• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.35-42
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• 2018

Semi-transparent Photovoltaics (STPV) works as an exterior material replacing windows as well as functioning as a electricity generator. As a result, it also affects the building's heating, cooling and lighting loads. In this study, we used the concept of Net Electricity Benefit(NEB) to conduct a parametric analysis of building energy impact of STPV. The NEB of STPV is from $-1kWh/m^2$ to $6kWh/m^2$. Since NEB represents the amount of energy increase or decrease when STPV is applied compared to the standard window, a value of 0 or less means that the demand for building energy can be increased rather than applying a general window having high thermal performance and high visible light transmittance value. Therefore, it is necessary to perform a comprehensive performance evaluation considering both the performance evaluation based on the existing power generation performance and the influence on the building energy.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권7호
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• pp.329-333
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• 2001

The pulsed poser system has been widely used to many applications, such as E/P(Electrostatic Precipitator), DeNox/DeSOx power system, ozon generator, etc. A pulse energy efficiency for load depends on the rising time, peak value, pulse duration and impedance matching, etc. The pulse generator generally required for short pusle duration and high peak value was forced to consider its volume and economy. In this study, developing a compact pulse generator that applied for cascading method to be made of two pulse transformers, we compared cascading voltage with non cascading one by applying the pulse energy to load. Adopting cascading technique to pulse transformer, we found that average cascading voltage was about 60[%] of theoretical value. Maximum cascading ratio was calculated at 60 times compared with non cascading voltage.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1758-1771
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• 2017

In this study, to determine the most effective alloy for shielding against gamma-rays, the gamma-ray shielding parameters of six types of cerrobend alloys have been investigated. Gamma-ray interaction with the cerrobend alloys has been discussed mainly in terms of total mass attenuation coefficient (${\mu}_t$), half value layer (HVL), tenth value layer (TVL), effective atomic number ($Z_{eff}$), and effective electron density ($N_{eff}$). These parameters have been calculated by theoretical approach using the ParShield program in a photon energy range between 0.1 MeV and 100 GeV. The dependence of these parameters on the incident photon energy and chemical composition of the cerrobend alloys has been studied.

• 전력전자학회논문지
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• 제23권2호
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• pp.106-111
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• 2018

In this work, we propose techniques for estimating the SOC of Li-air battery. First, we describe and explain the operation principle of the Li-air battery. Energy density of the Li-air battery was compared with that of the Li-ion battery. The capacity and impedance value of the fully discharged voltage is analyzed, and the OCV value for SOC estimation is measured through the electrochemical characterization of the Li-air battery. Estimation value is obtained by SOC modeling through extended Kaman filter and is compared with the measurement value from the Coulomb counting method. Moreover, the performance of SOC estimation circuit is evaluated.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.126-133
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• 2008

Geotechnical limit state design methods; LRFD of North America is an approach that estimates resistance using design model and then multiplies resistance factor by calculated resistance to reflect the uncertainty of geomaterials and design models; whereas, Eurocode of the Europe employs the partial resistance factor applied directly to each variable in the resistance equation that individual soil properties such as cohesion and angle of internal friction are applied. This discussion paper is a study on characteristic value which has globally been argued through processing of development of Eurocode 7 for geotechnical design even to the present. Estimating the characteristic value of soil properties affects not only determination of design value applied directly to design of geotechnical structures, but also economic feasibility and stability of the structures.

• Nuclear Engineering and Technology
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• 제49권1호
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• pp.216-223
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• 2017

In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and $10^{th}$ value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

• 한국환경보건학회지
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• 제26권4호
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• pp.38-44
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• 2000

Compared to other waste, waste tire has much discharge quantity and calorie. When we use waste heat from waste tire, it can be definitely better substitute energy than coal and anthracite in high oil price age. To use as a basic data for providing low cost and highly effective heating system, following conclusion was founded. Annual waste tire production was 19,596 million in 1999, Recycling ratio was almost 55% and more than 8.78 million was stored. Waste tire has lower than 1.5% sulfur contain ratio which is resource of an pollution, So it is a waste fuel which can be combustion based on current exhaust standard value without any extra SOx exclusion materials. Waste tire has 9,256Kcal/kg calorific value and it is higher than waste rubber, waste rubber, waste energy as same as B-C oil. When primary and second air quantity was 1.6, 8.0 Nm$^3$/min, dry gas production time was 270min and total combustion time was 360 min. In the SOx, NOx, HC of air pollution material density were lower than exhaust standard value at the back of cyclone and dusty than exhaust standard value without dust collector.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.642-648
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• 2021

In this paper, an experimental study was conducted on the performance of the cooling tower. In order to improve reliability in the cooling tower performance test, the measurement uncertainty of the instrument was estimated. Measurement uncertainty refers to the uncertainty of a measurement, estimates the range in which the expected value of the measurement can be within a certain confidence level, and suggests a range in which the measured representative value is incorrect. Therefore, the measurement result of the performance experiment is not an actual value, but a reasonable estimated value. The measurement uncertainty for the test was calculated and the measured results were presented.

• 문화기술의 융합
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• 제8권4호
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• pp.313-322
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• 2022

BIM의 생산성과 효율성 때문에 건축설계 방식으로 BIM을 선택하는 건축가들이 증가하고 있다. 또한 건물의 에너지 사용량에 대한 인식 제고와 환경에 대한 관심이 높아지면서 빌딩에너지 코드의 필요성에 대한 요구가 증가하고 있다. 현재 많이 사용하고 있는 2D CAD 설계방식으로는 건물 외피 에너지코드를 검정하는데 많은 시간과 노력이 소요되며 디자인 변경에 다른 즉각적인 대응이 어렵다. 이 연구의 목적은 BIM을 통한 건물 외피 에너지 모델링의 효율성을 보여주는 데 있다. 우리는 BIM을 통해 설계과정에서 디자인 변경에 따른 정보 값을 누락이나 재계산 과정 없이 동시에 산출할 수 있기 때문에 건물 외피 에너지코드 검증에서 생산성과 효율성을 높이는 데 기여할 수 있다. 연구의 절차는 다음과 같다. Revit 2011으로 만든 the Goldin at Essex Crossing 공동주택의 BIM을 사례 모델로 하여, 뉴욕시의 에너지 코드에 부합하기 위한 에너지 계획의 기준을 분석한다. Revit 모델의 설정을 통해 나온 결과 값과 뉴욕시의 에너지코드에서 요구하는 기준 값을 비교한다. 최종적으로 미국 에너지국 (U.S. Department of Energy)에서 제공하는 에너지 검증 프로그램인 COMcheck에 데이터값을 입력하여 건물 외피 에너지 성능이 뉴욕시 에너지 코드에 부합하는 지 여부를 체크한다.

• 분석과학
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• 제31권1호
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• pp.31-38
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• 2018

기존 폐기물 저위발열량 측정 분석 방법은 소량의 시료에 대한 발열량계 측정 및 원소분석 결과로 저위발열량 환산식을 적용하여 산정하도록 규정하고 있다. 즉, 기존 저위발열량 산정방법은 폐기물의 불균질성, 지역적 특성, 계절적 특성 등을 충분히 반영하지 못하여 대표성과 객관성 측면에서의 한계를 나타내고 있다. 이러한 문제로 환경부 고시(제2015-251호)에서는 저위발열량의 대표성 확보를 위하여 산정방법을 개정하였으며, "KS B 6205 육상용 보일러의 열정산방식"을 바탕으로 열정산방법을 적용한 사업장폐기물 소각시설에서의 저위발열량 산정방법을 제시하고 있다. 본 연구에서는 현재 운영 중인 사업장폐기물 소각시설을 대상으로 열정산법에 따라 시설별 투입 폐기물의 저위발열량을 분석 평가하였다. 사업장폐기물 소각시설 7 개소 (10 개호기)에 대한 저위발열량 평가 결과 평균 약 3,404.7 kcal/kg로 산정되었으며, 세부 산정 인자에는 실제 시설 운영 데이터를 수집 종합 하여 적용하였다. 본 연구에서 적용한 개정된 저위발열량 산정 방법은 불균질한 성상의 폐기물 특성을 반영할 수 있는 방법으로, 기존 폐기물 발열량 산정방법과 비교하여 보다 객관성을 확보한 방법인 것으로 판단된다. 본 연구의 결과는 추후 세부적인 저위발열량 산정방법 개선 및 산정인자 도출 등을 위한 기초자료로 활용 될 수 있을 것으로 판단된다.