• 제목/요약/키워드: university system

검색결과 129,628건 처리시간 0.106초

A Study on the Intrusion Tolerance System Applied to the Object Oriented Middleware Environment

  • Shin Seung Jung;Kim Young Soo;Kim Jung Tae;Ryu Dae Hyun;Na Jong Whoa
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2004년도 학술대회지
    • /
    • pp.693-698
    • /
    • 2004
  • The cyber attacks on the computer system in nowadays are focused on works that do not operate specific application. The main key point that we protect information security system has an access control to keep an application. Most of system has a main function to protect an infrastructure such as hardware, network and operating system. In this paper, we have presented an intrusion tolerance system that can service an application in spite of cyber attacks. The proposed system is based on the middle ware integrating security mechanism and separate function of application and intrusion tolerance. The main factor we use security system in nowadays is service to keep a persistency. The proposed intrusion tolerance system is applicable to such as medical, national defense and banking system.

  • PDF

PV-AF-SPE 복합시스템의 응용에 관한 연구 (A study on the application of PV-AF-SPE hybrid system)

  • 이동한;이석주;김종현;박민원;유인근
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
    • /
    • pp.341-343
    • /
    • 2006
  • In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

  • PDF

RTDS를 이용한 제주도 전력계통에서의 전압형과 전류형 직류송전 시스템 특성분석 (Characteristic analysis of LCC and VSC HVDC system in Jeju power system using RTDS)

  • 주창현;김진근;딘민차우;박민원;유인근
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2011년도 제42회 하계학술대회
    • /
    • pp.828-829
    • /
    • 2011
  • This paper performs a comparison analysis of two types of HVDC system in Jeju power system. A traditional HVDC transmission system had been composed of line commutated converter based on thyristors and the development of semiconductors enables to apply voltage source converter using IGBTs. The detailed parameters of Jeju power system were considered to make a similar condition with real system in real time digital simulator. Two types of HVDC transmission system were modeled and simulated to compare their characteristics in Jeju power system. The simulation results demonstrate that the VSC-HVDC system has more stable performance due to the fast response speed than LCC-HVDC when the transmission capacity was fluctuated.

  • PDF

PSCAD/EMTDC를 이용한 PV-AF-SPE 시스템의 특성분석 (Characteristic analysis of PV-AF-SPE system using PSCAD/EMTDC)

  • 이동한;이석주;김종현;박민원;유인근
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
    • /
    • pp.1205-1206
    • /
    • 2006
  • In this paper an integrated model of PV-AF (Photovoltaic-Active Filter) and PV-SPE (Photovoltaic Solid Polymer Electrolyte) system using PSCAD/EMTDC were explained in detail. The main concept of PV-AF system starts from the "harmonics". In order to deliver power to utility, PV system essentially needs a converter system. Here PV-AF system adds the function of active filter to the converter system installed in PV system, which was introduced already in several papers. PV-SPE system has been studied as a replacement of existing hydrogen production technology that emits large amount of carbon dioxide into atmosphere. Until now, these two systems, PV-AF and PV-SPE, have been considered separately. However, in this paper, characteristics and advantages of combined system are discussed in detail.

  • PDF

새로운 에이젼트 기반의 결함극복 IED시스템 및 신뢰성 분석 (A New Agent Based Fault Tolerant IED System and Its Reliability Analysis)

  • Fan, Weizhong;Lee, Dong-Wook;Lee, Seun-Jae;Lim, Sung-Il;Han, Seung-Soo
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
    • /
    • pp.1371-1373
    • /
    • 2005
  • Nowadays, Intelligent Electronic Devices(IED) are widely used in power system. In order to improve the selectivity, sensitivity, and reliability of the power system composed by IEDs, A new fault tolerant IED system based on agent technique is presented in this paper. in the presented system, different with existing IED systems, the redundancies are drawn out from IED devices, and compose a standby backup system. And those redundancies are not specified to a particular type of IEDs. By using the agent technique, redundancies can download agents to modify their functions to fit different types of IEDs. As a conclusion, the reliability of the presented system is estimated in this paper.

  • PDF

안면신경평가기준에 따른 구안와사(口眼喎斜)의 임상관찰 (The clinical observation on Bell's palsy according to facial nerve grading system)

  • 김종인;서정철;이상훈;최도영;강성길;고형균
    • Journal of Acupuncture Research
    • /
    • 제19권5호
    • /
    • pp.112-123
    • /
    • 2002
  • Background and Objective : The evaluation of facial nerve function is a complex procedure. The House-Brackmann facial nerve grading system(H-B grade)and the Yanagihara grading system(Y-system) have been recommended as universal standards for assessing the degree of facial nerve palsy. The purpose of this study is to compare the effectiveness of Y-system and H-B system and to know the advantages of each system for each stage of incomplete recovery or sequelae of facial paralysis. Materials and Methods : A comparison between H-B grade and Y-system was studied with 137 evaluations of 61 cases of incomplete recovery or sequelae of peripheral facial paralysis. Each case was graded by using H-B system as a gross system and Y-system as a regional system before treatment, after 12 weeks and 6 months Results and Conclusions : The range of score in the Y-system 0-6, 8-16, 14-22, 24-34, 32-38, 38-40 were matched with grade VI, V, IV, III, II and I in the H-B system. The percentage of H-B grade III was the greatest among 137 evaluations and y-system showed the greatest score range. H-B system is easy to use but Y-system is more objective, quantitative and convenient to use in the incomplete recovery or sequelae state.

  • PDF

LVDC 배전계통의 접지방식에 따른 인체안전 및 계통영향 분석 (Analysis of Human Safety and System Effect according to Grounding Scheme in LVDC Distribution System)

  • 오윤식;한준;권기현;김두웅;노철호;정택현;김철환
    • 전기학회논문지
    • /
    • 제63권5호
    • /
    • pp.608-614
    • /
    • 2014
  • Recent developments and trends in the electric power consumption clearly indicate an increasing use of DC in end-user equipment. According to the trends, new DC power distribution systems have been researched and developed although we presently enjoy a predominantly AC power distribution system. We can use various grounding schemes in DC distribution system as well as in AC distribution system to protect human body and equipments. However, we need to evaluate carefully which grounding scheme is appropriate for a specific system before applying those schemes. In this paper, we analyze the human safety and system effect according to various grounding schemes in Low Voltage DC (LVDC) distribution system. Some components in LVDC distribution system are modeled and computer simulations are conducted by using ElectroMagnetic Transient Program (EMTP).

A Ghost-Imaging System Based on a Microfluidic Chip

  • Wang, Kaimin;Han, Xiaoxuan;Ye, Hualong;Wang, Zhaorui;Zhang, Leihong;Hu, Jiafeng;Xu, Meiyong;Xin, Xiangjun;Zhang, Dawei
    • Current Optics and Photonics
    • /
    • 제5권2호
    • /
    • pp.147-154
    • /
    • 2021
  • Microfluidic chip technology is a research focus in biology, chemistry, and medicine, for example. However, microfluidic chips are rarely applied in imaging, especially in ghost imaging. Thus in this work we propose a ghost-imaging system, in which we deploy a novel microfluidic chip modulator (MCM) constructed of double-layer zigzag micro pipelines. While in traditional situations a spatial light modulator (SLM) and supporting computers are required, we can get rid of active modulation devices and computers with this proposed scheme. The corresponding simulation analysis verifies good feasibility of the scheme, which can ensure the quality of data transmission and achieve convenient, fast ghost imaging passively.

PV-AF 시스템의 개념설계 및 시제작 시스템에 관한 연구 (A Study on the Conceptual Design & Test System of PV-AF System)

  • 박영길;김종현;박민원;유인근
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
    • /
    • pp.1687-1689
    • /
    • 2005
  • In this paper, novel concept of a photovoltaic(PV) power generation system adding the function of active filter(AF) is proposed. Even PV power generation system can be treated to a harmonics source for the power distribution system, it is necessary that the function of AF system in grid connected PV power generation system. Active Filters intended for harmonic solutions are expending their functions from harmonic compensation of nonlinear loads into harmonic isolation between utilities and consumer, and harmonic damping throughout power distribution system. So, the PV system combined the function of AF system can be usefully applied in power distribution system. Here, the control strategy of PV-AF system is introduced.

  • PDF