• 전기학회논문지
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• 제59권11호
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• pp.2103-2107
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• 2010

This paper deals with the recognition of multiple mobile robots equipped with RFID tag. In the case that the number of robots recognized by each RFID reader is larger than that of allocated slots, the clashing recognition occurs. And, in the case that the total number of robots recognized by all RFID reader is larger than that of real robots, the repetitious recognition occurs. We employ the dynamic frame slot allocation by using the ALOHA algorithm to prevent the clashing recognition and estimate the number of robots by using the received signal strength indication to prevent the repetitious recognition. The numerical experiment shows the reliability and the efficiency of the proposed method.

• 디지털산업정보학회논문지
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• 제4권3호
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• pp.45-53
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• 2008

As internet is wide spread, the number of internet service provider is increased. Internet service providers gather the personnel information with inhabitants registration identification number for the user management and the adult authentication. The personnel information is spreaded thorough the Internet by the system hacking, mismanagement and malicious resale. And the personnel information is used for spam email, phishing scams, etc. by malicious others. So the Ministry of Information and Communication Republic of Korea developments I-PIN system of the personnel identification. But, I-PIN has some problem the guideline for it and the method of 5 I-PIN services. In this paper, we analyze the problem about the guideline for I-PIN and the method of 5 I-PIN services. And we propose the countermeasure about the problem.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.353-356
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• 2001

In this paper, we study the existence of fuzzy solution for the following differential system with fuzzy coefficient using the different two methods: (equation omitted), where a, b is the fuzzy natural number generated by fuzzy number l . The a-level set of the fuzzy number (equation omitted). The -level set of a is (equation omitted) and -level set of b is (equation omitted).

• Journal of Biosystems Engineering
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• 제41권3호
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• pp.201-207
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• 2016

Purpose: A water-spraying type automatic glochids removal system for cactus (Opuntia humifusa) stem was developed, and its performance was evaluated. The system was developed to reduce intensive human labor in removing glochids from cactus stem skin without inducing damage prior to further processing into value-added products. Methods: The developed system consists of conveyor and water-spraying systems. The conveyor system delivers cactus stems through water-spraying compartments and finally to a collecting box. In order to remove the glochids, rotating nozzles spray water over all areas (i.e., front and back faces and sides) of the cactus skin under controlled water pressure. Operating conditions such as conveyor speed, water pressure, angle of water-spraying nozzles, distance between conveyor belt and rotating nozzles, and angle of cactus flipping slide were adopted from our previous study and applied on the system design and manufacturing. The performance of glochids removal was evaluated by counting the number of glochids on the cactus stem before and after processing on the system. Results: The developed system performed efficiently and effectively under the pre-studied operating conditions except for the angle of cactus flipping slide. The new system had a glochids removal ratio of 94.1% without damaging the cactus skin. Considering the original number (approximately 30-60) of glochids, the remaining number was low (1-4), and most of them were found at the side edge of the cactus stem. This system can remove glochids from 360 cactus stems in 1 hr regardless of cactus size. Conclusions: The performance of the new system in glochids removal without damaging cactus skin is superior to any other existing device (i.e., brush type, rubber-friction type, and agitation type). The system is expected to be applied in cactus (O. humifusa) processing facilities.

• Journal of Animal Science and Technology
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• 제52권1호
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• pp.71-76
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• 2010

본 연구는 양돈 사육규모가 2,000두 이상 5,000두 이하인 국내 중규모 농장의 HACCP 시스템 적용 전 후의 항생제를 비롯한 동물용의약품의 사용 현황 및 생산성에 미치는 영향을 조사하고 이를 차후 수행될 농장 HACCP 연구의 기초자료로 활용코자 실시하였다. 본 연구에 선정된 HACCP 적용 양돈장의 평균 노동인력은 내 외국인 모두 6.55명으로 조사되었으며, 구간별 평균 사육 구성 비율은 모돈 11.23%, 자돈 38.37%, 육성-비육 50.40%로 조사되었다. 농장의 생산성지표인 분만율, 총산자수, 포유 개시두수, 평균 이유두수, 평균 이유기간, 모돈 두당 연간 이유 두수, 모돈 두당 연간 규격돈 출하 두수 등은 HACCP 시스템 적용 전에 비하여 적용후 증가하는 경향을 나타내었다. 출하두당 생산비와 사료비도 HACCP 시스템 적용 전에 비하여 적용 후 증가하였으나 이는 조사 당시 국제 곡물가격의 영향에 기인한 것으로 판단된다. 월평균 약제비와 사용항생제수는 HACCP 적용 전에 비하여 적용 후 각각 -13.27, -27.50% 감소하는 것으로 나타났다. 사육구간별 항생제 첨가농장수-사료공장에서 첨가와 사육구간별 항생제 첨가농장수-농장에서 첨가는 HACCP 적용 전 많은 농장에서 항생제가 첨가된 사료를 급여하였으나 적용 후에는 사용율이 평균 59% 감소하였으며, 특히 육성 및 비육구간에 사용되었던 항생제 첨가사료가 상당히 감소되는 경향을 보여 주었다.

• Industrial Engineering and Management Systems
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• 제15권2호
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• pp.131-142
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• 2016

We consider a multi-server queueing system without buffer and with two types of customers as a model of operation of a mobile network cell. Customers arrive at the system in the marked Markovian arrival flow. The service times of customers are exponentially distributed with parameters depending on the type of customer. A part of the available servers is reserved exclusively for service of first type customers. Customers who do not receive service upon arrival, can make repeated attempts. The system operation is influenced by random factors, leading to a change of the system parameters, including the total number of servers and the number of reserved servers. The behavior of the system is described by the multi-dimensional Markov chain. The generator of this Markov chain is constructed and the ergodicity condition is derived. Formulas for computation of the main performance measures of the system based on the stationary distribution of the Markov chain are derived. Numerical examples are presented.

• 한국멀티미디어학회논문지
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• 제12권6호
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• pp.876-881
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• 2009

Online game servers usually has been using the static thread pool system. But this system is not fit for huge online game server because the overhead is always up-and-down. Therefore, in this paper, we suggest the new algorithm for huge online game server. This algorithm is based on the prediction-based dynamic thread pool system. But it was developed for web servers and every 0.1 seconds the system prediction the needed numbers of threads and determine the thread pool size. Some experimental results show that the check time of 0.4 seconds is the best one for online game server and if the number of worker threads do not excess or lack to the given threshold then we do not predict and keep the current state. Otherwise we apply the prediction algorithm and change the number of threads. Some experimental results shows that this proposed algorithm reduce the overhead massively and make the performance of huge online game server improved in comparison to the static thread pool system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.531-534
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• 1997

A design system of dies for hot extrusion of structural shapes such as Z' s, L' s, T' s, U' s and H' s from aluminum alloys was developed in this study. The developed design system of dies is based of established die design rule system. The design rules for die design are obtained from the handbooks, plasticity theories and relevant references. The environment of the system is AutoCAD and AutoLISP, the graphic programming language was used for the configuration of the system. This system includes five major modules such as section shape design module, die opening number module. die opening layout module, die correction module and die bearing design module that are used to determine design variables. This system would be used to design of dies for hot extrusion from aluminum alloys and widely used in manufacturing course..

• 한국시스템다이내믹스연구
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• 제12권1호
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• pp.115-130
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• 2011

This study shows the operational availability(Ao) analysis of the supply chain with maintenance functions using the system dynamics simulation. The simulation uses 60 equipments which are serial systems composed by 4 major components. And every entities are connected each other by causal loops. So whole simulation executed like one organic system. Specially we consider 2 constraints, one is the number of spare parts and the other is maintenance capacity level. 2 constraints have 11 levels each so the simulation has 121(11*11) scenarios which scenario has 30 different random number seed. The simulation executed total 3,630(11*11*30) times. We analysis average Ao of total equipments by 121 scenarios and additionally the regression of the average Ao and 2 constraints. As the result, we can get the more accurate values by the system dynamics simulation than the regression to analysis complex system like the supply chain with maintenance functions.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권11호
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• pp.742-747
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• 1999

On-line diagnosis system has been developed and is now applied the detection of shorted turns in the field winding of large generator. This system consists of data aquisition system and display PC. The data aquisition system detects voltage waveforms from flux probe sensor installed in the stator slot. The display PC shows theshorted-turn situation of generator rotor winding. A shorted-turn diagnosis test wasperformed on five gas turbine generators at the Seoinchon combined cycle power plant. The test was conducted using an new diagnosis system and digital oscilloscope which can identify the pole location, the slot number and the number of shorted turns within each slot. It is confirmed that results of two systems are very same in the field tests.