• Title/Summary/Keyword: Draft system

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Performance Evaluations of the Lightning Impulse Voltage Measuring System by Intercomparative Test - in case of full lightning impulse voltage - (뇌충격 측정시스템의 비교시험에 의한 성능평가 - 전파 뇌충격전압 인가시 -)

  • Kim, Ik-Soo;Kim, Young-Bae;Lee, Hyeong-Ho
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1368-1370
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    • 1995
  • Lightning impulse voltage is essential to evaluate the insulation performance of electric power apparatus. Recently international standard(IEC-60) on high voltage measurement techniques are being revised. In the draft of this standard, a new calibration method is introduced and the accuracy of most industrial measuring systems is maintained by means of comparison test against the reference measuring systems. Intercomparison tests of dividers for lightning impulse measurement were carried out by KERI. The shielded resisitive divider with 700kV rating developed by KERI were done comparison test with PTB divider with 300kV rating which have the similar charateristics as that were circulated among the laboratories. This paper reports on the comparison test results with full lightning impulse voltages from 126kV to 240kV. It is demonstrated that KERI are capable of realizing the idea in the revision of the IEC standand, that is, to establish traceability.

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A Study on Parts Manufacturer Approval in Civil Aviation Law (항공기 부품제작자증명에 관한 연구)

  • Lee, Kang-Yi;Jin, Young-Kwon;Lee, Jong-Hee;Lee, Kwang-Hee
    • The Korean Journal of Air & Space Law and Policy
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    • v.17
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    • pp.133-152
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    • 2003
  • Certification by Civil Aviation Law is necessary for aircraft parts and appliances as well as aircraft, engines, and propellers to ensure safety and reliability in operation. Advanced countries in aerospace industry as like U.S.A require Parts Manufacturer Approval for aircraft parts and Technical Standard Order Authorization for designated appliances. However, there are no legal requirements for certification of aircraft parts and appliances in Korea until now. This study presents the draft to revise Civil Aviation Law, which is applicable to set up domestic certification system and maintain it equivalent to U.S. Federal Aviation Regulation.

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Investigations of DLC Films for Protection of Organic Photoconductors in Electrophotography

  • Ko, Myoung-Wan;Kim, Seong-Young;Shin, Seoung-Yong;Lee, Sang-Hyun;Akihiro Tanaka;Kazunori Umeda;Kazuyuki Mizuhara
    • The Korean Journal of Ceramics
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    • v.3 no.2
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    • pp.88-91
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    • 1997
  • The diamondlike (DLC) films were deposited by RF plasma CVD system which had cathode consisting of mesh sheet, for the purpose of a protection from wear of OPC surface of the electrophotographic photosensitive body. Material charateristics and tribological properties of the films were also investigated and finally copying performance was evaluated with DLC deposited OPC samples. The surface resistance of the DLC film unaffected by the surface potential of the OPC was about $10^{11}{\Omega}$ and its hardness was about 1200 kg/$\textrm{mm}^2$. In this case the film showed typical material strcture of dimondlike hydrocarbon. The friction coefficient of the film was lowered to 0.2~0.3 at the optimum condition in this investigation and their wear resistant was inproved by DLC-deposition on the OPC surface. DLC-deposited OPC samples with a good copying performance without image flow and draft could be obtained at some depositing conditions.

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Effective Local Exhaust Ventilation on Cooking Fumes of Seasoned Meats

  • Lee Byeong Kyu;Ellenbecker Michael J.
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.2 no.1
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    • pp.49-56
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    • 1998
  • This study identified the fumes produced from the cooking of the seasoned meats containing various condiments such as garlic, onion, pepper, soy sauce, and sesame oil. Concentrations, at the breathing zone of the cook, of volatile organic compounds (VOCs) and aldehydes included in the cooking fumes of seasoned meats were identified. Many chloro and fluoro-aliphatic hydrocarbons, aromatic hydrocarbons, ketones, and aldehydes, which could be carcinogen suspecting chemicals, were producing from the cooking fumes of the seasoned meats. This study also identified the ventilation efficiencies of the cooking fumes of the six exhaust ventilation systems, which were widely being used in the general apartments, houses, and small-food factories. For a comparison of the ventilation efficiencies of the systems, acetaldehyde was chosen as a marker pollutant and its concentrations at the breathing zone of the cook were identified. The laboratory fume hood showed the best ventilation efficiency of the six ventilation systems studied, and then the lateral hood ventilation and the down draft ventilation followed the laboratory fume hood. Finally, this study identified that both a wall factor nearby pollutant sources and a distance factor between the hood face and pollutant sources should be also considered for an effective local exhaust ventilation system design.

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A Study on the Improvement of Disaster Relief Aid (재해구호물자 개선에 관한 연구)

  • Park, Sang Hyun;Kim, Chan-O
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.138-144
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    • 2018
  • Disaster relief goods are those that help disaster victims to carry on ordinary life in a disaster. Along with the improvement of national economic level and raise of people's standard of living and diversified lifestyles, demands for relief goods in a disaster are also being diversified. In step with frequent and rather large-scale occurrence of disasters, diversity of related goods for disaster relief is likely to be needed ever more in the future, while more assistance to disaster victims is required from the aspect of securing their normal daily lives. To this end, the study conducted comparative analysis of how Korea, the US and Japan managed disaster relief goods and also examined, analyzed the opinions regarding the betterment of relief goods among disaster victims and ordinary people and civil servants in charge. Based on this, the study suggested the improvement draft for disaster relief goods, the point of which was to minimize disaster relief goods commonly prepared by the central government with goods that may assist victims' lives in shelters, while local governments may prepare relief goods appropriately according to actual situation.

Study on the Establishing a Guideline for Selecting Major Environmental Factors by the Project Type Criteria in EIA (환경영향평가 대상사업별 중점평가항목의 도출에 관한 연구)

  • Sung, Hyun-Chan;Han, Sang-Wook
    • Journal of Environmental Impact Assessment
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    • v.3 no.1
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    • pp.9-30
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    • 1994
  • Environmental Impact Assessment System, ever since its enactment in Korea fourteen years ago, has been steadily improved by introduction and implementation of new concepts and methodologies which include Environmental Impact Statement(EIS) preparation technique, selection of environmental factors, and the like. However, current guideline requires that every EIS, regardless of the specifics of the project type or characteristics of the site, must evaluate and study for all twenty-two environmental factors as set forth in the regulation. The situation causes many undesirable problems like; lack of site specific evaluation in most EISs, over-sized EIS drafts, consuming too much time and costs for EIS preparation, and so on. The objectives of this study are: - To establish a set of criteria to classify the types of the projects in terms of features of the project content and the characteristics of the site area. - To establish a guideline for selecting major environmental factors of the project type criteria, and - To provide basic materials for the preparation of complets draft EIS of the Amendment of Environmental Impact Assessment Act.

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A Study on the Considerations Relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferromanganese Crusts in the Area (해저 열수광상 및 망간각 자원 개발을 위한 국제적 논의에 대한 고찰)

  • Park, Seong-Wook;Lee, Yong-Hee;Kwon, Moon-Sang
    • Ocean and Polar Research
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    • v.25 no.2
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    • pp.227-235
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    • 2003
  • In August 1998, during the resumed fourth session of the Authority, the delegation of the Russian Federation reminded the Assembly that, in addition to polymetallic nodules, other mineral resources existed in the Area, including polymetallic sulphides and cobalt crusts, and requested the Authority to adopt rules, regulations and procedures for exploration for such resources. Pursuant to article 162, para. 2(o)(ii), of the 1982 UNCLOS, such rules, regulations and procedures are to be adopted within three years of the date of such a request. This article reviewed the 'Draft Rules and Regulations for the Exploration and Exploitation of Sea-Floor Massive Sulphides and Cobat-rich Ferromanganese Crusts in the Area' by ISA in 2001, and the 'Madang Guideline for Offshore Mineral Policy' written in 1999 in respect of the international trends of polymetallic sulphides and cobalt crusts. Issues for size of mining area and relinquishment, application of the site-banking system, procedure for dealing with overlapping claims and precautionary approach etc. for the establishment of the norm of polymetallic sulphides and cobalt crusts are reviewed as consideration factors.

Latching Control Technology for Improvement of Extracted Power from Wave Energy Converter (파력발전기 추출파워 향상을 위한 래칭 제어기법)

  • Cho, Il Hyoung
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.4
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    • pp.282-290
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    • 2015
  • In this study, a latching control technology, proposed by Sheng et al.(2015), was applied in order to maximize the extraction efficiency of WEC (Wave Energy Converter), which is the heaving buoy coupled with linear electric generator. The latching control is the phase-control technique for improving the wave energy conversion with appropriate latching duration of keeping the buoy fixed. From the time-domain analysis in regular waves, the latching control technology can significantly improve the heave velocity and extracted power, even though the resonance condition is not satisfied. By using the latching control technology, the draft of buoy as well as the required PTO damping force can be significantly reduced along with increased extracted power, which is a big advantage in manufacturing the WEC.

A Study on a Domestic Technical Standard and Effective Introduction of Class B AIS for Non-SOLAS Vessels (Non-SOLAS 선박용 Class B AIS의 국내 기술기준안 개발 및 효과적인 도입방안에 관한 연구)

  • Jeong Jung-Sik;An Kwang
    • Proceedings of KOSOMES biannual meeting
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    • 2005.11a
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    • pp.53-58
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    • 2005
  • An international study on Class B AIS for Non-SOLAS vessels is in progress through IMO and IEC. The IEC issued CDV(Committee Draft for Vote) on March 3, 2005, as IEC 62287, which includes operational and performance requirements, methods of test and required test results about Class B AIS. In this paper, we proposed the method of making Class B AIS properly onboard. This research deals with the problems of introducing Class B AIS which is properly applicable on small fishing vessels as well as domestic Non-SOLAS vessels. Moreover, several technical considerations were suggested to develop a national technical standards for Class B AIS.

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MPEG-7 Homogeneous Texture Descriptor

  • Ro, Yong-Man;Kim, Mun-Churl;Kang, Ho-Kyung;Manjunath, B.S.;Kim, Jin-Woong
    • ETRI Journal
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    • v.23 no.2
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    • pp.41-51
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    • 2001
  • MPEG-7 standardization work has started with the aims of providing fundamental tools for describing multimedia contents. MPEG-7 defines the syntax and semantics of descriptors and description schemes so that they may be used as fundamental tools for multimedia content description. In this paper, we introduce a texture based image description and retrieval method, which is adopted as the homogeneous texture descriptor in the visual part of the MPEG-7 final committee draft. The current MPEG-7 homogeneous texture descriptor consists of the mean, the standard deviation value of an image, energy, and energy deviation values of Fourier transform of the image. These are extracted from partitioned frequency channels based on the human visual system (HVS). For reliable extraction of the texture descriptor, Radon transformation is employed. This is suitable for HVS behavior. We also introduce various matching methods; for example, intensity-invariant, rotation-invariant and/or scale-invariant matching. This technique retrieves relevant texture images when the user gives a querying texture image. In order to show the promising performance of the texture descriptor, we take the experimental results with the MPEG-7 test sets. Experimental results show that the MPEG-7 texture descriptor gives an efficient and effective retrieval rate. Furthermore, it gives fast feature extraction time for constructing the texture descriptor.

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