• Title/Summary/Keyword: safety switch

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A study of efficiency for digital pressure switch in fire pump system (전자식기동용압력스위치의 효용성 연구)

  • Lee, Taick-Koo;Tak, Il-Cheon;Rie, Dong-Ho
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2011.04a
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    • pp.207-213
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    • 2011
  • 소방펌프는 소방설비 시스템에서 가장 중요한 설비임에도 불구하고 그동안 펌프의 기동 정지를 압력탱크(챔버)방식으로만 할 수 밖에 없었기 때문에 셋팅 및 유지관리 등에 많은 어려움이 있었으나 전자식기동용압력스위치를 이용한 새로운 펌프기동장치가 도입이 되었기에 이에 대한 특징과 장단점 등을 분석, 검토하였다.

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Prototype Development for KNGR Plant Protection Systems (차세대 원자력 발전소에서의 발전소보호계통 Prototype 기능의 구현)

  • Park, Jong-Beom;Kim, Chang-Ho;Cho, Whang
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.807-809
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    • 1998
  • Plant Protection Systems(PPS) are those systems that initiate safety actions to mitigate the consequences of design basis events by sending signals to Reactor Trip Switch Gear System(RTSS) and Engineered Safety Features-Component Control Systems(ESF-CCS). This paper illustrates distinctive features and improved design concepts of Korea Next Generation Reactor(KNGR) based on the experience obtained through prototyping of PPS.

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A Comparison Between the Tape Switch Sensor and the Video Images Frame Analysis Method on the Speed Measurement of Vehicle (차량 속도 측정의 실무적용을 위한 테이프스위치 센서 방식과 영상 프레임 분석방법의 비교연구)

  • Kim Man-Bae;Hyun Cheol-Seung;Yoo Sung-Jun;Hong You-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.9 s.351
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    • pp.120-127
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    • 2006
  • In Korea the vehicle enforcement system(VES) detects speeding vehicle using two inductive loop detectors. And the speed reliability of theirs are evaluated through the analysis of image frame which is captured from video camera. This method is validated to evaluate VES on Korea Laboratory Accreditation Scheme(KOLAS) but it needs much time and expense for the analysis of image frame. Because the number of VES are increasing rapidly, the requirement of new evaluation method is necessary. On this paper, the tape switch sensor as a substitution of existing method was introduced and its application on the site are discussed. On the site test we compared the tape switch sensor on the speed measurement of vehicle with the video image frame. As a result we have founded that the tape switch sensor is evaluated to be feasible system on site in respect to measure the overspeed vehicle.

Parametric Study on 3-way Switch Design Considering Levitation Stability of Maglev Train (자기부상열차의 부상안정성을 고려한 3방향 분기기의 설계 파라미터 연구)

  • Lee, Younghak;Han, Jong-Boo;Lim, Jaewon;Lee, Jong-Min
    • Journal of the Korean Society for Railway
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    • v.19 no.2
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    • pp.135-144
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    • 2016
  • It is essential to lighten the weight of switch girders in order to reduce their costs of manufacturing and make it easier to use them in construction. Lightening the weight of switch is also important to the Maglev 3-way switches system, however, the design variables should be considered very carefully if lightening is to be applied to the system, because these variables are vitally related to the levitation stability. Because Urban Maglev trains have a structure in which train bogie wraps around the guiderail, the adjustment of a girder's height is a possible way to reduce the weight. The safety of the application of this concept is ensured by repeated experiments in a test bed, however, due to a lack of space and budget limits, the design parametric study for the system model can substitute for actual application. The purpose of this paper is to study the design parameters that are concerned with levitation stability while a Maglev train is running on the Maglev 3-way system depending on the weight of the switch girders. In this study, switch girder weight is reduced by adjustment of girder height and girders are and modeled as a flexible body. The effect of the adjustment of girder height on the levitation stability can be analyzed by comparing the velocity of the train when it passes the switch girders, with the lateral gap, and the levitation gap which are obtained from the co-simulation of the Maglev train's dynamics model and flexible switching system. The results of this research will be used to design a Maglev switch.

One-year experience of oral substrate reduction therapy in three patients with Gaucher disease type I

  • Sohn, Young Bae;Kim, Yewon;Moon, Ji Eun
    • Journal of Genetic Medicine
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    • v.17 no.2
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    • pp.62-67
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    • 2020
  • Purpose: Eliglustat is an oral substrate reduction therapy (SRT) approved for adults with Gaucher disease type I (GD1) who are extensive, intermediate, or poor CYP2D6 metabolizers. Here we report one-year experience of eliglustat switch therapy from long-term enzyme replacement therapy (ERT) in three adult patients with GD1. Materials and Methods: Medical history, clinical (hemoglobin concentration, platelet count, and bone mineral density) and biochemical parameters (angiotensin converting enzyme, total acid phosphatase, and lyso-gb1) of the patients were collected and evaluated by retrospective review of medical records at every 3, 6, or 12 month after switch to SRT. Results: Patient 1 was a 43-year old female diagnosed GD1 and her clinical and biochemical parameters were stabilized for more than 20 years by ERT. Due to the burden of regular hospital visit, she switched to SRT. During one-year of SRT, clinical parameters and biomarkers were maintained stable. However, after suffering acute febrile illness during SRT, she decided to re-switch to ERT due to concerns about drug interaction. Patient 2 was 41-year old male, younger brother of patient 1 and Patient 3 was 31-year old male. They switched to SRT in clinically stable condition with long-term ERT. The one-year SRT was tolerable without specific safety issue and the clinical parameters were maintained stable. Conclusion: One-year eliglustat therapy in three adult patients with GDI was generally tolerable and effective for maintaining the clinical parameters and biomarkers. However, the drug compliance, concurrent drug interactions, and long-term safety of eliglustat should be carefully monitored.

A Study on the Design of Software Switching Mechanism for Develops the Flight Control Law (제어법칙 개발을 위한 소프트웨어 전환장치 설계에 관한 연구)

  • Kim, Chong-Sup;Cho, In-Je;Ahn, Jong-Min;Shin, Ji-Hwan;Park, Sang-Seon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1130-1137
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    • 2006
  • Relaxed Static Stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, the flight control systems are necessary to stabilizes the unstable aircraft and provides adequate handling qualities. The initial production flight control system are verified by flight test and it's always an elements of danger because of flight-critical nature of control law function and design error due to model base design method. These critical issues impact to flight safety, and it could be lead to a loss of aircraft and pilot's life. Therefore, development of an easily modifiable RFCS(Research Flight Control System) capable of reverting to a PFCS(Primary Flight Control System) of reliable control law must be developed to guarantee the flight safety. This paper addresses the concept of SSWM(Software Switching Mechanism) using the fader logic such as TFS(Transient Free Switch) based on T-50 flight control law. The result of the analysis based on non-real time simulation in-house software using SSWM reveals that the flight control system are switching between two computers without any problem.

Approach towards qualification of TCP/IP network components of PFBR

  • Aditya Gour;Tom Mathews;R.P. Behera
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.3975-3984
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    • 2022
  • Distributed control system architecture is adopted for I&C systems of Prototype Fast Breeder Reactor, where the geographically distributed control systems are connected to centralized servers & display stations via switched Ethernet networks. TCP/IP communication plays a significant role in the successful operations of this architecture. The communication tasks at control nodes are taken care by TCP/IP offload modules; local area switched network is realized using layer-2/3 switches, which are finally connected to network interfaces of centralized servers & display stations. Safety, security, reliability, and fault tolerance of control systems used for safety-related applications of nuclear power plants is ensured by indigenous design and qualification as per guidelines laid down by regulatory authorities. In the case of commercially available components, appropriate suitability analysis is required for getting the operation clearances from regulatory authorities. This paper details the proposed approach for the suitability analysis of TCP/IP communication nodes, including control systems at the field, network switches, and servers/display stations. Development of test platform using commercially available tools and diagnostics software engineered for control nodes/display stations are described. Each TCP link behavior with impaired packets and multiple traffic loads is described, followed by benchmarking of the network switch's routing characteristics and security features.

Cause Analyses of Boiler Accident and Their Counter-plans Based on Accident Cases (사고사례에 기초한 보일러 사고의 원인분석 및 대책)

  • 윤상권;장통일;임현교
    • Journal of the Korean Society of Safety
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    • v.18 no.3
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    • pp.131-140
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    • 2003
  • An accident involving a boiler can result in a disaster since it handles high-pressurized steam so that it may cause an explosion. Therefore, the boiler is very susceptible to industrial accidents. This thesis aimed to develop counter-plans to prevent industrial accidents involved the boiler. At first after collecting accident cases involving boilers, a survey on the trait of them was carried out. Ant on the other hand a qualitative analysis was conducted to draw out hazardous components in the boiler itself and their inherent relative importance was assessed. Through this procedure, 'negligence of unsafe condition' was noted as the major cause for unsafe acts whereas 'fault in work procedure' for unsafe condition. In the meanwhile, results of a hazard analysis using FMEA technique ranked gas safety devices, a switch preventing gas from under-pressurization, protect relays high. In particular, it was pointed out that the water feeding and steam subsystem has more components in hazard than other subsystems. Considering these analyses results, counter-plans to improve safety management was suggested also.

The Design, Fabrication, and Characteristic Experiment for Control Rod Position Indicator Using Reed Switch in System-Integrated Modular Advanced Reactor (리드스위치를 이용한 일체형원자로용 제어봉 위치지시기 설계 제작 및 특성해석)

  • Hur, Hyung;Kim, Jong-In;Kim, Kern-Jung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.8
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    • pp.452-461
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    • 2003
  • The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indicator system and its actual implementation in the existing nuclear power plants in Korea was performed first. The control rod position indicator having the high performance for SMART was developed on the basis of RSPT technology identified through the survey. The arrangement of permanent magnet and reed switches is the most important procedure in the design of control rod position indicator. The hysteresis of reed switches is one of the important factors in a repeat accuracy of control rod position indicator as well. This paper investigates efficiency of the magnetic flux concentrator and the hysteresis using FEM and verified differences in physicals characteristics by comparing the results of FEM and those of the experiment. As a result, it is shown that the characteristics of prototype control rod position indicator have a good agreement with the results of FEM.