• Title/Summary/Keyword: Safety problem

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A literature review of Korean and International research on the supply chain security (공급 사슬 보안에 관한 국내외 문헌 조사 연구)

  • Yang, Byoung-Hak
    • Journal of the Korea Safety Management & Science
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    • v.13 no.3
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    • pp.87-96
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    • 2011
  • This research is a literature survey on the Supply chain security. International organization and governments have build security regulations to improve the security in the shipment through supply chain. The researches on supply chain security were increasing during last 10 years. We were surveyed 53 research including Korean and international papers. ills study was classified by research subjects, security regulation, and research methods. Korean researches were focused to introducing and reviewing on the security regulation, but the researches on specific security reinforcement were very rare. International researches were concerned with the subject of the airport security scanning problem, transportation security problem, port selection problem.

An Experimental Study on Improving Water Tightness of Concrete Surface Applied High Growth Organic Crystalization Material (고성장 유기결정체의 성장 특성을 이용한 콘크리트 표층부의 수밀성 개선에 관한 연구)

  • Song Je-Young;Kang Hyo-Jin;Oh Sang-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.817-820
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    • 2004
  • Our country was much developments in change of construction environment along with fast economy development. But, various problems that must think in problem of safety and quality were appeared. Constructions which build through rapid economy development are getting many social criticisms to problem of crack and water leakage at use process. Is situation that huge repair expense to cure this is engaged. Safety problem of construction is indicated socially through various media mediums again.

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Structural Reliability Analysis of Automatic Fire Detectors for Reduction of False Alarms (화재감지기의 오보 감소를 위한 구조 신뢰도 분석)

  • 김주홍;임현교
    • Journal of the Korean Society of Safety
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    • v.8 no.1
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    • pp.6-12
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    • 1993
  • Now it is reported that there are many companies and factories which confront to the problem of false alarm in Automatic Fire Detecting System (AFDS). Though an AFDS is a high-priced and very important device in detecting a fire. the problem degrades the reliability and utility, eventually faith. of the system. This is a research concerned about the problem of false alarm of fire detectors in an AFDS. Structure of detectors was modeled up as a general K out-of n system. and reliability characteristics including false alarm rate and missed alarm rate, are derived from it. For decision of an optimal structure of detectors. preliminary analysis on various criteria is accomplished. It is concluded that appropriate modification of a detector with plural sensors may increase the system reliability and decrease the false alarm rate.

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A Study on Memetic Algorithm-Based Scheduling for Minimizing Makespan in Unrelated Parallel Machines without Setup Time (작업준비시간이 없는 이종 병렬설비에서 총 소요 시간 최소화를 위한 미미틱 알고리즘 기반 일정계획에 관한 연구)

  • Tehie Lee;Woo-Sik Yoo
    • Journal of the Korea Safety Management & Science
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    • v.25 no.2
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    • pp.1-8
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    • 2023
  • This paper is proposing a novel machine scheduling model for the unrelated parallel machine scheduling problem without setup times to minimize the total completion time, also known as "makespan". This problem is a NP-complete problem, and to date, most approaches for real-life situations are based on the operator's experience or simple heuristics. The new model based on the Memetic Algorithm, which was proposed by P. Moscato in 1989, is a hybrid algorithm that includes genetic algorithm and local search optimization. The new model is tested on randomly generated datasets, and is compared to optimal solution, and four scheduling models; three rule-based heuristic algorithms, and a genetic algorithm based scheduling model from literature; the test results show that the new model performed better than scheduling models from literature.

PCA Based Fault Diagnosis for the Actuator Process

  • Lee, Chang Jun
    • International Journal of Safety
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    • v.11 no.2
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    • pp.22-25
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    • 2012
  • This paper deals with the problem of fault diagnosis for identifying a single fault when the number of assumed faults is larger than that of predictive variables. Principal component analysis (PCA) is employed to isolate and identify a single fault. PCA is a method to extract important information as reducing the number of large dimension in a process. The patterns of all assumed faults can be recognized by PCA and these can be employed whether a new fault is one of predefined faults or not. Through PCA, empirical models for analyzing patterns can be trained. When a single fault occurs, the pattern generated by PCA can be obtained and this is used to identify a fault. The performance of the proposed approach is illustrated in the actuator benchmark problem.

THE IMPLEMENTATION OF BORON TRANSPORT EQUATION INTO A REACTOR COMPONENT ANLAYSIS CODE (원자로 기기 열수력 해석 코드에서 붕소 수송 방정식의 구현)

  • Park, Ik Kyu;Lee, Seung Wook;Yoon, Han Young
    • Journal of computational fluids engineering
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    • v.18 no.4
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    • pp.53-60
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    • 2013
  • The boron transport model has been implemented into the CUPID code to simulate the boron transport phenomena of the PWR. The boron concentration conservation was confirmed through a simulation of a conceptual boron transport problem in which water with a constant inlet boron concentration injected into an inlet of the 2-dimensional vertical flow tube. The step wise boron transport problem showed that the numerical diffusion of the boron concentration can be reduced by the second order convection scheme. In order to assess the adaptability of the developed boron transport model to the realistic situation, the ROCOM test was simulated by using the CUPID implemented with the boron transportation.

Study of Controlled Rest in the Cockpit (조종실내 Controlled Rest에 관한 연구)

  • Lee, JunSae;Choi, JinKook;Kang, MinJung;Jeun, HoSung
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.27 no.3
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    • pp.106-111
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    • 2019
  • Pilot has been fighting to get over fatigue during flight and thought it as a hinderance for safe flight. The fatigue related problem has been the biggest obstacle for aviation safety so far. Even though pilots and airlines try their best to overcome fatigue during flight, they couldn't overcome this problem. So the airliners let the pilot sleep during flight if pilots are too tired with the report. It is controlled rest used and managed by several European airliners. So this study tries to get Korean airline pilots' fatigue information and figure out the cause and reduce it.

Robust technique using magnetohydrodynamics for safety improvement in sodium-cooled fast reactor

  • Lee, Jong Hui;Park, Il Seouk
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.565-578
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    • 2022
  • Among Generation IV reactors, the sodium-cooled fast reactor (SFR) is attracting attention as a system having great potential for commercial use. Gas entrainment is a thermal-hydraulic issue related to the safety problem of the reactor core in the SFR. Typically, a dipped plate or baffles are installed under the free surface to suppress gas entrainment. However, these approaches can cause gas entrainment in other locations and require many trial-and-error and verifications. In this study, a new strategy using magnetohydrodynamics to suppress gas entrainment in the SFR is proposed. In a counter-flow model, a judgment criterion of gas entrainment occurrence was developed for both water and liquid metal. Moreover, the gas entrainment can be completely suppressed by applying a magnetic field.

A review of missing video frame estimation techniques for their suitability analysis in NPP

  • Chaubey, Mrityunjay;Singh, Lalit Kumar;Gupta, Manjari
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1153-1160
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    • 2022
  • The application of video processing techniques are useful for the safety of nuclear power plants by tracking the people online on video to estimate the dose received by staff during work in nuclear plants. Nuclear reactors remotely visually controlled to evaluate the plant's condition using video processing techniques. Internal reactor components should be frequently inspected but in current scenario however involves human technicians, who review inspection videos and identify the costly, time-consuming and subjective cracks on metallic surfaces of underwater components. In case, if any frame of the inspection video degraded/corrupted/missed due to noise or any other factor, then it may cause serious safety issue. The problem of missing/degraded/corrupted video frame estimation is a challenging problem till date. In this paper a systematic literature review on video processing techniques is carried out, to perform their suitability analysis for NPP applications. The limitation of existing approaches are also identified along with a roadmap to overcome these limitations.

SECOND ATLAS DOMESTIC STANDARD PROBLEM (DSP-02) FOR A CODE ASSESSMENT

  • Kim, Yeon-Sik;Choi, Ki-Yong;Cho, Seok;Park, Hyun-Sik;Kang, Kyoung-Ho;Song, Chul-Hwa;Baek, Won-Pil
    • Nuclear Engineering and Technology
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    • v.45 no.7
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    • pp.871-894
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    • 2013
  • KAERI (Korea Atomic Energy Research Institute) has been operating an integral effect test facility, the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS), for transient and accident simulations of advanced pressurized water reactors (PWRs). Using ATLAS, a high-quality integral effect test database has been established for major design basis accidents of the APR1400 plant. A Domestic Standard Problem (DSP) exercise using the ATLAS database was promoted to transfer the database to domestic nuclear industries and contribute to improving a safety analysis methodology for PWRs. This $2^{nd}$ ATLAS DSP (DSP-02) exercise aims at an effective utilization of an integral effect database obtained from ATLAS, the establishment of a cooperation framework among the domestic nuclear industry, a better understanding of the thermal hydraulic phenomena, and an investigation into the possible limitation of the existing best-estimate safety analysis codes. A small break loss of coolant accident with a 6-inch break at the cold leg was determined as a target scenario by considering its technical importance and by incorporating interests from participants. This DSP exercise was performed in an open calculation environment where the integral effect test data was open to participants prior to the code calculations. This paper includes major information of the DSP-02 exercise as well as comparison results between the calculations and the experimental data.