• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.75-82
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• 2002

This paper propose a new mathematical modelling method about optimum operational schedule for cogeneration systems. Proposed algorithm solving the energy product cost function in this paper is very similar to the real model that is, proposed algorithm solve nonlinear type of real model using mixed integer programming based on the piecewise linear function while the conventional algorithms used before could not solve that kind of problems. The effectiveness of the proposed method is ascertained by the simulation results with varius case studies which are similar to real operation circumstances.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.23-34
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• 2011

Reliable progress management at construction requires integrated information of cost and schedule, and information is used as a basis for project performance measurement. However, separate handling of cost and schedule information at construction projects makes objective measurement more difficult and decreases management productivity due to additional works for breaking down bill of quantities into corresponding activities. Recently, research related to BIM addresses issues on effective progress management based on BIM with incorporation of daily progress management. Therefore, the objective of this paper is to propose information model for daily progress rate and budgeted cost of work performed by utilizing BTM-based quantity and location information.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.58-67
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• 2005

To overcome limitations of test scope, schedule and cost, M&S(Modeling & Simulation) technique has been applied for T&E(Test and Evaluation) of the state-of-art weapon systems. This paper proposes an air defense simulation software framework to reduce both redundancy an[1 programming errors in system simulator. The proposed framework consists of a 'model' and a 'middleware' The 'middleware' is a reliable communication service layer that supports not only HLA(High Level Architecture) which is an international standard in M&S but also TCP/IP, UDP and etc. The main role of 'model' is to schedule and to run the real-time distributed simulation. The proposed framework has been applied to M-SAM(Middle range Surface to Air Missile) system simulator. The proposed framework's scheduling and communication performance results are satisfactory and were measured by hardwired NTP(Network Timer Protocol) time-stamp with GPS(Global Positioning System) timer for better precision.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.81-87
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• 2001

In a dynamically changing environment, the manager of a maintenance and remodeling (M/R) program is confronted with an increasing complexity of coordinating and cooperating multi-resource constrained multiple projects. The root causes of the complexity, uncertainty and interdependence, cause an internal disruption of an activity and chain reactions of disturbance propagation that deteriorate the stability and manageability of the program. This paper evaluates previous endeavors to apply production control and management techniques to the construction industry, and investigates the possibility of applying other management concepts and theories to organizational program management. In particular, this paper proposes a buffer allocation model by which periodic buffers are allocated in the flows of program constraint resources to stabilize a program master schedule instead of protecting individual activities. Comparative experiments by Monte Carlo simulations illustrate improved performance of the proposed model in terms of program's goals: productivity, flexibility, and long-term stability.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.2
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• pp.11-22
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• 1989

The problem of scheduling n-jobs on m-uniform parallel machines is considered, in which each job has a release time, a deadline, and a processing requirement. The job processing requirements are allocated to the machines so that the maximum of the load differences between time periods is minimized. Based on Federgruen's maximum flow network model to find a feasible schedule, a polynomially bounded algorithm is developed. An example to show the effectiveness of our algorithm is presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.2
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• pp.131-145
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• 1993

This paper deals with scheduling problem of the chemical process system where aircraft parts go through a given sequence of tanks filled with chemical solutions. The system has two hoists which move carriers holding the parts between tanks. A mixed integer programming model is developed from which a maximum throughput schedule can be found for the hoist movements. To show the validity of the model, a real world problem is solved and the results are compared with those with an existing approach.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.53-68
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• 1999

지금까지 전통적인 EPQ(Economic Production Quantity) 모델에서는 생산율이 수요율보다 큰 경우만을 다루어 왔으나, 실제 시장에서는 그 반대로 수요율이 생산율보다 큰 경우도 종종 발생한다. 그러나 이러한 상황에 대한 EPQ 연구는 찾아보기 어려운 실정이다. 따라서 본 논문에서는 수요율이 생산율보다 큰 상황을 고려한 확장된 EPQ 모델(Extended EPQ Model)을 유도하고, 이를 생산재고의 유한보충률 상황(Finite Replenishment Rate Environment)에서의 MPS(Master production Schedule)와 MRP(Material Requirements Planning)에 적용하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.14 no.24
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• pp.15-21
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• 1991

Jones [11], [12]developed a measurement method of the economic depreciation by infinite-horizen linear program model. This paper models an economic depreciation schedule in constant price based on the infinite-horizen LP. And the appropriate application of the maintenance/operating cost, the discount rate, the taxation and the price fluctuation in the model was suggested.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.1
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• pp.145-152
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• 2021

Environmental change due to construction of large offshore wind farm has been a debate for a long time in Korea. There are various data acquired on hydrodynamics around this area before and during construction of offshore wind farm but no data during operation could be made due to delayed schedule. In this study, environmental change such as bathymetry change and scouring was forecasted using MIKE, numerical hydrodynamics model, and its results were validated using the observation data before and during construction.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.43-51
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• 2016

Recently, the cost of construction projects has escalated due to a significant increase in size and complexity. Many construction projects have failed to meet their originally intended project deadline due to various factors such as weather, labor supply, equipment, procurement, accidents, etc. Consequently, emergency construction work scenario has to be implemented in order to shorten the duration and satisfy the original estimated schedule. However, many critical decisions in emergency scenario rely solely on the experience of a construction manager. Thus, this paper proposes TCTO optimization model to decide the most effective alternative out of various working scenarios which are generated by the combination of work group and work time. The developed TCTO model provides the optimum schedule that satisfies the practical constraints. Future research could involve the integration of resource leveling with the proposed model. This would make the model more versatile.