• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.171-180
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• 1992

This paper proposes a solution approach to linear problems with many constraints of variable upper bound (VUB) type. This type of constraints are commonly found in various scheduling type problems for which tighter bounds are essential to achieve an efficiency in enumeration. An analytical framework based on factorization is adopted to devise a solution approach to the problem and extend it for more generalized VUB problem (GVUB). This research shows why the VUB type constraints are amenable to the factorization and gives a unified approach to generalized upper bound(GUB) problems, VUB problems and GVUB problems. Implementation issues are also included.

• Korean Management Science Review
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• v.18 no.2
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• pp.1-10
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• 2001

Due to environmental change in market, delivery satisfaction to customer end redaction of LeadTime are critical In the Make-to-Order manufacturing system. This paper focuses on Order Feasibility Decision System Based on SNS System. We suggest BOP (Bill of Process) in which aggregated information is used When the load p1anning problem is solved while more detailed information is used when the scheduling problem is solved.

• Management & Information Systems Review
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• v.5
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• pp.287-300
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• 2000

Project Managers want to reduce the cost and the completion time of the project simultaneously. But the project completion time tends to increase as the project cost is reduced, and the project cost has a tendency to increase as the project completion time is reduced. In this paper, the resource constrained project scheduling problem with multiple crashable modes is considered. An exact solution method for finding the efficient solution set and the computational results are introduced.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.114-119
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• 2002

사출성형금형은 일반적으로 주문설계생산(Engineer-to-Order)방법에 의해 단품 또는 소량으로 제작된다 금형을 제작하기 위한 생산일 정계획은 여러 금형을 동시에 생산하기 위하여 자원을 언제 어떤 공정 및 부품에 할당할 것인가를 결정한다. 일반적으로 제조공장의 능력은 유산하므로 자원의 제약이 일정계획에 직접적인 영향을 준다. 본 논문에서는 자원제약 하에 있는 금형 공장에서 공정외주 비용과 납기 미준수 비용을 고려하여 금형을 구성하는 각 부품의 생산일정과 내외작 여부를 결정하는 최적화 모형과 이를 현실적으로 해결하는 휴리스틱 모형을 제시한다. 제시된 휴리스틱 모형은 조립공정배치 알고리듬인COMSOAL을 기반으로 job shop 형태의 생산공장과 프로젝트 일정계획을 혼합한 형태를 갖는다.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.83-94
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• 2003

Managing a call center is a complex and diverse challenge. Call center becomes a very important contact point and a data ware house for successful CRM. Improving performance of call center is critical and valuable for providing better service. In this study we applied forecasting technique to estimate incoming calls and ProModel based simulation model to enhance performance of a mobile telecommunication company's call center. The simulation study shows reduction in managing cost and better customer's satisfaction.

• Journal of the Korea Safety Management & Science
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• v.5 no.3
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• pp.165-177
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• 2003

크로스도킹이란 창고나 물류센터에 하역된 물품이 저장됨이 없이 도착지별로 재분류되어서 직출하되는 물류 시스템이다. 크로스도킹은 물류비용의 큰 비중을 차지하는 보관비용을 감소시킬 수 있을 뿐만 아니라 고객의 요구에 빠른 대응을 할 수 있다는 장점을 지니고 있다. 크로스도킹이 성공적으로 수행되기 위해서는 창고나 물류센터의 입고에서부터 출고까지의 모든 작업들이 계획적이고 원활하게 수행되어져야만 한다. 본 연구에서는 임시보관 장소를 보유하지 않은 크로스도킹 시스템의 총 운영시간을 최소화하기 위한 입고 트럭과 출고 트럭의 일정계획 수립을 위한 수학적 모델을 개발하였다.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.139-153
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• 2000

To develope a domestic machinery industry, international competition through reducing cost by increasing productivity is as important as evolving technology and increasing quality. In this study, we have studied in application of GT technology. GT is a skill that acquires high productivity using part's resemblance for multi part and small size production like mass production. We have classified group, such as design, layout and the others, to be applied systematically. The design group includes retrieval for drawings and study for GT design. The layout group includes GT layout, analysis of production process and study for composition method. And others include scheduling, standardization and standard process.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.61-68
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• 2007

There has been a lot of research on and release of commercial systems that enable evaluation and visualization of construction methods. These have enabled the selection of good construction plans. However, the process in which engineers build 3D geometry, formulate a schedule and eventually synchronize them is still a time-consuming process. Changing any aspect of the geometry or the schedule and re-linking them is also time-consuming. Therefore, the engineers may compromise on getting the best solution. This paper describes a technique to automate the generation of multiple sets of schedules, quantity takeoffs and 4D visualization from a single 3D model.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.114-116
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• 2015

This paper presents a Stochastic Time-Cost Tradeoff analysis system (STCT) that identifies optimal construction methods for activities, hence reducing the project completion time and cost simultaneously. It makes use of schedule information obtained from critical path method (CPM), applies alternative construction methods data obtained from estimators to respective activities, computes an optimal set of genetic algorithm (GA) parameters, executes simulation based GA experiments, and identifies near optimal solution(s). A test case verifies the usability of STCT.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.109-110
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• 2015

This paper presents a computational method that identifies an exact set of optimal overlap rates between critical activities to meet job site specific needs by using rework cost-slope. The procedures to compute the exact solution are provided in peudocode algorithm. The method is coded into Exact Concurrent Construction Scheduling system that allows practitioners to make more informed decision in accordance with the site-specific condition involved in the overlapping of critical activities. Test cases verify the validity of the computational method and the usability of the system.