• 한국항행학회논문지
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• 제16권6호
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• pp.960-967
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• 2012

무선 센서 네트워크는 주변의 정보를 얻고자 하는 환경에 사용되며, 이러한 정보는 무선 링크를 통해 전송되기 때문에 재전송이 발생하여 노드의 에너지 소모가 크다는 단점이 있다. 이 때문에 신뢰성이 높고 에너지 효율이 좋은 링크를 선택하기 위해 LQI(link quality indication), hop count 등을 이용하여 무선 링크에 대한 품질을 추정하는 기법이 필요하다. 본 논문에서는 무선 센서 네트워크에서 노드들의 데이터 전송률을 높여 재전송을 줄임으로서 에너지 소모를 줄이는 라우팅을 위해 각 경로 내의 LQI를 구한 후 LQI 표준편차가 작은 경로를 선택하는 LQI 표준편차 라우팅 알고리즘을 제안한다. 또한 제안하는 알고리즘을 기존 LQI 알고리즘인 minimum-LQI. Hop-LQI weight과 RF 출력 -7dBm에서 비교하였다. 결과에 의하면 제안하는 알고리즘은 기존 알고리즘에 비해 경유 노드수, 재전송률, 네트워크 수명이 각각 우수하였다. 따라서 LQI 표준편차 라우팅 알고리즘을 에너지 소모에 제한적인 무선 센서 네트워크에 적용할 경우 에너지 소모를 효율적으로 줄일 수 있다.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.299-303
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• 2016

Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM) R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2) associated with the determined value was 2.4%.

• 한국태양에너지학회 논문집
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• 제34권1호
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• pp.8-18
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• 2014

Building simulation is used in a variety of sectors. In its early years, building simulation was mainly used in the design phase of a building for basic functions. Recently, however, it has become increasingly important during the operating phase, for commissioning and facility management. Most building simulation tools are used to estimate the thermal environment and energy consumption performance, and hence, they require the inputting of hourly weather data. A building simulation used for prediction should take into account the use of standard weather data. Weather data, which is used as input for a building simulation, plays a crucial role in the prediction performance, and hence, the selection of appropriate weather data is considered highly important. The present study proposed a technique for generating real-time weather data files, as opposed to the standard weather data files, which are required for running the building simulation. The forecasted weather elements provided by the Korea Meteorological Administration (KMA), the elements produced by the calculations, those utilizing the built-in functions of Energy Plus, and those that use standard values are combined for hourly input. The real-time weather data files generated using the technique proposed in the present study have been validated to compare with measured data and simulated data via EnergyPlus. The results of the present study are expected to increase the prediction accuracy of building control simulation results in the future.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.27-30
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• 2009

In this paper, we introduce the status of certificate test on crystalline silicon photovoltaic module in Korea. Up to 3. 2009, about 149 models have passed certificate test under KS C IEC61215 standard. Most products are from Korea, Japan, China. And some are from USA, German and Taiwan. A few environmental test items' results and standard test methods will be discussed. The detail discussion will be shown in the following paper.

• KDI Journal of Economic Policy
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• 제41권4호
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• pp.67-99
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• 2019

This paper, focusing on the renewable portfolio standard (RPS), evaluates alternative renewable energy policies. We propose a tractable equilibrium model which provides a structural representation of Korea's electricity market, including its energy settlement system and renewable energy certificate (REC) transactions. Arbitrage conditions are used to define the core value of REC prices to identify relevant competitive equilibrium conditions. The model considers R&D investments and learning effects that may affect the development of renewable energy technologies. The model is parameterized to represent the baseline scenario under the currently scheduled RPS reinforcement for a 20% share of renewable generation, and then simulated for alternative scenarios. The result shows that the reinforcement of the RPS leads to higher welfare compared to weakening it as well as repealing it, though there remains room to enhance welfare. It turns out that subsidies are welfare-inferior to the RPS due to financial burdens and that reducing nuclear power generation from the baseline yields lower welfare by worsening environmental externalities.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3672-3681
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• 2022

This study investigates the environmental footprint impacts of nuclear energy consumption in the presence of environmental technology and globalization of the ten largest ecological footprint countries from 1990 up to 2017. By considering a set of methods that can help solve the issue of cross-sectional dependence, we employ the Lagrange multiplier bootstrap cointegration method, Driscoll-Kraay standard errors for long-run estimation and feasible generalized least squares (FGLS) and panel-corrected standard errors (PCSE) for robustness. The finding revealed significant negative effects of nuclear energy consumption, environmental-related technology, population density and significant positive effects of globalization and economic growth on ecological footprint. These results are also robust by assessing the long-run impacts of predictors on carbon footprint and CO₂ emissions as alternate ecological measures. These conclusions provide the profound significance of nuclear energy consumption for environmentally sustainable development in the top ten ecological footprint countries and serve as an important reference for ecological security for other countries globally.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년 추계학술발표대회 논문집
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• pp.261-265
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• 2008

To solve the lack of housing, our country has supplied an enormous volume of apartments, and these days it occupies 75% of our buildings. As apartments occupy most of our housings, the rate of energy usage from them are also high. On this, setting apartment energy reduction as a target, by researching the actual conditions of energy consumption and drawing a basis data, we can apply this as a way of saving energy, rationalization of the scale of energy supply facilities and a standard when planning facilities. To grasp the present condition of energy usage of the urban rental apartment, this research analysed the use of electricity, gas and water monthly and annually of a rental apartment that is located in Daegu. The results showed that in 2003 the electricity usage was 1,198MWh but 1,315MWh in 2007, which means 9% of electricity usage increases every year. The average of water usage was $85,072m^2$ per year and they used $604.2MJ/m^2$ Typical energy consumption unit on $74.4m^2$ of area and $448.8MJ/m^2$ on $105.8m^2$. By showing the usage of energy and water of the urban rental apartment, understanding the tendency and preparing an Typical energy consumption unit standard through this research, apartments should use energy more efficiently.

• KIEAE Journal
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• 제16권2호
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• pp.23-31
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• 2016

Purpose: Recently energy consumption is rapidly increasing due to continuous development of social evolution in various field. In this situation, there is a lot of effort to reduce this energy consumption in many ways, especially in building energy. Preceding studies already started to analyze the housing area such as zero energy house and passive house by researching annual building energy consumption, but to apply the results of housing to office building is insufficient since it has different consumption tendency. Method: In this study, eQuest program was used for simulation and the base model is selected among standard office building in ASHRAE 90.1. Variables are divided into passive and active factors for comparison. Result: In passive factors, glazing system showed the highest energy saving rate by 21.3% with triple low-e glass and enhancing wall u-value showed the lowest energy saving rate by 3.6% with 0.15 m2/K. In active factors, VAV system showed 30.9% energy saving rate when compared to CAV system, and heat exchanger showed 10.2% energy saving rate. For regeneration energy part, photovoltaic panel generated 10.4% of base annual energy usage.

• KIEAE Journal
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• 제16권1호
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• pp.21-28
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• 2016

Purpose: The purpose of this study is to analyze & suggest the variation of energy consumption consequent on thermal insulation performance strengthening from early 2000s when modernization of barracks began until the present targeting a large barracks. Method: To carry out this research, this study surveyed the standard of thermal insulation by year, which is being applied to a barracks by conducting literature search, and selected the standard model for a barracks. Also, this study analyzed energy consumption by year & region by performing simulation(ECO2)of the selected standard model. Result: As a result, it was analyzed that in case of a building which was completed in 2015, the energy consumption for air-conditioning & heating, lighting, and hot water supply over the year 2000 reduced by 11% on the average in central district, 10% on the average in southern district, and 17% on the average in Jeju, respectively.

• Nuclear Engineering and Technology
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• 제36권3호
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• pp.248-262
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• 2004

Turbulence models are separately assessed for a three dimensional thermal-hydraulic analysis of the integral reactor SMART. Seven models (mixing length, k-l, standard $k-{\epsilon},\;k-{\epsilon}-f{\mu},\;k-{\epsilon}-v2$, RRSM, and ERRSM) are investigated for flat plate channel flow, rotating channel flow, and square sectioned U-bend duct flow. The results of these models are compared to the DNS data and experiment data. The results are assessed in terms of many aspects such as economical efficiency, accuracy, theorization, and applicability. The standard $k-{\epsilon}$ model (high Reynolds model), the $k-{\epsilon}-v2$ model, and the ERRSM (low Reynolds models) are selected from the assessment results. The standard $k-{\epsilon}$ model using small grid numbers predicts the channel flow with higher accuracy in comparison with the other eddy viscosity models in the logarithmic layer. The elliptic-relaxation type models, $k-{\epsilon}-v2$, and ERRSM have the advantage of application to complex geometries and show good prediction for near wall flows.