• Journal of the Korean Wood Science and Technology
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• v.40 no.1
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• pp.10-18
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• 2012

A high airtightness is required for the residential spaces constructed recently to save cooling and heating energy through improving insulation performance. Because the chances to release steam formed by human activity in building and inflow of water vapor in outdoor air to residential space are reduced, the natural humidity control performance of interior materials has become more important. In this study, hygroscopic performance of thermo-physically treated wood (Pinus koraiensis) was estimated. At various relative humidity condition, the water vapor adsorption and desorption rates of wooden materials were measured as well as equilibrium moisture content. Effects of roughness and surface microstructure as physical factors and functional groups as chemical factors on the hygroscopicity were analyzed. It is expected that the results from this study and further study of measuring moisture generation in residential spaces could contribute to install a system for evaluating the hygrothermal performance of wooden building.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.252-258
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• 2018

A larger energy consumption and concentration of population induced green house gas glowing and heat island effect in the urban space. Roof green system was a effect method to reduce green house gas and heat concentration in the city. Therefore, construction of this system was increasing. Most of lightweight soil used in roof green system was perlite, but this caused dust and skin disease. So it needed to develop another new lightweight soli for roof green system. Meanwhile, a thermoelectric power plant generated bottom ash as a by-product. According to previous research, bottom ash could be used for artificial lightweight soil with 60 wt% of mixing rate. But this study was proceed to develop a artificial lightweight soil using bottom ash with higher mixing rate by 65 wt% and different organic ingredients. First, physical and chemical properties of bottom ash was investigated. Then test according to landscaping design standard was proceeded for various artificial lightweight soil mix types using bottom ash, bark, compost and coco peat. As a result, the artificial lightweight soil with 65% of bottom ash, 30% of bark and 5% of compost was suitable for low and middle range of soil standard.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.347-355
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• 2021

During the earthquake, for multi-story structure, if the first floor is soft, the deformation will concentrate on that floor causing a serious damage to the column members which might leads to the collapse of the whole structure like Piloti structure during the Pohang earthquake in Korea. According to the 2016 National Disaster Management Research Institute's "Investigation of Seismic Reinforcement and Cost Analysis of Domestic Non-seismic Buildings", the rate of seismic resistance of private reinforced concrete buildings was 38.3 %. Among them, it was reported that the seismic-resistance ratio of the two to five-story structures was less than 50 %. Accordingly, the government is trying to improve the seismic rate through support projects, but the conventional seismic reinforcement methods are still expensive, and emergency construction is difficult. Therefore, in this study, the field applicability was evaluated by improving the reinforcement method using Velcro, which was developed through the research project of the Ministry of Land, Transport and Maritime Affairs in 2014. In order to improve the performance of the Velcro reinforcement method, introducing the initial tension of Velcro using high foaming rigid urethane filling between the Velcro and concrete of the columns was applied. Additionally, an experiment was conducted to evaluate the ductility of Velcro specimen from the concrete confinement effect. As a result, the ductility of the Velcro specimen was improved compare to Normal specimen. However, the energy dissipation capacity of VELCRO2 is better than VELCRO1, yet the maximum ductility of those two specimens did not show a significant difference. Therefore, the improvement of the internal filler material is still needed to have a better maximum ductility.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.12-21
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• 2023

Green remodeling proposed in the Korean New Deal is a project to build or remodel eco-friendly and energy-efficient buildings using renewable energy facilities and high-performance insulation for public buildings. The government intends to achieve the carbon emission reduction target by conducting green remodeling. Major overseas cities that conduct green remodeling are actively promoting technology support and promotion along with energy performance evaluation according to building characteristics, subsidies for private revitalization, and tax benefits. With this background, the analysis of the current status and problems of the green remodeling project was performed and the Activation factors of Green Remodeling were derived from survey results. This study suggested strategic measures such as a participation of civil society, promotion, and priority selection of administration and policy measures such as a leading role of the public sector, expanding support for the socially underprivileged, and financial support and tax benefits. And this study results are expected to be utilized as basic data to promote the green remodeling project.

• KIEAE Journal
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• v.15 no.6
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• pp.57-62
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• 2015

Purpose: This study, which is based on the investment payback periods, aims to suggest the proper insulation level which can be adapted to the Defense Military Facility Criteria regarding the military residential condominiums. For the energy performance simulation, it is required to collect the residential data regarding the military condominiums and climatic data concerning the regions they belongs to. The estimates through energy performance simulation are the regional heating loads and the heating transmission coefficients of building components. Method: With the heating loads, the annual heating cost saving per square meters is assessed. With the heating transmission coefficients of building components, the additional insulation installment cost per square meters is evaluated. With two outcomes, one as an annual value and the other as a present value, the investment payback period is calculated. Result: In result, it could be concluded that 55~70% insulation ratio can lead a superior residental environments as well as be contributed to the national policy associated with zero-energy buildings because the estimated investment payback period is shorter than the life span of the military residental condominiums. This upshot can be used as a foundation to enactment the Defense Military Facility Criteria associated with military residential condominiums.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.17.1-17.1
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• 2009

발포금속은 1948년에 Sosnik에 의해 알루미늄에 수은을 증발시키는 방법으로 발포 알루미늄을 제조한 이래, 1951년 Elliot에 의해 진보된 방식인 발포 매개체를 용탕에혼입하는 방법으로 발포금속을 제조하기 시작하였다. 현재 이들 선진국가의 생산방법 및 현황은 균질 기공의 조절, 연속주조 방식과 원가절감, 그리고 제조기술의 진보를 통하여 다양한 분야에 적용되고 있다. 그러나 실용화를 위해서는 요구특성을 만족하고 동시에 가격 경쟁력을 가진 제조기술의 보유 및 개발과 독특한 특성을활용한 새로운 적용 분야의 개척이 필요하다고 생각되며, 이를 위해 Harvard, MIT, Aachen, HMI 등 구미 유수 대학과 NASA, 미국방성등의 연구기관, ERG, 신강(新鋼) wire등 산업체를 중심으로제조 및 특성평가에 관한 기초연구와 활용방안이 활발히 모색중에 있다. 그리고 일부 자동차 생산 업체를중심으로 발포금속을 적용한 초경량, 에너지 절감형의 자동차 부품 소재,항공기 방열판 등에 대한 연구가 활발하게 진행되고 있다. 특히 금속 기체의 GASAR 공법은 Lotus 공법으로 Osaka 대학에서 개발되어 열교환기, 항공기, 방열기 등으로 응용이 확대되고 있다 국내에서 완제품생산은 실내장식용 복합패널로서 한소 프라임이 운영상의 문제로 생산을 중단하였으며, 유닉슨(주), 금강(주)에서 Batch식, 금성산업에서 Pot식이 일부 생산 및 연구가 진행되었으나 현재는 본연구실의 협조로 (주) 폼텍에서 발포패널을 주로 생산하고 있고 (주)드림메탈과 (주)아크로폼텍에서일부 생산되고, (주)동일알루미늄에서는 폐 scrap을 이용한 발포 Al 제조가 연구단계에 있다. 생기원에서는 분말 가열 흡음패널이 개발되었으나 강도와 내열성이 낮아 이들 특성을 향상시크는 연구가 진행중이다. 이들 제품은 성능상으로는 동양강판의 흡음패널과 KIMM의 필터용은연구개발이 낮은 수준이며, 본 연구팀과 공동 개발한 (주)폼텍의 복합패널은 10여 가지의 실용특허로 건축마감재로서 오히려 선진국수준을능가한 상태이다, 한편, 발포금속 기능성 개발은, 이들이 가지고 있는 우수한 특성 때문에 군수용으로부터 민수 산업용까지 전분야에 적용이 가능한 소재이므로 수요처를확장하고 있으므로 제품의 균질성, 안정성과 기능성 개발 향상을 위해 지속적이고 체계적인 연구가 필요하다고 생각된다.

• KIEAE Journal
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• v.11 no.6
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• pp.87-93
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• 2011

This study examines building's power consumption unit cost and Building Integrated Photovoltaic (BIPV)'s generation efficiency and load rate with the subjects of university dormitory buildings in order to suggest foundational data for new and recycled energy use and management to plan and operate university dormitories afterwards. Thereby, this research gained the following findings. 1. The quantity of solar radiation and efficiency change in the BIPV system applied to the research subject buildings after the lapse of time was averagely 8.7%, and it is thought that temperature increase determines conversion efficiency with the influence of surrounding outside temperature and the module's temperature. 2. The generation efficiency of the BIPV system in the research subject buildings was averagely 10.9%. In May, it was 13.9%, and in January, it was the lowest as 10.25%. Considering the fact that power consumption reduces during an intermediate period, it will be necessary to establish measures for equipment and power consumption load balancing. 3. The monthly load rate of the BIPV system was averagely 4.09%. In May, it was the highest as 4.94%, and in July, it was the lowest as 3.24%. 4. It is intended to conduct constant follow-up research on estimating university dormitory building's power consumption unit cost and examining the generation efficiency and load rate of the BIPV system.

• KIEAE Journal
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• v.17 no.3
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• pp.5-13
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• 2017

Purpose: Various studies have been performed to address the issue of increased energy use by buildings. In particular, research on complex envelopes that combines diverse envelope element techniques is currently in progress in the building sector. The present study aimed to develop an awning system using a light shelf, and to verify its validity through performance evaluation. Method: In the present study, a testbed was established for the performance evaluation of the awning system using a light shelf, and the uniformity ratio and lighting energy consumption were compared and analyzed relative to those with no awning and light shelf installation (Case 1), awning installation (Case 2), and light shelf installation (Case 3). Result: 1) In the present study, an awning system using a light shelf (Case 4) where an opening is made on the awning screen and natural light can be introduced through the light shelf located at the bottom was developed. 2) The optimum standard for Case 4 obtained through the performance evaluation was a 0.6m lighting length and a 2m extension length at a light shelf angle of $30^{\circ}$. 3) Case 4 with the optimum standard had a 5.5% lower uniformity ratio than Case 2, but had a higher uniformity ratio than Case 1 and Case 3. 4) Case 4 with the optimum standard showed 13.3%, 44.6%, and 0%~8.7% lighting energy reductions compared to Case 1, Case 2, and Case 3, respectively. 5) Based on the above results, Case 4 suggested in the present study was found to be effective for indoor light environment improvement and lighting energy reduction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5045-5050
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• 2015

As modern houses are constructed with high-density and high-insulation, there is benefit to reduce energy consumption, but there are many side effects raised from polluted air. To solve the problem, a ventilation system is used to improve a indoor air quality. In this study, we tested the parallel flow type heat exchanger used in a heat exchanger of an automotive air conditioner. And we experimentally estimate ventilation performance of HRV(heat recovery ventilator) with heat-pipe according to working fluid filling quantity and ventilation. The working fluid was R22, which was filled from 40 to 60 (%vol.) by 10(%vol.). Ventilation based on the front velocity was measured from 0.3 m/s to 1.5 m/s by 0.3 m/s intervals. Refrigerant filling quantity with the highest efficiency was found to depend on the ventilation. From this study the optimal refrigerant filling quantity in accordance with the ventilation of the detachable heat pipes was found experimentally.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.4
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• pp.531-540
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• 2019

Existing dozer productivity computation models use different input variables, formulas, productivity correction factors, and experimental data source. This paper presents a method that characterizes the productivity outputs obtained by the PLS model and the Caterpillar model that are accepted as industry standards. The method identifies the input variables to be collected from the site, the performance charts to be referenced, and the formulas and implements them in a single computational tool. This study verifies that the PLS model may replace the manual computational process of Caterpillar model by eliminating reliance on graphics manipulation. Replacing the Caterpillar model with the PLS model and implementing the process as a function contributes to assess the productivity of a dozer timely by encouraging to utilize real-time information collected directly from the site. This study allows researchers and practitioners to effectively deal with the values of productivity correction factors collected from the job site and to control the productivity. The practicality and effectiveness of the method have been validated by applying to a project case.