• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.4
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• pp.311-318
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• 2010

U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.3
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• pp.119-126
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• 2017

In the clinical setting, the pressure bio-feedback device is used for the spinal rehabilitation of patients with back pain, but it has several disadvantages. The purpose of this study was to develop a digitalized pressure biofeedback system that provides precise exercise method and posture in real time during the spinal rehabilitation exercise by sensing and monitoring body movements and balance of users and providing biofeedback to users. After that, the usability testing for a digitalized pressure biofeedback system will be conducted to identify problems such as safety, performance, operability, and satisfaction, and suggest improvement directions. A total of 33 subjects were participated in the usability testing. The experts group and the users group evaluated the developed digitalized pressure biofeedback system on a scale of 5 points after using the equipment. In the user group, safety was 3.59, operability was 4.38, satisfaction was 4.49. In the expert group, safety was 2.86, operability was 3.91, and performance was 4.28. Based on the usability evaluation, if the problems of stability of the cradle for tablet PC, air injection, screen display, etc. are solved, it becomes a exercise device capable of accurately exercising and evaluating the function of the spine by checking its own motion state while the spinal stabilization exercise.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.103-106
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• 1998

일반적으로 교환기에 수용되는 전원장치는 일반 산업용 장비 보다 높은 신뢰성이 요구된다. 특히, ATM 교환기와 같이 회로팩의 고밀집도를 요구하는 시스템에서는 전원장치도 시스템에 부합되는 안정성, 내환경성, 내구성, 고 집적화, 최소화 등의 필수 기술 요건들로 접근되어야 한다. 동시에 ATM 교환기의 수명시간을 보장하기 위한 운용, 유지보수 능력도 만족되어야 한다. 따라서, 본 고에서는 ATM 교환기가 운용중 점검 및 정비가 요구되는 전원장치의 운용유지보수성에 관련된 기술 사항들을 제안한다.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.7-10
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• 1998

The pump safety related to the functions in nuclear power plants must be designed to meet load conditions considering seismic requirements. In order to satisfy both structural integrity and operability of these pumps, the initial step in the seismic qualification is to establish the resonant frequencies of the structure. Applications are made to the design of the vertical and horizontal type pump. Computational results are analyzed with respect to the dynamic characteristics and are compared to the expected design requirements.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.193-200
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• 2000

Hazard and operability Review(HAZOP) is widely used as a process safety analysis which systematically identifies potential process deviations and settles the problems. In this paper, we carried out a process hazard analysis using HAZOP in K chemical plant. As a result, we showed that the plant could be operated more safely and be saved a lot of money by eliminating several existing hazardous factors through the change of processes and designs.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.89.4-89
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• 2001

We propose an electric wheelchair that is suitable for the upper-limbs disabled with sufficient operability and low expenses. Features of this wheelchair, 1) By instating a simple mechanical module, existing electric wheelchairs can be readily converted to a special version for the upper-limbs disabled. 2) The electric wheelchair can be freely operated by motion of a head. 3) A vision system to assure safety operation by the disabled is introduced.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.835-840
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• 1989

We present new efficient interaction measures which can be used for control operability analysis and Control Structure selection in decentralized control systems. These measures can indicate not only the stability of decentralized control systems but also the true closed-loop Performance of the decentralized control structure. Relationships between published measures and proposed ones are clarified. Some important characteristics of these. measures are rigorously analyzed. The significance and the usefulness of the proposed method have been illustrated through examples found in the literature.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.613-618
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• 1986

In this study a s/w system(HENSPIN) for the automatic synthesis of HEN(heat exchanger network) was developed based on Pinch Design Method. The synthesized HEN by HENSPIN are satisfying performance targets such as minimum utility usage with as few as possible capital items. The invented network is near optimal in capital and operating cost. It will be used as initial structure for evolution to the structure which has optimal operability.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2004.11a
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• pp.22-22
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• 2004

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.77-84
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• 1998

Hazard and operability (HAZOP) analysis is one of the safety analysis method that is used in the chemical complex, because it can systematically identify causes and consequences of all the deviation that could occur. Since this method needs to hire specialized experts, it is costly and time-consuming. Therefore HAZOP Expert System has been developed to automate this analysis. This approach introduced object-oriented method and knowledge representation which is hierarchical tree of units to supply flexibility in the system, functional semantic network, propagation equation and rule-chaining method to set up the expert system for automating HAZOP analysis.