• Title/Summary/Keyword: Iterative Calculation

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Nonlinear Iterative Solution for Adhesively Bonded Tubular Single Lap Joints with Nonlinear Shear Properties (튜브형 단면겹치기 접착조인트의 비선형 반복연산해에 관한 연구)

  • 이수정;이대길
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.7
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    • pp.1651-1656
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    • 1995
  • The adhesively bonded tubular single lap joint shows large nonlinear behavior in the loaddisplacement relation, because structural adhesives for the joint are usually rubber toughened, which endows adhesives with nonlinear shear properties. since the majority of load transfer of the adhesively bonded tubular single lap joint is accomplished by the nonlinear behavior of the adhesive, its torque transmission capability should be calculated incorporating nonlinear shear properties. However, both the analytic and numerical analyses become complicated if the nonlinear shear properties of the adhesive are included during the calculation of torque transmission capabilities. In this paper, in order to obtain the torque transmission capabilities easily, an iterative solution which includes the nonlinear shear properties of the adhesive was derived using the analytic solution with the linear shear properties of the adhesive. Since the iterative solution can be obtained very fast due to its simplicity, it has been found that it can be used in the design of the adhesively bonded tubular single lap joint.

MOM-Based Born Iterative Method for Medical Microwave Imaging (의용 전자파 영상을 위한 MoM 기반 Born 반복법의 적용)

  • Son, Jae-Gi;Kim, Bo-Ra;Lee, Taek-Kyung;Son, Seong-Ho;Jeon, Soon-Ik;Lee, Jae-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.4
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    • pp.524-532
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    • 2012
  • In this paper, we used MOM-based BIM(Born Iterative Method) algorithm to implement the inverse scattering for the detection of cancer. We adopted two-dimensional breast structure, integral equations and two-dimensional Green's function is solved with MoM(Method of Moment) to analyzing electromagnetic scattering phenomena. In addition, verifying the calculation of developed inverse scattering algorithm and analyzing medical applicability and limitations of the algorithm.

A comparative study on the iterative eigenvalue calculation method in AESOPS algorithm and Newton Raphson Method (AESOPS 알고리즘의 고유치 반복계산식과 Newton Raphson법과의 비교연구)

  • Kim, Deok-Young;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.259-262
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    • 1998
  • This paper presents a new eigenvalue calculation methods in AESOPS algorithm. The source program of the AESOPS algorithm is modified to practice in PC environment. Window95 is used as an operating system of PC and MicroSoft Power Station is used to compile the fortran source program. The heuristically approximated eigenvalue calculation method of the AESOPS algorithm is transformed to the Newton Raphson Method which is largely used in the nonlinear numerical analysis. The new methods are developed from the AESOPS algorithm and thus only a few calculation steps are added to practice the proposed algorithm.

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Dosimetric Effects of Low Dose 4D CT Using a Commercial Iterative Reconstruction on Dose Calculation in Radiation Treatment Planning: A Phantom Study

  • Kim, Hee Jung;Park, Sung Yong;Park, Young Hee;Chang, Ah Ram
    • Progress in Medical Physics
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    • v.28 no.1
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    • pp.27-32
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    • 2017
  • We investigated the effect of a commercial iterative reconstruction technique (iDose, Philips) on the image quality and the dose calculation for the treatment plan. Using the electron density phantom, the 3D CT images with five different protocols (50, 100, 200, 350 and 400 mAs) were obtained. Additionally, the acquired data was reconstructed using the iDose with level 5. A lung phantom was used to acquire the 4D CT with the default protocol as a reference and the low dose (one third of the default protocol) 4D CT using the iDose for the spine and lung plans. When applying the iDose at the same mAs, the mean HU value was changed up to 85 HU. Although the 1 SD was increased with reducing the CT dose, it was decreased up to 4 HU due to the use of iDose. When using the low dose 4D CT with iDose, the dose change relative to the reference was less than 0.5% for the target and OARs in the spine plan. It was also less than 1.1% in the lung plan. Therefore, our results suggests that this dose reduction technique is applicable to the 4D CT image acquisition for the radiation treatment planning.

On the Thick Axisymmetric Boundary Layer and Wake Around the Body of Revolution (몰수분의 두꺼운 경계층 및 반류해석)

  • Gang, Sin-Hyeong;Hyeon, Beom-Su;Lee, Yeong-Gil
    • 한국기계연구소 소보
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    • s.9
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    • pp.141-151
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    • 1982
  • An iterative procedure for the calculation of the thick axisymmetric boundary layer and wake near the stern of a body of revolution is presented. Procedure consists of the potential flow calculation by a method of the integral equation of first kind and the calculation of boundary layer and wake by a differential me¬thod of the boundary layer theory. Additionally, higher order terms are included in the conventional momentum equations and continuity equation for the consider¬ation of the characteristics of axisymmetric flow different from the one of two dimentional flow and the thick boundary layer. These solutions are matched at the edge of boundary layer and wake. The results obtained by the present me¬thod are compared with the experimental data and it is found that the nominal wake distribution at the propeller plane of a axisymmetric body is in good agree¬ment with the experiment.

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A Modified Fault Distance Calculation in the Power Quality Monitoring System (전기품질 모니터링 시스템에서의 사고거리계산 알고리즘)

  • Kang, Hyun-Gu;Chung, Il-Yop;Won, Dong-Jun;Moon, Seung-Il
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.167-168
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    • 2006
  • This paper proposes a new fault distance calculation method in the power quality (PQ) monitoring system. The proposed method calculates the fault impedance and the fault distance based on the measurement data of the PQ monitors and the information of the topology of the distribution systems. By using the iterative calculation method, the proposed method can find more exact location of the PQ events than the existing methods. The proposed method is applied to the IEEE 34 bus test feeders by using the PSCAD/EMTDC$^{TM}$.

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An Eigenvalue Sensitivity Analysis of the Iterative Eigenvalue Calculation Algorithm (반복계산에 의한 고유치 계산 알고리즘에서의 고유치 감도해석)

  • Kim, Deok-Young
    • Proceedings of the KIEE Conference
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    • 2001.07a
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    • pp.217-219
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    • 2001
  • This paper presents a new eigenvalue sensitivity analysis method based on AESOPS algorithm. The additional calculation steps are derived from the original AESOPS algorithm. The additional calculation steps are performed directly from the AESOPS algorithm after iteratively calculating electro-mechanical oscillation modes in small signal stability problems. Owing to the structural characteristics of partitioned sub-matrix of state space equations, the partial differentiation terms of system state matrix for obtaining eigenvalue sensitivity indices can be calculated very simply. By the method presented in this paper, the AESOPS algorithm can be used in controller design problem as well as analysis of small signal stability problem.

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Reasonably completed state assessment of the self-anchored hybrid cable-stayed suspension bridge: An analytical algorithm

  • Kai Wang;Wen-ming Zhang;Jie Chen;Zhe-hong Zhang
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.159-175
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    • 2024
  • In order to solve the problem of calculating the reasonable completed bridge state of a self-anchored hybrid cable-stayed suspension bridge (SA-HCSB), this paper proposes an analytical method. This method simplifies the main beam into a continuous beam with multi-point rigid supports and solves the support reaction forces. According to the segmented catenary theory, it simultaneously solves the horizontal forces of the main span main cables and the stay cables and iteratively calculates the equilibrium force system on the main beam in the collaborative system bridge state while completing the shape finding of the main span main cable and stay cables. Then, the horizontal forces of the side span main cables and stay cables are obtained based on the balance of horizontal forces on the bridge towers, and the shape finding of the side spans are completed according to the segmented catenary theory. Next, the difference between the support reaction forces of the continuous beam with multiple rigid supports obtained from the initial and final iterations is used to calculate the load of ballast on the side span main beam. Finally, the axial forces and strains of each segment of the main beam and bridge tower are obtained based on the loads applied by the main cable and stay cables on the main beam and bridge tower, thereby obtaining analytical data for the bridge in the reasonable completed state. In this paper, the rationality and effectiveness of this analytical method are verified through a case study of a SA-HCSB with a main span of 720m in finite element analysis. At the same time, it is also verified that the equilibrium force of the main beam under the reasonably completed bridge state can be obtained through iterative calculation. The analytical algorithm in this paper has clear physical significance, strong applicability, and high accuracy of calculation results, enriching the shape-finding method of this bridge type.

Accelerating Numerical Analysis of Reynolds Equation Using Graphic Processing Units (그래픽처리장치를 이용한 레이놀즈 방정식의 수치 해석 가속화)

  • Myung, Hun-Joo;Kang, Ji-Hoon;Oh, Kwang-Jin
    • Tribology and Lubricants
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    • v.28 no.4
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    • pp.160-166
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    • 2012
  • This paper presents a Reynolds equation solver for hydrostatic gas bearings, implemented to run on graphics processing units (GPUs). The original analysis code for the central processing unit (CPU) was modified for the GPU by using the compute unified device architecture (CUDA). The red-black Gauss-Seidel (RBGS) algorithm was employed instead of the original Gauss-Seidel algorithm for the iterative pressure solver, because the latter has data dependency between neighboring nodes. The implemented GPU program was tested on the nVidia GTX580 system and compared to the original CPU program on the AMD Llano system. In the iterative pressure calculation, the implemented GPU program showed 20-100 times faster performance than the original CPU codes. Comparison of the wall-clock times including all of pre/post processing codes showed that the GPU codes still delivered 4-12 times faster performance than the CPU code for our target problem.