• Title/Summary/Keyword: Stability Criteria

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A Study for Stability Criteria of Small Fishing Vessel (소형어선 복원성 판정 기준에 관한 연구)

  • 박제웅;김주남;허진호
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.5 no.2
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    • pp.45-55
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    • 1999
  • The majority of fishing vessels(under 20 tonnages) in Korea have a high casualty accident of the flood and capsizing occurred by lack of stability. Actually, it is so difficult to make out the data of inclining and stability tests of small fishing vessels after building, because most of them were built on experiences of manufacturer. According to above reasons, the aim of this study is an attempt to propose a stability criteria of small fishing vessels as follows: Firstly, it is examined that the stability is driven from a transverse metacenter height of actual ships, which is able to obtain a basic drawing and stability data. Secondly, it is examined the heeling at high-speed turning, and the period of rolling according to B/D(breadth/depth). Finally, it is suggested the stability criteria by using a dynamic state which is applied in passenger boat and fishing vessels over 24 meters.

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Evaluation of Running Stability of Tilting Trains in Conventional Curved Track (틸팅차량의 기존선 곡선부 주행안정성 평가)

  • 엄기영;엄주환;유영화;최정호
    • Journal of the Korean Society for Railway
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    • v.7 no.4
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    • pp.367-373
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    • 2004
  • The investigation of running stability of the train for curved track is necessary in view of preventing the train from derailment caused by unbalanced forces transferred from the wheel and guaranteeing moderate level of running safety in curve sections. This paper carried out an analysis of running stability of tilting trains in conventional line which the test operation of tilting trains under development are scheduled. For this purpose, the wheel load and lateral pressure to the rail are evaluated. The criteria for the calculated wheel load and derailment coefficient are compared to the design criteria for running stability. It is founded that the running stability of tilting trains for curved track is guaranteed to have sufficient safety and the train speed in curve is governed by the geometric layout of track rather than the criteria for running stability.

Improved Stability Criteria for Linear Systems with Time-varying Delay (시변 지연이 존재하는 선형시스템의 개선된 안정성 판별법)

  • Kwon, Oh-Min;Park, Ju-Hyun;Lee, Sang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2284-2291
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    • 2010
  • In this paper, improved stability criteria for linear systems with time-varying delays are proposed. By constructing a new Lyapunov functional, novel stability criteria are established in terms of linear matrix inequalities (LMIs). Two numerical examples are carried out to support the effectiveness of the proposed method.

On the Stability Criteria adopted by the Society of Naval Architects of Korea (대한조선학회(大韓造船學會) 복원력기준(復原力基準)에 관(關)하여)

  • Hun-Chol,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.6 no.2
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    • pp.17-23
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    • 1969
  • The Stability Criteria adopted by the 1969 Standard Ship Design Committee of the Society of Naval Architects are presented and discussed from a personal point of view. The Stability criteria are derived primarily from a similar standard now in practice in Japan expect the design wind condition and a addition of a buoyancy standard.

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Loading condition decision considering MARPOL damage stability criteria (MARPOL 손상 복원성 기준을 고려한 Loading Condition 결정)

  • Kim, Seong-Hoon
    • Special Issue of the Society of Naval Architects of Korea
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    • 2015.09a
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    • pp.93-95
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    • 2015
  • In case of crude oil tanker, loading condition must be satisfied MARPOL damage stability criteria (Reg.28). But some specific demands are hard to content the criteria. So, it takes a lot of time and efforts to make loading condition reflecting these demands. In this study, PSO (Particle Swarm Optimization) is used to make loading condition to be satisfied the criteria. Study result is applied 'CROSSWAY (160,000 DWT Crude Oil Tanker)' in NAPA. The result shows that satisfy the criteria and other constraints and limitation.

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Reliability analyses of a prototype soil nail wall using regression models

  • Sivakumar Babu, G.L.;Singh, Vikas Pratap
    • Geomechanics and Engineering
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    • v.2 no.2
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    • pp.71-88
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    • 2010
  • Soil nailing technique is being widely used for stabilization of vertical cuts because of its economic, environment friendly and speedy construction. Global stability and lateral displacement are the two important stability criteria for the soil nail walls. The primary objective of the present study is to evaluate soil nail wall stability criteria under the influence of in-situ soil variability. Finite element based numerical experiments are performed in accordance with the methodology of $2^3$ factorial design of experiments. Based on the analysis of the observations from numerical experiments, two regression models are developed, and used for reliability analyses of global stability and lateral displacement of the soil nail wall. A 10 m high prototype soil nail wall is considered for better understanding and to highlight the practical implications of the present study. Based on the study, lateral displacements beyond 0.10% of vertical wall height and variability of in-situ soil parameters are found to be critical from the stability criteria considerations of the soil nail wall.

New Stability Criteria for Linear Systems with Interval Time-varying State Delays

  • Kwon, Oh-Min;Cha, Eun-Jong
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.713-722
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    • 2011
  • In the present paper, the problem of stability analysis for linear systems with interval time-varying delays is considered. By introducing a new Lyapunov-Krasovskii functional, new stability criteria are derived in terms of linear matrix inequalities (LMIs). Two numerical examples are given to show the superiority of the proposed method.

New Delay-dependent Stability Criteria for Uncertain Stochastic Systems with Time-varying Delays (시변 지연이 존재하는 불확실 스토캐스틱 시스템의 지연의존 안정성)

  • Kwon, Oh-Min;Park, Ju-Hyun;Lee, Sang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.11
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    • pp.2261-2265
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    • 2009
  • In this paper, the problem of delay-dependent stability of uncertain stochastic systems with time-varying delay is considered. The uncertainties are assumed to be norm-bounded. Based on the Lyapunov stability theory, new delay-dependent stability criteria for the system are derived in terms of LMI(linear matrix inequality). Two numerical examples are given to show the effectiveness of proposed method.

Analysis of Factors Influencing on Food Supplier Selection Criteria in the Health-care Foodservice Operations (의료기관의 식자재 공급자 선정기준에 영향을 미치는 요인 분석)

  • Kim, Jeong-Ri;Choe, Seong-Gyeong;Gwak, Dong-Gyeong
    • Journal of the Korean Dietetic Association
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    • v.8 no.4
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    • pp.372-386
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    • 2002
  • The purposes of this study were to find factor which influence on the selection criteria of food supplier. Questionnaire were distributed to 52 general hospitals with more than 400 beds located in Seoul and Kyongin province, and responded questionnaires were collected from 44 dietetic departments (84.6%) and 18 purchasing departments (34.6%). The main results of this study can be summarized as follows: (1) supplier selection criteria include quality, service, cost and supplier competency. (2) With having been met with tight competition and market opening, hospitals plan a strategy to improve quality, service and they tend to have more interest in various supplier selection criteria. (3) Purchasing departments estimate more highly the rate of reflection in considering supplier selection criteria than the rate of importance about cost criteria, which reveals that purchasing departments sensitively respond to cost cutdown. (4) When selecting suppliers, a significant(p<.01) influence of stability of supplier industry environment on the selecting criteria such as the importances of quality, service, and supplier quality are recognized only after recognizing the stability of food delivery industry. Food supplier industry secures stability more quickly through major companies' participation in food distribution industry and this will reveal the importance of supplier selection criteria. (5) Suppliers which are selected by the quality criteria, service criteria, supplier quality criteria make efforts to communicate with foodservice departments, to give more proper information about substitute food, new product, and to make commitments, while suppliers which are decided by cost criteria do not establish supportive relationships with foodservice departments.

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A New Augmented Lyapunov Functional Approach to Robust Stability Criteria for Uncertain Fuzzy Neural Networks with Time-varying Delays (시변 지연이 존재하는 불확실 퍼지 뉴럴 네트워크의 강인 안정성 판별법에 대한 새로운 리아프노프 함수법)

  • Kwon, Oh-Min;Park, Myeong-Jin;Park, Ju-Hyun;Lee, Sang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.11
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    • pp.2119-2130
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    • 2011
  • This paper proposes new delay-dependent robust stability criteria for neural networks with time-varying delays. By construction of a suitable Lyapunov-Krasovskii's (L-K) functional and use of Finsler's lemma, new stability criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed methods.