• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.135-142
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• 2004

This paper proposes the CPM bar chart (CBC), a hybrid of the bar chart and the critical pad method (CPM). The CBC overcomes shortages of the fenced bar chart, while still keeping advantages. The fence with direction is applied instead of the broken fence, which triggers considerable problems to identify and apply in the fenced bar chart. In addition, the notorious task to find dummy activities is no longer required. Upon the benefits of simplicity in the bar chart and logical work sequence in the CPM network. the CBC provides a relatively easy way to create and understand a schedule, thus improving communication quality between project participants. With the advantages, the CBC can also be effectively applied to various scheduling techniques such as resource constrained scheduling, resource leveling, scheduling with activity split, delay impact analysis, etc.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.174.1-174.1
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• 2012

현재 인공위성 개발 프로젝트들을 계획하고 일정계획을 수립하기위해 간트차트가 널리 활용되고 있다. 간트차트는 프로젝트의 각 작업들이 언제 시작하고 종료되는지에 대한 작업 일정을 막대 도표를 이용하여 표시하는 프로젝트 일정표로 다양한 형태로 변경하여 사용할 수 있으나 작업경로를 표시할 수 없으며 계획의 변화에 대한 적응성이 약한 단점이 있다. 또한 일목요연하게 눈으로 보여줄 수 있으나 효과적인 프로젝트 관리에 중요한 활동 사이의 어떤 관계에 대한 정보를 주지 못한다. 인공위성개발과 같은 복잡한 프로젝트에 대해 간트차트와 더불어 PERT(Program evaluation and review technique)와 CPM(critical path method)과 같은 네트워크 도(Network Diagram)와 함께 사용될 수 있도록 그 이론과 활용방안에 대해 기술하고자 한다. PERT와 CPM은 큰 프로젝트를 계획하고 조정하기 위해 폭넓게 사용되는 두 가지 기법이다. PERT와 CPM을 사용하면 프로젝트 활동에 대한 그래프를 통한 도시, 프로젝트 소요시간 추정, 프로젝트 완료시간 준수를 위해 중요한 활동의 식별, 전체 프로젝트에 대한 지연 없이 가능한 각 활동의 지연시간 추정과 같은 이점이 있다. PERT와 CPM은 독립적으로 개발되었지만, 많은 공통점이 있다. 더 나아가서 둘 사이에 원래 존재했던 차이점은 많은 부분은 서로의 특징을 도입하면서 거의 사라졌다. 실제적으로 볼 때, 두 기법은 지금 같은 기법이며, 기술된 특징과 절차는 PERT분석 뿐 아니라 CPM 분석에도 적용될 수 있을 것이다.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.54-64
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• 2011

Almost 40 years have been passed since the CPM was introduced to the construction industry in Korea. However most of construction projects in Korea do not prepare the CPM schedule neither operate it after established manually, as well as still depend on the Bar-chart schedule only. One of these reasons is because the CPM schedule does not reflect the site works realistically, it makes so difficult to recognize the actual progress clearly in visual format, and it is impossible to integrate and manage the time and cost oriented work progresses effectively. This paper proposes new concept of progress management that is able to integrate and manage the time oriented schedule progress and earned value oriented cost progress while maintaining the merits of CPM although the CPM schedule summarized automatically within a schedule hierarchy by the BDM that is a new CPM technique. We expect that this concept could make the applications of CPM technique to the domestic construction industry popular and help the advancement of the construction management in Korea as well.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.141-150
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• 2012

This paper suggests a critical path search algorithm that can easily draw PERT/GANTT chart which manages and plans a project schedule. In order to evaluate a critical path that determines the project schedule, Critical Path Method (CPM) is generally utilized. However, CPM undergoes 5 stages to calculate the critical path for a network diagram that is previously designed according to correlative relationship and execution period of project execution activities. And it may not correctly evaluate $T_E$ (The Earliest Time), since it does not suggest the way how to determine the sequence of the nodes activities that calculate the $T_E$. Also, the sequence of the network diagram activities obtained from CPM cannot be visually represented, and hence Lucko suggested an algorithm which undergoes 9 stages. On the other hand, the suggested algorithm, first of all, decides the sequence in advance, by reallocating the nodes into levels after Breadth-First Search of the network diagram that is previously designed. Next, it randomly chooses nodes of each level and immediately determines the critical path only after calculation of $T_E$. Finally, it enables the representation of the execution sequence of the project activity to be seen precisely visual by means of a small movement of $T_E$ of the nodes that are not belonging to the critical path, on basis of the $T_E$ of the nodes which belong to the critical path. The suggested algorithm has been proved its applicability to 10 real project data. It is able to get the critical path from all the projects, and precisely and visually represented the execution sequence of the activities. Also, this has advantages of, firstly, reducing 5 stages of CPM into 1, simplifying Lucko's 9 stages into 2 stages that are used to clearly express the execution sequence of the activities, and directly converting the representation into PERT/GANTT chart.

• Journal of the HCI Society of Korea
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• v.7 no.1
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• pp.11-17
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• 2012

A number of context information is shared through social network service(SNS). Among them, we focused on the information which is rarely shared for various reasons. The result indicated that users prefer to avoid certain types of context information because of： 1)containing socially unacceptable content, 2)laking of desire for disclosure, and 3)potential risk of privacy. Concerning privacy concern, it was found that users developed their own management strategy to control context information rather than employing existing system features. Drawing on Communication Privacy Management(CPM) theory, we analyzed findings and suggested guidelines for system design.

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

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.173-183
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• 2018

It is a very difficult task to establish a collaborative procedure in a new business that requires multilateral collaboration or to revise the regulation by analyzing and proving objectively the problems in the collaborative process conducted already by multilateral collaboration. In this paper, we proposed an optimization model for collaborative process to establish the operation procedure between collaborative parties using PERT/CPM network diagram which allows us to calculate the processing time. In order to verify the effectiveness and usefulness of our model for the collaboration process optimization developed in this study, we applied the developed collaborative procedure to student selection of the work-and-study-in-parallel course associated with a degree executed by Ministry of Employment and Labor. This study can be useful not only for newly establishing or reconfiguring collaborative procedures but also for standardizing the business procedures for building information systems between collaborative organizations.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.500-502
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• 2003

In this paper, we have designed a platform with MSC8101 processor for networked converter monitoring and diagnosis. MSC8101 is a dual processor type SOC(System On a Chip), which is consist of 16bit DSP and 32bit RISK CPM. As it have DSP and CPM, MSC8101 is competent for networking and data processing application. This MSC8101 platform is designed for networked monitoring and diagnosis, so it is important processing ability and networking capability.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.809-814
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• 2011

The major resource problem in sensor networks is energy efficiency. There are two major access methods to efficiently use energy. The first is to use dynamic power management (DPM). The second is to use energy efficient protocols. In DPM methods, the OS, the power manager, is responsible for managing the proper power state of CPU and each I/O with respect to the events, but the OS is not largely concerned about the internal operation of each network protocols. Also, energy efficient protocols are mainly focused on the power saving operation of the radio PHY. In addition, in wireless sensor network most of tasks are connected to communication. In such a situation, traditional power managers can waste unpredicted power. In this paper, we introduce an efficient power manger that can reduce a lot of unwanted power consumption through cooperative power management (CPM) in communication-related tasks between each units, such as radio, sensing unit, and CPU, for ad hoc wireless sensor nodes.

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