• Title/Summary/Keyword: higher order accuracy

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Research on detecting moving targets with an improved Kalman filter algorithm

  • Jia quan Zhou;Wei Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.9
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    • pp.2348-2360
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    • 2023
  • As science and technology evolve, object detection of moving objects has been widely used in the context of machine learning and artificial intelligence. Traditional moving object detection algorithms, however, are characterized by relatively poor real-time performance and low accuracy in detecting moving objects. To tackle this issue, this manuscript proposes a modified Kalman filter algorithm, which aims to expand the equations of the system with the Taylor series first, ignoring the higher order terms of the second order and above, when the nonlinear system is close to the linear form, then it uses standard Kalman filter algorithms to measure the situation of the system. which can not only detect moving objects accurately but also has better real-time performance and can be employed to predict the trajectory of moving objects. Meanwhile, the accuracy and real-time performance of the algorithm were experimentally verified.

Higher Order Zig-Zag Theory for Composite Shell under Thermo-mechanical load (열, 기계 하중을 고려한 지그재그 고차 복합재 쉘 이론)

  • Oh Jin-Ho;Cho Maeng-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.217-224
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    • 2005
  • A higher order zig-zag shell theory is developed to refine the predictions of the mechanical and thermal behaviors partially coupled. The in-plane displacement fields are constructed by superimposing linear zig-zag field to the smooth globally cubic varying field through the thickness. Smooth parabolic distribution through the thickness is assumed in the out-of-plane displacement in order to consider transverse normal deformation and stress. The layer-dependent degrees of freedom of displacement fields are expressed in terms of reference primary degrees of freedom by applying interface continuity conditions as well as bounding surface conditions of transverse shear stresses. Thus the proposed theory has only seven primary unknowns and they do not depend upon the number of layers. In the description of geometry and deformation of shell surface, all rigorous exact expressions are used. Through the numerical examples of partially coupled analysis, the accuracy and efficiency of the present theory are demonstrated. The present theory is suitable in the predictions of deformation and stresses of thick composite shell under mechanical and thermal loads combined.

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A Study on the Use of Hierarchical Elements for Incompressible Flow Computations (비압축성 유동계산을 위한 계층 요소 사용에 대한 연구)

  • Kim, Jin-Whan
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.422-429
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    • 2001
  • A two dimensional hierarchical elements are investigated for a use on the incompressible flow computation. The construction of hierarchical elements are explained through the tensor product of 1-D hierarchical functions, and a systematic treatment of essential boundary values has been developed for the degrees of freedom corresponding to higher order terms. The numerical study for the poisson problem showed that the present scheme can increase the convergence and accuracy of finite element solutions, and can be more efficient than the standard first order with many elements. Also, for Stokes and cavity flow cases, solutions from hierarchical elements showed better resolutions and future promises for higher order solutions.

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HIGHER ORDER ZIG-ZAG PLATE THEORY FOR COUPLED THERMO-ELECTRIC-MECHANICAL SMART STRUCTURES (열-기계-전기 하중이 완전 연계된 지능 복합재 평판의 지그재그 고차이론)

  • 오진호;조맹효
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.114-117
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    • 2001
  • A higher order zig-zag plate theory is developed to refine accurately predict fully coupled of the mechanical, thermal, and electric behaviors. Both the displacement and temperature fields through the thickness are constructed by superimposing linear zig-zag field to the smooth globally cubic varying field. Smooth parabolic distribution through the thickness is assumed in the transverse deflection in order to consider transverse normal deformation. Linear zig-zag form is adopted in the electric field. The layer-dependent degrees of freedom of displacement and temperature fields are expressed in terms of reference primary degrees of freedom by applying interface continuity conditions as well as bounding surface conditions of transverse shear stresses and transverse heat flux The numerical examples of coupled and uncoupled analysis are demonstrated the accuracy and efficiency of the present theory. The present theory is suitable for the predictions of fully coupled behaviors of thick smart composite plate under mechanical, thermal, and electric loadings.

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A New Economic Dispatch Algorithm Considering Any Higher Order Generation Cost Functions (고차 발전 비용 함수를 고려한 새로운 경제급전 알고리즘)

  • 박정도;문영현
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.12
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    • pp.603-610
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    • 2002
  • In this paper, a new economic dispatch algorithm for unit commitment is proposed to improve both the accuracy of the final solution and the calculation speed of economic dispatch. By using the inverse incremental cost functions, economic dispatch can be transformed into a simple optimization problem associated with an n-th order polynomial equation. The proposed method remarkably reduces the computation time with adaptability to any higher order generation cost functions. The proposed method is tested with sample system, which shows that the proposed algorithm yields more accurate and economical generation scheduling results with high computation speed.

Acoustic Analysis of Circular Simple Expansion Chamber with Arbitrary Location and Cross-Section Area of Inlet/Outlet (원형단순확장관의 입$\cdot$출구 위치와 단면 크기를 고려한 음향해석법)

  • 김봉준;정의봉;황상문
    • Journal of KSNVE
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    • v.9 no.5
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    • pp.914-921
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    • 1999
  • There are many theoretical investigations to analyze higher order mode of reactive type single expansion chambers with offset inlet/outlet locations. But the conventional method has the restriction that the ratio between the area of inlet(or outlet) pipe and that of chamber must be natural number. In the paper, a new method was suggested to apply the Kim's method to silencer with circular cross-section. Not only the offset location but also the magnitude of cross-section area of inlet/outlet pipe can be considered by the suggested method. The predictions by this new method also compared with those by the finite element method and Munjal's method in order to verify the accuracy of the suggested method presented here.

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Accurate Computations for Multi-dimensional Flows : Multi-dimensional Higher order Interpolation Scheme (다차원 유동의 정확한 수치해석 : 다차원 고차 내삽 기법)

  • Kim Kyu Hong;Kim Chongam;Rho Oh-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2003.08a
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    • pp.11-17
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    • 2003
  • The new multi-dimensional higher order interpolation scheme called MHIS is developed. Firstly, multi-dimensional TVD condition is derived based on one-dimensional TVD condition. Using multi-dimensional TVD condition, 2nd, 3rd and 5th order MHIS are presented. By help of multi-dimensional TVD condition, it is possible to captured a discontinuity monotonically even in a multi-dimensional flow. It is verified through several test cases that the accuracy and the robustness of MHIS are enhanced in regions of shock discontinuities as well as boundary-layers.

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Implementation of Eigenvalue Analysis Program for Microwave Components Using High Order Vector Elements (고차벡터요소를 사용한 초고주파 소자의 고유치 해석 프로그램 구현)

  • 김형석;김영태
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.6
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    • pp.296-302
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    • 2001
  • In this paper, the vector finite elements are adopted to calculate eigenvalues of RF and microwave components. Simulation results show that spurious are completely avoided because of the divergence free nature of the vector elements. This paper seeks to extend these low-order elements to higher orders to improve the accuracy of numerical solution. Investigation of numerical results for a rectangular waveguide was provided. A vector finite element program was implemented to allow propagation constants and electric field distributions to be directly computed in the rectangular and circular waveguides which are partially filled with the dielectric.

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Dynamic instability and free vibration behavior of three-layered soft-cored sandwich beams on nonlinear elastic foundations

  • Asgari, Gholamreza;Payganeh, Gholamhassan;Fard, Keramat Malekzadeh
    • Structural Engineering and Mechanics
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    • v.72 no.4
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    • pp.525-540
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    • 2019
  • The purpose of the present work was to study the dynamic instability of a three-layered, symmetric sandwich beam subjected to a periodic axial load resting on nonlinear elastic foundation. A higher-order theory was used for analysis of sandwich beams with soft core on elastic foundations. In the higher-order theory, the Reddy's third-order theory was used for the face sheets and quadratic and cubic functions were assumed for transverse and in-plane displacements of the core, respectively. The elastic foundation was modeled as nonlinear's type. The dynamic instability regions and free vibration were investigated for simply supported conditions by Bolotin's method. The results showed that the responses of the dynamic instability of the system were influenced by the excitation frequency, the coefficients of foundation, the core thickness, the dynamic and static load factor. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory.

Analysis of a Marine Propeller in Steady Flow by a Higher-Order Boundary Element Method (고차경계요소법을 이용한 정상 유동중의 프로펠러 해석)

  • K.J. Paik;S.B. Suh;H.H. Chun
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.3
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    • pp.31-40
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    • 2001
  • Low-order panel methods are being used to design marine propellers. Since the potential value over each panel for these methods is assumed to be a constant, the accuracy of prediction is known to be limited. Therefore, a higher order boundary element method(HOBEM) has been studied to enhance the accuracy of prediction. In this paper, a HOBEM representing the body boundary surfaces and physical quantities by a 9-node Lagrangian shape function is employed to analyse the flow around marine propellers in steady potential flow. First, the numerical results for a circular wing with thickness variations are compared with Jordan's linear solution. Then, the computational results of two propellers(DTRC 4119 & DTRC 4842 propeller) are compared with the experimental and numerical results published. The pressure distribution on the surface of the propeller is also compared with experimental data.

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