• 경영과학
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• 제20권2호
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• pp.33-43
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• 2003

In this paper we applied dynamic programming to determining work schedule type. In dynamic programming formulation, each day during a planning horizon represents a stage for which a decision is made. The alternatives are given by work schedule types that combine regular time, overtime, additional shift, and so on. In this case, their associated return function is labor cost. The state is defined as the amount of work time allocated to stage 1, stage 2,…, and current stage. A case study for a real manufacturing company was performed to apply dynamic programming to scheduling daily work hours during a week. The case study showed that total cost of our solution derived from dynamic programming decreased by about 6％ as compared with the solution obtained from the previous method.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.163-172
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• 2004

A fast, accurate model for calculating roll gap variables are critical to the implementation of computer based automation systems for cold rolling mills. Based on the work of Fleck and Johnson, rollgap simulator with non-circular arc model was developed using the influence function. This developed model is capable of predicting values of force, torque and slip which can be applied over the wide range of rolling conditions including cold rolling/DR/temper mill with high execution speed. Friction coefficient was obtained as a function of operation conditions through analyzing measured data. After combination of rollgap simulator with production strategy, draft schedule for No.3 RCM (Reversible Cold Rolling Mill) in Incheon works of Dongbu Steel was developed. This draft schedule will be installed in the setup computer of No.3 RCM replacing old Hitachi model.

• Journal of Construction Engineering and Project Management
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• 제3권2호
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• pp.21-34
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• 2013

Various risk factors affect construction projects. Due to the uncertainties created by risk factors, actual activity durations frequently deviate from the estimated durations in either favorable or adverse direction. For this reason, evaluation of schedule uncertainty is required to make decisions accurately when managing construction projects. In this regard, this paper presents a new computer simulation model - the Repetitive Schedule Risk Analysis Model (RSRAM) - to evaluate unit-based repetitive building project schedules under uncertainty when activity durations and risk factors are correlated. The proposed model utilizes Monte Carlo Simulation and a Critical Path Method based repetitive scheduling procedure. This new procedure concurrently provides the utilization of resources without interruption and the maintenance of network logic through successive units. Furthermore, it enables assigning variable production rates to the activities from one unit to another and any kind of relationship type with or without lag time. Details of the model are described and an example application is presented. The findings show that the model produces realistic results regarding the extent of uncertainty inherent in the schedule.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.554-562
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• 2007

This study determined tact process paths by separating the finish works according to the properties of work areas and work relations in order to apply the tact schedule management to the finish works. In addition, by suggesting preparing and sharing the workflow charts, the experiments can be shared between the executors and any possible frictions between the specialist works can be identified in advance. In addition, any errors on the plan can be reviewed and modified through the measurement stage of tact plan attainment rate. The process of tact schedule management is improved with such tools and methods and the efficiency of the process through the application of cases was verified.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.929-934
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• 2005

The complex and dynamic job nature and the ever-changing working environment of construction projects inevitably present uncertainties to construction operations. Identification, evaluation and control of uncertainties constitute main elements of risk management and critical tasks of project management in construction. This paper is focused on application of a simplified discrete-event simulation approach in management of schedule-overrun risks, each being the combination of the occurrence probability of an uncertain interruptive factor and its potential consequence in terms of time delay. A case study observed from a concreting operation in Hong Kong is converted into a simulation model and analyzed with an in-house-developed simulation package for demonstrating how the proposed approach can be implemented to manage multiple schedule-overrun risks on construction projects.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제8권1호
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• pp.25-35
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• 2002

멀티미디어 프리젠테이션 응용은 대개 여러 개의 협동 서버(collaborating server)로부터 데이타의 검색을 필요로하며, 검색된 데이타의 검색을 필요로 하며, 검색된 데이타의 프리젠테이션은 상호 의존적이다. 이것은 프리젠테이션을 위해서 다른 협동 서버에 저장되어 있는 데이타들이 주어진 시간적 제약 조건에 따라 연속적으로 검색되어 전달되어야 하기 때문이다. 이러한 응용에서 서버는 먼저 이용 가능한 네트워크 대역폭과 시스템 자원을 평가하여 초기 검색 스케줄을 생성하고 협동 서버는 시스템 부하에 따라 검색 스케줄에 적절한 변경을 제안할 수 있어야 한다. 전체 스케줄에서 이러한 부준적 변경은 연차적으로 다른 협동 서버의 검색 스케줄에 영향을 미친다. 따라서 멀티미디어 프리젠테이션을 구성하는 객체에 대한 검색 스케줄을 확정하기 위해서는 이러한 일련의 협상이 협동 서버 사이에 진행되어야 한다. 본 논문에서는, 협동적 멀티미디어 프리젠테이션을 위한 자원의 협상과 승인을 다루기 위해 RLCP(Resource Lock Commit Protocol)라는 프로토콜을 제안하고 분산 비디오 프리젠테이션 응용에 적용해 본다.

• 한국인공지능학회지
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• 제9권1호
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• pp.1-7
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• 2021

In this paper, We focused the issue of creating a socially problematic nurse schedule. The nurse schedule should be prepared in consideration of three shifts, appropriate placement of experienced workers, the fairness of work assignment, and legal work standards. Because of the complex structure of the nurse schedule, which must reflect various requirements, in most hospitals, the nurse in charge writes it by hand with a lot of time and effort. This study attempted to automatically create an optimized nurse schedule based on legal labor standards and fairness. We developed an I/O Q-Learning algorithm-based model based on Python and Web Application for automatic nurse schedule. The model was trained to converge to 100 by creating an Fairness Indicator Score(FIS) that considers Labor Standards Act, Work equity, Work preference. Manual nurse schedules and this model are compared with FIS. This model showed a higher work equity index of 13.31 points, work preference index of 1.52 points, and FIS of 16.38 points. This study was able to automatically generate nurse schedule based on reinforcement Learning. In addition, as a result of creating the nurse schedule of E hospital using this model, it was possible to reduce the time required from 88 hours to 3 hours. If additional supplementation of FIS and reinforcement Learning techniques such as DQN, CNN, Monte Carlo Simulation and AlphaZero additionally utilize a more an optimized model can be developed.

• 소성∙가공
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• 제14권8호통권80호
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• pp.689-695
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• 2005

Multi-pass wet wire drawing process is used to produce fine wire in the industrial field. The production of fine wire through multi-pass wet wire drawing process with appropriate dies pass schedule would be impossible without understanding the relationship among many process parameters such as material properties, dies reduction, friction conditions, drawing speed etc However, in the industrial field, dies pass schedule of multi-pass wet wire drawing process has been executed by trial and error of experts. This study investigated the relationship among many process parameters quantitatively to obtain the important process information fur the appropriate pass schedule of multi-pass wet wire drawing process. Therefore, it is possible to predict the many important process parameters of multi-pass wet wire drawing process such as dies reduction, machine reduction, drawing force, backtension force, slip rate, slip velocity rate, power etc. The validity of the analyzed drawing force was verified by FE simulation and multi-pass wet wire drawing experiment. Also, pass redesign was performed based on the analyzed results, and the wire breakage between the original pass schedule and the redesigned pass schedule was compared through experiment.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.682-686
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• 2007

건설사업은 다양한 시대적 요구를 충족시키기 위해 매우 다변화되었고, 그에 따라 참여주체들이 많아지고 복잡성이 증가하게 되었으며, 사업의 규모 측면에 있어서도 날로 대형화되어 가고 있는 실정이다. 하지만 현재의 건설 프로젝트 공정관리 수준은 1950년대에 만들어진 PERT나 CPM을 반세기가 지난 지금까지 그대로 사용하고 있을 정도로 후진성을 면치 못하고 있다. 또한 현재의 공정관리는 결과위주의 방식으로 건설사업 과정에서 나타나는 작업 간의 정보의 흐름과 변이요소의 발생을 충분히 고려하지 못하고 있다. 따라서 본 연구에서는 기존의 공정관리도구들의 단점을 개선하고 공정관리기술의 한계를 극복하기 위하여, 국내에는 잘 알려지지 않은 설계관리기법인 DSM(Dependency Structure Matrix)를 도입하여 건설사업 공정관리에 대한 적용성을 고찰해보고자 한다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 1999년도 춘계공동학술대회:정보화시대의 지식경영
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• pp.415-415
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• 1999