• Journal of the Korea Institute of Building Construction
• /
• v.10 no.4
• /
• pp.31-39
• /
• 2010

As the linear scheduling method has been used since the Empire State Building linear schedule in 1929, it is being applied in various fields, such as construction and manufacturing. When addressing concurrent critical paths occurring in a linear construction schedule, empirical researches have stressed resource management, which should be applied for optimizing workflow, ensuring flexible work productivity and continuous resource allocation. However, work relationships have been usually overlooked in making the linear schedule from an existing network schedule. Therefore, this research analyzes the previous researches related to the linear scheduling model, and then proposes a method that can be applied for adopting the relationships of a network schedule to the linear schedule. To this end, this research considers the work relationships occurring in changing a network schedule into a linear schedule, and then confirms the activities movement phenomenon of linear schedule due to workspace change, such as physical floors change. As a result, this research can be used as a basic research in order to develop a system generating a linear schedule from a network schedule.

• Korean Journal of Construction Engineering and Management
• /
• v.12 no.1
• /
• pp.23-32
• /
• 2011

Domestic leading construction companies has been establishing and performing TACT scheduling method, similar to linear scheduling model such as line of balance and repetitive schedule, and etc. in which repetitive construction works are involved like high-rise building. Linear scheduling model has been researched as a visual scheduling method presenting the work space and time information. Likewise scheduling constraints of CPM network such as finish-to-finish, start-to-start, finish-to-start, start-to-start, linear scheduling model also has the relationships constraints, namely boundary conditions, between activities. It is especially necessary to define the boundary conditions of the activities' relationships in order to apply the linear scheduling model to be compatible with the network schedule. Therefore, this research considers the boundary conditions between activities for establishing the linear scheduling model. This paper also applies the proposed boundary conditions to TACT schedule and then deduces the main considerations in order to establish and perform TACT schedule.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1994.04a
• /
• pp.198-207
• /
• 1994

공작기계부품 가공을 위한 공정표는 가공공정, 공정별 도면 분할, 가공기계 등을 결정하는 공정계획과 한 공정에 대하여 가공방법, 가공공구, 절삭조건, 공수등을 결정하는 작업계획을 통하여 발행된다. 작업계획에서 가공방법과 가공공구의 결정은 절삭조건과 공수에 영향을 주는 중요한 요소이다. 기존의 연구에서는 가공방법과 가공공구를 결정하기 위해 전문가 시스템 쉘(expert system shell)이용한 사례가 많았다. 이 경우, 지식 베이스(knowledge base) 의 구축에 많은 시간이 소요되고, 지식이 변했을 때 수정의 어려움이 있다. 본 연구에서는 표준화되지 않아 변경의 소지가 많은 가공방법과 가공공구 결정에 뉴럴 네트워크(neural network)의 한 종류인 백 프로퍼게이션 (back propagation) 학습 모델을 이용했다. 공정계획 후 분할된 공정별 도면으로부 터 크기 및 정밀도 등과 같은 특징형상(feature) 정보를 추출한 후, 특징형상 의 종류와 크기, 치수공차, 기하공차, 거칠기 등을 입력하여 가공방법 및 가 공공구가 출력되도록 학습패턴을 설정하여 학습시켰다. 학습패턴은 공정설계 전문가와 인터뷰하는 방법과 작업계획 과정을 분석하는 방법을 통하여 설정 했다. 백 프로퍼게이션 모델을 통하여 학습시킨 결과, 학습시킨대로 정확한 가공방법 및 가공공구를 결정할 수 있었다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.559-563
• /
• 1996

선박 건조는 선체를 수십에서 많게는 이백여개에 블럭으로 분활하여 각 블럭에 해당하는 원자재를 처리 가공한 후 소조립, 중조립, 그리고 대조립의 과정을 거쳐 블럭으로 완성하여 이들 블럭을 정해진 순서에 맞추어 탑재하는 과정을 거치면서 기타 공정을 완료하여 마지막으로 진수에 이르게 된다. 본 연구에서는 선박 건조 과정에서 탑재 공정 계획을 위한 블럭의 접속 관계를 체계적으로 확립하여 탑재 순서를 생성하는 방법론을 제시하고 이러한 방법론을 바탕으로 초기 탑재 네트워크을 생성 방안을 제시한다.

• Journal of the Korea Institute of Building Construction
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2011

Linear scheduling method limits to present works of work breakdown structure as a form of lines and was often developed manually. In other words, linear schedule could not utilize activity, work breakdown structure, and etc. information of network schedule such as CPM(Critical Path Method) and has been used only for reporting or confirming construction master plan. Therefore, it is necessary to develop system which can automatically generating the linear schedule based on the network schedule having many accumulated and useful construction schedule information. Thus, this research has an effort to establish data process model, data flow diagram, and data model in order to make linear schedule. In addition, this research addresses the system solution structure, user interface class diagram and logic diagram, and data type schema. The results of this paper can be used as a preliminary research for developing linear schedule generating system prototype by utilizing the network schedule information.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2010.05a
• /
• pp.131-133
• /
• 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.

• Korean Journal of Construction Engineering and Management
• /
• v.1 no.3 s.3
• /
• pp.75-80
• /
• 2000

In scheduling multi-unit projects, several alternatives can exist in network construction due to repetitiveness of their activities. Project duration is affected not only by the duration of each activity but also by the arrangement of repeating activities in such projects. This paper provides a network compression method that assigns predecessors to each activity to minimize its float time. Different to the previous efforts that utilized line of balance as the base scheduling-model, this research adopts precedence diagram arranged in two coordinates, the space axis and the resource one. This method seeks the most appropriate predecessors for each activity in each direction of the two coordinates for the purpose of minimizing the idle resource and space. This activity arrangement method was applied to a multi-unit apartment-construction project, to prove its capability of network compression. The result shows that the method successfully sought room for saving construction duration by changing the activity arrangement. The network compression method presented in this research can be utilized in multi-unit construction projects such as apartment complex projects.

• Journal of Advanced Navigation Technology
• /
• v.18 no.4
• /
• pp.268-277
• /
• 2014

It is very important to correlate flight plan for safe and prompt ATC(air traffic control) operation. In this paper, we design CWP(controller working position) MRT(multi radar tracking) processing module to achieve improvement of overall ATC automation system's performance by minimizing network traffic overload when correlating MRT with flight plan. This implemented module can guarantee efficiency and safety of ATC automation system by applying distributed correlated manner, and reduce network usage by using encoded flight plan correlated MRT data format. We found that this module has 8.54~12.11% lower network usage and 8.37~11.27% higher network traffic fairness than the module using standalone manner.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.2
• /
• pp.3-11
• /
• 2014

As the recent construction projects have been carried out as a mixed-use complex project that includes architecture, civil, mechanical, electrical, and landscape, as well as become bigger and high-rise with the increased repetitive works, the TACT technique has received more attention as an effective method for achieving a target completion date by securing the continuous works. Although the TACT technique can maintain a steady flow without the interruption of works in order to utilize the resources of the repetitive works, it can not be considered as the systematic scheduling technique because the schedule computations are not possible as well as a critical path can not be recognized. This paper proposes the applicabilities of scheduling and monitoring the TACT schedule by the BDM technique as comparing and analyzing the methodologies for apartment finish works by the Excel, the Primavera(P6) based on the PDM technique, and the Beeliner based on the BDM technique that is a new networking technique, respectively.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.6
• /
• pp.595-602
• /
• 2018

Network-based scheduling methods can be classified into CPM method and PERT method. In the network scheduling chart, critical path can be estimated by performing the forward calculation and the backward calculation though the paths in the network chart. In PERT method, however, it is unreasonable to simply estimate the critical path by adding the sum of the activity durations in a specific path, since it does not incorporate probabilistic concept of PERT. The critical path of a PERT network can change according to the target period and deviation, and in some cases, the expected time of the critical path may not be the path with longest expected time. Based on this concept, this study proposes a technique to derive the most-likely critical path by comparing the sum of estimated time with the target time. It also proposes a method of systematically deriving all alternate paths for a network of repetitive activities. Case studies demonstrated that the most-likely critical path is not a fixed path and may vary according to the target period and standard deviation. It is expected that the proposed method of project duration forecasting will be useful in construction environment with varying target date situations.