• Title/Summary/Keyword: safety performance function

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A Study on Hydrogen Impurity Effect in Anode of Proton Exchange Membrane Fuel Cell on Various Concentration of CO and H2S (고분자전해질 연료전지 연료극의 일산화탄소 및 황화수소 농도에 따른 불순물영향에 관한 연구)

  • LEE, EUN-KYUNG;BAEK, JAE-HOON;LEE, JUNG-WOON;LEE, SEUNG-KUK;LEE, YEON-JAE
    • Journal of Hydrogen and New Energy
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    • v.27 no.6
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    • pp.670-676
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    • 2016
  • Hydrogen town in Republic of Korea was established in 2013. Hydrogen as a byproduct produced by various processes of factories is used in hydrogen town facilities. As cell performance is affected by contaminations in fuel gas, various standards about impurities of fuel have been determined by many countries. This study shows performance degradation of single cell with impurities concentrations. Traces of carbon monoxide (CO) and hydrogen sulfide ($H_2S$)can cause considerable cell performance losses. For comparing the performances by poisoning of CO, acceleration test, I-V curve, constant current are performed. Both the CO and $H_2S$ poisoning rate are a function of their concentration. With the higher concentrations the higher poisoning rates are observed. And, it was confirmed that, oxidation behavior and side reaction generation are not affected. Under the lower $H_2S$ concentration condition, the poisoning rate is much higher than that of CO because of its different adsorption intensity. It can be possible that the result of this study can be used for enacting regulation as a baseline data.

A Study on the Development of Performance Based Fire Risk Assesment Program (FDS를 활용한 성능위주 화재위험성평가 프로그램개발에 관한 연구)

  • Rie, Dong-Ho
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.1-6
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    • 2008
  • `SOS', Simulator Of Safety assessment for fire, was developed to simulate fire safety assessment for a structure which is geometrically complex. The program(SOS) is intended to use for searching as well as designing tools to analyse the evacuation safety through a wide range of structure conditions. The computer program has a function which importing FDS's calculating results to each individual resident in the structure. These attributes include a walking speed reduction by producing visibility reduction for each person on the fire. $A^*$ pathfinding algorithm is adopted to calculate the simulation of escape movement, overtaking, route deviation, and adjustments individual speeds in accordance with the proximity of crowd members. This SOS program contributes to a computer package that evaluates the fire safety assessment of individual occupants as they walk towards, and through the exits especially for building, underground spaces like a subway or tunnel.

Performance Evaluation of Early Streamer Emission Lightning Air Terminal

  • Choi, Sang-Won;Her, Yong
    • International Journal of Safety
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    • v.5 no.2
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    • pp.18-23
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    • 2006
  • Studies have claimed that ESE (Early Streamer Emission) air terminals offer a vastly increased zone of protection over that of traditional lightning rods (Franklin rods) by causing the emission of an upward streamer/leader: The upward streamer/leader will propagate towards the tip of the downward leader at an early stage in the attachment process.. This paper shows the results of a performance evaluation test of a particular type of the ESE air terminal (called "ElecHippo") with a simple rod tested at the Korea Electrotechnology Research Institute (KERI). The corona emission current of the ElecHippo made by Yong-Jin Enterprise Corp. has also been measured at the Occupational Safety & Health Research Institute (OSHRI). The results show that the ElecHippo meets the French standard of NFC 17-102-1995. The results also verify the ESE performance by measuring the ion emission current generated in the discharge electrode gap as a function of the capacitance and inductance of the equipped devices. Finally, we propose a new method for grounding the system to reduce the lightning damage by combining the ESE air terminal, the early discharge earth plate, the lightning strike recorder and the surge protection device.

Life Cycle Cost Analysis Models for Bridge Structures using Artificial Intelligence Technologies (인공지능기술을 이용한 교량구조물의 생애주기비용분석 모델)

  • Ahn, Young-Ki;Im, Jung-Soon;Lee, Cheung-Bin
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.4
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    • pp.189-199
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    • 2002
  • This study is intended to propose a systematic procedure for the development of the conditional assessment based on the safety of structures and the cost effective performance criteria for designing and upgrading of bridge structures. As a result, a set of cost function models for a life cycle cost analysis of bridge structures is proposed and thus the expected total life cycle costs (ETLCC) including initial (design, testing and construction) costs and direct/indirect damage costs considering repair and replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses costs. Also, the optimum safety indices are presented based on the expected total cost minimization function using only three parameters of the failure cost to the initial cost (${\tau}$), the extent of increased initial cost by improvement of safety (${\nu}$) and the order of an initial cost function (n). Through the enough numerical invetigations, we can positively conclude that the proposed optimum design procedure for bridge structures based on the ETLCC will lead to more rational, economical and safer design.

A study on the weights on the evaluation items for utility tunnel performance evaluation (공동구 성능평가를 위한 평가항목의 가중치 산정 연구)

  • Yongjun Lee;Kyu-Nam Jin;Young-Jong Sim
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.5
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    • pp.477-488
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    • 2024
  • The Korean government amended the Facilities Safety Act in 2018 to establish a performance-based maintenance system. This system is designed to comprehensively evaluate the safety, durability, and usage performance of facilities required to maintain their function in use, and to establish corresponding maintenance plans. However, the current maintenance system of utility tunnels is managed by a safety-oriented evaluation method, which has limitations in conducting performance evaluations that consider durability and usage performance. Therefore, in this study, safety, durability, and usage performance items for utility tunnels were selected using the Delphi method, and the weight of each item was calculated using the entropy weighting method. The results of this study are expected to be used in future performance evaluations of utility tunnels to support rational decision making when establishing maintenance plans.

Shaking Table Test to Verify the Seismic Performance of Nuclear Electric Components (원자력 전기기기 부품의 내진성능 확인을 위한 진동대 실험)

  • Chang, Sung Jin;Jeon, Bub Gyu;Park, Dong Uk;Kim, Sung Wan
    • Journal of the Earthquake Engineering Society of Korea
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    • v.28 no.3
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    • pp.141-147
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    • 2024
  • Earthquakes of magnitude 3.0 or greater occur in Korea about 10 times on average yearly, and the number of earthquakes occurring in Korea is increasing. As many earthquakes have recently occurred, interest in the safety of nuclear power plants has increased. Nuclear power plants are equipped with many cabinet-type control facilities to regulate safety facilities, and function maintenance is required during an earthquake. The seismic performance of the cabinet is divided into structural and functional performances. Structural performance can be secured during the design procedure. Functional performance depends on the vibration performance of the component. Therefore, it is necessary to confirm the seismic performance of the components. Generally, seismic performance is confirmed through seismic simulation tests. When checking seismic performance through seismic simulation tests, it is difficult to determine the effect of frequency and maximum acceleration on an element. In this paper, shaking table tests were performed using various frequencies and various maximum accelerations. The seismic performance characteristics of the functions of electrical equipment components were confirmed through tests.

Empirical Study on the Performance Analysis and Function of Jindo Coastal Vessel Traffic Service (진도 연안VTS의 성과 분석 및 기능에 관한 실증적 연구)

  • Jeong, Jae-Yong;Jung, Cho-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.4
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    • pp.308-315
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    • 2012
  • Hebei Spirit Oil Spill that happened in 2007 had prompted the need of revisiting the coastal safety. In response to this, Korea had made an effort to implement VTS in every coastline in the country. There are a lot of theoretical studies on VTS function nowadays, but coastal VTS are less frequently studied. In this paper, performance analysis results and accident prevention activities of Jindo Coastal VTS center were summarized and the Coastal VTS function are investigated. Jindo Coastal VTS covers relatively wide area and various places with various maritime traffic characteristics are the major navigation vessels, which means that it is important to control these vessels. Since the probability of accidents due to human error is relatively high in coastal area due to negligence tendency of crews during coastal area navigation, coastal VTS has to provide sufficient assistance to navigating vessels. Like most harbour VTS, Coastal VTS provides not only main information service, navigational assistance and traffic organization services but also various services related with advanced search-and-rescue assistance, marine national security, maritime crime prevention, oil spill response, traffic services for non-service vessel, and safety supervision for water leisure boats.

A Study on Development of Balanced Scorecard System of Reverse Logistics Industry (회수물류업의 BSC(Balanced Scorecard) 시스템 개발)

  • Yun, Jun-Seop;Seo, Byeong-Ryun;Yang, Gwang-Mo;Gang, Gyeong-Sik
    • Proceedings of the Safety Management and Science Conference
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    • 2008.04a
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    • pp.333-337
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    • 2008
  • The Balanced scorecard has been evolved in various function. In the various functional Balanced scorecard, this paper focuses on the reverse logistics BSC, and the decision the weights of Key Performance Indicators. In this paper, a combination of Balanced scorecard and value evaluation based approach proposed multi-criteria provides a more accurate representation of the problem for measuring company.

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Analysis of IEC 61727 Photovoltaic (PV) systems Characteristics of the utility interface

  • Lee, Jeong Hyeon;Yoon, Yong Ho;Kim, Jae Moon
    • International Journal of Internet, Broadcasting and Communication
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    • v.7 no.2
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    • pp.90-95
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    • 2015
  • This paper describes IEC 61727 standard of Photovoltaic (PV) systems -Characteristics of the utility interface. IEC 61727 standard tests include utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1) voltage, current and frequency, 2) normal voltage operating range, 3) flicker, 4) DC injection, 5) normal frequency operating range, 6) harmonics and 7) waveform distortion, 8) power factor of PV inverter. Also personnel safety and equipment protection part includes test items 1)loss of utility voltage, 2)over/under voltage and frequency, 3)Islanding protection, 4)response to utility recovery, 5)earthing, 6)short circuit protection, 7)Isolation and switching of PV inverter. In this paper, each item of IEC 61727 standard test is studied and analyzed and finally full tested by PV inverter performance function.

A Study on the Stem Coefficient of Friction of Motor- operated Gate/Globe halves

  • Jeoung, Rae-Hyuck;Park, Sung-Keun;Lee, Do-Hwan;Kim, Yang-Seok
    • Nuclear Engineering and Technology
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    • v.35 no.2
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    • pp.133-143
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    • 2003
  • Stem-stem nut coefficient of friction(COF) in motor-operated gate/globe valves is one of the important factors which determine the performance of the valve/actuators. The COF is affected greatly by the type and condition of the stem-stem nut lubricants, environmental parameters, surface condition of the stem/stem-nuts, and the number of strokes after the lubrication. In this paper, the measured data of the COFs at stem threads of some safety-related motor-operated gate/globe valves in domestic nuclear power plants are presented. In addition, the performance of the lubricants is evaluated by comparing the COFs among those valves. The results show that the measured COF at torque switch trip are higher than the unwedging COF and conservatively applicable to the unwedging COF. It is also shown that the lubricating performance based on the measured COFs varies with the lubricants.