• Title/Summary/Keyword: Flexible Criteria

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Analysis of Behavior for Underground Flexible Pipes (지중 연성관의 거동특성 분석)

  • 김경열;상현규;이대수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.315-322
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    • 2001
  • Underground flexible pipes for electric cables are subject to external loads and surrounding soil pressure. Particularly, strain of flexible pipes is of great concern in terms of safety and maintenance for electric cables. In this paper, stress and strain of flexible pipes with various depth are calculated using traditional formula and FEM analysis. The results show that theoretical values are more conservative in strain whereas FEM analysis gives larger stress. Considering the strain criteria - 3.5 %, maximum, flexible pipes can be buried at the range of 50cm to 5m in depth without additional soil improvement.

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Analysis of Behavior for Underground Flexible Pipes Under Seismic Loads (지진발생에 따른 지중연성관의 거동특성 분석)

  • 김경열;홍성연;이대수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.709-716
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    • 2003
  • Flexible pipes (corrugated polyethylene pipes) are normally used for underground power distribution grids. In this paper, dynamic analysis was carried out through FEM in order to investigate the structural behaviour of pipes subjected to seismic loads. The burial depth and the number of pipes were major parameters in the numerical analysis to determine the response of pipes. The results show that the displacement of pipes under given conditions are all satisfactory in comparison of the allowable strain criteria -maximum 3.5 %.

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ISO/TC/108/SCI 11342(Mechanical vibration - Methods and criteria for the mechanical balancing of flexible rotors (탄성회전체의 기계적 평형잡기 방법과 기준(ISO 11342))

  • 최상규;전오성
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.811-818
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    • 2001
  • ISO 11342 classifies flexible rotors in accordance with their balancing requirements and establishes methods of assessment of residual unbalance. This International Standard also shows how criteria for use in the balancing facility may be derived from either vibration limits specified for the assembled and installed machine or unbalance limits specified for the rotor. If such limits are not available, this standard shows how they may be derived from ISO 10816 and ISO 7919 if desired in terms of vibration, or from ISO 1940- 1 if desired in terms of permissible residual balance. This International Standard also presents methods for adapting the criteria of ISO 1940- 1 to flexible rotors.

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On Flexible Bayesian Test Criteria for Nested Point Null Hypotheses of Multiple Regression Coefficients

  • Jae-Hyun Kim;Hea-Jung Kim
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.205-214
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    • 1996
  • As flexible Bayesian test criteria for nested point null hypotheses of multiple regression coefficients, partial and overall Bayes factors are introduced under a class of intuitively meaningful prior. The criteria lead to a simple method for considering different prior beliefs on the subspaces that constitute a partition of the coefficient parameter space. A couple of tests are suggested based on the criteria. It is shown that they enable us to obtain pairwise comparisons of hypotheses of the partitioned subspaces. Through a Monte Carlo simulation, performance of the tests based on the criteria are compared with the usual Bayesian test (based on Bayes factor)in terms of their respective powers.

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Evaluation of flexible criteria for river flow management with consideration of spatio-temporal flow variation (시·공간적 유량 변화를 고려한 탄력적 하천관리 기준유량 산정 및 평가)

  • Park, Jung Eun;Kim, Han Na;Ryoo, Kyong Sik;Lee, Eul Rae
    • Journal of Korea Water Resources Association
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    • v.49 no.8
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    • pp.673-683
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    • 2016
  • An Idea to estimate flexible criteria for river water use permits was proposed that takes the spatio-temporal flow variation along the river into account, which was applied to the Keumho River, one of the tributary of the Nakdong River in Korea. This idea implies the temporal division of four periods with different criteria, combining flood/non-flood seasons and irrigation/non-irrigation periods, while a single one has been applied throughout the year in the current practice. Through flow regime analysis of daily natural flow simulations at Dongchon and Seongseo, the control points of the study area, Q355 and 1Q10 for non-flood and non-irrigation period, Q275 for non-flood and irrigation period, Q185 for flood and irrigation period were suggested respectively. So, those values that subtract instream flow were determined as the flexible criteria in each season. From the comparison of current practice and the proposed method, it was estimated that $10.6\;million\;m^3/year$ is available for more water use permits without additional development of water storage. Therefore, it is conceived that flexible criteria for river water use permission suggested in this study can contribute to improve the national policies for more efficient water resources management in the future.

A Study on the Flexible Generator Maintenance Scheduling using Fuzzy Theory (퍼지이론을 이용한 유연한 발전기보수유지계획 수립에 관한 연구)

  • Kim, Hong-Sik;Moon, Seung-Pil;Choi, Jae-Seok
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1104-1107
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    • 1999
  • A new technique using search method based on fuzzy multi-criteria function is proposed fur flexible generator maintenance scheduling. Minimization of probabilistic production cost, maximization of system reliability level and air pollution are considered fur fuzzy multi-criteria function. To obtain an optimal solution for generator maintenance scheduling under fuzzy environment fuzzy multi-criteria relaxation method(fuzzy search method) is used. The practicality and effectiveness of the proposed approach are demonstrated by the simulation results of the real size model system of KEPCO-1997 SYSTEM.

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The Generator Maintenance Scheduling using Fuzzy Multi-criteria (퍼지다목적함수를 이용한 발전기보수유지계획의 수립)

  • 최재석;도대호;이태인
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1995.10b
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    • pp.131-138
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    • 1995
  • A new technique using integer programming based on fuzzy multi-criteria function is proposed for generator maintenance scheduling. Minimization maintenance delay cost and maximization reserve power are considered for fuzzy multi-criteria function. To obtain an optimal solution for generator maintenance scheduling under fuzzy environment, fuzzy multi-criteria integer programming is used. In the maintenance scheduling, a characteristic feature of the presented approach is that the crisp constraints with uncertainty can be taken into account by using fuzzy set theory and so more flexible solution can be obtained. The effectiveness of the proposed approach is demonstrated by the simulation results.

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A Multi-objective Production Planning Model in a Flexible Manufacturing System Using Multiple Criteria Analysis (다기준(多基準) 분석(分析)을 이용(利用)한 유연생산(柔軟生産)시스템에서의 다목적(多目的) 생산계획(生産計劃) 모형(模型)에 관한 연구(硏究))

  • Lee, Yeong-Gwang
    • Journal of Korean Society for Quality Management
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    • v.20 no.1
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    • pp.126-135
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    • 1992
  • The decision making process for production planning in FMS usually involves multiple conflicting objectives and criteria. This study consists of prescreening and analytical phase. In the prescreening phase, criteria are used to reduce the set of alternative system configuration down to a small number of candidates. After this phase, a multiobjected programming model is formulated for each remainning configuration.

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A Case Study of Flexible Sewer Pipes Behaviors - Compaction Ratio·Inner Deflection Ratiov·Ring Stiffness - (현장중심형 하수도용 연성관의 거동특성에 대한 고찰 - 다짐도·변형률·강성 간의 관계정립 -)

  • Kim, Young-Jin
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.4 no.2
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    • pp.31-38
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    • 2013
  • As the Sewer Pipe is transformed by the expansion of life cycle as a result of the technology development, flexible pipe is developed by the transformed environmental conditions. To change pipe design, three phases(compaction ration - inner deflection ratio - ring stiffness) should be considered in design conditions. The input data of pipe design were provided by compaction-inner deflection ratio-ring stiffness. M oreover, The guidelines of sewerage pipes should be considered by flexible pipes design criteria.

Multi-Criteria Decision-Making Model Using Quality Function Deployment (QFD) Method for the Most Suitable Temporary Earth Retaining System

  • Jung, Bae Yu;Byung, Cho Han;Jin, Han Sang;Won, Kwon;Ho, Jo Jae;Youl, Chun Jae
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.620-621
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    • 2015
  • In this study, the multi-criteria decision-making model based on Quality Function Deployment Method is proposed. Multicriteria decision-making is an attempt to link QFD method with the TOPSIS. By this effort, a model that makes client's decision-making more rational and objective in design phase is suggested. The multi-criteria decisionmaking model confirming to the Owner's requirements will improve the productivity of the construction industry and the satisfaction of the customer. Further study extending the range of the requirements, not only the Owner's requirement will be necessary to cover the various factors as much as possible. And then, finally as a flexible platform to achieve a sustainable quality management, web-based multi-criteria decision-making model can be utilized by the relevant stakeholders simultaneously with the feed-back and sharing the necessary informations.

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