• Title/Summary/Keyword: Simplified Assessment

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A Simplified Assessment Method and Application for Consideration of Survivability in Spatial Layout Design at the Early Design Stage of Naval Vessels (함정 초기 설계 단계에서 레이아웃 설계 시 생존성을 고려하기 위한 간이 평가 방법과 애플리케이션)

  • Jung, Jin-Uk;Jeong, Yong-Kuk;Ju, SuHeon;Shin, Jong Gye;Kim, JongChul
    • Journal of the Society of Naval Architects of Korea
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    • v.55 no.1
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    • pp.9-21
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    • 2018
  • Survivability of naval vessels is defined as the ability to perform functions and missions in a combat environment. Survivability has close relationship with the spatial layout of naval vessels. In order to maximize survivability, it must be considered from the early stage of design. However the existing concept of survivability was intended to be applied to unit vessels. So it was not suitable for assessment of spatial layout results at the early stage of design. In this paper, a simplified assessment method which can evaluate the spatial layout considering the survivability in the early stage of design has been proposed. For this, assessment layers were defined on survivability components such as susceptibility, vulnerability, and recoverability. Assessment layers of each component were overlapped to deduce a survivability layer of spatial layout alternatives. In addition, the proposed method and optimization algorithm were used to derive optimal spatial layout alternatives considering survivability.

Hydrologic Safety Evaluation of Small Scale Reservoir by Simplified Assesment Method (간편법에 의한 소규모저수지의 수문학적 안전성 평가)

  • Lee, Joo-Heon;Yang, Seung-Man;Kim, Seong-Joon;Kang, Boo-Sik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.2
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    • pp.9-17
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    • 2011
  • Based on the statistical annual report, there are 17,649 reservoirs are operating for the purpose of agricultural water supply in Korea. 58 % of entire agricultural reservoirs had been constructed before 1948 which indicate the termination of required service life and rest of those reservoirs have also exposed to the dam break risk by extreme flood event caused by current ongoing climate change. To prevent damages from dam failure accident of these risky small size dams, it is necessary to evaluate and manage the structural and hydrological safety of the reservoirs. In this study, a simplified evaluation method for hydrologic safety of dam is suggested by using Rational and Creager formula. Hydrologic safety of small scale dams has evaluated by calculating flood discharge capacity of the spillway and compares the results with design frequency of each reservoir. Applicability and stability of suggested simplified method have examined and reviewd by comparing the results from rainfall-runoff modeling with dam break simulation using HEC-HMS. Application results of developed methodology for three sample reservoirs show that simplified assessment method tends to calculate greater inflow to the reservoirs then HEC-HMS model which lead lowered hydrologic safety of reservoirs. Based on the results of application, it is expected that the developed methodology can be adapted as useful tool for small scale reservoir's hydrologic safety evaluation.

A Method to Calculate Flicker Emission of a Grid-Connected Wind Turbine System (계통연계 풍력발전 시스템의 플리커 지수 계산방법)

  • Ahn, Duck-Keun;Ro, Kyoung-Soo
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.310-312
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    • 2002
  • The development of IEC 61400-21 provides firm basis for assessment of the impact of wind turbines on voltage quality. This paper presents analysis and modeling of the flicker emission of wind turbines. The paper concentrates on the theoretical aspects of the flicker algorithm, wind turbine characteristics and the generation of flicker during continuous operation of wind turbines. It also introduces a simplified assessment to limit the flicker emission.

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A Quantitative Assessment on a Tension of Securing Rope to evade Marine Accidents caused by Improper Cargo-Securing

  • Kim, Young-Du
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.3
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    • pp.297-302
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    • 2015
  • To prevent cargo accidents by repeated loads, a continuous monitoring for securing rope or additional safety measures are needed, but most of prevention measures have been conducted only by operator's own experience not a quantitative assessment. Hence, the Load-Displacement curve and approximation formula of securing rope were drawn in this research for a quantitative assessment and simplified measurement on a tension of securing rope using a tensiometer. Moreover, a com parison was conducted between m easuring tension and calculated tension on securing rope with portable tensiometer, 'Load-Displacement' approximation formula. The calculated tension of securing rope is obtained 153.3kfg using the formula and that result has not much difference with initial tension 150.0kgf. Lastly, an analysis of the characteristics of various ropes was suggested to enhance the reliability about quantitative assessment of securing rope's tension through further research.

Reliability Expression for Complex System

  • Seong Cheol Lee
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.125-133
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    • 1996
  • In this paper, we present a algebraic technique for computing system reliability for complex system. The method was originally developed as an aid to fault tree analysis but it applies to general problems of reliability assessment. A success expression which directly gives the reliability expression is formed and simplified by the procedure. Several algorithms and examples are illustrated.

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Fatigue Assessment of High Strength Steel Welded Joints Under Bending Loading (굽힘 하중하의 고장력강 용접 연결부의 피로 평가)

  • Lee, Myeong-Woo;Kim, Yun-Jae;Park, Jun-Hyub
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.10
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    • pp.1163-1169
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    • 2014
  • In this study, a fatigue assessment method for vehicle suspension systems having welded geometries was established under a bending loading condition. For the fatigue life estimation of the actual product's welded joints made of different steels, bending fatigue tests were performed on welded specimens with a simplified shape for obtaining the moment-fatigue-life plot. Further, geometry modeling of the simplified welded specimens was conducted. Results of finite element analysis were used to obtain the stress-fatigue-life plot. The analysis results were also used to calculate the stress concentration factors for notch-factor-based fatigue life estimation. The test results were compared with results of the general notch-factor-based fatigue life estimation for improving fatigue assessment. As a result, it was concluded that both the welded fatigue tests and the notch-factor-based fatigue life estimation are necessary for accurate fatigue assessment.

GIS-based Tunnelling-induced Building/Utility Damage Assessment System-Development and Application (GIS기반의 터널시공에 따른 주변건물/매설관 손상평가 시스템-개발 및 적용)

  • 유충식;전영우;김재훈;박영진;유정훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.233-240
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    • 2003
  • A GIS-based tunnelling risk management system (GIS-TURIMS) has been developed in this study The developed system uses ArcView 8.2 as a basic platform and the built-in interface(VBA) has been used to perform first-order simplified analyses for prediction of tunnelling-induced ground movements and building damage assessment. The main emphasis in this study was to develop a working framework that can be used in the perspective of tunnelling risk management. The developed system is capable of carrying out computationally intensive first-order analyses for ground movement prediction as well as building/utilities damage assessment with fully taking advantage of the GIS technologies. This paper describes the concept and details of the GIS-TURIMS development and implementation.

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Development of A GIS-based Tunnelling-induced Building/Utility Damage Assessment System (GIS 기반의 터널굴착시 건물/매설관 손상평가 시스템 개발)

  • 유충식;김재훈;박영진;유정훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.311-318
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    • 2002
  • A GIS-based tunnelling risk management system (GIS-TURIMS) has been developed in this study, The developed system uses ArcView 8.2 as a basic platform and the built-in interface (VBA) has been used to perform first-order simplified analyses for prediction of tunnelling-induced ground movements and building damage assessment. The main emphasis in this study was to develop a working framework that can be used in the perspective of tunnelling risk management. The developed system is capable of carrying out computationally intensive analyses for ground movement prediction as well as building/utilities damage assessment with fully taking advantage of the GIS technologies. This paper describes the concept and details of the GIS-TURIMS development and implementation

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