• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.335-356
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• 2011

In this paper, we attempted to suggest a way to evaluate appropriateness and efficiency for the energy consumption structure. For this, based on Markowitz (1952)' mean-variance portfolio model, we constructed an optimal fossil fuel mix. In constructing the optimal mix, we first defined returns on fossil fuels (oil, coal and natural gas) as TOE (Ton of Oil Equivalent) per $1. Then, by using the dynamic latent common factor model, we decomposed the growth rates of the returns on each fossil fuel into two parts : the common part and the idiosyncratic part. Finally, based on the results from the dynamic latent common factor model, we constructed the optimal fossil fuel mix implied by the mean-variance portfolio model. Our results indicate that for the fossil fuel mix to be on the efficient frontier, it is crucial to reduce oil consumption as low as possible. Moreover, our results imply that it is more efficient to increase natural gas consumption rather than coal consumption in reducing oil consumption. These results are in line with the strategies for the future energy consumption structure pursued by Korea and indicate that reduction in oil use can improve overall efficiency in energy consumption.

• Journal of Biosystems Engineering
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• v.24 no.4
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• pp.351-358
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• 1999

In these days, we are faced to a couple of difficult problems, the one is the unstable price of the energy due to the shortage of fossil fuel resources and the other is the serious environmental pollution from the excessive consumption of fossil fuel. In order to save the thermal energy for the house heating, in this study the heat pump using the natural thermal energy resources was provided for Ondol heating and the thermal energy consumption of the heat was compared to that of oil boiler. The results could be summarized as follows: 1. In the Ondol room the temperature difference between the Ondol surface and room air was about 5∼$10^{\circ}C$ in accordance with the ambient temperature. 2. The Ondol room heating efficiency of the heat pump with compressor of 2PS was the highest at the water flow rate of 200 l/h. 3. The energy saving rate of the heat pump to the oil boiler for heating the Ondol system was 19.3%. 4. The Ondol heating cost of the heat pump was less 20.6% than that of oil boiler when oil price was 478 won/l.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.29-35
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• 2015

Environmental pollution is produced by consumption of fossil fuel, therefore alternative fuels is interested for development of new energy resources and reduction of exhaust emissions for air pollution prevention. Biofuels are produced from new vegetable oil and animal fat, may be used as fuel without change of engine structure in diesel engine. In this paper, the test results on specific fuel consumption, combustion characteristics of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine, especially this biodiesel was produced from biodiesel fuel at our laboratory by ourselves. This study showed that specific fuel consumption is increased slightly, on the other hand cylinder pressure, rate of pressure rise, rate of heat release and soot were decreased slightly in the case of biodiesel blends than neat diesel oil.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.103-108
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• 2015

Recent global warming has been recognized as the world economy development from fossil fuel use is the culprit. This study was reduce the fossil fuel has been developed in a number of alternative energy, As a fuel that can be produced in our country is a biofuel. Biofuels is a sustainable fuel having economically benefits and decreasing environmental pollution problems caused due to fossil fuel. A lot of research is progressing about the conversion of diesel biofuel as renewable clean energy. In this experiment were remodel the institution that has been used in fishing engine again produced an experimental apparatus were installed directly, were studied using various bio fuel like to help the economically and environmentally sound operation of the vessel. rapeseed oil, soybean oil, comprehensively analyzing the results the effects of the exhaust emission characteristics of the waste rapeseed oil is available in a marine engine with similar physical and chemical components of the fuel, and the fuel consumption ratio, NOx is slightly increased, but soot was confirmed a tendency to decrease much.

• Design & Manufacturing
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• v.16 no.2
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• pp.20-25
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• 2022

In line with the rapid economic growth of many countries, fossil fuel energy sources are also rapidly depleting. Therefore, the price is also rising rapidly, so it is necessary to develop new and renewable energy sources such as hydropower, geothermal power, nuclear power, wind power and solar energy to replace fossil fuel energy in the future. In this study, development of rotating concentrator module system, development of rotating module control control system, development of lamp and charge control controller, configuration and prototype production of rotating concentrating solar LED street light system, efficiency of rotating concentrating solar LED street light, and power production. The research was conducted in the order of evaluation of comprehensive performance tests such as consumption and consumption. As a result, the developed high-efficiency rotation-concentrating hybrid solar LED street light module system has a 50% higher light-gathering efficiency than existing products by tracing sunlight by self-developing a rotation-collecting module on existing solar LED street lamps according to the characteristics of Korea's topography. and the power generation was improved by more than 40%.

• Environmental and Resource Economics Review
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• v.22 no.2
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• pp.329-365
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• 2013

The purpose of this paper is to measure economy and environment efficiencies under fossil fuel and environment regulation by countries for 2000-2009. Distinguishing 83 countries with three groups of OECD, upper-middle, and low countries, we compare four models such as environment oriented, economy-oriented, environment-economy oriented, and two-stage types, which include a desirable output, GDP and an undesirable output, pollutant together in the production possibility set. OECD countries relatively showed high economy efficiency and low environment efficiency, whereas Non-OECD countries showed high environment efficiency and low economy efficiency. OECD countries reported a higher possibility to reduce fossil fuel and $CO_2$ emission.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.325-338
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• 1997

Review of the global change in various energy usages and resulting environmental impacts were made in terms of population increase, economic development and energy consumption. Greater use of fossil fuels in past couple of centuries give rise to acid rain and gradual climate changes mainly due to Green House inducing gases emissions from fossil fuel combustion. In view of the forthcoming Kyoto conference in December, various alternative options were assessed. To cope with rapidly developing robust Korean economy, the alternative energy options for the sustainable development in 21st Century would be the wider use of Nuclear Energy in parallel with constrained use of fossil fuel and renewable energy development. However there are many hurdles to overcome. One of the most important element is to improve public acceptability of those alternatives. Since public acceptance depend heavily upon individual perception on specific energy technology applications, the basic energy technologies education from primary up to high school education and the related curriculum organization is important. The suggested improvement in education for Nuclear Energy Application was made on the basis of advanced industrial countries with substantial Nuclear Energy Application programs.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.4
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• pp.99-109
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• 2008

As the price of traditional fossil fuels continue to increase, more people attach importance to the pollution of the environment caused by fossil fuel's burning, developing and using renewable energy resources has become a very important project all over the world. Also, the rural energy planning which is another method to improve energy utilization ratio and reduce environment pollution, is also regarded as a very effective way to reduce the energy consumption. There is a quantity of renewable energy resources and natural tribes in rural area, which is both feasible to develop the renewable energy and the regional energy planning. To carry out this, it is needs to know the area's quantity of renewable energy resources and the total energy consumption. This paper is to find out the relationship between rural energy consumption and rural conditions, and to found a energy consumption model which can conjecture the energy consumption in rural family. and the cost of rural family's energy consumption was founded to conjecture how much money dose it cost in rural family's energy consumption. The energy consumption model was concluded using the surveys of 76 families in 14 villages at the area of Chungcheongbuk-Do(province). The main factors to energy consumption was selected out which were number of family members, acreage of house, acreage of farmland and family's annual income.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.245-251
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• 2005

Recently, fuel reforming technology for the fuel cell vehicle has been applied to internal combustion engines, with various purpose. Syngas which is reformed from fossil fuel has hydrogen as a major component. It has better effort in combustion characteristics such as wide flammability and hig speed flame propagation. In this study, syngas was added to a gasoline engine for the improvement of combustion stability and exhaust emission in idle state. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to extend lean operation limit and ignition retard range. with dramatical reduction of engine out emissions.

• Journal of the Korean Society of Combustion
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• v.11 no.4
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• pp.14-21
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• 2006

In this study, syngas which is reformed from fossil fuel and has hydrogen as a major component, was added to a gasoline engine to improve combustion stability and exhaust emissions of idle state. Syngas fraction of the total supplied fuel varied to 0 %, 25 %, 50 % with various ignition timing and excess air ratio. Combustion stability, exhaust emissions, fuel consumption and exhaust gas temperature were measured to investigate the effects of syngas addition on idle performance. Results showed that syngas has ability to widely extend lean operation limit and ignition retard range with dramatical reduction of engine out emissions. It is supposed that the usage of syngas in the internal combustion engine is an effective solution to meet the future strict emission regulations.