• Korean Journal of Acupuncture
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• 제25권1호
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• pp.1-18
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• 2008

Objectives : The aim of this study is to investigate the properties of Meridian Gi in $\ulcorner$Huangdineijing(黃帝內經)$\lrcorner$, specially one of the movement properties like that comings and goings of Gi. Methods : Through searching concepts and properties of Meridian Gi in several chapters of $\ulcorner$Huangdineijing(黃帝內經)$\lrcorner$, many phrases concerned with that properties could be explained and reconstructed into new motional shape of Meridian Gi. Results : The basic characters of comings and goings of Meridian Gi or genuine Gi originate from food essence, and that are like a kind of waves. The most important moments of acupuncture treatment is such time of it's short passing the acupoints, carrying out tonifying and purging methods by controlling the spirit. Conclusions : The Meridian Gi consists of anti-pathogenic Gi so called genuine Gi and pathogenic Gi. Medical doctor must correctly knows the flow of Meridian Gi to operate tonifying and purging method of acupuncture treatments in order to get the desired results. Also maintaining very sensitive state in diagnostic process, the most important key points is to control the spirit and adjust mental activities of both doctors and patients. The motional properties of Meridian Gi are actually concerned with the arrival of Gi and reinforcement-reduction along and against Meridian Gi.

• 한국경영과학회지
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• 제33권1호
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• pp.107-115
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• 2008

We consider the discrete-time GI/G/1/K queue under the early arrival system. Using a modified supplementary variable technique(SVT), we obtain the distribution of the steady-state queue length. Unlike the conventional SVT, the modified SVT yields transform-free results in such a form that a simple two-moment approximation scheme can be easily established.

• 대한토목학회논문집
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• 제32권1D호
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• pp.13-22
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• 2012

국가가 운영하는 119 구조 구급 출동서비스는 응급상황에서 인간의 생명과 직결되는 매우 중요한 사회적 응급 운송시스템이며, 고령화 사회로의 급속한 전이를 보이는 우리나라의 현 사회구조를 비추어 볼 때 그 중요성은 더욱 커져가고 있다. 특히 긴급차량의 사고현장 도착시간은 환자의 초등 조치에 영향을 미치는 중요한 변수이며, 출동서비스 센터의 위치, 사고 현장까지의 접근성 등 도로네트워크 속성에 따라 영향을 받을 수 있다. 따라서 본 연구에서는 경상북도의 구조 구급활동자료를 바탕으로 119 긴급차량의 도착지체 및 출동배치의 효율성을 분석하고자 하였다. 먼저 구조 구급서비스의 출동분포 특성을 살피고, 구조 구급서비스 시설, 도로 네트워크의 위치정보가 주어진 상태에서 GIS의 공간분석을 활용하여 구조 구급서비스 시설의 일정 반경에 포함되지 않는 사고다발지역(사각지역)과 국가교통 DB상의 도로네트워크 입력속도, 실제 구조 구급일지 상의 현장 도착시간을 각각 입력 값으로 하는 긴급차량 도착지체 지역을 GIS 맵으로 표출하였다. 또한 출동거리가 10km 넘는 원거리 출동빈도가 높은 구조구급 서비스시설의 출동배치 효율성을 분석하고, GIS의 OD 네트워크 분석을 이용하여 도로네트워크상 최단거리에 위치한 서비스시설에서 출동이 이루어지도록 구조 구급서비스망을 개선하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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• pp.399-405
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• 2002

요즈음에는 GPS 및 GIS을 기반으로, 운전자에게 최단 경로탐색 및 예상도착시간을 인터넷 및 휴대폰으로 검색할 수 있다. 그러나, 아무리 좋은 자동항법 장치도 평균차량속도가 10-20 Km 일 때에는 최단경로를 생성할 수 없다. 그러므로 승용차대기시간과 평균차량속도를 개선하기 위해서, 서로 다른 교차로 길이 및 교차로 차선수 일때에도, 퍼지 적응 규칙을 이용한 최적녹색시간 알고리즘을 제안한다. 본 논문에서는 인터넷을 이용해서 위험한 도로, 공사중인 도로 및 목적지 예상도착시간 및 최적의 교통상황을 예보하는 기능을 제공할 수 있도록 하였다.

• 대한산업공학회지
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• 제42권5호
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• pp.304-313
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• 2016

This work suggests a new analysis approach for a discrete-time GI/G/1 queue with multiple vacations. The method used is called a modified supplementary variable technique and our result is an exact transform-free expression for the steady state queue length distribution. Utilizing this result, we propose a simple two-moment approximation for the queue length distribution. From this, approximations for the mean queue length and the probabilities of the number of customers in the system are also obtained. To evaluate the approximations, we conduct numerical experiments which show that our approximations are remarkably simple yet provide fairly good performance, especially for a Bernoulli arrival process.

• Industrial Engineering and Management Systems
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• 제12권3호
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• pp.281-287
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• 2013

In this paper, we introduce a roots method that uses the roots inside the unit circle of the associated characteristics equation to evaluate the steady-state system-length distribution at three epochs (pre-arrival, arbitrary, and post-departure) and sojourn-time distribution in GI/PH/1 queueing model. It is very important for an air base to inspect airplane oil because low-quality oil leads to drop or breakdown of an airplane. Since airplane oil inspection is composed of several inspection steps, it sometimes causes train congestion and delay of inventory replenishments. We analyzed interarrival time and inspection (service) time of oil supply from the actual data which is given from one of the ROKAF's (Republic of Korea Air Force) bases. We found that interarrival time of oil follows a normal distribution with a small deviation, and the service time follows phase-type distribution, which was first introduced by Neuts to deal with the shortfalls of exponential distributions. Finally, we applied the GI/PH/1 queueing model to the oil train congestion problem and analyzed the distributions of the number of customers (oil trains) in the queue and their mean sojourn-time using the roots method suggested by Chaudhry for the model GI/C-MSP/1.

• 대한산업공학회지
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• 제14권1호
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• pp.17-30
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• 1988

The aim of this project is to analyze the queueing model with the two types of customers which either can wait unrestrictedly or wait restrictively in the system depending on the condition of service facility unless they may be served immediately. This model consists of the three-dimensional state space and then quasi birth-death process is formulated. The steady-state probabilities and measures of performance of this system are derived by using Matrix Geometric method.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1101-1103
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• 2006

For a broad class of discrete-time FIFO queueing systems with D-MAP (discrete-time Markovian arrival process) arrivals, we present a distributional Little's law that relates the distribution of the stationary number of customers in system (queue) with that of the stationary number of slots a customer spends in system (queue). Taking the multi-server D-MAP/D/c queue for example, we illustrate how to utilize this relation to get the desired distribution of the number of customers.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.915-921
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• 2005

Accurate and reliable tracking system is essential for the central train control system. There are two systems widely being used. one is the fixed block system which utilizes the track circuit for the detection of train position. the other is the moving block system which has the advantage over the former since it enables shorter radio signal for the train position detection. In this paper a new algorithm is proposed which uses signal's phase difference of arrival to detect the train position. Experimental verification of the algorithm is presented in the paper.

• 산업공학
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• 제23권3호
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• pp.239-245
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• 2010

This paper considers a localization problem of a moving tag on RFID(Radio Frequency Identification) systems, where a positioning engine collects TDOA(Time-difference of Arrival) signal from a target tag to estimate the position of the tag. To localize the tag in the RFID system, we develop two heuristic algorithms and evaluate their performance in the estimation error and computational time by using randomly generated numerical examples. Based upon the performance evaluation, we can conclude our algorithms are valuable for localization the moving target.