• Title/Summary/Keyword: Safety State

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The System and Activity of Port State Control in Japan

  • Ichikawa, Yoshiro
    • Proceedings of KOSOMES biannual meeting
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    • 2000.05a
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    • pp.86-100
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    • 2000
  • The author of this document is generally in charge of Port State Control affairs at the headquarters of Ministry of Transport, Japan. In this document, the necessity of Port State Control, the brief history of japanese Port State Control and the present system of Port State Control in Japan are introduced. Also, the newest output of Japanese Port State Control which is an annual statistic of 1999 is explained, subsequently the policy and strategy on Port State Control in Japan is introduced.

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A Study on the Effect of the Machine State Considering Human Skillfulness (Kalman Filtering Approach) (작업자의 숙련도가 기계상태에 미치는 영향에 관한 연구 (최적 제어 이론(Kalman Filtering) 적용 중심으로))

  • 윤상원;갈원모;신용백
    • Journal of the Korean Society of Safety
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    • v.9 no.4
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    • pp.125-131
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    • 1994
  • This paper proposes a dynamic recursive model with the effect analysis of machine state considering human factor(human skillfulness) In a single lot man-machine production system. This model obtained using Kalman Filtering Algorithm Is based on input state, output state, machine state. For sensitivity analysis, this model constructed is examined according to the impact of human skillfulness with computer simulation. The model studied in this paper has a great advance from the point of view a combination of three factors( human engineering, dynamic control theory, quality control ) and can also be extended in several applications.

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Investigation of Actural State of Plastic Greenhouse Structures in Korea (플라스틱 하우스의 구조 실태의 조사 연구)

  • 김문기;고재군;이신호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.29 no.3
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    • pp.113-124
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    • 1987
  • The objective of this study was to disclose the problem of structural safety and the state of utilization of standard types of plastic film house through investigation of actural state of plastic greenhouses for the southern part of the Korean peninsula. And also, the application method of standard types were proposed. The results obtained are summarized as follows 1. Plastic film houses investigated were not designed by the structural design conditions of loads and materials. 2.The construction method of greenhouses was not standardized. 3.Single type of standard greenhouses was nearly used and double types were applied to the standard type. 4.The standard frames of plastic film house were appeared to have structural lack of stability at the design snow and wind loads for most regions. 5.Safety snow depths and safety wind velocities were proposed for the frame intervals and pipe diameters of standard greenhouses.

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Stability Analysis ofn HTS Current Lead with Constant Safety Factor (안전율이 일정한 초전도 전류도입선의 안정성해석)

  • Seol, Seoung-Yun
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.15-19
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    • 2000
  • The stability of variable cross-sectional area HTS current lead is considered. The cross-sectional area is varied to have a constant safety factor which is defined as the ratio of operating current and critical current of superconductor. As the constant area HTS lead, the variable cross-sectional area HTS lead also has three steady states above the bifurcation point and only one steady state below the bifurcation point. The temperature profiles and current sharing ratios for each steady state are calculated. The heat dissipation into cryogenic system for super-conducting, intermediate, and upper states are compared. For Bi-2333 sheathed with silver-gold alloy 2m length of current lead, and the maximum temperature of upper state seems to be burn-out free below 5m length.

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Strength Reliability Analysis of Continuous Steel Fiber Reinforced Concrete Beam (강섬유 보강 철근콘크리트 연속보의 강도신뢰성 해석)

  • 유한신;곽계환;조효남
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.267-273
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    • 2003
  • Steel fiber may be used to raise the effectiveness and safety of reinforced concrete structure and to relax its brittle-fracture behavior. However it is to be clearly stated that the uncertainty for the strength of fiber reinforced concrete(SFRC) is rather increased. Therefore, it is necessary to evaluate the safety of SFRC beam using reliability analysis incorporating realistic uncertainty. This study presents the statistical data and proposes the limit state model to analyze the reliability of SFRC bear In order to verify the efficiency of the proposed limit state model, its numerical application and sensitivity analysis were performed for a continuous SFRC beam. From the results of the numerical analysis, it is founded that the reliability of SFRC beam is significantly difficult from the conventional RC beams and proposed limit state model (or SFRC beam is more rational compared with that for conventional RC beams. Then it may be stated that the reliability analysis of SFRC beams must be carried out for the development of design criteria and the safety assessment.

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MODELING AND PI CONTROL OF DIESEL APU FOR SERIES HYBRID ELECTRIC VEHICLES

  • HE B.;OUYANG M.;LU L.
    • International Journal of Automotive Technology
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    • v.7 no.1
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    • pp.91-99
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    • 2006
  • The diesel Auxiliary Power Unit (APU) for vehicle applications is a complex nonlinear system. For the purpose of this paper presents a dynamic average model of the whole system in an entirely physical way, which accounts for the non-ideal behavior of the diode rectifier, the nonlinear phenomena of generator-rectifier set in an elegant way, and also the dynamics of the dc load and diesel engine. Simulation results show the accuracy of the model. Based on the average model, a simple PI control scheme is proposed for the multivariable system, which includes the steps of model linearization, separate PI controller design with robust tuning rules, stability verification of the overall system by considering it as an uncertain one. Finally it is tested on a detailed switching model and good performances are shown for both set-point following and disturbance rejection.

Performance measurement of safety-critical systems based on ordinary differential equations and Petri nets: A case study of nuclear power plant

  • Nand Kumar Jyotish;Lalit Kumar Singh;Chiranjeev Kumar
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.861-869
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    • 2023
  • This article proposes a novel approach to measure the performance of Safety-Critical Systems (SCS). Such systems contain multiple processing nodes that communicate with each other is modeled by a Petri nets (PN). The paper uses the PN for the performance evaluation of SCS. A set of ordinary differential equations (ODEs) is derived from the Petri net model that represent the state of the system, and the solutions can be used to measure the system's performance. The proposed method can avoid the state space explosion problem and also introduces new metrics of performance, along with their measurement: deadlock, liveness, stability, boundedness, and steady state. The proposed technique is applied to Shutdown System (SDS) of Nuclear Power Plant (NPP). We obtained 99.887% accuracy of performance measurement, which proves the effectiveness of our approach.

Reliability index for non-normal distributions of limit state functions

  • Ghasemi, Seyed Hooman;Nowak, Andrzej S.
    • Structural Engineering and Mechanics
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    • v.62 no.3
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    • pp.365-372
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    • 2017
  • Reliability analysis is a probabilistic approach to determine a safety level of a system. Reliability is defined as a probability of a system (or a structure, in structural engineering) to functionally perform under given conditions. In the 1960s, Basler defined the reliability index as a measure to elucidate the safety level of the system, which until today is a commonly used parameter. However, the reliability index has been formulated based on the pivotal assumption which assumed that the considered limit state function is normally distributed. Nevertheless, it is not guaranteed that the limit state function of systems follow as normal distributions; therefore, there is a need to define a new reliability index for no-normal distributions. The main contribution of this paper is to define a sophisticated reliability index for limit state functions which their distributions are non-normal. To do so, the new definition of reliability index is introduced for non-normal limit state functions according to the probability functions which are calculated based on the convolution theory. Eventually, as the state of the art, this paper introduces a simplified method to calculate the reliability index for non-normal distributions. The simplified method is developed to generate non-normal limit state in terms of normal distributions using series of Gaussian functions.