• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.371-374
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• 2002

Purpose of this study is to suggest the directions for development of a transportation and procurement system for JIT management of curtain walls. First, this study looks over the concept of JIT, and grasps the characteristics of the material and the problems of logistics in the construction field through the field and literature survey. And then, it develops countermeasures for the problems and with this, it suggests the directions for development of a transportation and procurement system for JIT management.

• Journal of the Korea Institute of Building Construction
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• v.5 no.4 s.18
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• pp.153-164
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• 2005

This study aims at establishing JIT production management system to enable manage the resources input into from procurement through construction based on correct identification of the process, an analysis on the amount of input materials and information sharing. This study has focused on the process control and working process of rebar work in domestic apartment house construction where the overall scope of Process from the planning phase to the construction phase has been analyzed in this study. Also construction phase was selected for the application of a sample case. A basic model for JIT production was generated with these processes. Furthermore A questionnaire and the on-site survey with process, checklist and control data were prepared and performed for the application of JIT production management model into rebar work. The governing scopes of JIT production management system include process management, material management, yard loading and moving management and inventory control, and the operation of each control item

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.341-344
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• 2003

There are many problems in management of high-rise building construction performed in downtown area due to limited spaces and equipments for increasing kinds and quantities of material. By these restrictions, problems such as increase of construction cost. delay of construction period, decrease of productivity, occurrence of accident are caused. Recently, studies on JIT concept have focused on construction materials as a solution for the problems. But, studies about finishing material are insufficient yet. Accordingly, this study suggests flowing of current material management, JIT management effect, and development direction of lifting-up and procurement system with Low-emissivity double Glazing, among of main finishing materials.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.20-26
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• 1995

본 연구는 JIT생산시스템에서 혼합조립라인에 대한 제품순서게획에 대한 연구이다. 본 연구에서 고려하는 조립라인을 효과적으로 수행하기 위해서는 서로 다른 제품들을 조립하기 위한 제품순서가 결정되어야 한다. 필요한 제품을 적시에 적당한 양만큼 생산하는 JIT생산시스템에서의 제품 순서계획의 목적은 라인에서 소비 되는 모든 부품들의 소비율을 일정하게 유지시키는 것이다. 본 연구에서는 부품소비율을 일정하게 유지시키 면서 동시에 순서계획수립시 계획파괴를 줄일수 있도록 그룹개념을 이용하여 순서계획문제를 정식화하고 이 에 대한 해법을 제시하였다. 본 연구에서 개발한 해법의 우수성을 평가하기 위해 총변동과 순서계획의 파괴빈도에 대한 실험을 통하여 기존해법과 비교한 결과 본 연구의 해법이 우수한 결과를 제공하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.517-520
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• 2003

Recently there is a used a word-outsourcing-in the corporation circumstance. Continuous recession impelling with IMF permitted restructuring measures downsizing unnecessary organization and offered opportunity to breakup structure of 'High cost and Low efficiency' -inefficient and uneconomic production method- in our corporation. Due to the effect of such circumstance change, the construction industry have already introduced and implemented outsourcing in many parts. For successful outsourcing in the construction industry, a mutually close relations and the cooperation are preceded and JIT system is needed to improve these relations. The study recognizes the importance and proportion that outsourcing is occupyed in the construction industry, and suggests the method to improve the productivity by evaluating the factors and usefulness for JIT system to apply to the construction industry.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.117-125
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• 2004

Recently, the word 'outsourcing' is used frequently in the corporation circumstance. Continuous recession with IMF caused restructuring measures which made unnecessary organization be downsized, and offered opportunity to breakup structure of $^{\circ}A$EHigh cost and Low efficiency, which is inefficient and uneconomic production method' in our corporation. Due to the effect of such circumstance change, the construction industry have already introduced and implemented outsourcing in many parts. For successful outsourcing in the construction industry, close relation and mutual cooperation should be preceded and JIT system is needed to improve the relation. In this study, the importance and proportion in which outsourcing is occupied in the construction industry are recognized, and the method for improving the productivity is suggested through evaluating the factors and usefulness of JIT system which can be applied to the construction industry.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.182-191
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• 2003

The material lift-up and procurement management for high-rise buildings is complex and critical key to the success of projects. It has been hardly managed by the heuristic or rule-of-thumb techniques which are adapted in usual construction building sites. Especially in downtown high-rise residential building project sites, the limit of heuristic management techniques is critical. It has space constraint for materials loading and site transportation especially in finish work phases in which construction period diverse work trades struggle for their own material and manpower transportation. Hence, it is essential to adapt JIT(Just-In-Time) concept in these particular types of building construction project sites. According to the analysis of the case project sites, the communication and flow of relevant information regarding material lift-up and transportation in project sites is the key factor for successful performance. Therefore, this study analyzes the flow and site transportation of the key materials and provides the system, PLUTO(Procurement & Lift-Up for material Transport Optimizing system). This study also applies the system in the case site and verifies the model validation in actual project.

• Journal of Industrial Convergence
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• v.5 no.2
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• pp.21-32
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• 2007

This paper deals with the sequencing problem in the operation of the manufacturing systems with the constraint of buffer capacity. Some of studies for this theme have been progressed for several years. And then most of them considered only one objective, such as maximum lateness, machine utilization, makespan, mean flowtime and so on. This study deal with two objectives of the delivery for customers and the idle time of machines for producers. For the decision of sequence, the utility function is used. The developed heuristic algorithm presents a good solution. Through a numerical example, the procedures of the job sequencing is explained.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.67-73
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• 2008

Recent trends in construction towards larger scale and taller buildings are causing problems by ineffective existing management approach in construction industry have emerged. Delivering necessary materials and mobilizing the human resources and equipment In a timely manner to keep labor on schedule have become a critical issue to be addressed. In particular, many specialty contractors carrying out multiple projects have been experiencing difficulties mobilizing the manpower on time and in right places due to poor communication at each stage of labor supply, resulting in waste of valuable resources. Hence, it's imperative for the specialty contractors to obtain specific information on labor demand so as to set up a communication and labor management system to ensure the right human resources will be mobilized in the right place at the right time. The study therefore is aimed at developing an optimal human resources management system for specialty contractors performing multiple projects. To that end, the study is focused on rebar and concrete work. The outcome of the study is expected to help allocate the right human resources to the right place in a timely fashion, thereby achieving an effective workflow at construction sites.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.40-48
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• 2009

In this article, scheduling of a casting sequence is studied in a casting foundry which must deliver products according to the Just-in-time(JIT) production policy of a customer. When a foundry manufactures a variety of casts with an identical alloy simultaneously, it frequently faces the task of production scheduling. An optimal casting schedule should be emphasized in order to maximize the production rate and raw material efficiency under the constraints of limited resources; melting furnaces and operation time for a casting machine. To solve this practical problem-fulfilling the objectives of casting the assigned mixed orders for the highest raw material efficiency in a way specified by the customer's JIT schedule, we implement simple integer programming. A simulation to solve a real production problem in a typical casting plant proves that the proposed method provides a feasible solution with a high accuracy for a complex, multi-variable and multi-constraint optimization problem. Employing this simple methodology, a casting foundry having an automated casting machine can produce a mixed order of casts with a maximum furnace utilization within the due date, and provide them according to their customer's JIT inventory policy.