• Journal of the Korean Wood Science and Technology
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• 제44권5호
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• pp.655-663
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• 2016

최근, 전 세계적으로 온실 가스 증가에 따른 기후 변화에 대한 문제가 논의되고 있다. 그중, 건축물에서의 에너지 소비량은 전체 에너지 소비량의 40%까지 증가할 것으로 예상된다. 따라서 건축물에서의 에너지 소비량 절감에 대한 노력이 필요한 실정이다. 본 연구에서는, 건물에너지 절감에 효과적으로 기여하는 재료 중 하나인 목재를 이용하여, 목질 제품 구성에 따른 중부지방과 남부지방의 난방에너지 요구량에 대하여 시뮬레이션을 통해 분석하였다. 시뮬레이션 도구는 미국 에너지부(Department of Energy)가 BLAST와 DOE-2의 장점을 결합해 만든 동적 에너지 해석 엔진인 EnergyPlus를 이용하였다. EnergyPlus는 다양한 건물 및 HVAC 시스템 구성요소(Object)에 대한 입력항목(Field)을 가지고 있으며, 특히 건물, 공조시스템, 열원기기 사이의 피드백을 통해 통합된 동시계산을 수행하며, ASHRAE Standard 140-2007 표준에 따라 상용 프로그램 간의 비교를 통해 검증된 프로그램이다. 시뮬레이션을 위한 기상데이터는 EnergyPlus에서 제공하는 IWEC 인천 지역과 광주 지역의 epw 형식 기상데이터를 이용하였다. 대상 모델은 한국농어촌공사에서 제시한 2012년 농 어촌주택 표준설계도면 중 '농림-12-26-가' 유형을 이용하였으며 총 10개의 실로 구성되어 있다. 시뮬레이션 분석 결과, 중부지방과 남부지방 별 목질 제품의 적용 범위를 실내마감재, 실외마감재, 창호, 목구조로 단계적으로 변경해 지역에 따라 각각 16 Case의 시뮬레이션을 수행한 결과 실내외의 마감재로 목재를 사용한 것만으로도 에너지 성능이 향상된 것을 확인할 수 있었다.

• KIEAE Journal
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• 제12권2호
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• pp.111-116
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• 2012

Faced with the international issue of environmental problems from global warming and energy consumption, the Korean Government has made many efforts on reducing energy and $CO_2$ emission under the motto of "Low-Carbon Green Growth". In order to reduce energy in the building sector, severe design standards and regulations on saving energy in new buildings have been established. Now, it is necessary to focus on deteriorated buildings where applications of energy saving designs and techniques have been insufficient, for maximizing energy saving in the building sector. Specially, it is very important to reduce energy through the remodeling process at deteriorated school buildings which were built over 20 years ago and sharply changed into the excessive energy consumption structure from new educational curricula. Thus, this paper examined the effects of potential factors to reduce energy at deteriorated elementary school buildings using the energy simulation on the Visual DOE 4.0 program. Among applied factors of insulations, southern louver, window's SHGC, indoor setup temperature, and system efficiency, all factors except window's SHGC turned out contribute to reduce energy at the deteriorated elementary school buildings, compared with the baseline energy performance.

• E2M - 전기 전자와 첨단 소재
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• 제11권10호
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• pp.100-105
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• 1998

Along with fusion energy, photovoltaic solar energy conversion has long been considered as one of the few sustainable options for large scale energy supply in the future. In the past, commercial use has been restricted largely to remote area applications where conventional electricity is expensive. However, 1998 marked a year of transition where the major application of the cells changed to become generation of residential electricity in urban areas already supplied by the conventional grid. The current state of the technology is discussed as are major overseas programs to accelerate the urban residential use of photovoltaics, particularly in Japan, Europe and the United States, includng the "million roof" program in the latter. Finally, the planned use of photovoltaics in the Sydney 2000 Olympics is described, where the technology will be used to provide most of the electricity requirements of the 665 residences which will be a legacy of the Olympic Village.

• Advances in materials Research
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• 제12권3호
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• pp.179-192
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• 2023

We have studied the structural and optical properties of the non-doped and Co 0.08 at.%, Co 0.02 at.%, and Co 0.11 at.% doped ZnO nanorods (NRs) synthesized using the simple low-temperature chemical bath deposition (CBD) method at 95℃ for 2 hours. The scanning electron microscope (SEM) images confirmed the morphology of the ZnO NRs are affected by Co incorporation. As observed, the Co 0.08 at.% doped ZnO NRs have a larger dimension with an average diameter of 153.4 nm. According to the International Centre for Diffraction Data (ICDD) number #00-036-1451, the x-ray diffraction (XRD) pattern of non-doped and Co-doped ZnO NRs with the preferred orientation of ZnO NRs in the (002) plane possess polycrystalline hexagonal wurtzite structure with the space group P63mc. Optical absorbance indicates the Co 0.08 at.% doped ZnO NRs have stronger and blueshift bandgap energy (3.104 ev). The room temperature photoluminescence (PL) spectra of ZnO NRs exhibited excitonicrelates ultraviolet (UV) and defect-related green band (GB) emissions. By calculating the UV/GB intensity, the Co 0.08 at.% is the proper atomic percentage to have fewer intrinsic defects. We predict that Co-doped ZnO NRs induce a blueshift of near band edge (NBE) emission due to the Burstein-Moss effect. Meanwhile, the redshift of NBE emission is attributed to the modification of the lattice dimensions and exchange energy.

• KIEAE Journal
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• 제13권1호
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• pp.57-63
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• 2013

Building Energy Efficiency Rating system was enforced in 2001 to enhance spreading high-energy performance and saving buildings. It was only for the new apartments, but expanded to new office buildings in 2010, and moreover, government offices require 1st grade of Building Energy Efficiency Rating system. Green Building Act, which is established to reduce the emissivity of carbon dioxide by reducing building energy consumption, will be enforced in 2013, and new apartments and office buildings will be subjected to it. Henceforward, it will extend to other types of buildings and will be phased in. In general, pumps and fans consume approximately half of the air-conditioning energy consumption, and about a quarter of the total building energy consumption when office buildings have total floor area of more than 10000 square meters. This study analyzed the energy demand when applying VAV(Variable Air Volume) and VWV(Variable Water Volume) System to reduce energy returns of the pumps and the fans by ECO2, which is a computer simulation program used for Building Energy Efficiency Rating system.

• 대한가정학회지
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• 제12권3_4호
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• pp.641-662
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• 1974

The purpose of this study is to present the basic rule on the planning standard menu for the improvement of nutritional school lunch program through analysis of their food habits and daily energy expenditure. 1. The purpose of the school lunch program is to get on adequate diet in quality and quantity through right food habits and nutrition education for the most active growing children. 2. At present time in Korea, school lunch program has not been carried out nutritionaly so that it should be improved immediately. 3. The ratio of the daily diet should be given to the students breakfast 1. lunch 1.1, dinner 1.5, through analysis of their daily energy expenditure by their activity. 4. The result of the analysis of for food habits shows that children like foods which were used at home commonly and dislike foods not commonly used. 5. The basic rule on the planning school lunch menu is presented as follows. 1) The ratio of the aily diet should be given as breakfast 1, lunch 1.1. dinner 1.5, for calories, and minerals and vitamins should be given 1/3 to 2/5 of a daily requirements. 2) It should be selected foods which most children like foods when plan menu for school lunch. 3) Green, yellow vegetables should be given over 50 gm. 4) Milk should be given 180cc.

• Current Optics and Photonics
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• 제4권3호
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• pp.247-252
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• 2020

Important determinants for selecting outdoor lighting are the color-rendering index (CRI) and scotopic-to-photopic (S/P) ratio of the lighting units. The higher the S/P ratio, the better energy savings and visual performance. In this study, CCT-tunable LED lighting units were optimized and fabricated by spectral combination of red, green, blue, and yellow LEDs. The measured results for RGB LEDs provided S/P ratios of 1.55~2.58 and those of RGBY LEDs gave 1.46~2.46 to the correlated color temperatures (CCTs) ranging from 2700 K to 6500 K, with CRI values of over 80 at the same time.

• 한국재료학회지
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• 제21권1호
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• pp.39-45
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• 2011

In this study, the heat flow of the plant scale aluminum extrusion process was investigated to establish optimum continuous heat treatment conditions. During the extrusion of 6061 aluminum alloy, processing parameters such as the extrusion pressure, speed and temperature histories of billets were logged as a function of time. The surface temperature of the billets increased at constant ram speed, while it decreased with decreases of the ram speed. In order to maintain the billet temperature within a solutionizing temperature range prior to the succeeding water quenching step, the ram speed or the temperature of the blower should be controlled. The temperature histories of the billets during the extrusion and hot air blowing processes were successfully simulated by using the velocity boundary model in ANSYS CFX. The methodology to design an optimum process by using a commercial simulation program is described in this study on the basis of the metallurgical validation results of the microstructural observation of the extrudates. The developed model allowed the advantages of taking into account the motion of the extrudate coupled with the temperature change based on empirical data. Calculations were made for the extrudate passing through the isothermal chamber maintained at appropriate temperature. It was confirmed that the continuous heat treatment system is beneficial to the productivity enhancement of the commercial aluminum extrusion industry.

• 에너지공학
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• 제20권4호
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• pp.267-277
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• 2011

후발국에서의 신재생에너지기술의 개발은 어떤 힘에 의해서 추동될까? 후발국의 '녹색 성장'은 '녹색'의 가치 실현을 위해서 추동되는가 아니면 '성장'을 지속하기 위한 새로운 분야의 개척인가? 본 연구는 한국의 신재생에너지 기술개발사업 사례 분석을 통해 후발국 신재생에너지기술개발의 동력에 대한 이해를 돕고자 한다. 환경문제와 기술개발, 기술개발과 '사회기술연맹' 그리고 후발국 '권위주의적 발전국가론'에 대한 기존의 논의를 통해 기술 개발의 동력은 사회기술연맹의 구성에서 찾을 수 있다는 것에 착안하여 연구의 틀을 구성하였고 이를 토대로 선발국 덴마크와 독일의 사례를 분석한 후 한국의 신재생에너지기술개발사업 사례를 분석하였다. 한국은 선진국과는 다르게 산업계와 정부 주도의 성장동맹을 바탕으로 신재생에너지기술개발이 추진되었고 환경시민단체는 정부의 시민단체 국정 참여 정책에 힘입어 신재생에너지정책협의회에 참여함으로써 사회기술연맹을 구성하였다. 따라서 한국의 신재생에너지 사회기술연맹은 '녹색'의 가치 실현보다는 '성장'중심이라는 한계를 갖는다.

• 한국태양에너지학회 논문집
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• 제23권2호
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• pp.81-90
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• 2003

UTAC(unglazed transpired air collector) system has unique advantage for space heating and tempering ventilation air over the conventional collector system such as flat plate and vacuum collector. UTAC can improve radiative and convective loss due to nonglazed component and enhanced plate surface configuration. and heating energy and its equivalent green house emission performance can be improved from the use of this like collector in building application. The Option D Calibration simulation approach of IPMVP(International Performance Measurement and Verification Protocol) in ESCO businesses has been recommended to use of the calibrated computer modules like these Energy-10. DOE2.1E and TRNSYS(transient system simulation). This study is to develop subroutine type-203 of TRNSYS15.2 program and appraise thermal performance of UTAC. With newely addeded subroutine type-203. 1) Thermal performance of unglazed transpired collector could be possible based on dimensionless variables such as efficiency and heat exchanger effectiveness. and 2) Assessement of energy consists of solar useful and insulation saving for UTAC could be possible.