• Clean Technology
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• v.14 no.2
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• pp.103-109
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• 2008

In this study, in order to develop evaluation method of the cleaning efficiency of residual flux which remains on the surface after soldering with solder paste, a specially designed metal tool is used to reduce spread uncertainty of flux while soldering. Using this tool, the measurement of cleaning efficiency of flux after soldering for some typical alternative semi-aqueous cleaners and 1,1,1-TCE by weighing method was conducted. As the test result of cleaning efficiency for each cleaner at several different cleaning times, the precision of the data is confirmed to within about 4% relative standard deviation (RSD) range. So, it is considered that this would be a good evaluation method for evaluating the cleaning efficiency of the residual flux which remains after solder paste soldering in the alternative cleaning. The results of this test method shows that the cleaning efficiency of ST 100SX and Neozal 750H in the cleaning of residual flux was better than other semi-aqueous cleaners, but its cleaning efficiency was clearly inferior to 1,1,1-TCE.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.19-29
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• 2010

In South Korea, as the living standard has been getting higher, meat consumption is steadily increasing. To meet the country's demand, livestock houses become larger and wider with increased raising density. In larger livestock houses, pollutants such as flake of pig skin, excrement, odor, various dusts and noxious gas like ammonia are excessively accumulated inside the facility. These will cause weak immunity for the pigs, diminution of productivity and degeneration of working condition. These problems can be solved through the ventilation performance of the facility. In the winter time, ventilation must be controlled to minimum to maintain a suitable thermal condition. However, this affects the other internal environmental condition because of the minimum ventilation. The installation of "wet air cleaner" especially in the winter time can be an alternative solution. For efficient application of this machine, there is a need to understand the existing ventilation condition and analyze the interaction of existing ventilation system with the wet air cleaner considering its appropriate location. In this study, the existing ventilation system as well as the internal environmental condition negatively inside the facility with the wet air cleaner has been studied using CFD technology. The CFD simulation model was validated from the study conducted by Seo et al. (2008). Results show that the elimination rate of ammonia was 39.4 % and stability could be improved to 35.1 % (Comparing case 5 to 1 where wet air cleaner machine was not used). It can therefore be concluded that case 5 shows the optimum location of a wet air cleaner in the livestock house.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.60-61
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• 2000

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.193-198
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• 2017

This paper discusses the design and control of a switched reluctance motor (SRM) drive system for a built-in car vacuum cleaner. The growing popularity of outdoor activities and recreation has led the automobile industry to expand technologies that increase the convenience of vehicles, and thus, a built-in car vacuum cleaner was introduced. However, the existing DC motor of a vacuum cleaning system has several disadvantages, such as maintenance cost and lifespan issues of its commutator-brush structure. An SRM can be a good alternative to the existing DC motor because of its high-speed capability, long lifespan, low maintenance cost, and high efficiency, among other advantages. A prototype SRM drive is designed and manufactured to verify its feasibility for use in a built-in car vacuum cleaning system. Dynamic simulation is conducted to determine the optimal switching angle for maximum efficiency and minimum torque ripple. Load test, noise measurement, and suction-power tests are also carried out.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1297-1301
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• 2007

The indoor air quality guideline of public transportation means was prepared recently. therefore we consider a countermeasure for the indoor air quality improvement of public transportation means. In this work, air-cleaner with roll filter system which developed alternative of indoor air quality guideline. The develpoed roll filter system is two function. the first function harmoniously circulated to heating and cooling air through HVAC system and secondary function removed PM(particluatie matters) which re-scatting to passenger's movement and suppled from outdoor air. Filter media of roll filter system select optimum electret mesh filter out of many filter media. Selected filter media was performanced tests of pressure drop, collection efficiency and dust holding capacity. Finally developed roll filter system was performanced bench test.

• Clean Technology
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• v.3 no.2
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• pp.36-46
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• 1997

CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.85-96
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• 2019

Renewable energy is emerging as a reliable alternative source of energy, it is much safer, cleaner than conventional sources and has contributed significantly in this sector. However, there are still some challenges that needed to address this evolving technology. Artificial Intelligence (A. I.) can assess the past, optimize the present, and forecast the future. Therefore, A. I. will resolve most of these problems. Artificial intelligence is complex in nature, but it reduces error and aims to reach a greater degree of precision which make renewables smarter. This paper provides an overview of frequently used A. I. methods in solar energy applications. A sample algorithm is also provided for literature purposes and knowledge transfer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.700-706
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• 2010

Carbon costs, either in the form of a carbon tax or through permit prices in an emissions trading scheme, would ultimately be reflected in higher electricity prices. This price "pass-through" is very critical to the effective design of new policies to curb the amount of carbon emissions. This paper sets out in a structured way the factors that determine price pass-through and how carbon costs would impact on the electricity market and the existing coal-fired power plants. It is shown that pass-through can vary drastically if the underlying dispatch potential of generators varies significantly across alternative emissions reduction scenarios. It can also vary depending on the availability of competing cleaner forms of generation. Pass-through as a measure of business performance is therefore hard to generalize across different circumstances and should be interpreted carefully.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.1.1-2
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• 2002

Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplaces. This implies the definition of permissible levels of exposure, that is, levels that according to the present status of knowledge are estimated to cause no adverse health effects during the lifetime of the workers, and the regular assessment of the possible health risk associated with exposure by comparing the current or the integrated exposure with the permissible exposure limits. Workers in solvent thinner-using occupation environment might be highly exposed to VOCs(volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate and propose the alternative control the VOCs from solvent thinner-using workplace.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.43-46
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• 2003

The economy of I.R.Iran is so related to oil that has had many environmental problems especially air pollution in urban areas in recent years. Statistics show that most of the time, the condition of air quality is in crisis level especially during fall and winter seasons. Rapid and high population growth has had large amount of fossil fuels consumption in all sectors including transportation, industry, agriculture, residential and commercial and public services and air pollution and healthy problems. Iran＇s abundance of fossil fuel resources has tended to discourage the country＇s incentive to shift to cleaner alternative energy sources for its energy needs that must be considered in future programming. These are discussed in this paper.