• Title/Summary/Keyword: PRA

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Prevalence of Canine Retinal Diseases in Korea: 65 cases (국내 개에서 발생한 망막질환 65례)

  • Jeong, Man-Bok;Park, Shin-Ae;Kim, Won-Tae;Kim, Se-Eun;Che, Je-Min;Yi, Na-Young;Seo, Kang-Moon
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.154-159
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    • 2007
  • The objective of this retrospective study was to investigate the prevalence of retinal diseases in dogs presented to the Veterinary Medical Teaching Hospital, Seoul National University from April 2004 to December 2005. Sixty-five dogs (120 eyes) with retinal diseases involving blindness were included in this study. Age, breed, and gender data for all breeds were collected from medical records documenting vision loss. Generalized progressive retinal atrophy (gPRA) was the most common manifestation. Other prevalent findings included sudden acquired retinal degeneration (SARD) and retinal detachment (RD). Bilateral gPRA was found in 32 dogs with a female-to-male ratio of 1 : 1. The mean $age{\pm}SD$ of all dogs in this group was $4.66{\pm}2.30$ years with a range of 3 to 12 years. Breeds with highest prevalence of gPRA were Miniature Schnauzer (24/32, $mean{\pm}SD$ age: $3.79{\pm}0.78$ yr) and Poodle (2/32, $6.50{\pm}0.71$ yr). Twelve dogs (24 eyes) were diagnosed with SARD bilateraly, ranging from 3 to 13 years of age ($mean{\pm}SD:\;6.91{\pm}2.61$ yr). There were no abnormalities in fundus of 11 dogs at presentation. Electroretinography (ERG) without anesthesia was performed in 7 dogs, and all response was totally extinguished. Retinal detachment was identified in 21 dogs (32 eyes): 11 bilateral and 10 unilateral (7 right eye, 3 left eye). The most common breed was Shih Tzu (15/21, $mean{\pm}SD$ age: $4.39{\pm}3.24$ yr). Four other breeds comprised the remaining 6 cases (8 eyes). The everall mean age of the group was: $4.18{\pm}2.89$ years (range 0.8 to 14 years) with a female-to-male ratio of 1 : 1.1 (10 females, and 11 males).

A new approach to quantify safety benefits of disaster robots

  • Kim, Inn Seock;Choi, Young;Jeong, Kyung Min
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1414-1422
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    • 2017
  • Remote response technology has advanced to the extent that a robot system, if properly designed and deployed, may greatly help respond to beyond-design-basis accidents at nuclear power plants. Particularly in the aftermath of the Fukushima accident, there is increasing interest in developing disaster robots that can be deployed in lieu of a human operator to the field to perform mitigating actions in the harsh environment caused by extreme natural hazards. The nuclear robotics team of the Korea Atomic Energy Research Institute (KAERI) is also endeavoring to construct disaster robots and, first of all, is interested in finding out to what extent safety benefits can be achieved by such a disaster robotic system. This paper discusses a new approach based on the probabilistic risk assessment (PRA) technique, which can be used to quantify safety benefits associated with disaster robots, along with a case study for seismic-induced station blackout condition. The results indicate that to avoid core damage in this special case a robot system with reliability > 0.65 is needed because otherwise core damage is inevitable. Therefore, considerable efforts are needed to improve the reliability of disaster robots, because without assurance of high reliability, remote response techniques will not be practically used.

Long-Term Biodiversity Research Programme for Mindanao, Philippines

  • Amoroso, Victor B.
    • The Korean Journal of Ecology
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    • v.23 no.2
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    • pp.141-147
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    • 2000
  • The Long-Term Biodiversity Research Programme (LTBRP) for Mindanao is envisioned to be a collaborative programme of the Philippines. It will be a programmatic research on biodiversity - its status, threats. and conservation and management. The chosen research site is Mt. Malindang in Misamis Occidental of Mindanao. The BRP will support a set of research projects that will generate knowledge on biological and ecological, socio-economic. cultural and policy aspects of biodiversity conservation. It will also enable researchers to develop and try new methods for research on these aspects, separately or crossing boundaries of academic disciplines. Moreover. the BRP will implement support programmes which will provide the linkages of research activities to development issues and needs in the research site. The support programmes will also draw from the research projects, the knowledge that can be lent or immediately available to policy and programme formulation. The support programmes will comprise: human resource development or capability-building; information, education and communication; database; networking; community organizing: and development action. The BRP will be undertaken by a group of academie and research institutions from the Philippines, in partnership with their respective government entities and local government units in Mindanao. The Biodiversity Research Programme (BRP) will comprise a set of research projects to be undertaken by small research teams in the site. Researchable areas have been identified initially through the National Biodiversity Research Agenda. and later enriched in the Participatory Rural Appraisal (PRA) Analysis workshops by the Mindanao researchers and Philippine resource persons. Results of the PRA are presented in the paper.

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Design and Implementation of PRA for a Power Supply of Electrical Vehicle (전기자동차의 전력공급을 위한 PRA 설계 및 구현)

  • Chai, Yong-Yoong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.7
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    • pp.653-658
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    • 2016
  • As this paper is related to the relay and its driving control method, it explains about the relay which connects or interrupts the DC high voltage battery's power to drive the electric car's inverter. The paper suggests a sub-relay which prevents strong sparks from relay's contact point when the relay connects to the DC high voltage battery and also compensates for the increasing internal resistance value that is caused by deterioration at contact point. The relay's rated power is approximately 10KW and the relay's electric property has been verified through electrical instantaneous power short test, etc.

Arabidopsis nucleoside diphosphate kinase-2 as a plant GTPase activating protein

  • Shen, Yu;Han, Yun-Jeong;Kim, Jeong-Il;Song, Pill-Soon
    • BMB Reports
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    • v.41 no.9
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    • pp.645-650
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    • 2008
  • Nucleoside diphosphate kinase (NDPK) is involved in multiple signaling pathways in mammalian systems, including G-protein signaling. Arabidopsis NDPK2, like its mammalian counterparts, is multifunctional despite its initial discovery phytochrome-interacting protein. This similarity raises the possibility that NDPK2 may play a role in G-protein signaling in plants. In the present study, we explore the potential relationship between NDPK2 and the small G proteins, Pra2 and Pra3, as well as the heterotrimeric G protein, GPA1. We report a physical interaction between NDPK2 and these small G proteins, and demonstrate that NDPK2 can stimulate their GTPase activities. Our results suggest that NDPK2 acts as a GTPase-activating protein for small G proteins in plants. We propose that NDPK2 might be a missing link between the phytochrome-mediated light signaling and G protein-mediated signaling.

Improvement of Pressurizer PROV System through Micro-Computer and PRA (마이크로 컴퓨터와 확률론적 리스크 평가를 통한 가압기 보호계통의 설계 개선)

  • Jong Ho Lee;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.17 no.4
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    • pp.302-316
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    • 1985
  • Small break LOCA caused by a stuck-open PORV is one of the important contributors to nuclear power plant risk. This paper deals with the design of a pressurizer surveillance system using microcomputer to prevent the malfunction of system and has assessed the effect of this improvement through Probabilistic Risk Assessment (PRA) method. Micro-computer diagnoses the malfunction of system by a process checking method and performs automatically backup action related to each malfunction. Owing to this improvement, we can correctly diagnose “Spurious Opening”, “Fail to Reclose” and “Small break LOCA” which are difficult for operator to diagnose quickly and correctly and reduce the probability of a human error by an automatic backup action.

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The feasibility study of the application of PRA(probabilistic reliability assessment) at the practical operational planning task (계통운영분야에 확률론적 신뢰도 평가 적용 가능성에 관한 연구)

  • Choi, H.S.;Song, T.Y.;Rju, H.K.;Jeon, D.H.;Kyak, N.H.;Choi, J.S.;Jeong, S.H.;Kwon, J.J.;Park, J.J.;Yoon, Y.T.;Lee, H.C.;Cha, J.M.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.50-51
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    • 2007
  • 과거 단일 회사로 구성된 전력산업 체제하에서의 신뢰도에 대한 인식과 중요성들이 전력시장과 경쟁이 도입된 다각화된 이해 주체들 이 존재하는 현행의 국내 전력산업 구조에서는 서로 다른 양상을 띄고 변화하고 있다. 전원 및 송?변전 시설계획에서부터 계통운영 계획 및 실시간 급전에 이르기까지 연속선상의 계통운영 업무에 있어 전력공급의 안정성 확보와 더불어 보다 합리적이고 효율적인 또는 경제적인 계획과 운영에 대한 요구(Needs)가 기존의 결정론적인 신뢰도 평가의 다각적 접근 즉, 확률론적인 신뢰도평가 기법을 개발하게 하였으며, 이에 미국 전력중앙연구소(EPRI)의 PRA(Probabilistic Reliability Assessment) S/W를 도입하여 실제 계통운영의 단위업무와 접목하여 리스크를 고려한 계통안전도평가 구현의 잠재적 가능성과 극복해야 할 한계를 파악하였다.

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AN OVERVIEW OF RISK QUANTIFICATION ISSUES FOR DIGITALIZED NUCLEAR POWER PLANTS USING A STATIC FAULT TREE

  • Kang, Hyun-Gook;Kim, Man-Cheol;Lee, Seung-Jun;Lee, Ho-Jung;Eom, Heung-Seop;Choi, Jong-Gyun;Jang, Seung-Cheol
    • Nuclear Engineering and Technology
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    • v.41 no.6
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    • pp.849-858
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    • 2009
  • Risk caused by safety-critical instrumentation and control (I&C) systems considerably affects overall plant risk. As digitalization of safety-critical systems in nuclear power plants progresses, a risk model of a digitalized safety system is required and must be included in a plant safety model in order to assess this risk effect on the plant. Unique features of a digital system cause some challenges in risk modeling. This article aims at providing an overview of the issues related to the development of a static fault-tree-based risk model. We categorize the complicated issues of digital system probabilistic risk assessment (PRA) into four groups based on their characteristics: hardware module issues, software issues, system issues, and safety function issues. Quantification of the effect of these issues dominates the quality of a developed risk model. Recent research activities for addressing various issues, such as the modeling framework of a software-based system, the software failure probability and the fault coverage of a self monitoring mechanism, are discussed. Although these issues are interrelated and affect each other, the categorized and systematic approach suggested here will provide a proper insight for analyzing risk from a digital system.