• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.480-493
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• 2005

The development of modem technology made people more aware of the importance of science education, which was followed by research on textbooks based on the new curriculum. This study compared physics textbooks that were published after the new curriculum started in 2000 and 2002 in Korea and Japan, respectively, and aimed to become a reference for further improvement of science curriculum and textbook reform. The results were as follows : 1. The number of teaching topics in Korean science textbook is greater than those in Japan. 2. In detail, the field of physics appeared to be relatively more important in Korea's textbooks, while it was the field of biology that was given more weight in textbooks in Japan. 3. The textbooks in Korea and Japan covered in more detail the concepts of 'power and energy' and 'electricity and magnetism', respectively. 4. The textbooks in Korea introduced the contents of magnetism initially, whereas their counterparts in Japan, the contents of light. As a whole, the contents of the science textbooks in Korea and Japan were very similar. However, more detailed concepts were included in Korea's textbooks, and therefore, Korea's textbooks seemed to have richer contents than Japan.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.8
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• pp.683-691
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• 2015

Circulating Fluidized Bed(CFB) combustion has the several advantages which are the fuel flexibility, the economy, the efficiency and the environment. It is necessary to apply a renewable energy to produce electricity due to the Renewable Portfolio Standard(RPS) mandates recently. So, in this study, co-combustion with a coal and a wood pellet was investigated to evaluate the combustibility and the environment as function of blending ratio of them in a Lab-scale CFB reactor. To investigate the characteristics of the co-combustion, the blending ratio which is the weight of wood pellet by the total calorific value of the supplied, was considered. Bed material was a river sand(No. 7). As increasing the blending ratio, the exhausted gas emissions such as CO, NOx, HC and SOx were decreased. But in case of wood pellet over 30%, CO, HC and SOx emission were increased. And the gas temperatures at the downstream were decreased.

• Nuclear Engineering and Technology
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• v.8 no.2
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• pp.101-116
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• 1976

An attempt is made to analyze the unit nuclear power cost of the Go-ri units 1 and 2 in terms of a set of model data. For the calculational purpose, the power cost is first decomposed into the cost components related to the plant capital, operation and maintenance, working capital requirements, and fuel cycle operation. Then, POWERCO-50 computer code is applied to enumerate the first three components and MITCOST-II is used to evaluate the fuel cycle cost component. The specific numerical results are the fuel cycle cost of Go-ri unit 2 for three alternative fuel cycles presumed, levelized unit power cost of units 1 and 2, and the sensitivity of the power cost to the fluctuation of the model data. Upon comparision of the results with the power cost of the fossil power plants in Korea, it is found that the nuclear power is economically preferred to the fossil power. Nevertheless, the turnkey contract value of Go-ri unit 2 appears to be rather expensive compared with the available data on the construction cost of the PWR plants. Therefore, it is suggested that, in order to make the nuclear power plants more attractive in Korea, the unfavorable contract of such kind must be avoided in the future introduction of the nuclear power plant. Capacity factor is of prime importance to achieving the economic generation of the nuclear electricity from the Go-ri plant. Therefore, it is concluded that more efforts should be directed to make the maximum use of the Go-ri plant.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.88-100
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• 2013

This study evaluated the direct and indirect environmental impacts of various unit operations of a industrial waste incineration plant by using the life cycle assessment tool and reviewed the improvement plan. During the incineration process, the direct environmental impact was decreased with decrease in emission of various air pollutants by incorporating an air pollution prevention facilities. However, an increase in indirect environmental impacts was observed as a consequence of resources and energy of consumption at the various operational facilities. Consequently, quantitative direct and indirect impact were 89.1%, 10.9%, respectively. The environmental impact analysis of system revealed the highest impact of incineration followed by the impacts of other unit processes such as semidry reactor, and bag-filter. The various air pollutants and ashes generated during the incineration process caused the most significant environmental impact. Among the various categories of environmental impact, global warming accounted the highest impact(more than 85%) followed by eutrophication, and abiotic depletion. As a result of the avoided impact by the utilization of heat generated during the waste incineration process, using an incineration heat for steam and electricity obtained the impact reduction of 45.5%, 19.8%. So, during siting of new incineration plant, the utilization of steam generated from the waste combustion is highly considered to reduce the environmental impact.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.590-595
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• 2016

The US is pursuing a plan to raise the subsidies for electric vehicles by more than 30%. The number of electric vehicles in Europe is expected to be one million by 2020 and 2030 and there are plans to expand in the center of Germany to supply six million electric vehicles on the dissemination and development policies. The development of the electric vehicle is not simply a technical trend but there is the potential to improve the access to this technology and the possibility of changing the entire social system and long-term energy security. Domestic competition is also increasing the supply of electric vehicles, as new blue ocean markets are emerging. The current domestic On-board Charger (Home Charger) plans to be suspended from the 2015 government-sponsored installation, This paper on the IEC 61851-1 and IEC 61851-22 specifications analyzes the development of a midnight electricity charger as a low-cost algorithm, the decrease in price and the improved convenience of the On-board Charger for Bluetooth module with the ATmega128 existing charger system, and the UI configuration via the LCD Panel to a Smartphone app are proposed.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.77-86
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• 2003

How to compare the environmental damage caused by vehicles with different foe]s and drive trains\ulcorner This paper describes a methodology to assess the environmental impact of vehicles, using different approaches, and evaluating their benefits and limitations. Rating systems are analysed as tools to compare the environmental impact of vehicles, allowing decision makers to dedicate their financial and non-financial policies and support measures in function of the ecological damage. The paper is based on the "Clean Vehicles" research project, commissioned by the Brussels Capital Region via the BIM-IBGE (Brussels Institute for the Conservation of the Environment) (Van Mierlo et at., 2001). The VriJe Universiteit Brussel (ETEC) and the universite Libre do Bruxelles (CEESE) have jointly carried out the workprogramme. The most important results of this project are illustrated in this paper. First an overview of environmental, economical and technical characteristics of the different alternative fuels and drive trains is given. Afterward the basic principles to identify the environmental impact of cars are described. An outline of the considered emissions and their environmental impact leads to the definition of the calculation method, named Ecoscore. A rather simple and pragmatic approach would be stating that all alternative fuelled vehicles (LPG, CNG, EV, HEV, etc.) can be considered as ′clean′. Another basic approach is considering as ′clean′ all vehicles satisfying a stringent omission regulation like EURO IV or EEV. Such approaches however don′t tell anything about the real environmental damage of the vehicles. In the paper we describe "how should the environmental impact of vehicles be defined\ulcorner", including parameters affecting the emissions of vehicles and their influence on human beings and on the environment and "how could it be defined \ulcorner", taking into account the availability of accurate and reliable data. We take into account different damages (acid rain, photochemical air pollution, global warming. noise, etc.) and their impacts on several receptors like human beings (e.g., cancer, respiratory diseases, etc), ecosystems, or buildings. The presented methodology is based on a kind of Life Cycle Assessment (LCA) in which the contribution of all emissions to a certain damage are considered (e.g. using Exposure-Response damage function). The emissions will include oil extraction, transportation refinery, electricity production, distribution, (Well-to-Wheel approach), as well as the emission due to the production, use and dismantling of the vehicle (Cradle-to-Grave approach). The different damages will be normalized to be able to make a comparison. Hence a reference value (determined by the reference vehicle chosen) will be defined as a target value (the normalized value will thus measure a kind of Distance to Target). The contribution of the different normalized damages to a single value "Ecoscore" will be based on a panel weighting method. Some examples of the calculation of the Ecoscore for different alternative fuels and drive trains will be calculated as an illustration of the methodology.

• Journal of Biosystems Engineering
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• v.8 no.1
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• pp.17-29
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• 1983

The milling process is considered as causing one of the greatest grain losses among all the processes in rice post-production. Major source of grain losses in the rice milling is considered as the whitening process. This study was attempted to develop an abrasive-type whitener, the whitening chamber of which being supplied by jet-air evenly and continuously. To investigate the milling performance by the new whitener, three kind of emery-stone grit(#36, #41, and #46), and three levels of rotational speed of emery stone roller (950, 1070, and 1200 rpm) were tested. The jet-air abrasive-type whitener was also compared with the conventional abrasive-type having no jet-air blower in terms of their milling performance. In addition, the effect of different combinations of sequential uses of the abrasive- and friction-type whiteners on the milling performance was also experimentally evaluated. The results of this study are summarized as follows; 1. In general, the whitening system combined with the abrasive type whitener with jet-air supply, which was newly designed, and the existing jet-air friction type whiteners produces more milled- and head-rice by about 0.3% points and 2.8% points, respectively than the system combined with the existing abrasive type without the jet-air supply under the same operational conditions. The former also consumed less electricity by 0.024 KwH per 100kg of milled rice production and gave more milling capacity by about 35 kg/hr. As compared with the conventional whitening system consisting of jet-air friction type whiteners only, the former yielded more milled- and head-rice by 1.5% points and 4.4% points, respectively. 2. The abrasive roller having 46 grit emery was better than the roller having 36 grit in aspects of milling performance and machine efficiency, in general. 3. With regard to the effect of combination method of abrasive type and friction type whiteners, one pass in abrasive type plus three passes in friction type gave better milling performance and energy efficiency than the two passes in abrasive type plus two passes in friction type regardless of the designs of the emery stone rollers. 4. The increase in rotational speed of the emery stone roller from 950 rpm to 1200 rpm presented negative effects on milled and head-rice yields and machine efficiency, but slightly positive effect on milling capacity.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.107-113
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• 2003

This study was carried out to improve the performance of pre-developed heat recovery devices attached to exhaust-gas flue connected to combustion chamber of greenhouse heating system. Four different units were compared in the aspect of heat recovery performance; A-, B-, and C-types are exactly the same with the old ones reported in previous studies. D-type newly developed in this experiment is mainly different with the old ones in its heat exchange area and tube thickness. But airflow direction(U-turn) and pipe arrangement are similar with previous three types. The results are summarized as follows; 1. System performances in the aspect of heat recovery efficiency were estimated as 42.2% for A-type, 40.6% for B-type, 54.4% for C-type, and 69.2% for D-type. 2. There was not significant improvement of heat recovering efficiency between two different airflow directions inside the heat exchange system. But considering current technical conditions, straight air flow pattern has more advantage than hair-pin How pattern (U-turn f1ow). 3. The main factors influencing on heat recovery efficiency were presumably verified to be the total area of heat exchange surface, the thickness of ail-flow pipes, and the convective heat transfer coefficient influenced by airflow velocity under the conditions of allowable pipe durability and safety. 4. Desirable blower capacity for each type of heat recovery units were significantly different to each other. Therefore, the optimum airflow capacity should be determined by considering in economic aspect of electricity required together with the optimum heat recovery performance of given heat recovery systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.533-540
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• 2012

The use of wind energy is gaining importance because of its many advantages. Nations worldwide are promoting the installation of wind farms to produce electricity in an attempt to tackle climate change and increasing oil costs. But, wind turbines can generate undesired signals which disturb the performance of military radar systems. Because the current generation of on and off-shore three bladed wind turbines have radar signatures consistent with their very large physical size. So this study considers the options available for the reduction of wind turbine radar signature and presents solutions for each of the main external turbine components. The radar signature reduction approaches are based on existing technologies developed for aerospaces stealth applications. However, the realization of these for the purposes of reduction wind turbine radar signatures is a novel development, particularly in the solutions proposed. This paper is presented techniques which reduce radar signatures of wind turbine. We know that radar signatures of wind turbine reduce by using these techniques.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.143-165
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• 2016

The amount of greenhouse gas emission reduction based on INDCs (Intended Nationally Determined Contributions) submitted to UN by each party is not sufficient to achieve the Paris Agreement's aim to "hold the increase in the global average temperature to well below $2^{\circ}C$ above pre-industrial levels and to pursue efforts to limit the temperature increase to $1.5^{\circ}C$" which was determined in the $21^{st}$ Conference of the Parties to the UNFCCC (COP 21). Accordingly, the emission reduction target of each party will be revised for the $2^{\circ}C$ goal. Among the several options to reduce the carbon emission, CCS (Carbon Capture and Storage) is a key option to curb $CO_2$ emissions from large emission sources such as fossil-based power plants, cement plants, and steel production plants. A large scale CCS demonstration projects utilizing $1^{st}$ generation $CO_2$ capture technologies are under way around the world. It is anticipated, however, that the deployment of those $1^{st}$ generation $CO_2$ capture technologies in great numbers without government support will be difficult due to the high capture cost and considerable increase of cost of electricity. To reduce the carbon capture cost, $2^{nd}$ and $3^{rd}$ generation technologies are under development in a pilot or a bench scale. In this paper, current status of large scale CCS demonstration projects and the $2^{nd}$ and $3^{rd}$ generation capture technologies are summarized. Novel capture technologies on wet scrubbing, dry sorbent, and oxygen combustion are explained in detail for all capture areas: post-combustion capture, pre-combustion capture, and new combustion technologies.