. DMVC with inter-view interpolation utilizes characteristics of multi-view videos to improve coding efficiency of the DMVC by using side information based on the inter-view interpolation. However, mismatch of camera parameters and illumination change between two views could bring about inaccurate side information generation. In this paper, a modified distributed multi-view coding method is presented by applying illumination compensation in generating the side information. In the proposed encoder system, in addition to parity bits for AC coefficients, DC coefficients are transmitted as well to the decoder side. By doing so, the decoder can generate more accurate side information by compensating illumination changes with the transmitted DC coefficients. We found that the proposed algorithm is $0.1{\sim}0.2\;dB$ better than the conventional algorithm that does not make use of illumination compensation.

• Journal of Service Research and Studies
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• v.7 no.4
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• pp.109-126
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• 2017

Designing cost-effective service recovery strategies mix has been recognized one of important issues by both service researchers and practitioners. In spite of the rising interest in them, there has been scarce studies on them. In this paper, we try to find cost-effective service recovery strategies mix via game-theoretic modeling. Especially, we focus on the possible incentives such as voucher type reward and service re-performance which have different cost structure. We investigated three questions about the topics as follows:(1) Should the service firm use the possible incentive scheme such as voucher and service re-performance for service recovery?, (2) How much voucher and service re-performance is adequate for service recovery under diverse service failure severity level?, (3) How much voucher and service re-performance is adequate for service recovery under diverse threshold level to make the customer repurchase? The results are as follows:(1) The use of both voucher and service re-performance for service recovery results in greater surplus for the service firm. (2) The higher gets the service failure severity level, the higher total incentives are required in the equilibrium. As service failure severity level gets higher, higher level of discount might be more useful to the service firm. However, service re-performance should be cut down above some critical level of service failure severity in the equilibrium. (3) The higher gets the threshold level to make the customer repurchase, the higher incentives are required in the equilibrium, and the higher portion of voucher incentive is required relative to that of service re-performance in the equilibrium.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.18-24
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• 2006

This paper proposed UPS system parallel connected in battery and ultracapacitor to compensate instantaneous voltage drop. Ultracapacitor parallel connected with battery compensate instantaneous voltage drop at failure and it's reduced the voltage regulation of output voltage. We are produced for fast instantaneous voltage drop compensation of ultracapacitor at UPS system and experiments are achieved. Experimental result was verified that the ultracapacitor indicated the fast compensation characteristics and regulation of the output voltage satisfied within 5[%] by using ultracapacitor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.84-90
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• 2004

Many control techniques have been proposed in order to improve the control performance in the control system. In the feedback control system the output of controller is generally used as the input of a plant But the undesired noise is included in the output of a controller. Therefore, there is a need to use a precompensator for rejecting the undesired noise and improving the response characteristic of a system. In this paper, the design method of a precompensator is proposed for the model following control in the I-PD control system. The proposed precompensator is implemented with a neural network. The games of a precompensator are adjusted automatically to obtain a desired response of a system when the response characteristic of a system is changed under a condition.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.5
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• pp.101-107
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• 1996

This paper proposed the voltage compensation analysis method in distribution system by EMTP. SVC (Static Var Compensator) of the thyristor controlled reactor type is used for compensation system. EMTP(E1ectr-o Magnetic Transient Program) model of SVC is proposed to analysis the voltage improvement characteristics at the high voltage system bus. It is composed with three parts ; rms detector, voltage regulator and gate pulse generator. The control signal of TCR is determined by rms value which was measured in system. As the result of EMTP simulation, all of the SVC characteristics like TCR current, firing pulse and bus voltage is very reliable. This method could be used to analysis the planning and the operation of compensation system in the large scale factory.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.486-489
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• 2004

대용량의 직류 전원을 연속적으로 얻기 위한 가장 손쉬운 방법은 상용 교류전력을 정류하여 사용하는 것이다. 이렇게 얻어진 직류 전압 원은 리플을 포함하는 문제와 허용된 법위에 있지만 전압 변동율이 존재하게 된다. DC-DC 컨버터나 인버터 제어에서 이러한 문제를 해결하기 위하여 많은 연구가 행해지고 있다. 그러나 보상제어시간이 길거나 제어나 제어 이론이 복잡하여 시스템이 복잡하게 되는 등 각각의 문제점을 가지고 있다. 본 연구에서는 아나로그 적분기의 적분시간이 적분기 입력전압의 크기에 반비례하는 원리를 이용하여 이 펄스 변조 스위칭 컨버터를 순시 추종 제어하는 방법을 제시한다. 제안된 제어방법의 주요 특징은 정주촉수로 동작한다. 보상제어시간은 스위칭 주기를 기본단위로 추종제어 한다. 제어결과는 한 주기의 평균치로 추종 제어한다. 정상상태는 물론 과도 상태에서도 정확하게 지령치에 추종하여 제어됨을 알 수 있다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.293-296
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• 2009

In order to protect the electrical fire, AFCI(Arc Fault Cirruit Interrupter) was obligated to adopted in United States of America since 2002. AFCI using by line resistor of neutral trace needs to compensate the resistance variation of the line resistor by temperature variation. In this paper, the ASIC including the temperature compensation circuit is implemented. The successful implementation is verified by showing the effectiveness of an electric and a temperature characteristics for ARC signals by simulation results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.9
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• pp.88-93
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• 2008

This paper proposes a frequency transfer function synthesis of a later compensated PID controller for an approximated low order model. The proposed method identifies the parameter vector of PID controller from a linear system that is formed by rearranging a loop frequency transfer function synthesis including the filter compensated PID controller obtained from the given frequency response bounds. And an example for the turbine speed control system of Chungju hydropower plant is given to illustrate the feasibilities of suggested schemes.