• Journal of Information Technology Services
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• v.9 no.4
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• pp.123-133
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• 2010

There are many occasions on which the critical decisions should be made in software projects. Those decisions are basically related to estimating and predicting project parameters such as costs, efforts, and duration. The project managers are looking for methods to make better decisions. The decisions about project parameters are recommended to be performed based on historical data of Similar projects. The measures of the tasks in past projects may have different shapes of distributions. we need to add those measures to get a predicted project measures. To add measures with different shapes of distribution, we need to use Monte Carlo Simulation. In this paper, we suggest applying Monte Carlo Simulation for supporting decision makings in software project. We implemented best-fit case and scheduling estimations with Cristal Ball, a commercial product of Monte Carlo simulation and showed how the suggested approach supports those critical decision makings.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.491-494
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• 2006

최근 국내에서도 IT 프로젝트 관리의 중요성이 대두 되고 있으나, 중소규모의 프로젝트를 관리 함에 있어서 PMBOK(Project Management Body Of Knowledge)의 프로젝트 관리 이론과 PERT/CPM(Program Evaluation and Review Technique/Critical Path Method)과 같은 관리 기법들을 이용한 효율적인 프로젝트 평가 및 관리 사례는 많지 않는 실정이다. 철저한 프로젝트 관리를 위해서 소요되는 추가적인 인적 및 시간적 자원에 대한 투자가 현실적으로 어려우며, 평가 기준이나 기법들이 너무 복잡하고 난해한 것이 주된 원인이라 생각된다. 이 논문은 이러한 현실적인 상황을 고려하여, 중소규모의 IT 프로젝트에 적용하기 쉬우면서 효율적으로 활용할 수있는 시간과 인적자원에 대한 일정 시뮬레이션 모델을 통해 프로젝트를 평가하는 정량적 기준을 제공하고 이를 통해 프로젝트의 성공적 완수를 돕는데 의의가 있다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.125-127
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• 2007

MoN 코팅막은 Ar과 $N_2$가 섞인 가스 상태 안에서 몰리브덴(Mo) 타겟을 사용해서 아크 이온 플레이팅법을 사용하여 stainless steel 표면 위에 증착을 시켰다. MoN 코팅막의 미세 결정 구조의 특징은 X-선 회절 분석(X-ray Diffractormeter, Phillips co. X'pert)과 XPS를 사용해서 측정하였다. MoN 코팅막은 순수 Mo 코팅막의 13GPa 보다 높은 25 GPa의 미세경도값을 나타냈으며, 또한 Mo 코팅막에 N의 함량이 증가할수록 마찰계수가 낮아지는 것을 알 수 있었다. 이번 연구에서는 MoN 코팅막에서 질소 함량을 변화 시켜 MoN 코팅막의 미세구조와 그 특성에 대하여 연구하였다.

• Journal of Technology Innovation
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• v.12 no.3
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• pp.111-134
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• 2004

Current technology innovation or new product development project is composed of various process elements that conduct researches on fundamental technologies. However, with the effects of PERT and CPM, the greater part of the existing project management researches have only focused on the resource allocation and scheduling. But in the multi-project environment, priorities between technology elements need to be considered. Furthermore, a disagreement of opinion between project managers and researchers should be considered. In this study, technology element priority was determined using modified QFD and Taguchi method. Outcome of each method was compared to analyze the difference between project managers and researchers. As a result, QFD method showed relatively high level of consistency between project managers and researchers.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.902-907
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• 2005

This study was undertaken to develop a comprehensive scheduling method which applied the core concept(DBR) of TOC to PERT, and to combine Monte Carlo Simulation to revise the uncertainties of activities then to eliminate project duration uncertainty. Most of the project duration overlooks the fact that in spite of minimizing the project duration, the uncertainty of constrained resources still puts the reliability of project duration in jeopardy. For the contractor, however, the most important thing is to comply the project scheduling with the planning to reduce the uncertainty of the project activities, operational interaction and project duration. In order to demonstrate that the model can be used in construction project, the scheduling of a steel-structure project was used as a case study to verify the validity of this model.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.366-370
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• 2005

The construction environment is dynamic in nature and is characterized by various degrees of uncertainties. The uncertainties such as lack of coordination, non availability of resources, condition of temporary structures and varying weather conditions have a significant impact on estimating the duration of activities. These are subjective, vague and imprecisely defined and are expressed in subjective measures rather than mathematical terms. Conventionally, various quantitative techniques such as CPM and PERT have emerged in construction industry. These techniques cannot solve the above problems and rely on human experts which may not always be possible. In such situations Artificial Intelligence tools such as fuzzy sets and neural networks handle such variables and provide global strategies. The present paper evaluates the effect of qualitative factors to identify the activity duration using new intelligent approach. The results are compared with conventional methods for effective project management. A case study is considered to demonstrate the applicability of fuzzy logic for project scheduling.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.744-747
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• 2005

The AEC (Architecture/Engineering/Construction) industry is facing a competitive world after it entered into the 21^st century. Due to improper planning and scheduling, the construction projects face severe delays in completion. Most of the present day construction organisations operate in multiple project environments where more than one projects are to be managed simultaneously. But the advantages of planning and scheduling as multiple projects have not been utilized by these organisations. Change in multi-project planning and scheduling is inevitable and often frequent, therefore the traditional planning and scheduling approaches are no more feasible in scheduling multiple construction projects. The traditional scheduling tools like CPM and PERT do not offer any help in scheduling in a resource-constrained environment. This necessitated a detailed study to model the environment realistically and to make the allocation of limited resources flexible and efficient. This paper delineates about the proactive model which will help the project managers for scheduling the multiple construction projects.

• International conference on construction engineering and project management
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• 2005.10a
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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.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.68-74
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• 2007

Critical Chain Project Management(CCPM) is a new project management system paradigm which maintains the advantages of PERT/CPM and improves the shortcomings of it. In CCPM the task durations are determined as 50% time estimates, ie average time discarding the their contingency. CCPM determines the critical chain the constraint of a projects considering the logical precedence relationship and resource conflict resolution. Project buffer is located at the end of critical chain to absorb the variations of critical chain. The size of project buffer is usually calculated as the half of the sum of critical chain length. Also feeding buffer is inserted after each non-critical chain which feeding into the critical chain to prevent the time delay of critical chain from uncertainties of non-critical chains. Resource buffer can be utilized to improve the availability of resources of critical chain. Buffer management is a project execution and control mechanism. Buffers are classified into 3 zones. They are OK zone, Watch and Plan zone and Expediting zone. If the project status is within Watch and Plan zone, contingency plan is established. And if it changes into Expediting zone, the preplanned contingency plan are executed to recover the time delay. In CCPM the workers are asked to work with relay runner work mechanism that they work fast if possible and report their completion to project manager for the succeeding task to start as soon as possible. The task durations are not considered as the promised time schedule. The multi-tasking is prohibited.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.41-41
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• 2009

본 연구에서 사용한 대향 타겟식 스퍼터링(Facing Targets Sputtering) 법은 일반 스퍼터링 법의 단점을 보완한 고밀도 저온 고속성막이 가능한 장점을 가지고 있기 때문에 플랙시블 디스플레이의 기체 투과 방지막으로 많이 쓰이고 있는 SiOxNy, SiOx, SiNx의 박막을 다층으로 증착하여 polymer 기판 위에 조건에 따라 증착 후 박막의 특성을 연구하였다. 제작된 박막의 광학적 특성을 UV-VIS spectrophotometer(Shimadzu Co.)를 사용하여 200~1100nm의 파장 영역에서 광 투과도를 측정하였으며 박막의 두께와 균일도는 $\alpha$-step(Veeco Co.)을 사용하여 측정하였고, 절대 정량이 가능하고 비파괴 분석법인 RBS(KOBE STEEL LTD.)를 이용하여 표면의 성질을 규명하고 XRR(PANalytical X'Pert PRO)을 분석하여 박막의 계면영역에 대한 물성 변화를 평가하고 박막의 밀도를 측정하였다. SEM(Digital Instrument Co.) 사진을 통해 단면과 표면을 관찰하였고 구조적 특성은 AFM(Digital Instrument Co.)와 XRD(Rigaku Co.) 통해 측정하였고 박막의 성분비는 EDS(JEOL Co.)를 사용하였으며 투습률 측정장치 (MOCON)을 이용하여 WVTR를 측정하였다.