• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.26-37
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• 2007

A virtual engine test based on "Numerical test cell" can extremely reduce the time and cost for the development of a hardware by coupling multidisciplinary analysis. This paper introduces the development activities of full engine simulation programs in U.S.A. and Europe, with the their related techniques(the engineering models, the simulation environment and high performance computing) based on the NPSS(Numerical Propulsion System Simulation). NASA Glenn research conte. leads the development efforts of NPSS by assembling the current codes and improving their Auctions. VIVACE(Value Improvement through a Virtual Aeronautical Collaborative Enterprise), a consortium of universities, research centers and companies in Europe, is developing the PROOSIS(PRopulsion Object Oriented Simulation Software). The capability for the domestic development is also estimated by surveying the current status.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.565-570
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• 2004

The construction Progress is widely used 3s a critical index for effective project management. However, the methods, structure, data, and accuracy of progress measurement may vary depending on specific characteristics of the project, organization, or location. Even in an organization, different projects may utilize different measurement methods to effectively achieve their own management purpose. The excessive effort required to manipulate very detailed progress data is also an issue Therefore the purpose of this study is to dove]op an automated progress measurement model utilizing standard progress measurement package (SPMP).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.237-237
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• 2010

고효율의 열전특성을 갖는 나노 구조체 열전재료 연구의 일환으로 이종물질인 $Bi_2Te_3$-PbTe계 열전소재의 미세구조와 특성을 조사하였다. 계단식 냉각법(step cooling)를 통하여 시편을 제조 하였고, EPMA를 이용하여 시편의 미세구조를 관찰하였다. 열전소재의 상분리를 유도하기 위하여 $700^{\circ}C$에서 용융 후 3일 동안 $400^{\circ}C$로 유지시킨 후 상온까지 용융로에서 서냉하였다. EPMA를 이용하여 제조된 시편의 미세구조와 정량 분석을 하였고, 각 상의 결정구조 확인을 위하여 XRD 분석법을 이용하여 다결정의 PbTe와 $Bi_2Te_3$ 그리고 준안정상인 $PbBi_2Te_4$가 관찰 되었다. 계단식 냉각법을 통한 시편의 열전특성을 측정하였다. 이를 통하여 제조된 시편은 급속 냉각법으로 제조된 시편과 비교되었으며, 제벡계수는와 열전도도는 상온에서 각각 약 -100mV/K와 0.9W/mK로 약90%, 40%의 열전특성 향상을 확인하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.369-374
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• 2010

최근 건설 산업에서 BIM이 각광 받으면서, BIM 기반의 다양한 엔지니어링 기술 도입 및 프로세스 적용이 시도 되고 있다. 이중 BIM 기반의 프로젝트 운영을 위해서는 BIM의 데이터의 저장, 수정, 배포뿐만 아니라, 관련 주체간의 협업이 가능한 환경이 요구되고 있으며, 이러한 환경 구축을 위해 제조업에서 활용되고 있는 PDM(Project Data Management) 또는 PLM (Product Life-cycle Management) 시스템을 벤치마킹한 CPLM (Construction Project Life-cycle Management)과 같은 BIM 기반 협업 시스템이 등장하고 있다. 하지만 기존의 이러한 협업 시스템의 경우, 건설 프로젝트가 가지는 다양한 계약 방식, 관리 단계, 관련 정보의 체계 등에 대한 종합적 계획 없이 프로젝트의 각 참여 주체들의 기존 관리 방식을 도입함으로써, 당초 BIM 기술을 도입하여 달성하고자 하는 원활한 협업 환경을 구축하는데 한계를 가지고 있다. 따라서 본 연구에서는 최근 BIM 가이드라인의 도입 등에서 시도되고 있는 BIM Planning이라는 개념을 활용하여, BIM 기반 협업 시스템의 구축 이전에 BIM을 관리하기 위한 관리 구조, 방식, 데이터 체계 등을 효과적으로 계획하고, 이를 시스템에 반영시킴으로써 보다 효과적인 BIM 기반 협업 환경이 구축될 수 있는 체계를 제안하였다.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1762-1764
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• 2003

변압기의 이상 징후를 조기에 검출하여 사고를 미연에 방지하기 위해 설치된 예방진단시스템은 현재 국내 9개 변전소에서 운영되고 있다. 이러한 예방진단시스템의 적극적인 활용을 위해서는 시스템을 구성하는 각 요소에 대한 신뢰성 검증과 주기적인 점검, 축적된 데이터의 분석을 통한 사고예방 검출 사례의 축적이 요구되고 있다. 변압기 예방진단시스템의 가장 중요한 항목인 유중가스 측정기는 변압기 드레인 밸브에 설치됨에 따라, 변압기 내부 절연유가 유중가스 측정기로 유동되는지에 대한 의문이 존재하여 왔다. 본 논문에서는 유동해석 프로그램인 Fluent 5.3과 Gambit 프로그램을 이용하여, 변압기 내부의 열에 의한 대류현상에 의해 순환하는 절연유가 좁은 파이프를 통하여 유중가스 측정기의 삼투막까지 도달하는 유동현상을 해석하였다. 유동해석 결과 절연유가 삼투막과 만나는 지점에서도 절연유의 유동에 의한 순환이 발생하여, 용존가스의 검출이 가능함을 알 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1153-1160
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• 2012

This study was intended to implement ankle joint dorsi flexion training against ankle muscule strength weakening that erodes stroke patients' gait performance to examine the effect of the training on stroke patients' plantar pressure and gait ability. In this study, 36 stroke patients diagnosed with stroke due to cerebral infarction or cerebral hemorrhage were divided to measure 10MWS which are stroke patients' gait variables maximum plantar pressure by area of the sole by collecting data using an F-scan system during gait. Given these results of the study, compared to other training groups, the ankle muscule strength reinforcing training group showed statistically significant increases of maximum plantar pressure in the great toe, the toe and the first metatasal areas too and thus it can be said that this training increases forward thrust during stroke patients' foot end taking off and positively affects stroke patients' ability to perform gait.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.608-611
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• 2004

Efficiency of the construction process is one of the most important factors to project success. However efficiency is not well defined or measured in construction projects in general. More importantly, efficiency of the construction should be viewed through the life-cycle of the whole production system not in a single phase of the construction process. Therefore, this study defines the concept of efficiency and suggests the efficiency measurement model in construction. As a case study, the suggested model was applied to the curtain wall construction process of the high rise buildings as well.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.612-615
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• 2004

Today, the curtain wall is used in many construction projects because of excellent economical efficiency and constructability. The life-cycle process of curtain wall construction consists of the architectural design, curtain wall design, manufacturing, const겨ction, and maintenance phase which has become one of the most important objects that have to be managed. Since the general management method focused on each separated phase, it has accompanied many problems such as increases of the cost and duration, and loss of productivity. To solve these problems, it is necessa교 to have a new management method based on supply chain management. Thus this research analysed the processes of stick system, semi-unit system, unit system, and panel system classified by the type of the curtain wall, and suggested proper methods of application of SCM concept to each type of curtain wall construction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.317-326
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• 1994

Panoramic radiographs of a dry skull were used to evaluate the accuracy of four panoramic dental X-ray systems in determining tooth angulations in the buccal segments. The four machines evaluated were the Philips Oralix Pan DC, the GE panelipse, the SS White panorex 1, and the SS White Panorex 2. Panoramic radiographs were taken at six different patient positions for each machine to evaluate the effects of patient positioning on determining tooth angulations in the buccal segments. All of the machines studied showed a significant correlation between the mean radiographic estimates and the actual measurements regardless of positioning(p<0.05). With correct placement of the skull, the results were analyzed for an error tolerance of +/-3/sup 0/ between the actual measurements and the radiographic estimates for tooth angulation. The SS White Panorex 1 was accurate 74% of the time, the GE Panelipse was accurate 67% of the time, the Philips Oralix Pan DC and the SS White Panorex 2 were accurate 64% of the time. When an error tolerance of +/-5/sup 0/ was permitted, the accuracy was 89% for the SS White Panorex 1 and the GE Panelipse, 85% for the Philips Oralix Pan DC, and 81% for the SS White Panorex 2.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.159-169
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• 2008

Recently, domestic construction projects Have become more high-rised, bigger, sophisticated, so necessity of logistics and progress management through application of various management theories has also been increased and development of IT technologies like RFID can help to improve management method, although the existing logistics and progress management studies are applied only to single progress or important material. It is a basic research for integrated framework for logistics and progress management. An analysis on the characteristics of RFID tech was performed for major materials or components of each work item in office building projects. This paper will make foundation of integrated framework for logistics and progress management in construction project, utilizing RFID technology by analysing materials type like materials which can be chased and measured, materials which can be chased and measured by certain methodologies, materials which can be chased and measured by future technologies, materials which are difficult to be chased and measured. So we can effectively control logistics and progress management, appling the optimum RFID technology to each construction project, and we need to study out solution in order to overcome RFID technology limitation through development of specification counterproposal about delicate materials of the RFID technology application.