• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1427-1430
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• 2009

The amount and the continuity of the precipitation data used in a hydrological analysis may exert a big influence on the reliability of the analysis. It is a fundamental process to estimate the missing data caused by such as a breakdown of the rainfall recording machine or to expand a short period of rainfall data. In this study the eight methods widely used as methods for estimating are compared. The data used in this research is the annual precipitation amount during 17 years at the Cheolwon station including an ungauged period of 15 years and its five surrounding stations. By use of this certified method the ungauged precipitation values at the Cheolweon station is estimated and the areal average of annual precipitation for 32 years at the Han River basin is calculated.

• 제어로봇시스템학회논문지
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• 제4권5호
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• pp.651-657
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• 1998

In this study, an intelligent scheduling with hybrid architecture, which integrates expert system and neural network, is proposed. Neural network is trained with the data acquired from simulation model of FMC to obtain the knowledge about the relationship between the state of the FMC and its best dispatching rule. Expert system controls the scheduling of FMC by integrating the output of neural network, the states of FMS, and user input. By applying the hybrid system to a scheduling problem, the human knowledge on scheduling and the generation of non-logical knowledge by machine teaming, can be processed in one scheduler. The computer simulation shows that comparing with MST(Minimum Slack Time), there is a little increment in tardness, 5% growth in flow time. And at breakdown, tardness is not increased by expert system comparing with EDD(Earliest Due Date).

• 한국컴퓨터산업교육학회:학술대회논문집
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• 한국컴퓨터산업교육학회 2003년도 제4회 종합학술대회 논문집
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• pp.95-98
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• 2003

Power semiconductors are being currently used as a application of intelligent power inverters to a refrigerator, a washing machine and a vacuum cleaner as well as core parts of industrial system. The rating of semiconductor devices is an important factor in decision on the field of application and the forward blocking voltage is one of factors in decision of the rating. The Power MOS device has a merit of high input impedance, short switching time, and stability in temperature as well known. Power MOS devices are mainly used as switches in the field of power electronics, especially the on-state resistance and breakdown voltage are regarded as the most important parameters. Power MOS devices that enable a small size, a light weight, high-integration and relatively high voltage are required these days. In this paper, we proposed the new lateral power MOS which has forward blocking voltage of 250V and contains trench electrodes and verified manufactural possibility by using TSUPREM-4 that is process simulator.

• 한국항해항만학회지
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• 제30권7호
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• pp.561-566
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• 2006

In this paper, we propose a new ship scheduling set packing model considering limited risk or variance. The set packing model is used in many applications, such as vehicle routing, crew scheduling, ship scheduling, cutting stock and so on. As long as the ship scheduling is concerned, there exits many unknown external factors such as machine breakdown, climate change and transportation cost fluctuation. However, existing ship scheduling models have not considered those factors apparently. We use a quadratic set packing model to limit the variance of expected cost of ship scheduling problems under stochastic spot rates. Set problems are NP-complete, and additional quadratic constraint makes the problems much harder. We implement Kelley's cutting plane method to replace the hard quadratic constraint by many linear constrains and use branch-and-bound algorithm to get the optimal integral solution. Some meaningful computational results and comments are provided.

• 산업경영시스템학회지
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• 제24권64호
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• pp.63-76
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• 2001

This paper presents a job-shop type flexible manufacturing system(FMS) scheduling problem and examines the effects of scheduling rules on the performance of FMS. Several machine and AGV scheduling rules are tested against the mean flow-time criterion. In this paper, I compare the rules under various experimental conditions by using an FMS simulation model. One of the objectives of this study is to discuss how the simulation-based scheduling problem can be operated. The other is to measure sensitivity of the rules to changes at inter arrival time, queue capacity, breakdown rates for machines and AGV, and AGV speed. Therefore, the results of simulation experiments were considered on FMS design and operating stages. A comprehensive bibliograph? is also presented in the paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.96-98
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• 1993

In accordance with increase of electrical power demanded, more efficient supervisory control of distribution system is required. This study contains development of MMI(man-machine-interface) system with GUI(graphic-user-interface), for the automatic power distribution system. The main function of MMI system are to edit network of power distribution, to view network, to warnning a breakdown and to management of data base for network. The GUI function of MMI system enables more efficient management of power distribution system.

• 전기학회논문지
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• 제64권11호
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• pp.1639-1644
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• 2015

Auxiliary air compressor(ACM) applied to railroad cars is a device which controls amount of compressed air in order that pantographs can be mounted correctly on the roof of an electric train. Existing ACMs consist of dc motors and brushes wear out due to friction with a commutator. Therefore, continuous maintenance is required. However, three phase BLDC motors have higher power density compared to dc motors and the machine maintenance is not needed because electric commutation is possible. The three phase generally uses hall sensors to get position information and this enables the accurate control. This paper suggests an algorithm that compensates the errors occurred when the hall sensors have a breakdown for stable operation.

• 한국초전도ㆍ저온공학회논문지
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• 제12권1호
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• pp.52-55
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• 2010

A sub-cooled liquid nitrogen system is known as a promising method to develop high voltage superconducting apparatuses such as superconducting fault current limiters (SFCLs) and superconducting cables. To develop a high voltage superconducting machine adopting the sub-cooled liquid nitrogen system with a constant pressure. injecting a non-condensable gas is indispensable. In this study. the dielectric characteristics of insulation gases are investigated and analyzed by using electric utilization factors ($\xi$). It is found that the maximum electric field at sparkover that occurs with 50 % probability. $E_{MAX.50%}$ exponentially decreases as the S increases. This means that the $E_{MAX.50%}$ at sparkover can be estimated with the $E_{MAX.50%}$

• 한국산업융합학회 논문집
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• 제9권1호
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• pp.51-59
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• 2006

The study is diagnosis about fatigue failure phenomenon of heating coil spring (sup9) and heat treatment method that is used to crusher. Because more than 80~90% of damage announcement of breakdown of machine and construction is been caused in fatigue present state, fatigue failure became important leading person at design. Calculated design load is imposed repeatedly that fatigue breakdown is safe. Is phenomenon that change load is imposed in the construction continuously. Used coil spring applies heat 30minute by Quenching temperature $860^{\circ}C$ if see manufacturing process and temperature of gasoline of $50^{\circ}C$ keep after quench that know tempering a $460^{\circ}C$ 90minute a product be. If doto apply heat $950^{\circ}C$ material at rolling process historically before quenching, austenite formation clay pipe being done AGS(Austenite Grain Size) by 2.5~4 become. Apply heat quenching 30minute by $820^{\circ}C$ by improvement method and after quench that keep $50^{\circ}C$ in oil tempering if do $450^{\circ}C$, 90minute spring ideal formation sorbite formation of the river form and condition that satisfy most more than AGS 7 appeared. Also, we can secure authoritativeness through MT since shot peening processing.

• 한국터널지하공간학회 논문집
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• 제22권2호
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• pp.197-217
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• 2020

서울지하철 7, 9호선에 적용한 쉴드TBM은 소음 및 진동, 막장면의 안정성 확보 측면에서 발파공법에 비해 매우 안전한 공법이다. 또한, 쉴드TBM은 지반조건이 연약한 경우 효과적이다. 그러나 지반조건과 토피, 지하수 등의 여건에 적합하지 않은 장비를 적용할 경우 장비고장, 잦은 굴진중단, 특히 예상치 못한 불량한 지반을 통과하게 될 경우 터널 굴진 중 트러블이 발생할 수 있다. 본 논문은 일본 쉴드TBM 굴착중의 사고 및 트러블에 대한 사례를 정리하였다. 이중 대표적인 트러블 사례를 이용하여 지반변위 형상에 대한 실제발생 경향을 파악하였으며 수치해석을 통해 역해석결과와 상호비교하였다. 이를 토대로 막장 지보압을 산정할 경우 수치해석 적용시의 오차를 줄이는 방안을 제안하였다.