• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3714-3721
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• 2015

Although sheath-type heating line is generally used for susceptor heater, performance deterioration problems in temperature uniformity occurs in the case of large scale and high temperature condition. We developed new design and prototype of the susceptor using sheet metal to provide performance improvement in temperature uniformity. Temperature uniformity below 1.4% in the surface temperature condition of $450^{\circ}C$ was verified in the susceptor prototype. Also we developed Kernel regression algorithm to estimate measured temperature using temperature learning data. The reliability of the measured temperature uniformity was confirmed by comparative analysis between predicted data and measured data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.48-49
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• 2005

한국형 고속철도시스템은 최고운행속도 350km/h로 주행하는 고속열차(시제열차 7량 편성)의 개발에 성공하여 현재 시운전 시험을 통해 신뢰성과 안정성을 검증하고 있다. 국내 기술로 새롭게 개발된 한국형 고속철도 시스템은 고속운행에 따른 엄격한 안전요구사항을 만족해야 하며, 특히 고속-대량의 수송수단으로서 승객의 안전을 최우선으로 하기 때문에 다른 어떠한 시스템보다 엄격한 안전확인 및 성능검증을 위한 철저한 시험평가 과정이 필요하다. 본 연구에서는 한국형 고속철도 시스템 개발에 적용한 안전설계 요건의 분석내용을 제시하고, 고속철도 차량시스템의 안전성능 요건을 입증하기 위한 성능시험 체계로서 구성품 시험, 완성차시험(단차 및 편성 시험) 및 시운전 시험으로 구분한 한국형 고속철도 차량시스템에 대한 성능시험기준안을 소개하고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4543-4552
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• 2010

A leader is a special process who roles as the coordinator within multiple processes of a group. In a distributed system, leader election is the procedure of electing a coordinator. This is a very important issue for building fault-tolerant distributed systems. When two normal mobile ad hoc networks are merged, there are two leaders. This violates the safety property, so a mechanism to detect and handle are required. In mobile ad hoc distributed computing system, we propose a leader competition protocol and to prove the temporal logic to it. This solution is based on the group membership detection algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.425-428
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• 2011

서비스 로봇과 펫 로봇 등 사람과 직접 상호작용하는 로봇기술의 필요성이 증가하고 있다. 대화시스템은 자연언어처리 기술을 활용하여 음성인식 기술과의 결합을 통해 현재 로봇에서 주로 사용되고 있는 버튼과 터치스크린 위주의 HRI(Human-Robot Interface)보다 자연스러운 HRI를 제공한다. 이러한 자연스러운 HRI를 수행할 수 있는 로봇을 구성하기 위해서는 로봇이 서비스를 제공할 실제 영역에 맞는 대화시스템의 연구가 필요하다. 본 논문에서는 자질사전, 단일화 문법(unification grammar), 대화 흐름도(dialogue flow diagram)를 사용한 레스토랑 영역의 자질기반(feature-based) 대화시스템을 제시한다. 자질 정보는 형태소, 시제, 어휘의 의미구조 등을 나타내며 화행(speech act) 결정에 사용하고 문장 자질과 구문 자질을 파서에서 활용한다. 자질기반 대화시스템을 통하여 레스토랑 영역에서 사용자 화행 이해 및 주문, 안내 등의 서비스를 성공적으로 수행할 수 있음을 보인다.

• Polymer(Korea)
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• v.34 no.6
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• pp.574-578
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• 2010

In this study, the caprolactone modified hydroxy acrylates (CHAs) were synthesized by ring-opening reaction of caprolactone and 2-hydroxyethyl acrylate (2-HEA) as initiator. Also, the caprolactone modified urethane acrylate (UA) oligomers were synthesized by condensation reaction of previously synthesized CHAs, 2-hydroxyethyl acrylate (2-HEA) and hexamethylene diisocyanate trimer (HDT). Using the hydroxy number of CHAs, the molecular weights of the CHAs were calculated easily and their molecular weight was similar to the theoretical molecular weight of them. The viscosity of UA oligomers decreased as increasing a content of CHA in the UA oligomer. Cure films were prepared from UA oligomer, reactive diluents, and UV initiator to investigate their physical properties. The thermal stability and color difference on high temperature for the cured film were improved as increasing the crosslinking density. Their surface hardness was also increased as increasing crosslinking density of the cured films, but their elongation at break was decreased.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.860-872
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• 2002

Fault tree analysis is the most widely used saftly analysis technique in industry. However, the analysis is often applied manually, and there is no systematic and automated approach available to validate the analysis result. In this paper, we demonstrate that a real-time model checker UPPAAL is useful in formally specifying the required behavior of safety-critical software and to validate the accuracy of manually constructed fault trees. Functional requirements for emergency shutdown software for a nuclear power plant, named Wolsung SDS2, are used as an example. Fault trees were initially developed by a group of graduate students who possess detailed knowledge of Wolsung SDS2 and are familiar with safety analysis techniques including fault tree analysis. Functional requirements were manually translated in timed automata format accepted by UPPAAL, and the model checking was applied using property specifications to evaluate the correctness of the fault trees. Our application demonstrated that UPPAAL was able to detect subtle flaws or ambiguities present in fault trees. Therefore, we conclude that the proposed approach is useful in augmenting fault tree analysis.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1114-1118
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• 1999

Barrier rib for the plasma display panel(PDP) was made by photolithographic process utilizing photosensitive barrier rib paste. The barrier rib paste was prepared by first dissolving ethylcellulose(binder polymer) in butyl carbitol(BC)/butyl carbitol acetate(BCA) =30/70 wt % mixture solvent at 15 wt % concentration. To this solution a mixture of functional monomers consisted of tripropyleneglycol diacrylate/ pentaerythritol triacrylate = 50/50 wt %, Irgacur 651 photoinitiator, and barrier rib powder were added and then the whole mixture was mixed in the three roll mill for 2 hr. The effect of component and concentration of photosensitive barrier paste on the photolithographic process was studied. After optimization of the paste formulation and photolithographic process, barrier rib could be obtained with good resolution up to $100{\mu}m$ height.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1027-1037
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• 2009

The development of a combustion chamber for a 30-$ton_f$ regeneratively-cooled space liquid rocket engine is described. Starting from the development of bi-propellant swirl coaxial injectors, essential technologies were verified through subscale combustion chambers and afterwards applied to the full-scale combustion chambers. A total of 5 full-scale combustion chambers have been utilized to verify ignition, combustion efficiency and stability, cooling, and duration requirements. A total of 46 combustion tests were performed among which 23 tests were parallely performed with stability rating tests using a pulse gun device. The test results have revealed that the 30-$ton_f$ regeneratively-cooled combustion chamber fully complies to the performance and combustion stability requirements and thus concluded that the development is successfully completed.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.265-270
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• 1972

An attempt was made in this study to investigate the possibility of processing squid along with pork into an intermediate moisture food, as an acceptable new item in Korea. To obtain a palatable and low cost product, portions of mixture consisting of equal amounts of ground squid and pork were cooked in soy sauce for 20 min, soaked in glycerol for 20 min at $80^{\circ}C$, and then air dried for 90 min at $60^{\circ}C$. During storage for 42 days in saturated humidity incubator at $37^{\circ}C$, the total microbial counts of the products packaged in polyethylene (0.05 mm), polypropylene (0.05 mm) and plastic laminated aluminum foil were decreased from 230 per gram to 40, 20 and 10 per gram respectively. In another long range storage test of 6 months, the results paralleled the above trends. Even though the TBA value of the samples increased during the storage, it was not so serious as to damage on the organoleptic quality of this product. The results indicate that stored product was as acceptable as the freshly prepared one.

• Polymer(Korea)
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• v.35 no.2
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• pp.183-188
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• 2011

Pentaerytritol triacrylate (PETA) was synthesized by a condensation reaction between pentaerytritol and acrylic acid. The highest yield of PETA was obtained when heptane was used as a solvent under the 1:4 mole ratio of pentaerytritol and acrylic acid. The 6-functional urethane acrylates(UA) were also synthesized by a condensation reaction between PETA and diisocyanate. Cured films were prepared from the mixtures of UA oligomer, reactive diluents and UV initiator to investigate their physical properties. The thermal stability of the aliphatic urethane acrylate was better than that of the aromatic urethane acrylate. The UA-2 showed good hardness and scratch resistance properties while the UA-l with a high degree of curing density exhibited a better chemical resistance. All the UA oligomers showed fairly good adhesion strengths but the other physical properties of UA-3 were poor due to its low curing density.