• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.77-80
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• 2003

Complying with highly demand of information through internet. the utility of computer and network is rapidly provided with to schools. This situation brings about many problems. For example, the stolen information through false identification(Hacking) is the most greatest concern. In this paper it tells that the efficient way of preservating computer use is by using operating system of Open Source, which is Linux system. Further more, it shows the system which was organized by IP-Tabling (offered service-Packet Filtering method from the Linux system) functions well as a security system.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.273-276
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• 2003

대기 침적은 환경 내에서 침적된 물질들이 미치는 악영향으로 인하여 그에 대한 관심이 증대되고 있다. 특히 이 중에서 건식침적이란 대기 중 입자상이나 가스상 오염물질들이 눈이나 비가 오지 않을 때 지구 표면으로 이동되어 제거되거나 반응하는 기작을 말한다. 이러한 건식침적에 관한 연구는 그 측정의 어려움으로 인하여 주로 간접 측정법에 의하여 추정한 것이 대부분이었으나, 최근 대체 표면을 사용하여 건식침적량을 직접 측정을 하고자 하는 시도가 이루어져왔다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.181-182
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• 2001

도시 집중화로 교통난과 토지 과부족 현상이 야기되었으며, 초고층빌딩과 지하공간의 개발이 급속히 진행되고 있다. 또한, 지하공간의 이용률 급등에 따라 지하공기를 포함한 실내공기질에 관한 관심이 높아지고 있다. 기존 연구문헌에 의하면, 현대인의 대부분은 하루 중 80 ∼ 95 %를 다양한 실내 공간에서 생활하고 있으며 (Wiley et al., 1991), 실내오염원이 존재할 경우 실외대기보다 실내공기의 오염도가 극심하다는 연구결과도 있었다 (Hines et al., 1993). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.65-66
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• 2001

교통수단의 발달과 경제활동이 활발해짐에 따라 많은 오염문제가 발생하였는데, 특히 대도시를 중심으로 증가한 차량과 경제활동에 필요한 에너지 소비의 증대로 대기오염의 심각성은 더욱 커지게 되었다. 일반적으로 대기중 부유 분진의 발생원은 토사의 재 비산이나 해염 입자, 화분 등과 같은 자연적인 발생원과 산업시설, 소각시설, 가정난방, 수송수단의 이용 등의 인간활동에 의한 인위적인 배출원으로 대별되는데, 인위적인 배출원의 영향은 자연적 발생원에 비해 그 영향이 보다 폭넓고 중요하게 다루어지고 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.723-724
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• 2011

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.101-111
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• 1999

In previous study, the local trends in dustfall chemistry and deposition were determined and the characteristics of chemical compositions among dustfall, TSP and rainwater were also compared. Based on the previous results, in this study, the effects of sea salts and soil and soil on the chemical composition of dustfall were studied and then the sources of dustfall in Cheju area were tentatively identified by principal component analysis(PCA)

• Korean Journal of Microbiology
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• v.13 no.1
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• pp.24-30
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• 1975

this work was designed to study the species belonging to Family Rhodospirillaceae in Korea. The species of Rhodopseudomonas palustris and R. gelatinosa were isolated and identified. The utilization of various substrates such as malate, succinate, citrate, pyruvate, propionate and acetate were tested with isolated KS 007 and KS o16. Though there were some differences according to nitrogen source in media it was thought that he intermediates of TCA cycle were comparatively good substrates, Also it was confirmed that isolated strains have the ability of nitrogen fixation.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.288-289
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• 2002

최근 환경오염에 대한 인식과 규제가 증가하고 쾌적한 주변환경에 대한 관심이 높아짐에 따라 대기, 물, 토양, 생물 등과 같은 여러 가지 환경시료의 분석을 통하여 오염의 정도를 파악하고 오염원을 규명하여 환경관리정책에 반영하려는 노력이 추진되고 있다. 여러 가지 환경시료 중 대기분진은 자연적 또는 인위적 발생원에 따라 다양한 원소들을 함유하고 있기 때문에 대기관측시료로 이용되고 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.353-356
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• 2003

Acoustic holography is adopted in identifying the noise sources of a vehicle's underbody. Wind noise from a vehicle's underbody accounts for a large portion of the overall noise level due to the complex flow structure. Current study presents the development process of acoustic holography in the vehicle underbody, and discusses the results obtained using the method. Difficulties associated with using acoustic holography as well as the implication of the results regarding future noise reduction possibilities are discussed.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.190-199
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• 2014

In the last years, fault problem in power electronics has been more and more investigated both from theoretical and practical point of view. The fault problem can cause equipment failure, data and economical losses. And the analyze system require to ensure fault problem and also rectify failures. The current errors on these faults are applied for identified type of faults. This paper presents technique to detection and identification faults in three-phase voltage source inverter (VSI) by using time-frequency distribution (TFD). TFD capable represent time frequency representation (TFR) in temporal and spectral information. Based on TFR, signal parameters are calculated such as instantaneous average current, instantaneous root mean square current, instantaneous fundamental root mean square current and, instantaneous total current waveform distortion. From on results, the detection of VSI faults could be determined based on characteristic of parameter estimation. And also concluded that the fault detection is capable of identifying the type of inverter fault and can reduce cost maintenance.