• 제목/요약/키워드: inverse design technique

검색결과 77건 처리시간 0.023초

병렬 연산을 이용한 축류 블레이드의 역설계 (The Inverse Design Technique of Axial Blade Using the Parallel Calculation)

  • 조장근;안재성;박원규
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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    • pp.200-207
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    • 1999
  • An efficient inverse design technique based on the MGM (Modified Garabedian-McFadden) method has been developed. The 2-D Navier-Stokes equations are solved for obtaining the surface pressure distributions and coupled with the MGM method to perform the inverse design. The solver is parallelized by using the domain decomposition method and the standard MPI library for communications between the processors. The MGM method is a residual-correction technique, in which the residuals are the difference between the desired and the computed pressure distribution. The developed code was applied to several airfoil shapes and the axial blade. It has been found that they are well converged to their target pressure distribution.

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유체기계 임펠러의 최적 역설계 기법 (Optimization Inverse Design Technique for Fluid Machinery Impellers)

  • 김종섭;박원규
    • 한국전산유체공학회지
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    • 제3권1호
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    • pp.37-45
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    • 1998
  • A new and efficient inverse design method based on the numerical optimization technique has been developed. The 2-D incompressible Navier-Stokes equations are solved for obtaining the objective functions and coupled with the optimization procedure to perform the inverse design. The steepest descent and the conjugate gradient method have been applied to find the searching direction. The golden section method was applied to compute the design variable intervals. It has been found that the airfoil and the pump impellers are well converged to their targeting shapes.

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Design and FPGA Implementation of FBMC Transmitter by using Clock Gating Technique based QAM, Inverse FFT and Filter Bank for Low Power and High Speed Applications

  • Sivakumar, M.;Omkumar, S.
    • Journal of Electrical Engineering and Technology
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    • 제13권6호
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    • pp.2479-2484
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    • 2018
  • The filter bank multicarrier modulation (FBMC) technique is one of multicarrier modulation technique (MCM), which is mainly used to improve channel capacity of cognitive radio (CR) network and frequency spectrum access technique. The existing FBMC System contains serial to parallel converter, normal QAM modulation, Radix2 inverse FFT, parallel to serial converter and poly phase filter. It needs high area, delay and power consumption. To further reduce the area, delay and power of FBMC structure, a new clock gating technique is applied in the QAM modulation, radix2 multipath delay commutator (R2MDC) based inverse FFT and unified addition and subtraction (UAS) based FIR filter with parallel asynchronous self time adder (PASTA). The clock gating technique is mainly used to reduce the unwanted clock switching activity. The clock gating is nothing but clock signal of flip-flops is controlled by gate (i.e.) AND gate. Hence speed is high and power consumption is low. The comparison between existing QAM and proposed QAM with clock gating technique is carried out to analyze the results. Conversely, the proposed inverse R2MDC FFT with clock gating technique is compared with the existing radix2 inverse FFT. Also the comparison between existing poly phase filter and proposed UAS based FIR filter with PASTA adder is carried out to analyze the performance, area and power consumption individually. The proposed FBMC with clock gating technique offers low power and high speed than the existing FBMC structures.

Modified Garabedian-McFadden 방법을 이용한 프로펠러 날개 단면의 역설계 기법 (The Inverse Design Technique of Propeller Blade Sections Using the Modified Garabedian-McFadden Method)

  • 정철민;조장근;박원규
    • 대한조선학회논문집
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    • 제36권4호
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    • pp.28-36
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    • 1999
  • 본 연구에서는 MGM(Modified Grrabedian-McFadden)방법에 기초한 효율적인 역설계 방법을 개발하였다. 표면압력 분포를 얻기 위해 2-D Navier-Stokes 방정식을 풀었고, 역설계를 수행하기 위해 MGM방법을 사용하였다. MGM 방법은 설계 목적 압력분포와 Navier-Stokes 방정식에서 계산된 압력분포의 차인 잔여량을 보정하는 잔여-보정 기법이다. 코드 개발을 위하여 몇몇 익형과 프로펠러 형상설계에 적용하였다. 이들 모두 목표하는 형상에 잘 수렴해 갔다.

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Parameter estimation of four-parameter viscoelastic Burger model by inverse analysis: case studies of four oil-refineries

  • Dey, Arindam;Basudhar, Prabir Kr.
    • Interaction and multiscale mechanics
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    • 제5권3호
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    • pp.211-228
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    • 2012
  • This paper reports the development of a generalized inverse analysis formulation for the parameter estimation of four-parameter Burger model. The analysis is carried out by formulating the problem as a mathematical programming formulation in terms of identification of the design vector, the objective function and the design constraints. Thereafter, the formulated constrained nonlinear multivariable problem is solved with the aid of fmincon: an in-built constrained optimization solver module available in MatLab. In order to gain experience, a synthetic case-study is considered wherein key issues such as the determination and setting up of variable bounds, global optimality of the solution and minimum number of data-points required for prediction of parameters is addressed. The results reveal that the developed technique is quite efficient in predicting the model parameters. The best result is obtained when the design variables are subjected to a lower bound without any upper bound. Global optimality of the solution is achieved using the developed technique. A minimum of 4-5 randomly selected data-points are required to achieve the optimal solution. The above technique has also been adopted for real-time settlement of four oil refineries with encouraging results.

원통형 수중운동체 두부 형상 역설계 (An Inverse Design for Nose Shape of a Cylindrical-Shaped Submerged Body)

  • 정철민
    • 한국군사과학기술학회지
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    • 제7권3호
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    • pp.69-76
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    • 2004
  • In this paper, an efficient inverse design method for nose shape of submerged body based on the MGM(Modified Garabedian-McFadden) design method has been developed. The MGM design method is a residual-correction technique, in which the residuals are differences between the desired and the computed pressure distributions. 3-D incompressible Wavier-Stokes equation was adopted for obtaining the surface pressure distribution and combined with the MGM design method to perform the inverse design of nose shape of submerged body. The design method was verified by applying to several airfoil shapes. Improved design shapes could be obtained when the method was applied to nose shapes of submerged body.

Inverse Dynamic Analysis of Flexible Multibody Systems with Closed-Loops

  • Lee, Byung-Hoon;Lee, Shi-Bok;Jeong, Weui-Bong;Yoo, Wan-Suk;Yang, Jin-Saeng
    • Journal of Mechanical Science and Technology
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    • 제15권6호
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    • pp.693-698
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    • 2001
  • The analysis of actuating forces (or torques) and joint reaction forces (or moments) are essential to determine the capacity of actuators, to control the system and to design the components. This paper presents an inverse dynamic analysis algorithm for flexible multibody systems with closed-loops in the relative joint coordinate space. The joint reaction forces are analyzed in Cartesian coordinate space using the inverse velocity transformation technique. The joint coordinates and the deformation modal coordinates are used as the generalized coordinates of a flexible multibody system. The algorithm is verified through the analysis of a slider-crank mechanism.

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Manabe표준형을 이용한 제어기 설계에 관한 연구 (A Study on the Design of a Controller with the Manabe Standard Form)

  • 강환일;정요원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 B
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    • pp.537-539
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    • 1999
  • When dealing with a controller design in the two parameter configuration, there are some situations when neither a known pseudo inverse technique nor the inverse method can be applicable. In this case, we propose two methods of designing a controller by the gradient algorithm and the new pseudo inverse method such that the designed closed loop polynomial may be equal to or nearly equal to the desired closed loop polynomial. We compare the proposed methods with the known methods. We use the Manabe standard form as a desired closed loop characteristic polynomial.

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Direct Just-in-time Methods for Nonlinear Control Design

  • Qiubao Zheng;Kim, Hidenori ura
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.93.4-93
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    • 2001
  • Based on input and output data pairs of nonlinear systems, this paper proposes a simple and effective Just-In-Time (JIT) method, called Direct JIT Control, for nonlinear control design. It uses an inverse model of controlled plant to compute an initial control action, and then adapts the initial control action by adding a fine-tuning control action, depended on the errors between the real outputs and the expected reference signals. Meanwhile, the proposed JIT method accomplishes the adaptation of the inverse model just simply by means of the refreshment of input and output data pairs. In addition, the JIT modeling technique guarantees this method to obtain an approximate inverse model of the controlled nonlinear plant in the neighborhood of a query. Based on a ...

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역추기법을 이용한 해면골의 점탄성 특성 해석 (Estimation of Viscoelastic Properties of Trabecular Bone Using An Inverse Method)

  • 강신일;이원희;홍정화
    • 대한의용생체공학회:의공학회지
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    • 제18권3호
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    • pp.211-216
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    • 1997
  • An inverse method with regularization has been developed to determine the viscoelastic properties of trabecular bone. A series of stress relaxation experiments were performed under the condition of uniaxial compression stress state. Optimization has been formulated within the framework of nonlinear least-squares and a modified Gauss-Newton method with a zeroth-order regularization technique. The stress relaxation behavior of trabecular bone was analyzed using a standard viscoelastic model. The present study clearly shows that trabecular bone exhibits typical viscoelastic stress relaxation behavior, and the obtained material parameters well represent the viscoelastic behavior of trabecular bone.

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