• 산업경영시스템학회지
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• 제3권3호
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• pp.13-22
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• 1980

Research and Development has a property that involves uncertainity and risk in itself. Therefore, in order to scheduling of R & D activity, it Is needed of a certain probabilistic network technique with due regard to feedback process used to occur in the R & D proceeding. It is GERT that was developed as the need arises . In this study, the network structure of GERT-I and GERT-II was combined and then simulation analysis was used to it. According to that analysis , an advanced GERT model which covers the following stochastic problems was examined. 1 Evaluating success feasibility under the complex condition (time and cost). 2 Selecting acceptance range for the worst. 3. Selecting optimum path on basis of time, cost and success. 4. Evaluating project utility among the project alternatives. It is for managing R&D projects more effectively.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.791-795
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• 2005

A simulation model is proposed to evaluate the effect of correlations between activity durations on the overall project duration. The proposed model incorporates NORTA, a recent developed statistical method, into the simulation process to allow arbitrarily specified marginal distributions for activity durations and any desired correlation structure. The generality is of practical value when systematic data is not available and planners have to rely on arbitrary experts' estimation, which may involve a mixed situation when some activity durations are continuously distributed whereas others are discrete outcomes. The proposed model is validated by showing that the correlation coefficients of the simulation results are close to the originally specified ones. The simulation results are compared to two conventional approaches: PERT and simulation without correlation. The comparisons illustrate that the proposed model can provide important management information, which would otherwise be distorted due to the neglect of the correlations between activity durations.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.111-113
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• 2015

Floats are used by the parties involved in a construction project. The owner may use float by changing order(s) or by executing risk avoidance plan; the contractor may use it for leveling resources or substituting activities' construction methods to reduce costs. Floats are accepted either just as by-product obtained by critical path method(CPM) scheduling or as asset having significant value. Succinctly, existing studies involved in float value does not consider its' changes on project time domain. It is important to identify float ownership and to quantify its' corresponding values. This paper presents a method that quantifies float value of money that changes over project execution. The method which accurately computes the monetary value of float may contributes to resolve conflicts relative to float ownership and/or delay issues among project participants. It compares the difference between the monetary value of total float - on non-critical path in each and every schedule update. It makes use of critical path method (CPM) and commercial software with which practitioners are already familiar.

• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4791-4796
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• 2016

Objectives: The purpose of this investigation was to examine the association between endometrial cancer and possible etiological agents. Methods: A case-control study was conducted in Iran between March 2012 and May 2016. The demographic and reproductive factors of 205 women with endometrial cancer were compared, and 590 healthy cases were participated in the control group. For each endometrial cancer case, there were three controls, who were matched in terms of age and residence. The data were considered significant at $p{\leq}0.05$. Results: After adjusting the variables, the nulliparity (OR 6.23, 95% CI 2.86-13.59), the nulligravidity (OR 5.94, 95% CI 2.51-14.06), the positive family history of reproductive cancer (OR 4.97, 95% CI 2.33-10.59), the infertility history (OR 2.38, 95%CI 1.32-4.31), the obesity ($BMI{\geq}25$) (OR 1.71, 95% CI 1.16-2.52), the early menarche age (<12 years) (OR 2.10, 95% CI 1.17-3.75), and the hormonal contraception use (OR 1.69, 95% CI 1.15-2.49) were found to be associated with an increased risk of endometrial cancer. Nevertheless, the education level, the job of women, the marital age, the leisure activities, and the breast feeding were not found to be associated with the endometrial cancer after adjusting the variables. Conclusion: Scheduling of the screening program is vitally indispensable to identify endometrial cancer in women with nulliparity, nulligravidity and the positive family history of cancer. In addition, women with early menarche, those with the history of infertility, the obese ones, and those who use contraception pills need to be particularly aware of the potential risks.

• 한국건설관리학회논문집
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• 제6권2호
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• pp.92-101
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• 2005

초고층 건축물은 층수의 증가에 비해서 공기의 증가가 작기 때문에 공기초과가 발생하기 쉽다. 최근 초고층 프로젝트의 증가에 따라 공정계획의 중요성이 증대되고 있으며 공정관리를 개선하기 위해서 공정계획 소프트웨어의 도입과 교육이 활발히 이루어지고 있다. 하지만 공정계획의 많은 부분은 아직도 계획자의 경험에 크게 의존하고 있다. 따라서 새로운 자재, 장비 및 공법이 도입되는 초고층 프로젝트는 공정 계획자의 경험이 부족할 경우, 경험 미숙으로 인한 공기초과가 발생하기 쉽다. 공정 계획자의 경험 미숙으로 인한 공정계획의 편차를 줄이기 위한 방안으로 본 연구에서는 전문가의 경험적 지식을 초고층 공정계획 작성에 활용하는 방안을 제안하였다. 사례연구에서는 초고층 골조공종을 대상으로 하여 본 연구에서 제안한 초고층 공정계획 지원시스템의 지식획득과 지식활용방안을 고찰하였다. 본 연구에서 제안한 지식획득과 지식활용을 토대로 초고층 공정계획 지원시스템을 구축하여 활용한다면 초고층 공정계획의 정확성을 높일 수 있으며 공기초과를 예방할 수 있을 것이다.

• 한국추진공학회지
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• 제2권1호
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• pp.13-20
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• 1998

다목적으로 활용할 수 있는 터보축엔진의 개발을 위한 정상상태 및 동적모사 프로그램을 개발하였다. 개발비, 개발시간, 개발위험도의 절감을 위해 가스발생기 부분은 성능이 잘 알려진 기존의 터어보제트 엔진을 활용하였으며 수명연장을 위해 터빈재질을 교체하고, Larson-Miller 곡선을 이용하여 약 3000hr 이상의 수명을 확보하기 위한 최대회전속도와 최대 터빈입구온도를 결정하였다. 추가되는 동력터어빈의 구성품 성능선도는 압축기 터어빈의 성능선도를 축척하여 사용하였다. 정상상태 성능해석에는 유량 및 일평형 방정식을 이용하였으며, 가스발생기와 동력터빈의 공회전 상태에서부터 최대 회전속도까지 동력터빈은 10% 간격, 가스발생기는 5%RPM 간격으로 해석하였다. 동적모사시에는 일정유량평형방법(Constant Flow Method : CMF)을 이용하였으며, 급 가속의 상황을 가정하고 연료유량이 Step 증가하도록 Scheduling 하였다. 이 때 터빈 입구온도에 오버슈트가 발생하여 제한온도를 초과하는 것을 확인할 수 있었다.

• 한국전문물리치료학회지
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• 제17권1호
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• pp.53-61
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• 2010

This study investigated the relationships between Work-related musculoskeletal disorders (WMSDs), contributing factors, and the occupational stress of physical therapists. Self-reported questionnaires were given to 180 physical therapists in Gangwon Province. Variables examined included the prevalence of pain sites related to WMSDs; pain intensity; pain pattern; and job stress, which is thought to involve the physical environment; job demand; insufficient job control; interpersonal conflict; job insecurity; organizational system; reward system; and occupational culture. Among physical therapists, work-related musculoskeletal pain commonly affected the low back (30.1%), shoulder (29.3%), and wrist (12.2%). The sites of work-related musculoskeletal pain treated medically were the low back (22.8%), shoulder (19.8%), neck (12.7%), and wrist (12.1%). "Repeating the same work constantly" was suggested to be the major cause of the pain. The younger therapists were significantly more likely to feel high job stress due to the physical environment (p<.05), job demand (p<.05), and organizational system (p<.01). Women were more likely to feel greater job stress related to job demand, insufficient job control, the organization system, and job rewards. Men were more likely to feel greater job stress related to job insecurity. Weak positive relationships were observed between work-related musculoskeletal pain and job stress, which is thought to involve the physical environment; job demand; insufficient job control; interpersonal conflict; job insecurity; organizational system; reward system; and occupational culture. Physical therapists appear to be at higher risk of WMSDs because 80.1% of the physical therapists studied experienced work-related musculoskeletal pain. To reduce the risk, we need intervention strategies such as preventive education, ergonomically designed medical equipment, a psychosocial approach to work conditions, improved mechanical conditions related to therapeutic patterns, and an institutional infrastructure with sufficient personnel and scheduling.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.509-512
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• 2003

Critical Path Mettled(CPM)은 공정을 계획하고 관리하는데 효과적인 도구이다. CPM의 장점 중 한 가기는 여유시간(Float)을 계산할 수 있다는 것이다. 여유시간은 프로젝트 전체의 공기에 영향을 주기 않고 연장할 수 있지만 공정관리 상의 부산물이기 때문에 소유권에 대한 개념과 범위가 명확하지가 않다. 때문에 사업참여자들이 여유시간을 사용할 때에는 이해관계가 얽혀있어 많은 분쟁을 일으켰다. 이를 해결하기 위해 여유시간 분배와 소유권에 대한 연구가 진행되어 왔으나 여유시간 분배의 기준을 전체 공정에 대한 비율에 두고 있어 합리적인 분배가 이루어지기 못했다. 따라서 본 연구에서는 여유시간 활용목적에 대해 분석한 결과를 기반으로 하여 여유시간 분배 기준을 공기지연 리스크로 제시하였고, 소유권의 개념을 적용시키기 위해 사업참여자 주체별로 공기지연 리스크인자를 구분하였다. 또한 공기지연 리스크인자가 전체 공정에 대해 일률적으로 영향을 끼치는 것이 아니기 때문에 공종에 따라 공기지연 리스크인자들의 영향력을 평가하기 위한 Framework을 구축하였고, 평가를 위한 방법과 기준을 활용할 수 있는 분배방법을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.364-365
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• 2011

This study develops a new system for generation system simulation and operational planning (namely, KPWR-X) including GMS(Generator Maintenance Scheduling), UC(Unit Commitment), and LF(Load Forecasting) for new power system environment in recent. The KPWR-X provides operator and planner to help the generation system more safely and economically. GUI developed in this study makes operator feel in convenient to control whole power system. In future, it is expected that generation company, ISO, and fuel procurement, etc. may use an instructional tool developer's suggestion for application. It will be also applicable to establish the operational strategies for generation control, fuel procurement and power system risk management.

• 산업경영시스템학회지
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• 제35권2호
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• pp.212-219
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• 2012

This study focus on what methods of MOT are needed and utilized to solve a technical problem in the MOT leading company. We first classified the MOT methods by project life cycle and R&D job quality based on the several discussion with working group. In order to study, the survey was carried out by 168 experts working on MOT practices. Our main research findings are as follows. The level of utilized MOT methods was above average because MOT sector was beginning to represent an increasing share of total R&D business. But the satisfaction level on the MOT majors was below average. The more utilized MOT methods in practices were 'environment analysis and opportunity research,' 'business feasibility,' 'roadmapping,' 'portfolio,' 'technology tree,' 'scheduling,' 'risk management,' 'six sigma,' 'design of experiment,' 'quality control,' 'cost analysis' etc. And the subjects of product realization process were also needed to MOT practice such as 'design for reliability,' 'design for cost,' 'design for performance,' 'design for safety' deeply involved to product quality. Finally, the capability requested to University students were 'problem define and solving,' 'technology planning and strategy,' 'creative thinking.'