• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.139-145
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• 2002

Recently, power-electronics equipments or machine that microprocessor is included and computers have been installed continuously in industrial process or region of electronics customer. So concern for power quality, especially sags has been increased. Because those equipments are very sensitive to sags. The sag is phenomenon that magnitude of load voltage temporarily decreases because of power system fault. If a certain equipment in industrial process have any trouble result from sag, it can cause utility to be charged for enormous economics loss. Therefore it need to analyze the characteristic of sag and then mitigation method for sags in distribution system in odor to increase reliability. This paper gives an overview of sags characteristic due to short circuit fault in distribution system and after a general discussion of the various forms mitigation, gives a sags mitigation method with concentrating on changing the distribution system like spot network, on-site generation.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.352-354
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• 2002

The sag is phenomenon that magnitude of load voltage temporarily decreases because of power system fault. If a certain equipment in industrial process have any trouble result from sag. it can cause utility to be charged for enormous economics loss. Therefore it need to analyze the characteristic of sag and then mitigation method for sags in distribution system in odor to increase reliability. This paper gives an overview of sags characteristic due to short circuit fault in distribution system and after a general discussion of the various forms mitigation, gives a sags mitigation method with concentrating on changing the distribution system like spot network, on-site generation.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.228-230
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• 2000

본 연구에서는 시청각 위주의 VR 멀티미디어 환경에 후각자극을 제시함으로써 더욱 현장감 있는 상황을 느낄 수 있는 칩타입 향 발생장치를 개발하였다. 셀마다 향과 Heating Coil을 함유하고 있는 IC 타입의 향 Container, DC Motor와 IC Holder를 포함하는 향 Housing, 전체적인 제어를 담당하는 Hardware Controller와 후각정보가 Encoding된 멀티미디어로 구성된다. 멀티미디어 매체 제작시 각 Object에 대한 Bounding Box를 설정하여 해당 영역에서만 향이 발산되도록 하였고 향발생장치를 Virtual Driving Simulator에 적용하여 화면의 영상과 함께 해당 향이 잘 발산되어 더욱 현실감 있는 VR 멀티미디어를 구현하였다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.277-280
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• 1999

인간은 환경의 변화나 외부로부터 입력되는 여러 가지 혼합된 자극 중에서 필요한 정보만을 선택적으로 또는 종합적으로 감지 할 수 있는 기능을 가지고 있다. 그 중에서도 향에 의한 후각자극은 생리·심리적으로 미치는 영향을 통해서 현실 생활에서 여러 가지 중요한 역할을 담당하고 있다. 본 연구에서는 시청각 위주의 멀티미디어 환경에 후각 자극을 추가적으로 제공할 수 있는 향 발생장치를 개발함으로써 현재까지는 경험하지 못한 새로운 차원의 감성적인 삶을 영위할 수 있도록 하였다. 개발된 시스템은 container에 담긴 고체향을 heater 또는 소형 motor를 사용하여 사용자의 코 밑으로 발산시킨다. 이때 멀티미디어 매체로부터 coding 된 신호는 사용자가 가지고 있는 원격 수신기로 수신되고 microprocessor에 의해 처리되어 발산시키고자 하는 향의 종류를 선택하여 일정시간동안 향 발생장치를 동작시킴으로써 원하는 향을 발산시키도록 하였다.

• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.94-100
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• 2003

Gel-like compounds containing flammable solvents were prepared to use fur cleaning agents in field of innovative industries and general purposes. And experiments were conducted to improve the defects of liquified flammable solvents from the view point of safety and health hazards. Flammable solvents used in this study were several single component flammable solvents(turpentine oil, N-methyl-2-pyrrolidone(NMP), d-limonene) and multi component flammable solvent(gasoline and ethanol). For gelation of flammable solvents, commercially Known as Aerosil(equation omitted) 200 fumed silica and triethanolamine(TEA) were used as gelation agent dispersant. The analyses on properties of gel-like compounds was studied by gelation and viscosity test pH test, volatility test and differential scanning calorimetry(DSC) measurement. The experimental results indicate that gel-like compounds containing flammable solvents have pH stability, high viscosity, volatile organic compounds(VOC) control by the decrease of volatility and odor component generation, fluidity control etc. From the experimental values, it can be predicted that the safety in the working place is improved by manufacturing flammable solvents into gel-like compounds.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.13-20
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• 2009

There have been increasing interests in the odor generation problems as concerns about the quality of life has been increased recently. Especially, approximately 67% of the odor complaints from environmental facilities are those from sewage treatment facilities and food waste treatment facilities. Moreover, sewage ocean dumping will be prohibited from 2012 by the international and domestic ocean laws, and thus, demand for alternative management plans is increasing. Therefore, it was first selected 5 sewage treatment facilities and 5 food waste treatment facilities where the amounts of waste are relatively immense in Busan, and collect their sludge samples. Then it was investigated the samples' physical and chemical characteristics through proximate analysis, elemental analysis, XRF analysis, and calorific value analysis. Finally, estimate the $H_2S$ emission rates were estimated in order to apply the results as the basic data for providing the fundamental solution for the oder complaints. As a result, the concentration of $H_2S$ in sewage sludge and in food waste treatment facility were 57.3 mg/kg and 19.7 mg/kg in average, respectively. Finally, the units of $H_2S$ in wastes stored in total 10 waste treatment facilities was estimated 16,017,910.0 mg/d.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.612-617
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• 2007

This research was performed to evaluate the effect of 'Food Wastes (FW) Direct Landfilling Prohibition' on characteristics of landfill gas (LFG) and leachate and the appropriateness of current legislation. Approximately 45% (Exp.45) and 15% (Exp.15) of FW were filled in two lysimeters. During 570 days, 1400 L of LFG was generated from Exp.45%, which was much more than 906 L of Exp.15. There was no significant difference of LFG composition between Exp.15 and Exp.45. 2~30 ppmv of odorous hydrogen sulfide was detected in Exp.45, while 2~7 ppmv was in Exp.15. There was also no significant difference in the leachate generation between the two. On day 570, $BOD_5$ of Exp.45 and Exp.15 were 37000 mg/Land 25630 mg/L and $COD_{Cr}$ of Exp.45 and Exp.15 were 45480 mg/L, 30294 mg/L. TOC of Exp.45 was 2~3 times higher than Exp.15. Higher portion of FW in landfilling increased LFG generation. However, it generated more odor and made the quality of leachate. Therefore, 'FW direct Landfilling Prohibition' was evaluated as an appropriate legislation.

• KSBB Journal
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• v.11 no.6
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• pp.649-653
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• 1996

Imnmobilization characteristics of Thiobacillus sp. IW which oxidizes sulfur compound was studied to use the bacterium in odor controlling equipment for the future. The optimum growth conditions for Thiobacillus sp. IW were pH7, $30^{\circ}C$ and the generation time was 38min, which was extremely fast compared with other sulfur oxidizing bacteria. Optimum growth conditions in activated carbon as a carrier was pH5, $35^{\circ}C$ and those in bioceramics was pH 7∼8, $35^{\circ}C$. Cell growth immobilized in bioceramics was more stable in pH, temperature change than that immobilized in activated carbon and total number of cells in bioceramics were also higher. Based on these results, the bioceramics is thought to be better carrier in immobilization of Thiobacillus sp. IW.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.310-314
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• 2020

Although waste oil derived fuel (WDF) production technology was developed under a government initiative ~10 years ago, it became stagnant owing to the small size of participating companies, residents' rejection of foul odor, and the nature of the technology for recycling waste that was avoided. However, this subject is under the spotlight again because of recent developments, such as garbage crisis. In particular, plastic is the most difficult waste to dispose of, with more than 4 million tons of plastic waste produced every year according to statistics from the Ministry of Environment. The most effective method for treating plastic waste is to produce WDF through low temperature thermal decomposition. The WDF includes several volatile ingredients that mostly limit the use of fuel for boilers, owing to safety concerns. In particular, flash point is legally stipulated because of secondary contamination in the distribution process and the risk of fire and explosion. It is required that external shipments (distribution) should be maintained in the range of at least 30~60℃ (excluding explosion prevention facilities) for diesel power generation. Therefore, this study seeks to find the flash point that is best suited to WDFs produced from plastic waste.

• Korean Journal of Remote Sensing
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• v.18 no.3
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• pp.181-186
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• 2002

One of the most important procedure in stereo DEM generation is the stereo matching process which finds the conjugate pixels in a pair of stereo imagery. In order to be found as conjugate pixels, the pixels should have distinct spatial feature to be distinguished from other pixels. However, in the homogeneous areas such as water covered or forest canopied areas, it is very difficult to find the conjugate pixels due to the lack of distinct spatial feature. Most of erroneous elevation values in the stereo DEM are produced in those homogeneous areas. This paper presents a simple method for improving the quality of stereo DEM utilizing the texture filters. An entropy filter was applied to one of the input stereo imagery to extract very homogeneous areas before stereo matching process. Those extracted homogeneous areas were excluded from being candidates for stereo matching process. Also a statistical texture filter was applied to the generated elevation values before the interpolation process was applied in odor to remove the remaining anomalous elevation values. Stereo pair of SPOT level 1B panchromatic imagery were used for the experiments. The results showed that by utilizing the texture filters as a pre and a post processor of stereo matching process, the quality of the stereo DEM could be dramatically improved.