• 제목/요약/키워드: protection system

검색결과 5,945건 처리시간 0.034초

Design of A Downlink Power Control Scheme in Unequal Error Protection Multi-Code CDMA Mobile Medicine System

  • Lin, Chin-Feng;Lee, Hsin-Wang;Hung, Shih-Ii;Li, Ching-Yi
    • 한국정보기술응용학회:학술대회논문집
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    • 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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    • pp.335-338
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    • 2005
  • In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

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소형 미사일 탐지를 위한 Facet 기반의 고속 영상처리 기법 (A High-Speed Image Processing Algorithm Based on Facet Filter for Small Missile Detection)

  • 김지은
    • 한국군사과학기술학회지
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    • 제12권4호
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    • pp.500-507
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    • 2009
  • This paper presents a novel method which can detect a target in IR image for active protection system. The target in IR image for the active protection system is small, moreover it moves with enormous speed. The proposed algorithm is comprised of robust clutter rejection methods and target optimized detection algorithms for small target, and an advanced method of selecting a final target position in target area, it can work in some milliseconds. The proposed algorithm provides the active protective system with more correct positions than those of radar, so that helps the active protection system can defense all threats with the utmost precision.

한국형 태양열 온수급탕 시스템의 대책과 제안 (Measures and Proposal for Korean Solar Water Heating System)

  • 김성수;홍희기
    • 설비공학논문집
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    • 제20권9호
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    • pp.631-636
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    • 2008
  • Solar thermal systems are recently refocused by higher oil prices, but did not completely restore the people's confidence owing to the past bad systems. Several types of solar water heating systems were analyzed in characteristics and some proper systems were proposed under Korean climates and system scale. As a small system, natural circulation system should be installed only in a southern region of Korea, with a freeze protection valve instead of heating coil for freeze protection. In most area of Korea, the forced circulation type with a heat exchange coil inside a thermal storage tank or with a spiral-jacketed storage tank, proposed and verified by the authors, has a merit of stable performance and freeze protection.

Determination of Low-temperature Electrochemical Properties of Selected Cation-exchange Membranes for Cathodic Protection Analysis

  • Ko, Moon-Young;Kwon, Byeong-Min;Hong, Byung-Pyo;Byun, Hong-Sik
    • Korean Membrane Journal
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    • 제10권1호
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    • pp.8-12
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    • 2008
  • The electrochemical properties of Nafion type membranes as a function of temperature to examine the key factors affecting the cathodic protection process at low temperatures was investigated in this study. Variable temperature experiments for AC impedance, DC resistance were conducted. The resistances of 3 Nafion membranes (N 324, N 450, N MAC) were measured in 30% KOH (aq) for a range of temperatures between $-30^{\circ}C$ and room temperature. Membrane resistance increases exponentially with decreasing temperature. This behaviour is most significant at operational temperatures below $0^{\circ}C$. These membranes are stable under the low temperature and caustic conditions of the heat exchange system, but they place a much higher restriction on the cathodic protection of the stainless heat exchange stack. N 450 has the lowest AC impedence and DC resistance at temperatures below $0^{\circ}C$ and consequently is most suitable membrane of the three, for low temperature applications.

공격 트리를 이용한 다양성보호계통 사이버보안 위험 평가 (Cybersecurity Risk Assessment of a Diverse Protection System Using Attack Trees)

  • 정성민;김태경
    • 디지털산업정보학회논문지
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    • 제19권3호
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    • pp.25-38
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    • 2023
  • Instrumentation and control systems measure and control various variables of nuclear facilities to operate nuclear power plants safely. A diverse protection system, a representative instrumentation and control system, generates a reactor trip and turbine trip signal by high pressure in a pressurizer and containment to satisfy the design requirements 10CFR50.62. Also, it generates an auxiliary feedwater actuation signal by low water levels in steam generators. Cybersecurity has become more critical as digital technology is gradually applied to solve problems such as performance degradation due to aging of analog equipment, increased maintenance costs, and product discontinuation. This paper analyzed possible cybersecurity threat scenarios in the diverse protection system using attack trees. Based on the analyzed cybersecurity threat scenario, we calculated the probability of attack occurrence and confirmed the cybersecurity risk in connection with the asset value.

Rogowski 코일을 이용한 과전류 폴트 차단 기법에 관한 연구 (A Study on Shortcircuit Fault Protection Method Using Rogowski Coil)

  • 윤한종;조영훈
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2018년도 전력전자학술대회
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    • pp.108-110
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    • 2018
  • This paper proposes shortcircuit fault protection method in a synchronous buck converter using the PCB pattern Rogowski coil. The PCB pattern Rogowski coils are embedded in the gate driver to measure the device currents of the top and bottom side. When shortcircuit occurs in the system, the gate signal is blocked by the proposed fault protection method using the device current. The simulation and experimental results show that the proposed fault protection method is verified in the shortcircuit system.

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The Practice and Effect of Water Conservation Legislation in China

  • Liu, Dingxiang;Li, Jianguo
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.19-19
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    • 2012
  • After more 60 years' legislative practice of water resources protection, the Chinese government has initially established a legislative system of water resources protection, based on Water Law. From the development course of water resources protection legislation, the paper mainly analyzes the legal framework, main content & management system of water resources protection, and pointed out the improved direction of water resources conservation legislation in China in the future.

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Design of SPS in the Korean Power System Against Faults on 765 KV Lines

  • Park Jong-Young;Park Jong-Keun;Jang Byung-Tae
    • KIEE International Transactions on Power Engineering
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    • 제5A권2호
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    • pp.132-137
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    • 2005
  • In Korea, the protection systems against the instability of the nation's power system are insufficient in contrast with many other countries. In addition, there have just been studies carried out on detecting power system instability, while only a few studies pertaining to protection plans against instability exist. This paper focuses on systems to protect against the instability phenomena in the Korean power system. In this paper, we survey possible contingencies in the Korean power system and suggest outline and specs of the SPS (System Protection Scheme) against faults on the 765 kV line, based on simulations. It is concluded that event-based SPS for transient stability is appropriate for the Korean power system. In the simulations, the most severe contingency on the Korean power system is the fault on 765 kV transmission lines. If one of these lines is tripped by a fault, synchronism may be lost on the power plants near this line because of heavy power flow carried by them. In addition, undervoltage in the Metropolitan region is a serious problem in this case since this region receives about half its total power flow through these lines. In order to prevent a synchronism loss, some power plants have to be rejected according to the situations in the simulations.

부식촉진에 의한 해양.항만 철근 콘크리트 구조물의 철근 방식에 관한 실험적 연구 (Rapid Corrosion Test on Marine Reinforcing Steel)

  • 정근성;문홍식;송호진;이상국;정영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.537-542
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    • 2001
  • Recently long-span bridges, such as Kwang-Ahn Grand bridge, Seo-Hae Grand Bridge, Young-Jong Grand Bridge, etc, have been designed and constructed near the shore. It needs to maintain the durability of marine concrete structures which are exposed to severe chloride environments. It is well known that corrosion of reinforcement steels in concrete structure is the most important cause for the durability of concrete structure which can be controlled by systematic preparatory corrosion protection works for economic and safe infrastructures. Various corrosion protection systems have been used for the corrosion protection of reinforcement steels from detrimental chemical components such as chloride, sulphate and etc. Since chloride can be penetrated into concrete in a variety way, an effective method has to be adopted by taking into full economical aspects and technical data of each protection system. The objective of this experimental study is to investigate the corrosion behavior of reinforcing steel in laboratory concrete specimens which are exposed to cyclic wet and dry saltwater, and then to develop pertinent corrosion protection system, such as corrosion inhibitors and cathodic protection for reinforced concrete bridges exposed to chloride environment. Resistance of various corrosion inhibitors and impressed current system have been experimentally evaluated under severe environmental conditions, and thus effective corrosion protection systems could have been Practically developed for future concrete construction.

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Current Status of Internal Dosimetry Methods and Radiological Regulations in Korea, Ukraine and European Community

  • Lee, Tae-Young;Lee, Jong-Il;Berkovski, Vladimir
    • Journal of Radiation Protection and Research
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    • 제28권1호
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    • pp.65-73
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    • 2003
  • The paper discusses results of recent international intercomparison exercises on internal dose assessments, status of up to date internal dosimetry methods and the radiological legislation developed and implemented in Korea, European Union and Ukraine. The system of radiation protection in Korea is based on the Korean Atomic Energy Regulatory Enforcement on Safety Standards (Ministry Notice No. 2001-2). The notice is based on the recommendations in ICRP Publication 60 (1990) and IAEA Basic Safety Standards (1996). But the full implementation of the notice by the end of the year 2002 is not required because of the socio-economic situation and inexperience in internal radiation dosimetry Regulatory framework for internal radiation dosimetry is under development toward the full implementation of the notice from January 1, 2003. The system of radiation protection in Ukraine is based on the National radiation protection regulatory code NRBU-97. The code was developed and adopted in 1998 and replaced the Regulations of Former Soviet Union. The document is based on the ICRP Publication 60, Euratom Directive 96/29 and IAEA Basic Safety Standards (1996). The transitional period of 5 years (effected till January 2003) is established for implementation of all requirements of this new regulation. The system of radiation protection in the European Community is based on the Council Directive 96/29/Euratom, adopted in 1996 and enforced from 13 May 2000. Directive 96/29/Euratom has the status of the European law.