• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.415-422
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• 1994

Recent new town construction project proouced large numbers of apartment houses using precast concrete (P. C.) panels. l'bst construction companies involved in this project put their management focus on to the individual control of P.C. panel producing plants and the job sites. Little attention was paid to the integrated management of the production. transportation. and im;tallation of P. C. panels. Numerous job site delays experienced in the new town project were largely based on the poor coordination between these three key disciplines of the P. C. apartment construction. This stlldy was initiated with an .intention to improve coordination between these disciplines. Activities of these disciplines were identified and related data were gathered. This was performed through the interv:iews with the personnel involved in P. C. constructlon and through the analy::;is of the related documents and publications. Based on this information. the authors are nolol developing a model IoIhich will provide a foundation for opt:iJnal.ly coorc.inated control of the proouction. transportation, and installation of P. C. panels for apartment construction. In this paper. the authors briefly present intermediate results of this study.

• Journal of Korean Society of Steel Construction
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• v.25 no.6
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• pp.649-658
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• 2013

Recently, an urgent issue of the global environment in the 21st century is the well-established paradigm of a sustainable and circulatory system. In the field of construction, it is important to approach sustainablity issues from a structural engineering point of view. The reusable steel structural system, which can adapt to changes in socio-economic conditions and varied demands, realized that the consumption of natural resources was minimized, the environmental load was reduced as much as possible. In order to reuse and recombinant the structural members, removable PC slab connection was introduced. This paper investigates the structural performance and serviceability by the dynamic characteristics of the steel beam to concrete slab connection.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.557-560
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• 2008

This was done by analyzing the sandwich panels that are now widely used in construction work. Sandwich panels are used for diverse purposes in construction work worldwide. In Korea, polystyrene panels that have organic materials as their core material are used. These panels are thus very vulnerable to fire, with risks of core melting, sheet deformation, and hazardous gases. Accordingly, sandwich panels' fire-resistant or non-flammable properties must be secured. To solve these problems, the optimal mixing proportion of lightweight foamed concrete for the sandwich panel core was determined. A new method of doing this was introduced that is completely different from the existing method, wherein a foaming agent is added to realize lightweight concrete. For lightweight concrete, the foaming mechanisms via diverse chemical reactions were identified, H$_2$O$_2$ was added for heating in the reaction, and the concrete foaming was maximized. Through diverse experiments to determine the optimal mixing proportion of lightweight foamed concrete and to examine the filling characteristic of lightweight foamed concrete for sandwich panel cores using waste materials, the physical and mechanical properties of lightweight foamed concrete were examined.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.92-101
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• 2005

The duration of highrise building projects is more shorter than its increasing of the numbers of floors. The project is liable to overrun of the time in which the project must be complete. AS highrise buildings are increased, time management has been reorganized as critical success factor. To improve time management, time management softwares are introduced and the software's education is made lively in construction company. However a large amount of time management works still have been based on not the software but scheduler's experience. We often can find the time overrun risk of highrise building because of the shortage of scheduler's experience. To diminish the mistake of the scheduler who does not have much experience, we suggested HRB Expert which uses expert's knowledge to make the time plan of highrise building. We made an example of knowledge acquiring and knowledge usage which cased on reinforced concrete work of highrise building by literature review and interview with scheduling expert. The precision of time plan will be enhanced and time overrun will be prevented on condition that HRB Expert is constructed and used

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.29-36
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• 2009

Recycling of wood wastes or residues is a good solution for a shortage of wood resources and a rise in the price. Shipbuilding wood wastes were almost used to produce the boards by milling. However, considering the economic value and insufficient resource, recycling with milling is dissatisfied method. This study has been carried out to investigate the recycling possibility of shipbuilding wood waste. There are two kinds of shipbuilding wastes: plywood waste and solid waste. From the results of this study, the following conclusions have been made: 1. Bending properties of plywood and laminated plywood lumber were tested by Korean Standard. 2. The main fracture mode of plywood waste and laminated plywood lumber is that of simple tension. 3. The recommended application for the recycling of shipbuilding wood waste are outdoor wood furnishings, indoor wood furnishings and some wooden building construction materials: interior raw material, wooden pallet, siding, paneling, flooring. picnic table, deck components, porch swing, landscaping timbers, residential fencing, patios, and boardwalks etc.

• Fire Science and Engineering
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• v.19 no.3 s.59
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• pp.70-75
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• 2005

The heat of combustion of polymer materials is an important fire characteristics, which can be used with other fire parameter to predict the potential fire hazard in the polymer handling process. The aim of this study is to predict the heat of combustion for polymers which used in the building interior materials. By using the literature data and multiple regression, the new equation for predicting the heat of combustion of polymers is proposed. The A.A.p.E.(average absolute percent error) and the A.A.D.(average absolute deviation) of the reported and the calculated heat of combustion by means of the oxygen consumption calorimeter and the stoichiometric coefficient were 4.46 and 1.09, and the correlation coefficient was 0.972. The values calculated by the proposed equations were in good agreement with the literature data. Therefore, it is expected that this proposed equations will support the use of the research for other polymer materials.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.416-421
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• 2001

The domestic reinforcement concrete works have mainly worked the process of re-bar fabrication/assembly on site and re-bar works affected by structural safety, durability, and schedule with form work. Accordingly, This study analyzes the process of re-bar fabrication/assembly on site to apply lean production principles to construction Value Stream Analysis(VSA) is analyzed into value-adding activity and non-value-adding activity on construction process through value analysis and Value Stream Mapping(VSM). In the results, non-value-adding activity generates waste such as the activity steps, labors, equipments, materials, time, and so on. Additionally, push-driven production is investigated making low productivity from the overproduction and so on. To resolve the problems in the process, The purpose of this paper eliminates waste factor through maximizing the value-adding activity generating value added and minimizing non-value adding activity. Particularly, it makes flow production and pull-driven production through minimizing work-in-process(WIP ).

• Korean Journal of Construction Engineering and Management
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• v.5 no.4 s.20
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• pp.71-78
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• 2004

In this study, the concept of Just-In-Time, Lean Construction and Supply Chain Management have been applied to furniture works of high-rise residental building. For the purpose of systematic furniture work planning, it should be established to analyse furniture-work process from design phase through contract, and procurement to construction phase. The analysis of process and data for furniture-work provides the roles of conducting subjects and presents management items at each phase. This proposal will provide the systematic furniture-work managements and reduce construction time and cost, and also raise the quality of furniture works.

• Korean Journal of Construction Engineering and Management
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• v.16 no.2
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• pp.21-28
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• 2015

Construction defects are major components that result in cost overruns and schedule delays in construction projects. There have been extensive research efforts to investigate the cause of defects. However, little effort has been devoted to analyze correlation among various reasons of construction defects while a defect is not usually an outcome of a single cause, but rather occurs when several interrelated causes combine. Based on this recognition, this paper analyzes 831 nonconformity reports collected from 30 construction projects in Korea from 2011 to 2014. The correlation analysis revealed that a significant portion of construction defects occurred in the procurement and construction phase and as the pattern of function defect and installation defect. Triggered by human error, defective material and faulty method, these defects are treated by conccession, repair, rework that can significantly lower the cost and schedule performance. This paper is significant in terms of providing a theoretical basis for analyzing correlation among various reasons of construction defects and quantitative measures for establishing effective defect prevention strategies.

• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.73-78
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• 2013

Hexadecane and exfoliated graphite nanoplate (xGnP)composite was prepared as a shape-stabilized phase change material (SSPCM) in a vacuum to develope thermal energy storage. The Hexadecane as an organic phase change material (PCM) is very stable against phase separation of PCM and has a melting point at $18^{\circ}C$ that is under the thermally comfortable temperature range in buildings. The xGnP is a porous carbon nanotube material with high thermal conductivity. Scanning electron microscope (SEM) and Fourier transformation infrared spectrophotometer (FT-IR)were used to confirm the chemical and physical stability of Hexadecane/xGnP SSPCM. In addition, thermal properties were determined by Deferential scanning calorimeter(DSC) and Thermogravimetric analysis (TGA). The specific heat of Hexadecane/xGnPSSPCM was $10.0J/g{\cdot}K$ at $21.8^{\circ}C$. The melting temperature range of melting and freezing were found to be $16-25^{\circ}C$ and $17-12^{\circ}C$. At this time, the laten heats of melting and freezing were 96.4J/g and 94.8J/g. The Hexadecane was impregnated into xGnP as much about 48.8% of Hexadecane/xGnP SSPCM's mass fraction.