• Journal of Korea Trade
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• 제24권6호
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• pp.61-81
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• 2020

Purpose - This paper examines how the consumer animosity of partner country influences the purchase of foreign products. We analyzed news sentiment to determine whether Chinese consumer's animosity affect the purchase of the products made in Korea around the time when the U.S. Terminal High Altitude Area Defense missile system was deployed in South Korea. Design/methodology - To measure the tone of Chinese consumer animosity more carefully, we utilized a text mining technique of the Chinese language to read the public's opinion. Using Chinese news paper's editorials of 2015.1-2018.10, we analyzed the sentiment toward Korea and regressed it with Korean export to China. Findings - Empirical results report that Chinese consumers tended to reduce their purchase of consumer goods from Korea when the animosity increased, that is, the sentiments of Chinese news editorials were negative. In contrast, the animosity did not affect the purchase of Korean intermediates or raw materials. We further analyzed the effect by dividing the animosity into three categories; politics, economics, and culture. Among these groups, political news exhibits a unique effect on Chinese purchase on consumer goods from Korea. Originality/value - Existing literature on animosity models has measured the animosity by collecting the consumers' opinions through survey at a given time point, whereas it is measured by analyzing the tone of the press release by sentiment analysis during the time period around the event occurrence in this study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.46-48
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• 2007

This paper presents research about improvement of fault detection algorithm in FRTU on the feeder of distribution system. FRTU(Feeder Remote Terminal Unit) is applied to fault detection schemes for phase fault, ground fault, and cold load pickup and Inrush restraint functions distinguish the fault current and the normal load current. FRTU is occurred FI(Fault Indicator) when current is over pick-up value also inrush current is occurred FRTU indicate FI. Discrete wavelet transform(DWT) analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate inrush current from the fault status by a gradient descent method. In this paper, fault detection is improved using voltage monitoring system with DWT and neural network. These data were measured in actual 22.9kV distribution system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.104.2-104
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• 2001

In the intelligent integrated systems, the delay time must be reduced using highly parallel processors, as well as high throughput performance. In this paper, we propose a new concept for building 3D highly parallel processors using multi-layer printed wiring boards with built-in soldering heater (BISH-PWB). The proposed BISH is realized with the long and narrow cupper wiring pattern on the internal layer in the terminal pattern area. Based on the linearity of the cupper resistance vs. temperature, we can measure the BISH, temperature and its calorific value from the heater voltage and current measurements. If we provide the BISH temperature control systems for each BISH, selective multi-point soldering can be realized with same ...

• Journal of applied mathematics & informatics
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• 제13권1_2호
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• pp.183-194
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• 2003

We will explain a new method for obtaining the nearly optimal domain for optimal shape design problems associated with the solution of a nonlinear wave equation. Taking into account the boundary and terminal conditions of the system, a new approach is applied to determine the optimal domain and its related optimal control function with respect to the integral performance criteria, by use of positive Radon measures. The approach, say shape-measure, consists of two steps; first for a fixed domain, the optimal control will be identified by the use of measures. This function and the optimal value of the objective function depend on the geometrical variables of the domain. In the second step, based on the results of the previous one and by applying some convenient optimization techniques, the optimal domain and its related optimal control function will be identified at the same time. The existence of the optimal solution is considered and a numerical example is also given.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.98-101
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• 1999

Proposed in this paper is an algorithm in which the maximum value of transmission delay due to collision during the reservation request minicell transmission in the uplink period is guaranteed for each traffic type in order to support real time multimedia traffic in wireless ATM environment. Also proposed is a scheme that uses minislots in which dynamic parameters can be transmitted without collision by using only 1-bit piggyback flag of each cell. Setting the piggyback flag is determined according to traffic characteristics and buffer length of each mobile terminal. It is shown that there has been a great improvement in performance of the proposed algorithm through performance analysis using simulation although the algorithm has little overhead.

• 대한전자공학회논문지SD
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• 제37권1호
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• pp.60-66
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• 2000

본 논문에서는 자체 테스트기능과 보안기능을 각춘 공중전화 가드 IC를 검증함으로써 향후 공중전화 시스템의 국산화에 응용 가능성을 확인한다. 본 연구에서 설계된 공중전화용 IC는 개의 명령어를 지원하고 금액 등 여러 가지 정보를 저장할 수 있는 비휘발성 메모리를 갖는다. 하나의 직렬 I/O로써 이루어지는 외부와의 통신 때문에 야기되는 테스트 시간 문제를 보완하기 위해 대부분의 테스트가 칩 내부에서 동작하도록 자체 테스트 기능을 추가하였다. 또한 여러 가지 보안기능이 소프트웨어, 하드웨어적으로 구현되었다.

• 전력전자학회논문지
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• 제8권5호
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• pp.442-449
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• 2003

본 논문은 PQR 순시전력 이론을 이용하여 순시전압보상장치 (DVR)에서 기준보상전압을 결정하는 방법을 제시한다. 측정된 3상 단자 전압은 시간지연 없이 PQR 좌표계로 변환된다. PQR 좌표계의 기준전압은 단일한 직류값이므로 DVR의 전압제어기는 단순하고 쉽게 설계가 가능해 진다. 제안된 제어방식은 피드백 제어기나 피드포워드 제어기에 모두 적용될 수 있다. 본 논문에서는 피드포워드 제어기에 대하여 이론을 적용하였으며 실험 및 시뮬레이션으로 검증을 하였다.

• 산업경영시스템학회지
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• 제32권4호
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• pp.142-152
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• 2009

We developed two heuristic methods to solve the problem considering a fleet of ships delivering chemical products from terminals to terminals. We need to decide how much of each product to carry, on which ship, subject to the conditions that all terminals must have sufficient products to meet demand, and the stock levels of the products cannot exceed the inventory capacity of that terminal. Mathematical formulation and the optimal objective value for the small size problems are compared with two greedy heuristic methods developed in terms of solution qualities and computing time. Numerical experiments on test problems indicate that the heuristics are effective at finding good solutions quickly.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권10호
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• pp.555-561
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• 1999

This paper proposes a new compensation algorithm for stator resistance that is crucial for improving the direct vector control performance of an induction motor. This algorithm is based on the flux estimator that is derived from the stator voltage equation. Since a flux estimator is dependent on the stator resistance, a flux error originates from the variation of the stator resistance. This parameter mismatch in the estimator thereafter affects the flux and torque response. Accordingly, a new compensator has been designed to offset this degradation in the responses. The proposed compensator is very simple to implement and does not require any modifications to the motor model or any special interruptions of the controller. The value of the stator resistance is attained in real time through measuring the terminal voltage and current. The effectiveness of the proposed scheme has been confirmed through both simulation and experimentation.

• Journal of Power Electronics
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• 제16권1호
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• pp.217-226
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• 2016

A new method is proposed based on a hidden Markov model (HMM) to estimate and analyze battery states of health. Battery system health states are defined according to the relationship between internal resistance and lifetime of cells. The source data (terminal voltages and currents) can be obtained from vehicular battery models. A characteristic value extraction method is proposed for HMM. A recognition framework and testing datasets are built to test the estimation rates of different states. Test results show that the estimation rates achieved based on this method are above 90% under single conditions. The method achieves the same results under hybrid conditions. We can also use the HMMs that correspond to hybrid conditions to estimate the states under a single condition. Therefore, this method can achieve the purpose of the study in estimating battery life states. Only voltage and current are used in this method, thereby establishing its simplicity compared with other methods. The batteries can also be tested online, and the method can be used for online prediction.