• Title/Summary/Keyword: Overall stabilizing

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Assesment on the Characteristics of Foundation Bearing Capacity in Reinforced Soil Wall Structure of Large Scale (대규모 보강토옹벽 구조물에서의 기초지반 지지력특성 평가)

  • Han, Jung-Geun;Yoo, Seung-Kyung;Cho, Sam-Deuk;Lee, Kyang-Woo;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.1
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    • pp.9-14
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    • 2006
  • The reinforced soil retaining wall structures of serious types with environmental are widely expanding more and more in Korea, which divided conventional type's reinforced soil retaining wall on segmental retaining wall. The causes of most crack occurred at block in reinforced soil retaining wall structure caused by the differential settlement of foundation. It is difference of settlement for significant factor that with overall slope stability. In this study, design assessment of foundation bearing capacity related to differential settlement of foundation ground was considered. And, also, through case study, the countermeasure methods and its application were suggested that the bearing capacity of foundation had to stabilize. The foundation ground in charge of bearing capacity should be affected by the resisting force of sliding, because the foundation parts of reinforced soil retaining wall were belongs to potential slope sliding area in overall stabilizing including retaining wall structures. Therefore, the analyzing or the designing of bearing capacity for foundation should be considered control capacity on the overall slope sliding.

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Conformation of Antifungal Agent Fluconazole

  • Han, Seong Jun;Kang Kee Long;Lee Sung Hee;Chung Uoo Tae;Kang Young Kee
    • Bulletin of the Korean Chemical Society
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    • v.14 no.2
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    • pp.262-265
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    • 1993
  • Conformational free energy calculations using an empirical potential function and a hydration shell model (program CONBIO) were carried out on antifungal agent fluconazole in the unhydrated and hydrated states. The initial geometry of fluconazole was obtained from two minimized fragments of it using a molecular mechanics MMPMI and followed by minimizing with a semiempirical AM1 method. In both states, the feasible conformations were obtained from the calculations of conformational energy, conformational entropy, and hydration free energy by varying all the torsion angles of the molecule. The intramolecular hydrogen bonds of isopropyl hydroxyl hydrogen and triazole nitrogens and the structural flexibility are of significant importance in stabilizing the conformations of fluconazole in both states. Hydration is proved to be one of the essential factors in stabilizing the overall conformation in aqueous solution. Two F atoms of phenyl ring are not identified as an essential key in determining the stable conformations and may be responsible for the interaction with the receptor of fluconazole.

Output Feedback Semi-Global Stabilization for Input-Affine Nonlinear Systems

  • Hyungbo Shim;Seo, Jin-Heon
    • Transactions on Control, Automation and Systems Engineering
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    • v.2 no.2
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    • pp.104-109
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    • 2000
  • In this paper, the output feedback stabilizing problem is solved using any given state feedback control law. Compared to the linear systems is not so straightforward for nonlinear systems. We briefly explain the intrinsic obstructions for this problem and provide new output feedback scheme which achieves the semi-global stabilization with the high-gain state observer. THe overall uniform observability of the plant. Therefore, the result can be regarded as an extension of the separation principle for linear systems in some aspect.

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Comparison of Aerodynamic Responses for Cable-Stayed Bridges during Construction with Temporary Stabilizing Measures (내풍케이블 배치에 따른 가설 중 사장교의 공기역학적 거동 비교)

  • Cho, Jae Young;Kim, Young Min;Lee, Hak Eun
    • Journal of Korean Society of Steel Construction
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    • v.19 no.2
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    • pp.147-160
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    • 2007
  • In this paper, we described the aeroelastic full-bridge model tests that were conducted to investigate the effect of alternative temporary stabilizing measures for thecable-stayed bridge during construction to ensure aerodynamic stability in the event of a typhoon or similar disasters. The effect of alternative temporary stabilizing measures was investigated through various configurations on two cable-stayed bridges with a main span of 475 m and 230 m, respectively. To investigate the bridge's aerodynamic behaviour and dynamic wind force during construction, the deflections at the end of the cantilever, the accelerations atthe top of the pylon and the moments at the lower part of the pylon were measured. As the result, the system with two sets of vertical cables per cantilever seemed to be the overall most effective solution, but the system with single vertical cable may also work. The combined system using the caisson support and vertical cables and the system with two sets of inclined cables per cantilever on the same anchor block may also be a solution. The inclined cables from the caisson to the girder were effective for some early stages of erecting the deck.

Application to Stabilizing Control of Nonlinear Mobile Inverted Pendulum Using Sliding Mode Technique

  • Choi, Nak-Soon;Kang, Ming-Tao;Kim, Hak-Kyeong;Park, Sang-Yong;Kim, Sang-Bong
    • Journal of Ocean Engineering and Technology
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    • v.23 no.2
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    • pp.1-7
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    • 2009
  • This paper presents a sliding mode controller based on Ackermann's formula and applies it to stabilizing a two-wheeled mobile inverted pendulum in equilibrium. The mobile inverted pendulum is a system with an inverted pendulum on a mobile cart. The dynamic modeling of the mobile inverted pendulum was established under the assumptions of a cart with no slip and a pendulum with only planar motion. The proposed sliding mode controller was based upon a class of nonlinear systems whose nonlinear part of the modeling can be linearly parameterized. The sliding surface was obtained in an explicit form using Ackermann's formula, and then a control law was designed from reachability conditions and made the sliding surface attractive to the equilibrium state of the mobile inverted pendulum. The proposed controller was implemented in a Microchip PIC16F877 micro-controller. The developed overall control system is described. The simulation and experimental results are presented to show the effectiveness of the modeling and controller.

Disturbance Torque Suppression Control of Servo Motors for Missile Fin Actuators (미사일 Fin 액츄에이터용 서보모터의 외란 토크 억제 제어)

  • Kim, Chang-Hwan
    • Journal of National Security and Military Science
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    • s.1
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    • pp.311-343
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    • 2003
  • In this paper, we propose a generalized disturbance torque suppression control scheme of servo motors for missile fin actuators. Our controller consists of both a model based feed-forward controller and a stabilizing feedback controller. The feed-forward controller is designed such that the output of nominal plant tracks perfectly the reference position command with a desired dynamic characteristics. The feedback controller stabilizes the overall closed loop system. Furthermore, the feedback controller contains a free function that can be chosen arbitrary. The free function can be designed so as to achieve both the suppression of disturbances and the robustness to model uncertainties. In order to illuminate the superior performance of our control scheme to the conventional ones, we present some simulation results.

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A Study on the Energy Saving through Pollutant removal of Intake gate (취수구 스크린 협잡물 제거를 통한 에너지 절감효과 분석)

  • Kim, Byeong-Kakg;Park, Inn;You, Si-Og;Jang, Seung-Don
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.930-931
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    • 2011
  • As the upsurge in oil prices and global warming, Energy saving is needed to overall industry. If The head of Intake gate screen is high. The pumping process involves a loss of energy and results in high emissions of greenhouse gases. Therefore, blockages in intake gate should be free. Another advantage of cleaning is stabilizing pumping system. Because vibration and cavitation decreases when loss of head is low.

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Average Particle Size Prediction of Rubber Dispersed Phase in High Impact Polystyrene (내충격성 폴리스티렌의 고무상 입자경 예측)

  • Lee, Seong-Jae;Chung, Kyung-Ho
    • Elastomers and Composites
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    • v.31 no.5
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    • pp.327-334
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    • 1996
  • A correlative analysis has been carried out to predict the average particle size of rubber dispersed phase In high impact polystyrene manufactured by bulk polymerization. To do the correlation, a mechanistic model suggested previously by the author was used for describing the size of stabilizing particles agitated under the turbulent viscous shear subranges in a prepolymerization reactor, where the rubber particles were assumed to be formed at the time of phase inversion in the reactor. Viscosities required for the model were postulated to describe the overall behavior of butadiene rubber and polystyrene mixture along the wide range of conversion. The good agreement between the model and the experimental data from a plant was quite satisfactory for the prediction of the average rubber particle size of high impact polystyrene.

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Optimization of Transient Stability Control Part-I: For Cases with Identical Unstable Modes

  • Xue Yusheng;Li Wei;Hill David John
    • International Journal of Control, Automation, and Systems
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    • v.3 no.spc2
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    • pp.334-340
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    • 2005
  • Based on the stability margin provided by the EEAC, the unstable contingencies can be classified into sets according to their unstable modes. This two-part paper develops a globally optimal algorithm for transient stability control to coordinate preventive actions and emergency actions. In the first part, an algorithm is proposed for a set of contingencies having identical unstable modes. Instead of iterations between discrete emergency actions and continuous preventive actions, the algorithm straightforwardly searches for a globally optimal solution. The procedure includes assessing a set of insufficient emergency schemes identified by the EEAC; calculating the related preventive actions needed for stabilizing the system; and selecting the scheme with the minimum overall costs. Simulations on a Chinese power system highlight its excellent performance. The positive results obtained are explained by analogizing settlements for 0-1 knapsack problems using the multi-points greedy algorithm.

Reduced-order controller design via an iterative LMI method (반복 선형행렬부등식을 이용한 축소차수 제어기 설계)

  • Kim, Seog-Joo;Kwon, Soon-Man;Lee, Jong-Moo;Kim, Chun-Kyung;Cheon, Jong-Min
    • Proceedings of the KIEE Conference
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    • 2004.07d
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    • pp.2242-2244
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    • 2004
  • This paper deals with the design of a reduced-order stabilizing controller for the linear system. The coupled lineal matrix inequality (LMI) problem subject to a rank condition is solved by a sequential semidefinite programming (SDP) approach. The nonconvex rank constraint is incorporated into a strictly linear penalty function, and the computation of the gradient and Hessian function for the Newton method is not required. The penalty factor and related term are updated iteratively. Therefore the overall procedure leads to a successive LMI relaxation method. Extensive numerical experiments illustrate the proposed algorithm.

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