• International Journal of Reliability and Applications
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• v.16 no.1
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• pp.35-53
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• 2015

This investigation deals with reliability and sensitivity analysis of a repairable embedded system with standby wherein repairman takes multiple vacations. The hardware system consists of 'M' operating and 'S' standby components. The repairman can leave for multiple vacations of random length during its idle time. Whenever any operating unit fails, it is immediately replaced by a standby unit if available. Moreover, governing equations of an embedded system are constructed using appropriate birth-death rates. The vacation and repair time of repairman are exponentially distributed. The matrix method is used to find the steady-state probabilities of the number of failed components in the embedded system as well as other performance measures. Reliability indexes are presented. Further, numerical experiments are carried out for various system characteristics to examine the effects of different parameter. Using a special class of neuro-fuzzy systems i.e. Adaptive Network-based Fuzzy Interference Systems (ANFIS), we also approximate various performance measures. Finally, the conclusions and future research directions are provided.

• Journal of the Korean Data and Information Science Society
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• v.13 no.2
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• pp.157-165
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• 2002

Since 1997, when a new educational system that encourages faculties instead of departments in universities is first introduced, students have much more chance to choose and leave their majors than before. As a result, colleges of basic arts and sciences confront with a serious problem since lots of students have left their majors at the colleges. In this paper, we analyze and provide a predictive model for those students in a university using decision trees.

• 전기의세계
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• v.45 no.4
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• pp.36-39
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• 1996

1949년 이후, 중국에서의 전력사업은 급속히 증가하였으며, 1949년부터 1994년까지의 에너지 생산의 연평균성장률과 기존에 장치용량은 각각 12.68%와 10.97%이다. 하지만 중국의 많은 인구와 발전중인 산업의 엄청난 수요로 인하여 전기에너지의 부족은 여전히 중국의 가장 심각한 문제이다. 그래서, 서부에서 동부로 전력에너지를 전송하기 위해서도 더욱더 고압의 AC와 DC 전송 system 채택이 적절하다. 최근까지는 많은 500kV AC 계통과 하나의 .+-.500kV DC link를 운영하였다. 다른 한편으로는, 설치된 전력기기의 안전운전을 어떻게 보장 할 것인가가 또 다른 중요한 문제이다. 그러므로, 절연진단이 온 나라이 전력설비에 더 많은 관심이 기울어지고 있다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.475-481
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• 2004

This paper presents a force model of the clean tube system, which was developed as a means of transferring air-floated wafers inside a closed tube filled with super clean air. The recovering force from the holes for floating wafers is modeled as a linear spring and thus the wafers motion is modeled as a mass-spring-damper system. The propelling forces are modeled as linear along with the wafer location. The paper also proposes a control method to emit and stop a wafer at the center of a control unit. It reveals the minimum value of the propelling force to leave from the control unit. In order to stop the wafer, it utilizes the exact time when the wafer arrives at the position to activate the propelling force. Experiments with the clean tube system built for the 12 inch wafer shows the validity of the proposed model and the algorithm.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.36-39
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• 2006

This paper proposes a support vector machine (SVM) based power system voltage stability classifier using local measurement data. The excellent performance of the SVM in the classification related to time-series prediction matches the real-time data of PMU for monitoring power system dynamics. The methodology for fast monitoring of the system is initiated locally which aims to leave sufficient time to perform immediate corrective actions to stop system degradation by the effect of major disturbances. This paper briefly describes the mathematical background of SVM, and explains the procedure for fast classification of voltage stability using the SVM algorithm. To illustrate the effectiveness of the classifier, this paper includes numerical examples with a 11-bus test system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.459-462
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• 2003

This paper presents a force model of the clean tube system, which was developed as a means for transferring the air-floated wafers inside the closed tube filled with the super clean air. The recovering force from the holes for floating wafers is modeled as a linear spring and thus the wafer motion is modeled as a mass-spring-damper system. The propelling forces are modeled as linear along with the wafer location. The paper also proposes the control method to emit and stop a wafer at the center of a control unit. It shows the minimum value of the propelling force to leave from the control unit. In order to stop the wafer, it utilizes the exact time when a wafer arrives at the position to activate the propelling force. Experiments with the clean tube system built for 12 inch wafer shows the validity of the proposed model and the algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2166-2171
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• 2007

In this paper, we proposed a Sequential Download System(SDS) to provide high steaming QoS in p2p network. SDS is able to receive a media file simultaneously from multiple source peer by download manager and deal with unexpected leave of source peer. Also It can provide stable streaming services with minimum buffering delay and manage request of other peer by memory map in process of downloading.

• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.703-712
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• 2003

With the explosive growth n the numbers and sizes of imaging technologies, Content-Based Image Retrieval (CBIR) has been attacked the interests of researchers in the fields of digital libraries, image processing, and database systems. In general, in the case of query-by-image, in user has to select an image from database to query, even though it is not his completely desired one. However, since query-by-sketch approach draws a query shape according to the user´s desire it can provide more high-level searching interface to the user compared to the query-b-image. As a result, query-by-sketch has been widely used. In this paper, we propose a Java-based image retrieval system that consists of sketch query and image classification. We use two features such as color histogram and Haar wavelets coefficients to search similar images. Then the Leave-One-Out method is used to classify database images. The categories of classification are photo & painting, city & nature, and sub-classification of nature image. By using the sketch query and image classification, w can offer convenient image retrieval interface to user and we can also reduce the searching time.

• Journal of Fisheries and Marine Sciences Education
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• v.5 no.1
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• pp.23-30
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• 1993

The Korea Seaman's Act is providing that fishermen s salaries are exceptionally defined and working hours and paid leave are not defined at all. Significant problems of Fishermen's Labor Condition are, (1) It is hard to guarantee the basic right of fishermen as their wages are variable depending on the catch. (2) Excessive working hours would hamper the labor reproduction ability and increase the frequency of disaster. (3) Moreover, fishermen have to search for a new job following the lay off after working aboard during the period defined by contract. The possible implement of Seamen's Act are : (1) The wage system must be unified by regular wages. If it is hard to perish the lay system its relative importance should be diminished whereas the fixed minimum wages and the allowance depending on the position and working days should be paid. (2) This discrimination of the fishing vessels from merchant should be eliminated by removing the item on the Act which excludes the fishermen on the working hours. If it is hard to do so practically the lower regulations defining the maximum periods of duty and minimum periods of rest for fishermen must enact separately as in Japan and England. (3) The difference in the provisions of paid leave between the merchant seamen and fishermen must be abolished (4) It is the most desirable to improve the fishermen's labor conditions through the completion of the Act. However, before doing this, the employers and employees must try to solve the problems through the collective agreement by themselves.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.5
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• pp.340-348
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• 2015

The "stamp rally" is an event that participants go the round with predetermined points for the purpose of collecting stamps. They bring the stamp card to these points. They, however, sometimes leave or lose the card. In this case, they may not reach the final destination of the stamp rally. The purpose of this research is the construction of the stamp rally system which distinguishes each participant with his or her hand instead of the stamp card. We have realized our method distinguishing a hand posture by the image processing. We have also evaluated it by 30 examinees. Furthermore, we have designed the data communication between the server and the checkpoint to implement our whole system. We have also designed and implemented the process for the registering participant, the passing checkpoint and the administration.