• 제목/요약/키워드: Mixed method approach

검색결과 341건 처리시간 0.029초

A Study on Assessment of Composite Couplings for Helicopter Rotor Blades with Multi-cell Sections

  • Jung, Sung-Nam;Park, Il-Ju;Shi, Eui-Sup;Chopra, Inderjit
    • International Journal of Aeronautical and Space Sciences
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    • 제4권1호
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    • pp.9-18
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    • 2003
  • In this work, a closed-form analysis is performed for the structural response of coupled composite blades with multi-cell sections. The analytical model includes the effects of shell wall thickness, transverse shear, torsion warping and constrained warping. The mixed beam approach based on Reissner's semi-complementary energy functional is used to derive the beam force-displacement relations. The theory is validated against experimental test data and other analytical results for coupled composite beams and blades with single-cell box-sections and two-cell airfoils. Correlation of the present method with experimental results and detailed finite element results is found to be very good.

도매전력시장에서 N명 발전사업자의 꾸르노 모델을 이용한 혼합 내쉬 균형점 도출 방법론 개발 연구 (A Study on Evaluation Method of Mixed Nash Equilibria by Using the Cournot Model for N-Genco. in Wholesale Electricity Market)

  • 임정열;이기송;양광민;박종배;신중린
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 A
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    • pp.639-642
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    • 2003
  • This paper presents a method for evaluating the mixed nash equilibria of the Cournot model for N-Gencos. in wholesale electricity market. In the wholesale electricity market, the strategies of N-Genco. can be applied to the game model under the conditions which the Gencos. determine their stratgies to maximize their benefit. Generally, the Lemke algorithm is evaluated the mixed nash equlibria in the two-player game model. However, the necessary condition for the mixed equlibria of N-player are modified as the necessary condition of N-1 player by analyzing the Lemke algorithms. Although reducing the necessary condition for N-player as the one of N-1 player, it is difficult to and the mixed nash equilibria participated two more players by using the mathmatical approaches since those have the nonlinear characteristics. To overcome the above problem, this paper presents the generalized necessary condition for N-player and proposed the object function to and the mixed nash equlibrium. Also, to evaluate the mixed equilibrium through the nonlinear objective function, the Particle Swarm Optimization (PSO) as one of the heuristic algorithm are proposed in this paper. To present the mixed equlibria for the strategy of N-Gencos. through the proposed necessry condition and the evaluation approach, this paper proposes the mixed equilibrium in the cournot game model for 3-players.

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H$_{\infty}$제어법을 이용한 부유식 플랫폼의 동위치 제어 (Dynamic Positionning Control of Floating Platform Using H$_{\infty}$ Control Method)

  • 유휘룡;김성민;김상봉
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.437-442
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    • 1996
  • The paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$control technique. The norm band of uncertaintyis captured by multiplicative perturbation between nominalmodel and reduced order model. A controller robust to theuncertainty is designed applying $H_{\infty}$synthesis. The control law satisfying robust stability and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$synthesis are compared to those of the traditional LQ synthesis method. method.

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Flexible Mixed decomposition Method for Large Scale Linear Programs: -Integration of a Network of Process Models-

  • Ahn, Byong-Hun;Rhee, Seung-Kyu
    • 한국경영과학회지
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    • 제11권2호
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    • pp.37-50
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    • 1986
  • In combining dispersed optimization models, either primal or dual(or both) decomposition method widely used as an organizing device. Interpreting the methods economically, the concepts of price and resource-directive coordination are generally well accepted. Most of deomposition/ integration methods utilize either primal information of dual information, not both, from subsystems, while some authors have developed mixed decomposition approaches employing two master problems dealing primal and dual proposals separately. In this paper a hybrid decomposition method is introduced, where one hybrid master problem utilizes the underlying relationships between primal and dual information from each subsystem. The suggested method is well justified with respect to the flexibility in information flow pattern choice (some prices and other quantities) and to the compatibility of subdivision's optimum to the systemwide optimum, that is often lacking in conventional decomposition methods such as Dantzig-Wolfe's. A numerical example is also presented to illustrate the suggested approach.

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동선체계와 환경요소의 상관관계가 복합용도건물의 길찾기에 미치는 영향에 관한 코엑스몰 사례연구 (A COEX mall Case study on the Correlation between Circulation system and Environmental elements for a Better Wayfinding design in Mixed-use buildings)

  • 박민지;이현수
    • 한국실내디자인학회논문집
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    • 제25권1호
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    • pp.151-162
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    • 2016
  • Various mixed-use buildings have been developed in the process of resolving the issue of 'urban regeneration' in the modern city. In this urban regeneration process, the size of the mixed-use buildings and the level of their functional complexity have been increased. It requires a quantitative and systematic approach in order to analyze the internal circulation flow within the large-scale commercial mixed-use buildings. Circulation system and environmental factors, respectively, have been vital criteria for the effectiveness of a Wayfinding design within the mixed-use buildings. The circulation system in this paper consists of 1) the number of the incoming paths at each node, and 2) the angle of directional transition from the incoming paths at the node. The environmental factors include 1) color tone, 2) materials, 3) lighting, and 4) pattern of the interior design of the mixed-use buildings. In this paper, the author develops a method of investigating the influence of the correlation between the circulation system and the environmental factors on the design of Wayfinding on the view of the remodeled COEX MALL interior design.

화자간 변별력 최대화를 위한 혼합 모델 방식과 심볼 확률 가중함수에 관한 연구 (A Study on the Mixed Model Approach and Symbol Probability Weighting Function for Maximization of Inter-Speaker Variation)

  • 진세훈;강철호
    • 한국음향학회지
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    • 제24권7호
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    • pp.410-415
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    • 2005
  • 최근 대부분의 화자확인 시스템은 패턴 인식 접근방식에 기인하고 있다. 패턴 분류기의 성능은 화자의 특징 파라미터를 어떻게 분류하는가 하는 데에 기인한다. 그 특징 파라미터를 잘 분류하기 위해서는, 화자간 변이를 최대화하고 특징 파라미터 간 거리를 효과적으로 측정하는 것이 매우 중요하다. 따라서, 본 논문에서는 개인 모델과 월드 모델을 동시에 배치함으로써 화자간 변이를 최대화 할 수 있는 개선된 혼합 모델 구조를 제안한다. 결정 과정 시 제안한 혼합 모델 방식을 사용함으로써 화자간 변별력을 최대화 할 수 있었다. 또한, 입력데이터에 대한 개인 모델과 월드 모델의 거리비율에 따라 심볼 확률 값을 가중하여 벡터 양자화 에러를 줄이는 가중치 함수를 제안 한다. 실험 결과, 이두 가지 방법을 취함으로써 DCF (Detection Cost Function)를 $2.37\%$에서 $1.16\%$로 낮출 수 있었다.

삼각형 요소와 사각형 요소에 기초한 상승기포의 모사를 위한 Level set 방법 (Level set method for the simulation of rising bubble based on triangular and Quadrilateral elements)

  • 조명환;최형권;전병진;유정열
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2011년 춘계학술대회논문집
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    • pp.10-13
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    • 2011
  • A level set method is proposed to simulate the incompressible two-phase flow considering the effect of surface tension. For reinitialization of level set junction, a direct approach method is employed, instead of solving hyperbolic type equation. A mixed element is adopted, so that the continuity mid Navier-Stokes equations are solved by using the quadratic elements (six-node triangular element mid nine-node quadrilateral element), mid the level set function is solved by using the linear elements (three-node triangular element mid four-node quadrilateral element). In order to verify the accuracy mid robustness of the codes, the present methods are applied to a few benchmark problems. It is confirmed that the present results are in good qualitative mid quantitative agreements with the existing studies.

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$H_2 / H_{\infty}$ 혼합 기법을 이용한 2자유도 PI 제어기의 설계 (Design of Two-Degree-of-Freedom PI Controllers using the Mixed $H_2/H_{\infty}$ Methods)

  • 조용석;박기헌
    • 전자공학회논문지B
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    • 제33B권6호
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    • pp.12-22
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    • 1996
  • A numerous designs of PI controllers have been suggested to solve out trade-off between tracing and regulating problems. We constructed the PI controller system with two-degree-of-freedom that is more analytic and a better approach to a practical one. In the conventional H$_{2}$ design of optimal PI controllers, the cost function includes only the plant output terms due to the divergent problems. Since the platn input temr is not considered in PI controller design, occasionally, the plant input thends to be either very large or saturated. To solve the prior mentioned problems, we employed a mixed $H_2/H_{\infty}$ method that combines the H$_{2}$ design method to decide optimal parameters of PI controller and the $H_2/H_{\infty}$ design method to minimize the maximum amplitude of plant input. The calculation time of the H$_{infty}$ norm was considerably reduced by the simple scalar function obtained by the wiener-hopf factorization of non-scalar functions.

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An Analytical Approach for Structural Synthesis of Substructures

  • Eun, Hee-Chang;Park, Sang-Yeol;Lee, Eun-Taik
    • Journal of Mechanical Science and Technology
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    • 제18권9호
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    • pp.1529-1536
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    • 2004
  • A structure is broken down into a number of substructures by means of the finite element method and the substructures are synthesized for the complete structure. The divided substructures take two types: fixed-free and free-free elements. The flexibility and stiffness matrices of the free-free elements are the Moore-Penrose inverse of each other. Thus, it is not easy to determine the equilibrium equations of the complete structure composed of two mixed types of substructures. This study provides the general form of equilibrium equation of the entire structure through the process of assembling the equilibrium equations of substructures with end conditions of mixed types. Applications demonstrate that the proposed method is effective in the structural analysis of geometrically complicated structures.

$H_{\infty}$ 제어법을 이용한 부유식 플랫폼의 동위치 제어 (Dynamic Positioning Control of Floating Platform using $H_{\infty}$ Control Method)

  • 유휘룡;김환성;김상봉
    • 한국해양공학회지
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    • 제10권3호
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    • pp.153-161
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    • 1996
  • This paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$ control technique. The norm band of uncertainty is captured by multiplicative perturbation between nominal model and reduced order model. A controller robust to the uncertainty is designed applying $H_{\infty}$ synthesis. The control law satisfying robust stabillity and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$ synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$ synthesis are compared to those of the traditional LQ synthesis method.

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