• 한국BIM학회 논문집
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• 제5권2호
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• pp.1-11
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• 2015

Despite a lot of research on BIM, there is no quantitative study to measure accurately the performance of BIM coordination service. Thus, this study suggested method to measure the performace of BIM coordination services, applying queueing models in the field of management science. To analyze queuing system of BIM coordination services, a group of BIM coordinator were selected. Through focus group interviews with experts were used in the analysis to derive mean arrival rate(${\lambda}$), mean service rate(${\mu}$) of BIM coordination services. Single-server queuing model(M/M/1), multiple server queuing model(M/M/s) is utilized for the BIM coordination services performance measurement in construction phase. This study has significant quantitative performance measurement approaches that can be utilized in the decision-making for the improvement of the BIM coordination services and to support the review of the alternatives accordingly. But There is a limit but it is difficult to take into account the increase or decrease of the cost of alternatives according to the review.

• 상하수도학회지
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• 제11권1호
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• pp.21-32
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• 1997

Optimum design of water distribution network(WDN) in many times means just reducing redundancy. Given only a few situations are taken into consideration for such design, WDN deprived of inherited redundancy may not work properly in some unconsidered cases. Quantifying redundancy and incorporating it into the optimal design process will be a way of overcoming just reduction of redundancy. Expected shortage is developed as a reliability surrogate in WDN. It is an indicator of the frequency, duration and severity of failure. Using this surrogate, Expected Shortage Optimization Model (ESOM) is developed. ESOM is tested with an example network and results are analyzed and compared with those from other reliability models. The analysis results indicate that expected shortage is a quantitative surrogate measure, especially, good in comparing different designs and obtaining tradeoff between cost and. reliability. In addition, compared other models, ESOM is also proved useful in optimizing WDN with reliability and powerful in controlling reliability directly in the optimization process, even if computational burden is high. Future studies are suggested which focus on how to increase applicability and flexibility of ESOM.

• Structural Engineering and Mechanics
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• 제56권4호
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• pp.695-705
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• 2015

Distressed structures require necessary remedial measures in order to restore their original structural properties like strength and stiffness. Validating the effectiveness of the proposed qualitative remedial measure experimentally is of utmost importance as there is no well-established analytical method to verify the effectiveness of the same quantitatively. Prototype testing which would have been the best option for this purpose would not only prove costly but also be associated with numerous practical difficulties; hence model testing is resorted as the only option for the purpose. This paper presents one such typical experimental study on the structural behavior of a distressed bridge, mainly observed in the form of prominent tilt in the bearing plate in transverse and longitudinal direction on downstream side. The main focus of the proposed experimental investigation is to assess the structural behavior particularly the load carrying capacity. The extent of deformation of some models with specific structural arrangements and some models with specific need based remedial measures were also studied. This study also assessed the contribution of each remedial measure towards restoration individually and collectively.

• 시스템엔지니어링학술지
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• 제6권1호
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• pp.33-39
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• 2010

Anti-surface missiles have been the most dangerous threat to the surface ships, therefore analyzing the defense effectiveness of surface ships against diverse anti-surface missiles attack strategies is very important to evaluate and anticipate the naval combat ship's abilities in terms of AAW (Anti-Air Warfare). In this paper, we don't study on the defense effectiveness of a ship against a missile, but focus on the defense effectiveness for surface ships against multiple missiles specialized in strategies of anti-surface missiles; ripple fire attack and simultaneous time on target attack (STOT). So, we conduct a variety of monte-carlo simulations with high-fidelity simulators, analyze the measure of defense effectiveness for the key factors of strategies and evaluate the effects and possible interactions of several factors through the analysis of the design of experiment (DOE).

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.295-298
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• 2009

Bent duct 는 손실을 가중시키고, 효율을 저하시킨다. 지금까지 bent duct에 대한 많은 연구가 진행되었지만, 입구와 출구가 같은 형상에 대해서 연구가 되어왔다. 이번 연구에서는 입구는 환형이지만, 출구는 원형을 가진 bent duct에 대해서 진행되었다. 입구 속도 54 m/s, 레이놀즈수 238,000에서 수행된 이번 연구에서는 bent duct 바깥에 태핑홀을 배치하여 정압분포를 확인하고, 입구와 출구에서 5공 프로브로 유동을 측정하여 스트림 방향 속도 프로파일과 전압 손실 계수를 얻었다. 본 연구에서는 전압 손실 계수, 0.243를 얻었다.

• 가정과삶의질연구
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• 제9권1호통권17호
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• pp.241-257
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• 1991

The objectives of this study are : to measure the level of rent burden. to examine the independent influences of the variables related to rent burden. to measure the level of family economic problem perception. to examine the differences in the level of family economic problem perception due to rent burden, household characteristics, housing characteristics and rent incresing. For these purpose, a survey is conducted using questionaires. The data used in this study included 369 renters living in Seoul. Statistics uses for data analysis were Frequency Distribution. Percentile, men, Pearson's Correlation, Partial Correlation, One-way ANOVA, Breakdown and Multiple Regression Analysis. Major findings are as follows : The average score of rent burden was 35.87, Therefore rent burden of large cities, rental households is very heavy. Family income, housing facility quality, rent type, and rent incresing have independent influences on rent burden. The average of family economic problem perception is above the mid-point of the scale. The level of family economic problem perception differs due to rent burden, family income, family life cycle, family size, occupation of household head, education leval of household head and homemaker, rent type, housing type, housing size, housing facility quality and rent increases. If the level of rent burden is below 25, family economic problem perception is adequate.

• The Journal of Asian Finance, Economics and Business
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• 제7권8호
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• pp.645-651
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• 2020

The concept of social entrepreneurship (SE) is gaining attention in developing economies for the purpose of greater societal welfare maximization. Still, findings in the field of SE studies have been riddled with conflicting results and counterstatement. Also, the determinants of developing SE are not robustly investigated in developing economies like Bangladesh. This context has mobilized the authors of this current study to focus on determining student's intention to pursue SE as their career choice. Hence, the study aims to examine the predictive determinants of social entrepreneurial intentions (SEI) among Bangladeshi students. The study has investigated the influence of entrepreneurial self-efficacy, social support, prior experience, and educational support on SEI. The survey was conducted from a public university of Bangladesh, and 231 students participated in the study. Questionnaire items under each construct variable have been adopted from pre-tested research studies. Five-point Likert scale questionnaire was applied to measure the variables. SPSS version 23.0 has been used for statistical analysis through which correlation and multiple regression analysis were conducted to measure the impact of the independent variables on SEI. Results exhibited that self-efficacy, social support, and educational support positively and significantly predicted SEI, while prior experience does not influence SEI.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.252-257
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• 2004

Nanometer-sized structures are being applied to many devices including micro/nano electronics, optoelectronics, quantum devices, MEMS/NEMS, biosensors, etc. Especially, the thin film with submicron thickness is a basic structure for fabricating these devices, but its mechanical behaviors are not well understood. The mechanical properties of the thin film are different from those of the bulk structure and are difficult to measure because of its handling inconvenience. Several techniques have been applied to mechanical characterization of the thin film, such as nanoindentation test, micro/nano tensile test, strip bending test, etc. In this study, we focus on the strip bending test because of its high accuracy and moderate specimen preparation efforts, and measure Au thin film, which is a very popular material in micro/nano electronic devices. Au film is deposited on Si substrate by evaporation process, of which thickness is 100nm. Using the strip bending test, we obtain elastic modulus, yield and ultimate tensile strength, and residual stress of Au thin film.

• 디지털융복합연구
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• 제8권4호
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• pp.205-213
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• 2010

오늘날 정보자원관리는 정보시스템 조직에 있어서 매우 중요한 요소이다. 따라서 민간부문 뿐만 아니라 많은 공공기관 역시 정보자원에 대한 관리를 강화하고 있다. 특히, 이러한 정보자원관리의 핵심 요소 중 하나가 서버의 성능관리이다. 따라서 서버의 성능을 결정하는 것은 서버의 구매조직에 있어서 중요한 이슈이다. 본 논문에서는 공공부문 정보화사업을 중심으로 서버의 성능측정 및 검증, 성능 측정 관련 국내 현황, 통합전산센터의 사례들 토대로 공공부문의 도입서버의 성능측정 및 검증 관련 이슈와 문제점 등을 살펴보고 성능측정 및 검증 관련 이슈와 문제점에 대한 해결방안으로 서버 성능에 영향을 미치는 요소를 재시하였으며, 아울러 공공부문의 환경적 요인을 고려한 서버의 성능측정 및 검증방안을 제시한다.

• 전자공학회논문지 IE
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• 제47권1호
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• pp.48-55
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• 2010

본 논문은 특정목적의 수행을 위해 설계될 임베디드 플랫폼의 효율적인 선택에 관하여 다룬다. 특히, 영상 및 음향 신호 처리를 통해 실시간 상황인지를 목적으로 하는 차량 시스템을 예로 들어 설명한다. 실험을 위하여 검증된 성능평가 프로그램들 중에서 응용목적에 맞는 프로그램을 선택한 후 시뮬레이터를 사용하여 ARM7, ARM9, ARM10 프로세서 코어를 기준으로 코드 및 데이터 메모리 크기, 명령어 수, 실행 사이클을 측정하였다. 이 연구에서 제안된 방법으로 특정목적을 수행하기 위한 하드웨어 최소사양이 측정 가능하였으며, 이 결과는 설계 및 구현에 많은 시간이 소요되는 임베디드 시스템의 설계단계에서 시스템의 목적 수행에 필요한 플랫폼 사양을 도출하여 효율적인 플랫폼선택의 기준을 제시하는 것이 가능함을 보였다.