• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.267-275
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• 2023

As aged infrastructures have been increased, the importance of accurate maintenance costs and proper budget allocation for infrastructure become prominent under limited resources. This study proposed a mapping algorithm between representative defects, repair methods, and the estimated maintenance costs for concrete bridges. In this regard, using BMS (Bridge Management System) data analysis, bridge repair methods were classified and matched with defects according to their locations, types, and sizes. In addition, the maintenance costs were estimated based on the amount of work-load and quantity per unit using CSPR (Cost Standard Production Rate). As a result, the level of accuracy was an average of 85.1 % compared with the actual bill of quantity for Seoul bridge maintenance. The accuracy of maintenance costs is expected to be enhanced by considering the various site conditions such as pier height, extra charge conditions, additional equipment, etc.

• Journal of the Korean housing association
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• v.22 no.5
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• pp.101-110
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• 2011

The Ministry of Land, Transport and Maritime Affairs has announced a policy which can enable the building of urban type housing with the use of a prefabrication method 2010. However, such may possibly be at standstill owing to the prefabrication methodology that has not been currently developed in Korea. Moreover, small households of consisting of one or two family members have been steadily increasing, but the small housing units in which they reside has been decreasing. Due to this situation, urban type housing has been proposed. To expand the propagation of such urban type housing and to promote prefabrication methods, the top priority project is to develop a technology that is able to reduce construction costs, as well as to shorten the actual construction period. In consideration of this prefabrication system for an avenue to solve such problems, a series of systems and policies for the fostering of prefabricated urban type housing has been proposed. This study is to review a series of methods, technologies and policies that are required for such urban type housing and henceforth, to utilize such as preliminary data for further prefabricated urban type housing.

• KIEAE Journal
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• v.16 no.6
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• pp.13-19
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• 2016

Purpose: In this study, we examined outdoor air fraction using historical data of actual Air Handling Unit (AHU) in the existing building during intermediate season and analyzed optimal outdoor air fraction by control types for economizer. Method: Control types for economizer which was used in analysis are No Economizer(NE), Differential Dry-bulb Temperature(DT), Diffrential Enthalpy(DE), Differential Dry-bulb Temperature+Differential Enthalpy(DTDE), and Differential Enthalpy+Differential Dry-bulb Temperature (DEDT). In addition, the system heating and cooling load were analyzed by calculating the outdoor air fraction through existing AHU operating method and control types for economizer. Result: Optimized outdoor air fraction through control types was the lowest in March and distribution over 50% was shown in May. In case of DE control type, outdoor air fraction was the highest of other control types and the value was average 63% in May. System heating load was shown the lowest value in NE, however, system cooling load was shown 1.7 times higher than DT control type and 5 times higher than DE control type. For system heating load, DT and DTDE is similar during intermediate season. However, system cooling load was shown 3 times higher than DE and DEDT. Accordingly, it was found as the method to save cooling energy most efficiently with DE control considering enthalpy of outdoor air and return air in intermediate season.

• Journal of the Korean housing association
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• v.11 no.3
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• pp.53-63
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• 2000

The purpose of this study is to improve design method for renovating an environmental friendly residential space where nature and humans could coexist. In the present study, five deteriorated multi-family housing complexes have been selected and one hundred and thirty eight dwellers have been asked about ecological important factors through the questionnaire. This study presents the adaptable solutions, such as are the enlargement of unit space or area, the renovation of facade, the functional change for dwellings on the ground level, the open piping of circulation systems, the expansion of community facilities(include greenarea), the build up of spatial hierarchy and the housing development set reuse planning forth as a premise, for the aspects of dwelling unit, building block and site planning.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.183-190
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• 2020

Currently, the multi-unit houses are the largest in the ratio of housing types, and the number of households in multi-unit houses is steadily increasing. As the multi-family housing project continues, the accuracy of estimates for decision-making and feasibility assessment are required in the early stages of the project. Therefore, this study selected the influential factors affecting the estimated estimate and showed the relative importance of each factor through weight analysis and suggested the method of calculating the estimated estimate to improve the accuracy. The calculation plan presented through this study will be used as a useful data for project feasibility review and is expected to make a great contribution in preventing the economic loss of the client.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.113-114
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• 2012

The productivity of the construction industry is lower than other industries. Modular system is suggested to enhance the productivity of the construction industry. Modular system is a construction method which installs units manufactured in factory on site. It enables to reduce the duration and improve the quality of the constructions. However, the construction technique applied to modular system has not overcome certain structural problems. To solve the problems and motivate the application of modular system, this study propose the hybrid system which use core to resist a lateral force.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.8
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• pp.787-795
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• 2001

An experimentation on the on-line fault detection and diagnosis(FDD) system has been performed with HVAC system in he experimental building constructed inside the large scale environmental chamber. Personal computer with a home-made FDD program by pattern recognition method utilizing artificial neural network was connected on-line via Ether-net TCP/IP to the supervisory control server for HVAC system. The FDD program monitored the HVAC system by 1 minuted interval. The results showed that he FDD program detected the sudden or abrupt faults such s those in fans, sensors and heater, etc.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.67-68
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• 2010

Recently, there were not enough studies regarding the mix adjustment and changes of normal physical properties of slump flow type concrete in domestically. Therefore in this paper, it is aimed securing the fundamental data about flow its mix design method by experimental research. The experiment includes the adjustment of the way for slump flow type concrete by the variation of size of coarse aggregate. In the result, it is advisable raising the ratio of fine aggregate and unit water amount by considering the specific surface when increasing the Gmax size.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.72-73
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• 2019

As the physical functions of school buildings and the changes in the functions of educational facilities due to social change are increasing, the demand for fundamental and long-term measures for the maintenance of educational facilities is expanding. However, depending on the function of the facility, the maintenance work has been carried out only when it is directly related to the safety problem, or when the request of the school facility manager is requested, rather than supporting preventive maintenance. In this study, we investigate the maintenance process of educational facilities and propose a method to manage the maintenance process of the educational facilities in the unit of space for establishing an efficient maintenance management system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.130-135
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• 2001

In this study, I have researched into the causes of defects in apartment house, The results of this study are listed below. (1) Water leakages which result from land sinking and cracks, results of misuse of back filling method, are the main reason of defects in civil engineering work and architectural work. (2) Inexperience and unwillingness are the main reason of defects in plaster work. (3) In windows work and painting work, the main reasons are lacks of precision construction and efflorescence resulting from outdoor air, respectively. (4) Defects in waterproofing work and electric work result from fault construction by low unit Costs. (5) Equipment work requires uses of standardized construction materials and management, and landscape architecture work requires minimizing human mistakes, for instance, degin carelessness. For the reasons stated above, the causes of defects in apartment house are insufficient construction labors, inferior construction materials, urgent construction process time, and conscientiousless industrialists who only seek after a profit margin.