• 제목/요약/키워드: Inverse function

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Inverse Dynamics 함수를 이용한 골프스윙 3분절 시스템의 적용 (An Application of Triple Segmental System in Golf Swing through an Inverse Dynamics Function)

  • 임정;문건필
    • 한국운동역학회지
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    • 제15권2호
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    • pp.57-67
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    • 2005
  • The purpose of this study was to analyze the kinetic factors of the golf driver swing using the Inverse Dynamics function. For this purpose, joint force were calculated. In order to test the possibility of Inverse Dynamics function(motion-dependent interaction), a triple segmental system was set for wrist, left shoulder and lumbar and joint force working on the anatomical joint region was estimated. For this study, 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint force and torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint force was generated on wrist, shoulder and lumbar joints in the direction of the target, and that the joint force was stronger in the direction of target immediately before impact. The joint force was generated towards the target to activate the nodes, and then, it was generated in the reverse direction to increase the speed during impact.

역해석기법을 이용한 불포화토 투수계수함수 산정에 관한 연구 (Evaluation of Hydraulic Conductivity Function in Unsaturated Soils using an Inverse Analysis)

  • 이준용;한진태
    • 한국농공학회논문집
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    • 제55권4호
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    • pp.1-11
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    • 2013
  • Unsaturated hydraulic conductivity function is one of key parameters to solve the flow phenomena in problems of landslide. Prediction models for hydraulic conductivity function related to soil-water retention curve equations in many geotechnical applications have been still used instead of direct measurement of the hydraulic conductivity function since prediction models from soil-water retention curve equations are attractive for their fast and easy use and low cost. However, many researchers found that prediction models for the hydraulic conductivity function can not predict the hydraulic conductivity exactly in comparison with experimental outputs. This research introduced an inverse analysis to evaluate the hydraulic conductivity function corresponding to experimental output from the flow pump system. Optimisation process was carried out to obtain the hydraulic conductivity function. This research showed that the inverse analysis with flow pump system was suitable to assess the hydraulic conductivity in unsaturated soil, and the prediction models for the hydraulic conductivity were led to the significant discrepancy from actual experimental outputs.

A REMARK ON THE REGULARIZED GAP FUNCTION FOR IQVI

  • Kum, Sangho
    • 충청수학회지
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    • 제28권1호
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    • pp.145-150
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    • 2015
  • Aussel et al. [1] introduced the notion of inverse quasi-variational inequalities (IQVI) by combining quasi-variational inequalities and inverse variational inequalities. Discussions are made in a finite dimensional Euclidean space. In this note, we develop an infinite dimensional version of IQVI by investigating some basic properties of the regularized gap function of IQVI in a Banach space.

자동미분법과 Broyden 혼합법을 이용한 2차원 원통형상에서의 경계온도 역추정 (Inverse Boundary Temperature Estimation in a Two-Dimensional Cylindrical Enclosure Using Automatic Differentiation and Broyden Combined Method)

  • 김기완;김동민;백승욱
    • 대한기계학회논문집B
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    • 제30권3호
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    • pp.270-277
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    • 2006
  • Inverse radiation problems were solved for estimating boundary temperature distribution in a way of function estimation approach in an axisymmetric absorbing, emitting and scattering medium, given the measured radiative data. In order to reduce the computational time fur the calculation of sensitivity matrix, automatic differentiation and Broyden combined method were adopted, and their computational precision and efficiency were compared with the result obtained by finite difference approximation.. In inverse analysis, the effects of the precision of sensitivity matrix, the number of measurement points and measurement error on the estimation accuracy had been inspected using quasi-Newton method as an inverse method. Inverse solutions were validated with the result acquired by additional inverse methods of conjugate-gradient method or Levenberg-Marquardt method.

A comparison of inverse transform and composition methods of data simulation from the Lindley distribution

  • Okwuokenye, Macaulay;Peace, Karl E.
    • Communications for Statistical Applications and Methods
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    • 제23권6호
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    • pp.517-529
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    • 2016
  • This study compares the inverse transform and the composition methods for generating data from the Lindley distribution. The expression for the inverse of the distribution function for the Lindley distribution does not exist in closed form. Hence, authors of many empirical studies on the Lindley distribution used methods for generating Lindley variates other than the inverse transform. We generated data from the Lindley distribution using the inverse transform approach by obtaining the Lindley variates numerically; we also generated data from this distribution using the composition approach. Following the generation of the Lindley variates using these two methods, we compare some statistical properties of the estimates of the Lindley model parameters based on the generated data. We conclude that the two methods produce similar results.

A p-DEFORMED q-INVERSE PAIR AND ASSOCIATED POLYNOMIALS INCLUDING ASKEY SCHEME

  • Savalia, Rajesh V.
    • 대한수학회논문집
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    • 제34권4호
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    • pp.1175-1199
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    • 2019
  • We construct a general bi-basic inverse series relation which provides extension to several q-polynomials including the Askey-Wilson polynomials and the q-Racah polynomials. We introduce a general class of polynomials suggested by this general inverse pair which would unify certain polynomials such as the q-extended Jacobi polynomials and q-Konhauser polynomials. We then emphasize on applications of the general inverse pair and obtain the generating function relations, summation formulas involving the associated polynomials and derive the p-deformation of some of the q-analogues of Riordan's classes of inverse series relations. We also illustrate the companion matrix corresponding to the general class of polynomials; this is followed by a chart showing the reducibility of the extended p-deformed Askey-Wilson polynomials as well as the extended p-deformed q-Racah polynomials.

Notes on a skew-symmetric inverse double Weibull distribution

  • Woo, Jung-Soo
    • Journal of the Korean Data and Information Science Society
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    • 제20권2호
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    • pp.459-465
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    • 2009
  • For an inverse double Weibull distribution which is symmetric about zero, we obtain distribution and moment of ratio of independent inverse double Weibull variables, and also obtain the cumulative distribution function and moment of a skew-symmetric inverse double Weibull distribution. And we introduce a skew-symmetric inverse double Weibull generated by a double Weibull distribution.

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정규화된 고차 inverse Chebyshev함수를 이용한 능동 필터 설계 (An Active filter Design using Normalized High Order Inverse Chebyshev Functions)

  • 신홍규;김동용
    • 한국통신학회논문지
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    • 제13권4호
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    • pp.322-331
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    • 1988
  • 본 논문에서는 고차 inverse Chebyshev 함수를 이용하여 능동 RC필터로 설계할 때 최대 동적범위를 갖고, 감도가 낮은 종속연결법으로 실현하는 방법을 제시하였다. 이때, 최대 동적범위를 만족시키도록 평탄행렬에 의한 최적 극점-영점 결합과 종속 연결순서 및 이득 분배에 대한 알고리즘을 제시하였으며, 능동 RC 회로의 단점인 감도 문제를 향상시키기 위하여 부 궤환을 갖는 2차 블록과 1차 블록을 설계하였다. 제시된 설계 방법을 이용하여 규준화된 7차 inverse Chebyshev함수의 능동 RC저역통과 필터를 설계한 결과 주어진 설계 명세조건과 일치함을 보였다.

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An inverse approach based on uniform load surface for damage detection in structures

  • Mirzabeigy, Alborz;Madoliat, Reza
    • Smart Structures and Systems
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    • 제24권2호
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    • pp.233-242
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    • 2019
  • In this paper, an inverse approach based on uniform load surface (ULS) is presented for structural damage localization and quantification. The ULS is excellent approximation for deformed configuration of a structure under distributed unit force applied on all degrees of freedom. The ULS make use of natural frequencies and mode shapes of structure and in mathematical point of view is a weighted average of mode shapes. An objective function presented to damage detection is discrepancy between the ULS of monitored structure and numerical model of structure. Solving this objective function to find minimum value yields damage's parameters detection. The teaching-learning based optimization algorithm has been employed to solve inverse problem. The efficiency of present damage detection method is demonstrated through three numerical examples. By comparison between proposed objective function and another objective function which make use of natural frequencies and mode shapes, it is revealed present objective function have faster convergence and is more sensitive to damage. The method has good robustness against measurement noise and could detect damage by using the first few mode shapes. The results indicate that the proposed method is reliable technique to damage detection in structures.

Variable Selection in Sliced Inverse Regression Using Generalized Eigenvalue Problem with Penalties

  • Park, Chong-Sun
    • Communications for Statistical Applications and Methods
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    • 제14권1호
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    • pp.215-227
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    • 2007
  • Variable selection algorithm for Sliced Inverse Regression using penalty function is proposed. We noted SIR models can be expressed as generalized eigenvalue decompositions and incorporated penalty functions on them. We found from small simulation that the HARD penalty function seems to be the best in preserving original directions compared with other well-known penalty functions. Also it turned out to be effective in forcing coefficient estimates zero for irrelevant predictors in regression analysis. Results from illustrative examples of simulated and real data sets will be provided.