• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.917-923
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• 2005

Scheduling is one of the main functions in construction project to determine the sequence of activities necessary to complete a project. The scheduling techniques provide important information crucial to a project's success. Highway construction project the paving activity can be considered a linear activity. Linear scheduling technique may be better suited for linear projects than other scheduling techniques. A new type of scheduling in linear project is calling Linear Scheduling Model (LSM). The Project monitoring and controlling is very ease to identify that all the stage of linear project and have more advantages.

• 한국건설관리학회논문집
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• 제12권1호
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• pp.23-32
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• 2011

국내 일부 건설사는 초고층 건축공사와 같이 반복 공종이 많은 건축물에 일종의 선형 공정계획인 택트 공정계획을 수립하고 수행하고 있다. 선형 공정계획 모델(Linear Scheduling Model: LSM)은 작업 공간과 시간의 정보를 제공하는 시각적 도구로써 연구가 되어왔다. CPM 네트워크 공정표의 구속조건(종료 후 종료, 시작 후 종료, 종료 후 시작, 시작 후 시작)과 마찬가지로 선형계획모델 또한 작업간의 관계간의 구속조건이 발생한다. 특히, 네트워크 공정표를 호환하기 위하여 작업간의 중요 속성간의 관계성의 경계 조건을 정의하는 것이 필요하다. 따라서 본 연구는 선형 공정계획을 수립 시 발생하는 액티비티간의 공간상의 경계조건을 분석한다. 또한 선형 공정계획의 액티비티 간의 관계성을 고려하여 현재 일부 건설회사를 중심으로 사용하고 있는 택트 공정계획에 제안한 경계조건을 반영하여 택트 공정계획 수립과 관리를 위해 고려해야 하는 주요 사항을 제시하는 것이 본 연구의 목적이다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.802-807
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• 2005

For linear projects, it has long been known that resource utilization is important in improving work efficiency. However, most existing scheduling techniques cannot satisfy the need for solving such issues. This paper presents an optimization model for solving linear scheduling problems involving resource assignment tasks. The proposed model adopts constraint programming (CP) as the searching algorithm for model formulation, and the proposed model is designed to optimize project total cost. Additionally, the concept of outsourcing resources is introduced here to improve project performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.131-133
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• 2010

As linear scheduling method has been used since 1929, Empire State Building linear schedule, it is being applied in various fields such as construction and manufacturing. When addressing concurrent critical path occurring on linear schedule of construction, the empirical researches stress the resource management which should be applied for optimizing work flow, flexible work productivity and continuos resource allocation. However, work relationships has been usually overlooked for making the linear schedule from existing network schedule. Therefore, this research analyze the previous researches related to linear scheduling model and then propose the method that can be applied for adopting the relationships of network schedule to the linear schedule.

• 한국ITS학회 논문지
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• 제8권1호
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• pp.1-8
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• 2009

본 연구는 기존의 버스 운영계획모형을 시스템 다이나믹스(System Dynamics : SD) 관점에서 검토하는 것을 주된 목적으로 하고 있다. 결정변수들 간의 선형적 관계에 기초한 교��비용모델에 SD관점을 적용하여 순환적 관계로의 재구성을 시도하였으며, 그 결과물로 최적배차간격모형의 인과지도(Causal Loop Diagram)을 제시하였다. 또한 계량적 시뮬레이션이 가능한 저유량 인과지도(Stock & Flow Diagram)을 작성하여 시뮬레이션 결과의 의미를 논의하였다. 연구결과, 시뮬레이션에 적용한 수식이 기존의 교통비용모형에 토대를 두고 있기 때문에 시뮬레이션 결과가 기존의 연구와 큰 차이를 보이지 않았다.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.403-411
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• 2013

Horizontal construction projects such as oil and gas pipeline projects typically involve repetitive-work activities with the same crew and equipment from one end of the project to the other. Repetitive scheduling also known as linear scheduling is known to have superior schedule management capabilities specifically for such horizontal construction projects. This study discusses on expanding the capabilities of repetitive scheduling to account for the variance in production rates and visual representation by developing an automated alignment based linear scheduling program for applying temporal and spatial changes in production rates. The study outlines a framework to apply changes in productions rates when and where they will occur along the horizontal alignment of the project and illustrates the complexity of construction through the time-location chart through a new linear scheduling model, Linear Scheduling Model with Varying Production Rates (LSM_VPR). The program uses empirically derived production rate equations with appropriate variables as an input at the appropriate time and location based on actual 750 mile natural gas liquids pipeline project starting in Wyoming and terminating in the center of Kansas. The study showed that the changes in production rates due to time and location resulted in a close approximation of the actual progress of work as compared to the planned progress and can be modeled for use in predicting future linear construction projects. LSM_VPR allows the scheduler to develop schedule durations based on minimal project information. The model also allows the scheduler to analyze the impact of various routes or start dates for construction and the corresponding impact on the schedule. In addition, the graphical format lets the construction team to visualize the obstacles in the project when and where they occur due to a new feature called the Activity Performance Index (API). This index is used to shade the linear scheduling chart by time and location with the variation in color indicating the variance in predicted production rate from the desired production rate.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.777-786
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• 2007

This paper presents a modified simulated annealing algorithm to optimize linear scheduling projects with multiple resource constraints and its effectiveness is verified with a proposed problem. A two-stage solution-finding procedure is used to model the problem. Then the simulated annealing and the modified simulated annealing are compared in the same condition. The comparison results and the reasons of improvement by the modified simulated annealing are presented at the end.

• 한국건축시공학회지
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• 제10권4호
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• pp.31-39
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• 2010

선형 공정계획 방법은 1929년 엠파이어 스테이트 빌딩에서 그래픽한 용도로 사용되면서 현재는 다양한 작업 공간, 현장 작업과 조립 작업에 적용되고 있다. 선형 공정계획 상에 동시적인 크리티칼 패스가 발생하면 자원 관리는 작업흐름의 최적화 문제로 연결되어 유연한 작업생산성과 지속적인 자원의 할당을 하기 위해 적용되고 있다. 그러나 선형 공정계획 모델 연구에서 간과하고 있는 선형 공정계획 모델의 작업 관계성을 고려하는 것이 필요하다. 이에 본 연구는 선형 공정계획 모델에 관한 기존 연구를 분석하여 네트워크 공정표의 관계성을 선형 공정표에 적용할 수 있는 방법을 제시한다. 네트워크 공정표를 선형공정표로 변환 시에 발생하는 작업의 관계성을 고찰하고 건축물의 물리적 층수 변화와 같이 작업공간의 변화에 따라 선형 공정표에 반영되어야 할 선형 공정표상의 액티비티의 이동 문제를 고찰하여 네트워크 공정표를 선형 공정표로 호환할 수 있는 시스템 개발을 위한 기초연구를 제공하는 것이 본 연구의 목적이다.

• 한국항해항만학회지
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• 제30권7호
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• pp.561-566
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• 2006

In this paper, we propose a new ship scheduling set packing model considering limited risk or variance. The set packing model is used in many applications, such as vehicle routing, crew scheduling, ship scheduling, cutting stock and so on. As long as the ship scheduling is concerned, there exits many unknown external factors such as machine breakdown, climate change and transportation cost fluctuation. However, existing ship scheduling models have not considered those factors apparently. We use a quadratic set packing model to limit the variance of expected cost of ship scheduling problems under stochastic spot rates. Set problems are NP-complete, and additional quadratic constraint makes the problems much harder. We implement Kelley's cutting plane method to replace the hard quadratic constraint by many linear constrains and use branch-and-bound algorithm to get the optimal integral solution. Some meaningful computational results and comments are provided.

• 한국항해학회지
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• 제24권5호
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• pp.385-395
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• 2000

In the transportation literature, many useful decision making models for ship routing and ship scheduling have been studied. But the majority of these studies are on industrial carriers, bulk carriers, or tankers. It is quite recent that a few optimization models have been developed for liner fleet routing and scheduling problems. However there have been few academic studies on decision making models for the routing or scheduling problems of passenger ships in spite of their economic importance in the entire shipping industry. The purpose of this study is to develop analytic decision making models for ship routing and scheduling for the passenger ship fleet. This study gives two optimization models, one is a linear programming model and the other a goal programming model. These two models are solved easy by commercial linear programming softwares and suggest optimal ship routing plans and many other useful implications for passenger ship fleet managers.