• 대한전기학회논문지:시스템및제어부문D
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• 제53권2호
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• pp.94-102
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• 2004

The digital electronic switching system has some problems, when this system processes OAM(Operation, Administration And Maintenance) messages about the fault, the traffic, the account, and the performance, etc., at the present. One of these problems is that each the module processing these messages in the digital electronic switching system can not process OAM messages out of another digital electronic switching system. Each the module processing these OAM messages, that is, has been programmed in order to process only the OAM message out of the digital electronic switching system mounting itself, not to process the message out of the digital electronic switching system based on another platform. Therefore, we studied on methods that could process OAM messages out of all digital electronic switching systems and, first of all, developed the MGS(Message Gathering System) to be able to accept and process the fault message of OAM messages out of all digital electronic switching systems in real time.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.145-145
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• 2009

In this paper, we suggest how to adapt RFID system to train switching process, and then what we get the merit or problem. We analyze the train switching process to adapt RFID system on the process and have field test. The role of RFID system in train switching process is to automatically read car position information. The specification of the test system is 900MHz, and Gen2 passive tag. If we get the system which automatically read car position information in train switching yard, it prevents human errors and makes more reliability, the performance of train operation will grow up. Even though the environment of train switching yard is outdoors, the test result gives us the ability to adapt RFID system to train switching process and the process will be more simple.

• 충청수학회지
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• 제26권4호
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• pp.787-791
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• 2013

In this paper we present one factor model of commodity prices with a single jump regime-switching process. And we derive an analytic formula for pricing futures contracts when the parameters of commoditiy process have governed by a Markov regime-switching process.

• 대한수학회논문집
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• 제21권3호
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• pp.533-541
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• 2006

We consider a autoregressive moving average process of order p and q with Markov switching coefficients and find sufficient conditions for irreducibility of the process. Identifying small sets is also examined.

• 대한수학회지
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• 제41권2호
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• pp.309-318
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• 2004

We consider a nonlinear AR-ARCH type process subject to Markov-switching and give sufficient conditions for geometric ergodicity of the process. Existence of moments is also obtained.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제24권1호
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• pp.1-22
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• 2020

An accurate and efficient gradient estimation method on unstructured grid is presented by proposing a switching process between two Least-Square methods. Diverse test cases show that the gradient estimation by Least-Square methods exhibit better characteristics compared to Green-Gauss approach. Based on the investigation, switching between the two Least-Square methods, whose merit complements each other, is pursued. The condition number of the Least-Square matrix is adopted as the switching criterion, because it shows clear correlation with the gradient error, and it can be easily calculated from the geometric information of the grid. To illustrate switching process on general grid, condition number is analyzed using stencil vectors and trigonometric relations. Then, the threshold of switching criterion is established. Finally, the capability of Switching Weighted Least-Square method is demonstrated through various two- and three-dimensional applications.

• 대한전자공학회논문지TC
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• 제40권10호
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• pp.16-23
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• 2003

본 논문에서 광 네트워크에서 광 버스트 스위칭(Optical Burst Switching, OBS)과 광 회선 스위칭 (Optical Circuit Switching, OCS) 기술의 장점을 동시에 가지는 새로운 광 hybrid 스위칭(Optical Hybrid Switching) 시스템을 제안한다. 이 시스템은 들어오는 IP 트래픽을 hybrid 스위칭을 위해 짧은(short-lived) 흐름과 긴(long-lived) 흐름 구분한다. 성능 분석을 위하여 시스템을 Markovian 환경에서 단일 서버 큐로서 모델링 한다. 버스트 생성 프로세스는 two-state Markov Modulated Poisson Process (MMPP)를 따른다고 가정하고 서비스 율은 동시에 발생하는 OCS 세션의 수에 따라 변한다. OBS 버스트에 대한 평균 지연 및 큐 사이즈의 결과를 보인다.

• Journal of Power Electronics
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• 제16권6호
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• pp.2327-2337
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• 2016

The mode-switching control of transient process is important to grid-connected 400 Hz solid-state power supply systems. Therefore, this paper analyzes the principle of on-grid and islanding operation of the system with or without local loads in the grid-connected process and provides a theoretical study of the effect of different switching sequences on the mode-switching transient process. The conclusion is that the mode switch (MS) must be turned on before the solid-state switch (STS) in the on-grid process and that STS must be turned off before the MS in the off-grid process. A strategy of mode-switching smooth control for transient process of the system is proposed, including its concrete steps. The strategy utilizes the average distribution of peak currents and the smooth adjustment of peak currents and phases to achieve a no-shock grid connection. The simulation and experimental results show that the theoretical analysis is correct and that the method is effective.

• 농촌지도와개발
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• 제19권3호
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• pp.699-727
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• 2012

Conditions of farm crop switching are affected by several important external factors such as agricultural products import opening, policy support, and climate change. Farming environment is always changing; barriers to imports are becoming lower and lower because of FTA and others, and climate change affects a boundary line of cultivation. Those situations give farmers motivation to change crops in order to cope with them. In addition, crop switching has been done in response to the local government measures about purchase of local agricultural products according to the local food and the expansion of organic agricultural products in school meal. Even though the favorable environment toward crop switching has been created, there are not many researches or outcomes regarding crop switching. Only few studies focus on the list of decision-making in crop switching, and locally suitable crop selection is not treated. In order to utilize crop switching as a farm management strategy, the proper frame should be studied and practical researches on application possibility also need. Therefore, study on crop switching is in a timely, proactive manner because farms catch the chance of expansion of school meal by changing crops. This paper applies HERO model used for venture foundation process to crop switching process. Success factors of HERO model are comprised of Habitate, Entrepreneurship, Resource, and Opportunity, and these phased application factors are applied to crop switching process. By doing so, each phase success factor of crop switching can be uncovered. Three farm organizations supplying organic agricultural products to schools are studied in Gyeonggi province. As a result, the stabilization stage cannot be achieved because of the habitate conditions and social conditions with low risk bearing of crop switching and current school meal systems are the main problems to block the diversification of risks. In order to succeed in crop switching, constructing the habitate in local districts or in systems of school meal is more effective than supporting each farm.

• Journal of Power Electronics
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• 제16권1호
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• pp.374-387
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• 2016

This paper derives an improved analytical model to estimate switching loss and analyze the effects of parasitic elements on the switching performance of SiC MOSFETs. The proposed analytical model considers the parasitic inductances, the nonlinearity of the junction capacitances and the nonlinearity of the trans-conductance. The turn-on process and the turn-off process are illustrated in detail, and equivalent circuits are derived and solved for each switching transition. The proposed analytical model is more accurate and matches better with experimental results than other analytical models. Note that switching losses calculated based on experiments are imprecise, because the energy of the junction capacitances is not properly disposed. Finally, the proposed analytical model is utilized to account for the effects of parasitic elements on the switching performance of a SiC MOSFET, and the circuit design rules for high frequency circuits are given.