• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.11a
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• pp.753-753
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• 2017

과학기술의 사회적 역할과 책임 확대, 기술개발을 통한 실질적인 문제해결이 강조되면서 국가 사회적 문제해결과 국민생활 전반의 삶의 질 제고를 위한 R&D 정책과 관련 사업에 대한 투자가 확대되고 있다. 정부가 사회이슈 해결을 위한 과학기술의 정책적 지향을 명확히 하면서, 출연(연) 역시 기존의 경제성장 견인과 성장동력 창출 중심의 기능에서 사회문제의 선제적 해결과 공공성 확장을 위한 출연(연)의 역할 수행을 요구받고 있다. 출연(연)은 공적임무 기반을 확대함으로써 국민들의 삶의 질 제고에 실질적으로 기여하겠다는 실천방안을 제출하는 등 다양한 모색과 자생적 혁신을 꾀하고 있으나, 연구자 연구현장의 수용성 문제와 출연(연)이 갖는 여러 특성과 맞물려 기대에 부합하는 변화의 폭과 속도를 내지는 못하고 있다. 본 발표에서는 출연(연)의 R&D환경과 사회문제 해결형 연구사업 현황을 살펴보고, 사회문제 해결을 위한 ETRI의 추진내용과 연구자 기술공급 중심의 경향성을 보완하기 위한 노력들을 소개하였다. 또한 출연(연)의 특성을 기반으로 전략적 투자와 효율적 운영, 성과의 확산 측면에서 사회문제 해결형 R&D 활성화를 위한 시사점을 제시하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.323-326
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• 2004

최근 세계적으로 게임 산업은 문화콘텐츠 산업의 핵심으로 인정받고 있으며 우리 정부도 21세기 국가성장 동력의 핵심영역으로서 게임을 지목하고 있다. 그 중 2002년 아케이드 게임을 제치고 처음으로 1위로 등극한 온라인게임은 2003년에는 플랫폼 생산매출 $50\%$를 차지하며 국내 게임시장을 견인하고 있다. 그러나 게임 산업의 인기와 온라인게임의 확산에 비해 대부분의 게임제작업체들은 짧은 기간의 간단한 베타테스트에 의존하고 있어 콘텐츠의 품질평가에 대한 인식 부족과 만족스러운 테스트 결과를 얻기에는 부족함이 많다. 이러한 문제점을 해결하기 위해서는 온라인 콘텐츠의 특성을 반영한 체계적인 품질모델 및 모델에 기반을 둔 품질평가 프로세스 그리고 각 품질특성을 시험하기 위한 시험기법들이 필요하다. 본 논문에서는 ISO/IEC 9126 및 14598 기반의 온라인 게임콘텐츠 품질평가 모델 선정과 품질평가 프로세스를 제시하고자 한다.

• The korean journal of orthodontics
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• v.36 no.6
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• pp.412-421
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• 2006

Objective: The result of finite element analysis depends on material properties, structural expression, density of element, and boundar or loading conditions. To represent proper elastic behavior, a finite element model was made using Hounsfield unit (HU) values in CT images. Methods: A 13 year 6 month old male was used as the subject. A 3 dimensional visualizing program, Mimics, was used to build a 3D object from the DICOM file which was acquired from the CT images. Model 1 was established by giving 24 material properties according to HU. Model 2 was constructed by the conventional method which provides 2 material properties. Protraction force of 500g was applied at a 45 degree downward angle from Frankfort horizontal (FH) plane. Results: Model 1 showed a more flexible response on the first premolar region which had more forward and downward movement of the maxillary anterior segment. Maxilla was bent on the sagittal plane and frontal plane. Model 2 revealed less movement in all directions. It moved downward on the anterior part and upward on the posterior part, which is clockwise rotation of the maxilla. Conclusion: These results signify that different outcomes of finite element analysis can occur according to the given material properties and it is recommended to use HU values for more accurate results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1085-1090
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• 2011

To assure the safety of rolling stock, it is important to perform the fatigue analysis of reduction gear unit in rolling stock considering a variation of velocity and traction motor capability. This paper presents fatigue analysis of the damage of reduction gear unit of railway vehicle under variable amplitude loading(VAL) based on quasi-static fatigue analysis using finite element model and linear Miner's rule. The VAL for the simulation was constructed from the tractive effort curve and train run curves of railway vehicle under commercial operation condition using MSC.ADAMS dynamic analysis. The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the middle gear based on strain-life based approach. The results showed that the frequent high starting torque due to a quick start as well as increasing numbers of stops at station would decrease the fatigue life of reduction gear unit.

• Korean journal of communication and information
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• v.27
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• pp.183-212
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• 2004

Mobile phone media have extended the terrain of human communication. Starting from the notion of McLuhan, this study suggests that the extension of human communication is a concept of multiple dimension, such as 'extension of function' and 'extension of ego' Mobile phone speed the pare and efficiency of life, but also allow more flexibility at business and professional levels as well as family and personal life. On the other hand, mobile phone is also conceived as a personality kit, that is as a symbol of user's identity. So we ran classify the mobile phone users as a typology of motivation. Group I, entitled 'hyper-coordination', has high instrumental and high expressive motivation. Group II(='instrumental') is high instrumental but low expressive. Group III(='expressive') is low instrumental and high expressive, and Group IV(='minimal') is low in both instrumentality and expressiveness of mobile phone use. Then would the hyper-coordination group have different usage pattern with the other groups? A sample of 482 university students completed survey questionnaire. , which states hyper-coordination group would most frequently make calls and text, and have largest extensity and variety of usage, is supported statistically. states that hyper-coordination group would have larger and deeper social network than the other groups. This hypothesis is also supported with statistics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.4
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• pp.693-703
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• 2017

Rover wheel's mobility depends on soil's condition and wheel's design. The purpose of this study is to evaluate the effect of soil conditions, which are Jumunjin sand and Korean lunar soil simulant (KLS-1), on wheel's motion performance. The experiments were performed by using a single wheel testbed with a wheel which grouser height is 15mm on Jumunjin sand and KLS-1, respectively. Also the influence of grouser length to wheel's mobility performance was studied. The experimental results of torque, drawbar pull and sinkage relating to slip ratio were discussed and analyzed to evaluate wheel's motion performance. Results showed wheel moving on KLS-1 has high performance than Jumunjin sand. Wheel's mobility performance was influenced by soil's properties of cohesion and frictional angle. In addition, wheel's performance of drawbar pull and Torque increased with the increasing of grouser length.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.868-869
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• 2015

지하 매설된 가스배관을 정기적으로 검사하기 위해서 가스 공급 및 용역업체에서는 주로 비피과검사 탐상장비인 MFL(Magnetic Flux Leakage) PIG(Pipeline Inspection Gauge)를 사용한다. 기존의 MFL PIG는 배관 내 유체(가스,오일 등)의 전후차단 압력의 흐름을 이용해 별도의 구동장치 없이 피그를 진행시켜 배관의 결함 유무를 평가하는 시스템이다. 하지만 10기압 이하의 낮은 운영압력과 T 분기관과 같이 급격한 곡관부가 존재하는 직경 16인치 이하의 도시가스 배관에는 기존의 시스템을 적용하기 어렵다. 이처럼 기존 MFL PIG의 적용이 불가한 도시가스 배관(직경 16인치 이하)을 활주하기 위해서는 우선 비파괴검사 시스템을 견인할 수 있는 추진 로봇이 필요하고 추진로봇에 적합한 자기누설 비파괴검사 시스템의 개발이 필요하다. 또한 비파괴검사 장비의 센서 시스템은 결함신호를 탐지하여 결함의 발생유무 및 결함의 형상을 판별하는 성능도 중요하다. 본 논문에서는 16인치 도시가스 배관의 검사를 위한 자기누설 비파괴검사 시스템의 기초설계와 대상 시스템의 자기적 특성을 분석한다. 또한 배관 외벽의 결함 발생 유무에 따른 자기누설 신호의 크기 및 분포변화를 3차원 유한요소법을 이용해 해석하여, 결함 검출 신호의 특성을 분석하는데 초점을 둔다.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.398-403
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• 2008

The propulsion for locomotive application has changed from the DC motor system to the induction motor system. Although the induction motor system has almost reached the stage of maturity, this system also needs to be changed to the PM motor system for the direct drive without using reduction gear. Thus, the IPMSM (Interior buried Permanent Magnet Synchronous Motor) has been adopted to meet the locomotive driving specification. Where the wheel is directly dirven by the traction motor. In this paper, the investigation on IPMSM satisfying driving specifications for the direct drive has been performed using the advanced FEM.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1235-1237
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• 2002

Insulation system(200 class} for stator coil is designed for traction motor with VVVF inverter. Sample coils for stator of the traction motor were tested by accelerative thermal degradation which composed of heat, vibration, moisture, and overvoltage apply. Reliability and expected life were evaluated on the insulation system for 200 class traction motor. After aging of 10 cycles, tan ${\delta}$ increased with voltage. This result is due to increase of internal defects and change of insulation structure.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.3-5
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• 2008

This paper presents a hybrid winding connection method for torque characteristics improving of a traction SRM. In order to get a high torque in wide speed range and torque ripple reduction, series and parallel winding connection are changed according to operating speed. From the analysis of torque character operation mode and efficiency, the proposed control scheme is verified.