• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.139-147
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• 2005

During a typical construction project, a contractor nay often find that the time originally available or normally expected to perform its work has been severely reduced. To finish the project by the completion date, the contractor is forced to find a way to speed up the progress of its work to compensate for the reduction in available time. The most frequent initial reaction of contractors to this situation is to increase on-site manpower by working longer time (overtime), adding more workers (overmanning), or implementing shift work (shift work) to increase the rate of progress. The goals of this study were to investigate how these three methods affect labor productivity and to quantify their impact on labor productivity by analyzing real project data collected from sheet metal contractors and mechanical contractors in the US.

• Journal of applied mathematics & informatics
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• v.20 no.1_2
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• pp.119-132
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• 2006

This paper presents an approach for using right-truncated exponentially distributed random variables to model activity times in stochastic activity networks. The advantages of using the right-truncated exponential distribution are discussed. The moments of a project completion time using the proposed distribution are derived and compared with other estimated moments in literature.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.343-352
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• 1993

In this study, a modified algorithm for the exchange heuristic is developed and applied to a resource-constrained scheduling problem. The problem involves multiple projects and multiple resource categories and allows flexible resource allocation to each activity. The objective is to minimize the maximum completion time. The exchange heuristkc is a multiple pass algorithm which makes improvements upon a given initial feasible schedule. Four different modified algorithms are proposed. The original algorithm and the new algorithms were compared through an experimental investigation. All the proposed algorithms reduce the maximum completion time much more effectively than the original algorithm. Especially, one of four proposed algorithms obviously outperforms the other three algorithms. The algorithm of the best performance produces significantly shorter schedules than the original algorithm, though it requires up to three times more computation time. However, in most situations, a reduction in schedule length means a significant reduction in the total cost.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.125-129
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• 2010

The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.542-549
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• 2005

Naval ships are complex weapon systems which play the integrated performance by system integration of many kinds of weapon systems and their leading ships are usually not disposed after test and evaluation but militarised. Then, strict project management is required for naval ship building projects by identifying problems early and by taking prefer measures in time against unexpected situations encountered in the process of the projects. EVMS is a project management system which can manage the schedule and the budget of a project concurrently and estimate the project's time duration and the cost at project completion. In this paper, the applicability and usefulness of WMS is studied for a assumed navai ship building project, in the environment of monetary fluctuations such as price index, wage increase rate and exchange rate.

• Industrial Engineering and Management Systems
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• v.11 no.4
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• pp.397-405
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• 2012

This research proposes a framework of buffer management for multi-project systems in the critical chain project management (CCPM) method, expressed in the form of max-plus linear (MPL) representation. Since time buffers are inserted in the projects for absorbing uncertainties in task durations and protecting the completion times, the proposed method provides a procedure for frequently surveying the rates of consumed buffers and the rate of elapsed times. Their relation expresses the performance of the projects which is plotted on a chart through the completed processes. The chart presents the current performance of the projects and their interaction, which alerts managers to make necessary decisions at the right time for managing each project and the entire multi-project system. The proposed framework can analyze the complex system readily, and it enables managers to make an effective decision on scheduling. The effectiveness of the framework is demonstrated through a numerical example.

• Journal of the Korean Professional Engineers Association
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• v.43 no.4
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• pp.44-49
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• 2010

Th Rach Gia Bypass Project, to be implemented under EDCF Loan VNM-12, constitutes a strategically important part of the Greater Mekong Sub-region Southern Coastal Corridor Project(the GMS-SCCP). The main goal of the GMS strategy is to promote sustainable economic growth, improve employment, and achieve poverty reduction by tapping the comparative advantages of Vietnam, Cambodia and Thailand. As a project manager who once took a responsible position for the completion of RGBP's detailed design, I would like to briefly introduce what our design team including the local sub-contractors had performed for the D/Design of this Project last year, especially in the field of highway, bridge and soft soil treatment method widely used in Mekong Delta area. With the performance of nearly two Projects due to the V.O. in one year on the prescribed time, it was a hard year but a rewarding one. To expand our horizon more about overseas projects, several recommendations for the brighter future of overseas projects are shown herein this paper.

• Journal of the Korea Society of Computer and Information
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• v.21 no.9
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• pp.139-147
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• 2016

In recent, android application developments have been done widely that intensify smart phone utilization. In this paper, we propose a curriculum that undergraduate students can improve their mobile programming abilities as well as integrate experiences of application development based on android. And also a series of practices to advance their sense of accomplishment are added by offering an opportunity to carry out a real project to use a variety of sensors embedded in smart phone during the course of study. The project is composed of a series of modules for implementing a trekking App that helpful to people who enjoy spending time in outdoors through their favorite activities such as trekking, cycling, and climbing with their own smart phones. Through practical curriculum operation and project implementation, we show that the proposed curriculum is appropriate to a mobile programming education that combine learning and practice.

• Journal of Construction Engineering and Project Management
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• v.2 no.3
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• pp.40-47
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• 2012

Construction management is essential for a achieving any pre-determined objective. It is however seen that in spite of construction management, majority of the project do not keep up their original time schedule and their completion cost is also higher as compared with the estimated cost The main reason for overrun in time and cost is that the planning at the outset of the project was not adequate or method of planning was not a refined one. In this research work, I showed the overall conditions of construction work and management in Sylhet city of Bangladesh and found many drawbacks in the construction management after completing my research. I found several factors affecting proper construction management and I have provided brief results. I have also provided some recommendations after my research work.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.9-16
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• 2016

The project schedule risk in the engineering and facility construction industry is increasingly considered as important management factor because the risks in terms of schedule or deadline may significantly affect the project cost. Especially, the project-based operating companies attempt to find the best estimate of the project completion time for use at their proposals, and therefore, usually have much interest in accurate estimation of the duration of the projects. In general, the management of projects schedule risk is achieved by modeling project schedule with PERT/CPM techniques, and then performing risk assessment with simulation such as Monte-Carlo simulation method. However, since these approaches require the accumulated executional data, which are not usually available in project-based operating company, and, further, they cannot reflect various schedule constraints, which usually are met during the project execution, the project managers have difficulty in preparing for the project risks in advance of their occurrence in the project execution. As these constraints may affect time and cost which role as the crucial evaluation factors to the quality of the project result, they must be identified and described in advance of their occurrence in the project management. This paper proposes a Bayesian Net based methodology for estimating project schedule risk by identifying and enforcing the project risks and its response plan which may occur in storage tank engineering and construction project environment. First, we translated the schedule network with the project risks and its response plan into Bayesian Net. Second, we analyzed the integrated Bayesian Net and suggested an estimate of project schedule risk with simulation approach. Finally, we applied our approach to a storage tank construction project to validate its feasibility.