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

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.80-90
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• 2005

Activity durations retain probabilistic and stochastic natures due to diverse factors causing the delay or acceleration of activity completion. These natures make the final project duration to be a random variable. These factors are the major source of financial risk. Extending the Stochastic Project Scheduling Simulation system (SPSS) developed in previous research; this research presents a method to estimate how the final project duration behaves when activity durations change randomly. The final project cost is estimated by considering the fluctuation of indirect cost, which occurs due to the delay or acceleration of activity completion, along with direct cost assigned to an activity. The final project cost is estimated by considering how indirect cost behaves when activity duration change. The method quantifies the amount of contingency to cover the expected delay of project delivery. It is based on the quantitative analysis to obtain the descriptive statistics from the simulation outputs (final project durations). Existing deterministic scheduling method apply an arbitrary figures to the amount of delay contingency with uncertainty. However, the stochastic method developed in this research allows computing the amount of delay contingency with certainty and certain degree of confidence. An example project is used to illustrate the quantitative analysis method using simulation. When the statistical location and shape of probability distribution functions defining activity durations change, how the final project duration and cost behave are ascertained using automated sensitivity analysis method

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1497-1500
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• 2011

최근, 스마트폰 가입자 수가 급격히 증가하는 가운데, 사람과 사람의 관계에 중심을 두는 서비스인 SNS가 급격히 성장하고 있다. 모바일 디바이스를 사용한 소셜 네트워크가 접목되어 사용자들 사이에 자연스러운 의사 교류 관계가 형성되며, 장소나 이벤트를 기반하여 빠르고 끊임없이 정보들이 발생하게 되었다. 그러나 너무 많이 발생하는 불필요한 데이터들로 인해 의미 있는 정보, 필요한 정보를 파악하는 데 어려움이 생긴다. 이러한 문제점을 해결하기 위해, 소셜 네트워크 서비스를 통해 제공되는 정보들 가운데 영향력 있는 정보가 무엇인지 판단하는 연구가 중요시 되고 있다. 본 논문에서는 소셜 네트워크 영향력 측정을 위해 장소를 기반으로 한 동적 소셜 커뮤니티에서의 소셜 네트워크 액티비티를 중심으로 이벤트에 대한 영향력을 측정하는 방법에 대해 고찰하고, 새로운 영향력 측정 방안에 대해 제안한다.

• 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.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.113-121
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• 2005

The construction industry has also enolved according to the changes and requirements, therefore it coms to manage the relationships with customers. However, the customer management in the construction industry has not been quite genuine, since it has been mainly oriented for public relations and advertisements of companies. The genuine customer management should not only systemize customer data but also provide strategy to utilize it through managing relationships with customers as well as customer themselves. In this research, I have focused mainly on Model House. Marketing is very important planning & coordination to project. And I know that the development power of new product and promotion strategy as to customer needs and wants. The key factor in housing industry is the analysis of customer's needs that key success factor is execution of action plan to our customer. His success in business is in result of satisfaction for our high quality customer. Therefore the CRM system is add to customer satisfaction and increase earning power to a business

• Journal of Digital Contents Society
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• v.11 no.4
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• pp.571-578
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• 2010

Recently, many social networking services using mobile devices are spread. Also, many studies based on location and time are increasing. However, existing studies have been difficult to resolve queries by place, time, and events. In the paper, we propose time and space modeling method for social services. We propose Human Activity Graph and Quad Relation Factors through time, place, event, and social activity of users, and we design the database scheme for data collect and analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.53-63
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• 2009

This study aims at presenting a plan to build an open space network system in the city of Daejeon, assuming that parks and the green space system as a broad concept are to make a network by connecting open spaces such as parks, green spaces, squares, pedestrian roads, historical spots, etc. In the case of old downtown in Daejeon, this study examined the possibility of applying an open space network in the city of Daejeon and categorize them according to the findings from examining the case area, which enables to make a plan for building an open space network system in Daejeon. As a result, public offices and business buildings as an active open space have public open spaces in front of buildings and these front public open spaces are connected to pedestrian roads(gray open space). Since these pedestrian roads are consequently connected to large parks and rivers(green or blue open space), this overall spatial sequence can form an open space system. In addition, parks and green spaces, which have been fundamental elements so far, exist in relatively small and scattered areas at the center of the city. Hence, more parks and green space are needed to improve a park and green space system. However, it is very difficult to create new parks and green spaces in downtown, especially in old downtown areas. Therefore making an open space network system which spreads out over the whole city will form a healthy open space network in the downtown area.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1436-1449
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• 2009

The value of sensing information is decided according to positions of sensor nodes, which are very important in sensor networks. In this paper, we propose a method that estimates positions of nodes by using adjacent node information and received signal strength in a sensor network. With the proposed method, we can find positions of nodes easily because we use information that nodes have. Moreover, we can find distribution easily for all the nodes because we can measure a relative position for a node whose position is not known based on anchor nodes whose positions are already known. We utilized Use case diagram, activity diagram and State machine diagram among several diagrams of UML to implement proposed method in sensor networks that is dynamic system. We can understand exact flow for each function of the proposed method in node position estimation system can be implemented easily. And we can be confirmed that the position of estimated nodes has a little error.

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