• 대한건축학회논문집:계획계
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• 제34권11호
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• pp.13-22
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• 2018

At the time when zero energy building is expected to be generalized, this study examines whether the investment in the passive element or the active element is more effective in terms of energy in the construction process of zero energy building. In other words, the effect of energy demand by passive element and the change of energy generation by active element are examined in terms of the same investment cost. The purpose of this study is to examine the change of energy demand by passive element and the change of energy generation by active element in zero energy building and to make reasonable investment decision by comparing energy with cost aspect. For this purpose, we selected the buildings to be subjected to energy simulation and derive the required energy amount and energy generation amount by using meteorological data of four regions in Korea. The change of energy demand and energy generation according to the change of application condition was derived. In order to compare and analyze the changes in energy demand and generation at the same cost standard through price survey and quotation of window and photovoltaic power generation equipment.

• KIEAE Journal
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• 제15권3호
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• pp.37-42
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• 2015

Purpose: Apartment is a typical residential type in Korea. In the past, apartment types were very monotonous. But today, the types of complex are changed because personal needs have been diversified and personalized. In order to meet those needs, construction companies are constructing various types of apartments. The more apartment types are diverse, the more the energy problems are taken place. So, the purpose of this study is to solve the problem of energy gap in the same complex through improving the thermal transmittance of wall. Method: Heating energy consumption of Building Energy Efficiency Rating System and heating energy usage of apartment show a similar trend on the graph. In order to identify the best position of heating energy consumption difference reduction, we change the building's U-value of front, back, side walls. Result: In the A complex, maximum and minimum heating energy consumption building's shapes are flat. the best efficiency is side U-value change and the worst is front change. In the E complex, maximum heating energy consumption building's shape is tower and minimum building shape is flat. Consequently, the front and back wall performance change was little effect to reduce energy gap, while the change of side wall's U-value show the great reduction between building's energy consumptions.

• 자원ㆍ환경경제연구
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• 제20권2호
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• pp.255-289
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• 2011

본 논문은 2000년, 2005년, 2008년의 3개년을 대상으로 접속불변에너지산업연관표(76개의 산업분류)를 작성하여 집계통계와 함께 산업별 미시적 통계를 제시하고, 이를 이용하여 산업별로 에너지소비량의 변화에 영향을 미치는 요인과 그 크기를 분석하였다. 본 논문에서 부가가치 총액 변화, 부가가치비중 변화, 산출구조 변화, 에너지원단위 변화의 4가지 요인을 고려하였다. 분석모형으로는 우리나라가 수출주도형의 산업구조를 갖고 있다는 점을 고려하여 공급측 모형을 이용한 구조분해분석을 적용하였다. 집계통계를 이용한 분석결과에 따르면 시기에 상관없이 부가가치 총액 변화는 에너지소비량을 증가시켰지만, 산출구조 변화는 에너지소비 변화량을 감소시켰다. 부가가치비중 변화와 에너지원단위 변화에서는 시기별로 에너지소비 변화량의 증감이 반대로 도출되었다. 산업별 통계를 이용한 결과에 따르면 부가가치비중 변화는 시점과 상관없이 전자기기에서 에너지소비 변화량을 증가시키고, 석유제품, 시멘트, 석탄제품에서 에너지소비량을 감소시켰다. 그리고 에너지원단위 변화는 석유제품, 화력, 사업서비스, 금융 및 보험, 보관 및 운수관련서비스에서의 에너지원단위 변화가 에너지소비 변화량을 증가시켰다. 이상의 결과처럼 집계통계를 이용하면 각 산업에서의 현상이 나타나지 않는다. 정부가 정책을 입안하고 시행할 때에 집계통계만을 기준으로 하면 효율적 성과를 거두기 어렵다.

• 한국기후변화학회지
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• 제7권1호
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• pp.59-68
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• 2016

The world's major countries have focused on the renewable energy industry as the solution to climate change and the energy crisis. Nevertheless, there are no studies on the economic effects of the renewable energy industry. This study analyzed the economic effects of Korea's renewable energy industry by using the 2010 Input-Output Table. It is estimated that Korea's renewable energy industry made a production-induced effect of 2.0262 won, and a value-added-induced effect of 0.6138 won through an increase in output growth of 1 won, and an employment-induced effect of 2.3046 labors through an increase in output growth of 1 billion won. Both the effect ratio and the response ratio were greater than 1, which means the renewable energy industry is an intermediate manufacturing industry whose forward linkage effect and backward linkage effects are large. These results show differences with previous studies that classified electricity sector and renewable energy industry into final primary production industries. It is expected that the economic effects of the renewable energy industry will become greater in the future. Therefore, research on statistics related to the renewable energy industry is needed for more precise analysis.

• Korean Journal of Acupuncture
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• 제26권3호
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• pp.1-11
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• 2009

Objectives : The object of this study is to investigate the balance/imbalance of skin capacitances between left and right meridians, and to analyze the change patterns of electric energy on meridians with the lapse of time. Method : Electric potential was measured on five source points (LU9, PC7, HT7, LI4, SI4) bilaterally for 4 hours. The energy balance/imbalance between left and right was investigated, and the change patterns with time were analyzed. Results and Conclusions : The amplitude of meridian energy on five source points and the energy balance/imbalance between left and right were varied in each individual. When a source point showed a balanced meridian energy bilaterally, the change patterns of meridian energy with time were similar between left and right. While, when it showed an imbalanced energy between left and right, the change patterns of meridian energy were also different between left and right. Through this study, we proposed a new diagnostic method of meridian energy.

• 한국태양광발전학회지
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• 제6권1호
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• pp.56-68
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• 2020

Cameroon is a lower middle-income country with a population of 25.87 million inhabitants distributed over a surface area of 475,442 ㎢. Cameroon has very rich potentials in renewable energy resources such as solar energy, wind energy, small hydropower, geothermal energy and biomass. However, renewable energy constitutes less than 0.1% of energy mix of the country. The energy generation mix of Cameroon is dominated by large hydropower and thermal power. Cameroon ratified the Paris Agreement in July 2016 with an ambitious 20% greenhouse gas (GHG) emission reduction. This study attempts to investigate some renewable energy deployment policy-instruments that could enable the country enhance renewable energy deployment, gain energy independence, fulfill Nationally Determined Contribution (NDC) and achieve Sustainable Development Goals. It begins with an analysis of the status of energy sector in Cameroon. It further highlights the importance of renewable energy in mitigating climate change by decarbonizing the energy mix of the country to fulfill NDC and SDGs. Moreover, this study proposes some renewable energy deployment policy-solutions to the government. Solar energy is the most feasible renewable energy source in Cameroon. Feed-in Tariffs (FiT), is the best renewable energy support policy for Cameroon. Finally, this study concludes with some recommendations such as the necessity of building an Energy Storage System as well a renewable energy information and statistics infrastructure.

• 한국대기환경학회지
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• 제32권4호
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• pp.384-393
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• 2016

In this study, two kinds of industrial filter bags were tested for their filtration performance to apply the existing bag filter systems. Experimental variables were examined for pressure drop, cleaning interval, residual pressure drop, cleaning efficiency, fractional grade efficiency, total collection efficiency according to the filter bag structure. According to these results, the filter bags tested in this study demonstrated good performance in dust collection. This was also true for the double surface filter bag. The lifetime was longer than the round type filter bag because the filtration area was more than 1.6 times wider and the filter quality factor was much higher. Therefore, double surface filter bags are suggested to be used in order to increase filtration performance of the bag filter systems.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2321-2326
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• 2018

We evaluated the optimal conditions for fluidization of nickel oxide (NiO) and its reduction into high-purity Ni during hydrogen reduction in a laboratory-scale fluidized bed reactor. A comparative study was performed through structural shape analysis using scanning electron microscopy (SEM); variance in pressure drop, minimum fluidization velocity, terminal velocity, reduction rate, and mass loss were assessed at temperatures ranging from 400 to $600^{\circ}C$ and at 20, 40, and 60 min in reaction time. We estimated the sample weight with most active fluidization to be 200 g based on the bed diameter of the fluidized bed reactor and height of the stocked material. The optimal conditions for NiO hydrogen reduction were found to be height of sample H to the internal fluidized bed reactor diameter D was H/D=1, reaction temperature of $550^{\circ}C$, reaction time of 60 min, superficial gas velocity of 0.011 m/s, and pressure drop of 77 Pa during fluidization. We determined the best operating conditions for the NiO hydrogen reduction process based on these findings.

• KIEAE Journal
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• 제12권4호
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• pp.97-104
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• 2012

A phase-change material is a substance with a high heat of fusion which, melting and freezing at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid. Therefore, PCMs are classified as latent heat storage (LHS) units. The purpose of this study is to analyze PCM wallboard design parameters using dynamic energy simulation. Among the factors of PCM, melting temperature, latent heat, phase change range, thermal conductivity are very important element to maximize thermal energy storage. In order to analyze these factors, EnergyPlus which is building energy simulation provided by department of energy from the U.S is used. heat balance algorithm of energy simulation is conduction finite difference and enthalpy-temperature function is used for analyzing latent heat of PCM. The results show that in the case of melting temperature, the thermal energy storage could be improved when the melting temperature is equal to indoor surface temperature. It seems that when the phase change range is wide, PCM can store heat at a wide temperature, but the performance of heat storage is languished.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.190-199
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• 2017

Air-blown Gasification of coal and torrefied biomass mixture is conducted on fixed-bed gasifier. The various ratio (9:1, 8:2, 7:3) of coal and torrefied biomass mixture are used. The contents of $H_2$, CO in the syngas were increased with gasification temperature. Carbon conversion tend to increase with temperature and equivalence ratio (ER). However, cold gas efficiency showed maximum point in ER range of 0.26-0.36. The torrefied biomass showed highest cold gas efficiency of 67.5% at $934^{\circ}C$, ER 0.36. Gasification of 8:2 mixture showed the highest carbon conversion and cold gas efficiency and synergy effect.