• Title/Summary/Keyword: criteria of stability

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Appliance of Slab tracks on the Prestressed Concrete Bridges (슬래브궤도의 콘크리트교량 적용성 검토)

  • Kim, Nam-Hoon;Lim, Young-Su;Shin, Yong-Joon
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1037-1043
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    • 2007
  • The railroad systems with the ballast tracks have been widely used for a long time. But recently, the use of the slab track is being increased gradually with a technical developments. So, this paper deals with the appliance of the slab tracks on the railroad bridges. Firstly, review the design criteria of the railroad bridges related to the slab tracks for the stability and serviceability, based on DIN and EURO code. Then, perform the analysis of the railroad prestressed concrete bridges, and check whether the results of the analysis satisfy the design criteria. Finally, find the construction condition of bridges that all the design criteria are satisfied. As a result, to maintain the stability and serviceability of the bridges, bridges must have some restrictions, including a time of installation of the slab tracks. So, the construction schedule for the erection of the bridges will be carefully considered in case of the concrete railroad bridges with the slab tracks.

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The Stability Assessment of Backfill Materials and External Loads in Pre-Insulated District Heating Pipes (지역난방 열배관의 외부작용력 및 되메움재의 안정성 확보에 관한 연구)

  • Kim, Jin-Man;Choi, Bong-Hyuck;Ko, Hyun-Il
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.656-661
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    • 2009
  • In this study, theoretical analysis and evaluation tests were performed to assess the pipe stability against compaction equipments and vehicle loads when conventional construction criteria for pre-insulation heating pipes are applied and the alternative material, crushed sand, are used for backfills. The research outcomes shows that (1) the conventional code criteria for pre-insulated heating pipes is well established to support compaction equipments and vehicle loads, (2) the crushed sands as an alternative is usable as backfill materials for pre-insulated heating pipes based on the suitability evaluations of various types of pipes, and (3) the crushed sand agree well with the design consideration of pre-insulated heating pipes construction in the points of economical efficiency and construction criteria.

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OBSTACLE-AVOIDANCE ALGORITHM WITH DYNAMIC STABILITY FOR REDUNDANT ROBOT MANIPULATOR WITH FRUIT-ILARVESTING APPLICATIONS

  • Ryu, Y.S.h;Ryu, K.H.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.1063-1072
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    • 1996
  • Fruit harvesting robots should have more diversity and flexibility in the working conditions and environments than industrial robots. This paper presents an efficient optimization algorithm for redundant manipulators to avoid obstacles using dynamic performance criteria, while the optimization schemes of the previous studies used the performance criteria using kinematic approach. Feasibility and effectiveness of this algorithm were tested through simulations on a 3-degrees-of-freedom manipulator made for this study. Only the position of the end-effector was controlled , which requires only three degrees of freedom. Remaining joints, except for the wrist roll joint, which does not contribute to the end-effector linear velocity, provide two degrees of redundancy. The algorithm was effective to avoid obstacles in the workspace even through the collision occurred in extended workspace, and it was found be to a useful design tool which gives more flexibility to design conditions nd to find the mechanical constraints for fruit harvesting robots.

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Delay-dependent Stability Criteria for Fuzzy Markovian Jumping Hopfield Neural Networks of Neutral Type with Time-varying Delays (시변지연을 가진 뉴트럴 타입의 퍼지 마르코비안 점핑 홉필드 뉴럴 네트워크에 대한 지연의존 안정성 판별법)

  • Park, Myeong-Jin;Kwon, Oh-Min;Park, Ju-Hyun;Lee, Sang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.2
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    • pp.376-382
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    • 2011
  • This paper proposes delay-dependent stability conditions of the fuzzy Markovian jumping Hopfield neural networks of neutral type with time-varying delays. By constructing a suitable Lyapunov-Krasovskii's (L-K) functional and utilizing Finsler's lemma, new delay-dependent stability criteria for the systems are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. A numerical example is given to illustrate the effectiveness of the proposed methods.

A Study on Reliability Based Design Criteria for Bridge Foundation (교량기초의 신뢰성 설계규준에 관한 연구)

  • 손용우;정철원
    • Computational Structural Engineering
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    • v.6 no.1
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    • pp.77-89
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    • 1993
  • Current Bridge foundation design is based on Working Stress Design(WSD), but Load Factor Based on Optimum Reliability(LFBOR) design method is more rational than the WSD. For this reason, this study proposes a reliability based design criteria for the bridge foundation, which is most common type of bridge foundation(Shallow, Pile and Caission), and also proposes the theoretical basis of nominal safety factors of stability analysis by introducing the reliability theory. The limit state equations of stability analysis of bridge foundation and the uncertainty measuring algorithms of each equation are also derived by Cornell's MFOSM(Mean First Order 2nd Moment Methods)using the stability analysis fourmula Highway Bridge Design Codes.

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A study on the stability criterion of the control systems for the drive systems in rolling mill plants (압연구동제어계(壓延驅動制御系)의 안정도(安定度) 판정법(判定法)에 관한 연구)

  • Jeong, H.S.;Baek, K.N.;Kang, M.J.
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.380-382
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    • 1989
  • It is necessary for us to maintain good the quality of products in iron and steel making process, especially in the rolling mill plants. Thus, we need check the stability criteria of control systems. In the frequency domain, the whole system including controllers can be identified using FFT analyzer. But this method is not adequete where precise identification is demanded. Thus a way to complement the defects In the frequency domain analysis using FFT analyzer is introduced. And In the time domain, to establish the stability criteria on the control systems, the assumed parameters obtained using least square method are presented in this report.

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NEW CONDITIONS ON EXISTENCE AND GLOBAL ASYMPTOTIC STABILITY OF PERIODIC SOLUTIONS FOR BAM NEURAL NETWORKS WITH TIME-VARYING DELAYS

  • Zhang, Zhengqiu;Zhou, Zheng
    • Journal of the Korean Mathematical Society
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    • v.48 no.2
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    • pp.223-240
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    • 2011
  • In this paper, the problem on periodic solutions of the bidirectional associative memory neural networks with both periodic coefficients and periodic time-varying delays is discussed. By using degree theory, inequality technique and Lyapunov functional, we establish the existence, uniqueness, and global asymptotic stability of a periodic solution. The obtained results of stability are less restrictive than previously known criteria, and the hypotheses for the boundedness and monotonicity on the activation functions are removed.

Stability of stochastic neutral neural networks with delays

  • Xiaoqi Sun;Ling Zhang
    • Advances in Computational Design
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    • v.9 no.2
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    • pp.97-113
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    • 2024
  • In this paper, we proposed a new class of stochastic neutral neural networks with uncertain and deterministic coefficients. Made the Sigmund activation and Lipschitz activation functions less conditional. The Lyapnov-Krasovskii functional is constructed. The linear matrix inequality (LMI) is constructed using Schur's lemma, and new criteria for the global asymptotic stability and global asymptotic robust stability of neural networks are obtained. Furthermore, we have verified that the method is effective and feasible through numerical examples.

Typology of Wholesalers in Dongdaemun Fashion Town according to Contractor Selection Criteria (동대문 패션 타운의 패션 타운의 도매업체 현황 및 협력 업체 선정 기준에 따른 유형화)

  • Seo, Min-Jeong;Lee, Ji-In;Lee, Kyu-Hye
    • The Research Journal of the Costume Culture
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    • v.17 no.5
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    • pp.819-833
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    • 2009
  • The current research focused on exploration of a well known Korean fashion and clothing industry cluster, Dongdaemun Fashion Town(DFT). Many clothing and fashion wholesalers in DFT with various business formats are trying to obtain competitive advantages. For the empirical study, a questionnaire was developed. Items measuring descriptive statistics for each business and contractor selection criteria were included in the survey. 161 data from Employees of various wholesalers of DFT were used for statistical analysis. Majority of DFT customers were buyers of Internet shopping malls and street retail shops. 64% of them used domestic contractors for sourcing products. Most of them managed less than three contractors. Contractor selection criteria were factorized as flexibility, production ability, stability, fame and location. Wholesalers were segmented into three groups: product oriented, flexibility oriented and stability oriented groups. Group differences in terms of business practices were assessed and strategic implications were included.

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