• International conference on construction engineering and project management
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• 2013.01a
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• pp.359-366
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• 2013

Although many research efforts have been conducted to address the effect of crew members' work skills (e.g., technical and planning skills) on work performance (e.g., work duration and quality) in construction projects, the relationship between skill and performance has generated a great deal of controversy in the field of management (Inkpen and Crossan 1995). This controversy can lead to under- or over-estimations of the overall project schedule, and can make it difficult for project managers to implement appropriate managerial policies for enhancing project performance. To address this issue, the following aspects need to be considered: (a) work performances are determined not only by individual-level work skill but also by the group-level work skill affected by work team members, each member's role, and any working behavior pattern; (b) work planning has significant effects on to what extent work skill enhances performance; and (c) different types of activities in construction require different types of work, skill, and team composition. This research, therefore, develops a system dynamics (SD) model to analyze the effects of both individual-and group-level (i.e., multi-level) skill on performances by utilizing the advantages of SD in capturing a feedback process and state changes, especially in human factors (e.g., attitude, ability, and behavior). The model incorporates: (a) a multi-level skill evolution and relevant behavior development mechanism within a work group; (b) the interaction among work planning, a crew's skill-learning, skill manifestation, and performances; and (c) the different work characteristics of each activity. This model can be utilized to implement appropriate work planning (e.g., work scope and work schedule) and crew management policies (e.g., work team composition and decision of each worker's role) with an awareness of crew's skill and work performance. Understanding the different characteristics of each activity can also support project managers in applying strategic work planning and crew management for a corresponding activity, which may enhance each activity's performance, as well as the overall project performance.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.126-134
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• 2004

Since a construction project is a series of works that utilizes resources to accomplish the project goal for a given time period, efficient resource management is a prerequisite for the success of the project. Two major areas of resource management are resource constrained scheduling focusing on the limited resource availability and resource leveling focusing on smoothing resource usage pattern on the fixed project completion time. It is not available, however, to apply both techniques to a project at the same time. This paper proposes a model to enhance the minimum moment algorithm of resource leveling, aiming to find an efficient usage of resources and an appropriate project completion time. A survey was performed to evaluate the major five factors in the model. A case study demonstrates the value of the proposed resource leveling technique.

• Journal of the Korean housing association
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• v.25 no.4
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• pp.39-46
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• 2014

This research was for the investigation and analysis of the illustration of modular construction application which is different use by each school facility since modular construction related examples are rare in domestic situation, and it has a limitation because of its being basic research material for generating the basic form of modular construction. The research results are as followings. First, in case of school facility from illustration investigation results, module measurement of class modulation is as similar as $3m{\times}10m$, but in resident facility the planning of more flexible plane shape can be possible since modules of 6 cases are free and various, and facade form of various types can be appeared by combination of module unit. Second, as a result of the generated characteristics in compared analysis of representative examples, school facilities were highly indicated for movability and duration reduction areas, and the flexibility, economic efficiency, and environment-friendliness was indicated low relatively. Third, the basic planning types of modular construction can be largely divided into layered type, horizontal (straightway) type, and compound type. The layered type has a short traffic line and facility system and is appropriate for the low-rise form unless separate construction method is used since it is susceptible to load. The horizontal type is advantageous for securing an opening since it has wide extent in light but has a long traffic line and facility system. Finally, the compound type can be possible for planning of various forms but needs the combination of various unit modules and traffic line and facility plan for it can be difficult.

• Journal of the Korea Institute of Building Construction
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• v.11 no.1
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• pp.73-81
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• 2011

The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.621-631
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• 2017

Many developing countries considering the introduction of nuclear power find that large-scale reactor plants in the range of 1,000 MWe to 1,600 MWe are not grid appropriate for their current circumstance. By contrast, small modular reactors are generally too small to make significant contributions toward rapidly growing electricity demand and to date have not been demonstrated. This paper proposes a radically simplified re-design for the nuclear steam cycle for a medium-sized reactor plant in the range of 600 MWe. Historically, balance of plant designs for units of this size have emphasized reliability and efficiency. It will be demonstrated here that advances over the past 50 years in component design, materials, and fabrication techniques allow both of these goals to be met with a less complex design. A disciplined approach to reduce component count will result in substantial benefits in the life cycle cost of the units. Specifically, fabrication, transportation, construction, operations, and maintenance costs and expenses can all see significant reductions. In addition, the design described here can also be expected to significantly reduce both construction duration and operational requirements for maintenance and inspections.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.467-470
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• 2006

The earth volume which is the basis of all the construction has gone through great development so far with the use of construction machine; however, systematic studies on the related area is in need since the appropriate compound engineering method of earth volume equipments which is a key factor for shortening the project duration and cost reduction is not systematically established and it is dependent on experience. Reasonable mechanical earth volume should take into consideration of performance and characteristics of the equipment, the kind of project, scale and conditions in advance. Also, the optimum compound engineering should be planned by selecting several available scales of equipment. In this study, the earth volume estimate model is established for optimum compound engineering of earth volume equipment for mechanized earth volume equipment loading and moving stage among many stages of earth volume task using system dynamics technique. The optimum compound engineering model of the earth volume equipment produced as a result of this is expected to make reasonable decisions in the shortest time in selecting earth volume facility.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.359-365
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• 2006

Since the start of the KSTAR (Korea Superconducting Tokamak Advanced Research) project, Instrumentation and Control (I&C) of the Neutral Beam Test Facility (NB-TF) has been striving to answer diverse requests arising from various facets during the project's development and construction phases. Hard-wired electrical circuits have been designed, tested, fabricated, and finally installed to the relevant parts of the system. In relation to the vacuum system I&C, controlling functions for the rotary pumps, a Roots pump, two turbomolecular pumps, and four cryosorption pumps have been constructed. I&C for the ion source operation are the temperature and flow rate signal monitoring, Langmuir probe signal measurements, gradient grid current measurements, and arc detector circuit. For the huge power system to be monitored or safely operated, many temperature measurement functions have also been implemented for the beam line components like the neutralizer, bending magnet, ion dump, and calorimeter. Nearly all of the control and probe signals between the NB test stand and the control room were made to be transmitted through the optical cables. Failures of coolant flow or beam line vacuum pressure were made to be safely blocked from influencing the system by an appropriate interlock circuit that will shut down the extraction voltage application to the system or prevent damages to the vacuum components. Preliminary estimation of the beam power through the calorimetric measurement shows that 87.9% of the total power of the 60kV/18A beam with 200 seconds duration is absorbed by the calorimeter surface. Most of these I&C results would be highly appropriate for the construction of the main NBI facility for the KSTAR national fusion research project.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.415-425
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• 2012

Green Frame was developed to embody a Green structural system that can provide long life, resource reduction, and availability of remodeling in apartment buildings. Composite precast concrete column and beam, the major structural material of Green Frame, can be installed precisely and promptly through connection of steels and concrete. The connection of Green Frame can be divided into four types, based on the method and characteristics of connection. To select an appropriate type for the site, a comparative analysis of the four types is necessary. The objective of this study is to compare the duration, cost, quality, and safety of four types. The findings of this study can be applied during the selection that appropriate composite precast concrete column reflected project characteristics in design phase.

• Journal of Construction Engineering and Project Management
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• v.3 no.4
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• pp.12-19
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• 2013

Green Frame is an environmentally friendly column-beam system composed of composite PC members that can increase buildings' life spans while reducing resource consumption. Typically, connections of PC and RC columns occur at the boundaries of each floor, which is at the upper section of slabs, causing the boundary of each floor to generate the maximum moment. Although it is not optimal in terms of structural safety to connect members at a location where the moment is high, this approach is highly adopted due to its constructability. We propose that a superior approach that employs the concept of connecting columns at the low bending moment zone can be applied to quickly and safely install green columns, the main structural members of Green Frame. Connection of green columns at the low bending moment zone can be classified into three techniques, depending on the method of reinforcing the joints, which have different connection characteristics and construction methods. Research is needed to compare the features of each method of reinforcing the joints so that the most appropriate column connection method can be chosen for the site conditions. This study aims to confirm the structural safety of the connection component at the low bending moment zone and to compare and analyze the construction duration, unit price, quality and safety performance of each column connection method. The study results are anticipated to activate the use of composite precast concrete and to be used as development data in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.95-105
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• 2022

Recently, as the scale of a construction project has become larger and more complicated, there are many cases where construction projects with complex structures are carried out in a fast track method to save construction duration. In the fast track method, the proper division of construction phases is an important issue in determining the overall project period. This study presents a rational phase division method that can be applied when a construction project with complex structures is carried out as a fast track. For this study, a subdivided work breakdown structure (WBS) is developed using the construction of 4 soccer stadiums as application examples, and the schedule is analyzed by dividing the construction process of major phases. To this end, five proposals are applied to analyze the adequacy of the fast track phase division. For the draft with the minimum construction period, the fast track phase division and the schedule model of by each phase were presented. This methodology can have an application in the appropriate phase division and schedule model by construction phase when fast track is applied in large construction project of a similar size.