• Title/Summary/Keyword: Dynamic method

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The dynamic response prediction of the structure by transient vibration using Semi-Empirical Method (준 경험적 방법을 이용한 충격성 진동에 대한 구조물의 동적 응답의 예측)

  • Lee, Hong-Ki;Baek, Jae-Ho;Kim, Kang-Boo;Woun, Young-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1945-1950
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    • 2000
  • When one build a building that posses Precison production process to be sensitive to vibration and SMD to procuce a large dynamic force, how do one predict & answer vibration control problem at building structure design at first stage, That is a question. It has tried to predict dynamic response and establish answering about global or local dynamic problem in building using experimental and analysis method. One of such a try, it be proposed Semi-Empirial Method that reduce error element of input information about dynamic analysis using dynamic experimental study and measurement data in the basis of real-structure. In this paper, the dynamic response problem about RC-structure building that will be set-up SMD produce large transient dynamic force using Semi-Empirical Method.

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A Genetic Algorithm for Dynamic Job Shop Scheduling (동적 Job Shop 일정계획을 위한 유전 알고리즘)

  • 박병주;최형림;김현수;이상완
    • Journal of the Korean Operations Research and Management Science Society
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    • v.27 no.2
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    • pp.97-109
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    • 2002
  • Manufacturing environments in the real world are subject to many sources of change and uncertainty, such as new job releases, job cancellations, a chance in the processing time or start time of some operation. Thus, the realistic scheduling method should Properly reflect these dynamic environment. Based on the release times of jobs, JSSP (Job Shoe Scheduling Problem) can be classified as static and dynamic scheduling problem. In this research, we mainly consider the dynamic JSSP with continually arriving jobs. The goal of this research is to develop an efficient scheduling method based on GA (Genetic Algorithm) to address dynamic JSSP. we designed scheduling method based on SGA (Sing1e Genetic Algorithm) and PGA (Parallel Genetic Algorithm) The scheduling method based on GA is extended to address dynamic JSSP. Then, This algorithms are tested for scheduling and rescheduling in dynamic JSSP. The results is compared with dispatching rule. In comparison to dispatching rule, the GA approach produces better scheduling performance.

NUMERICAL ANALYSIS OF DYNAMIC CONTACT ANGLE PROBLEMS IN ELECTROWETTING WITH LEVEL SET METHOD (레벨셋 기법을 이용한 전기습윤 현상의 동적 접촉각 문제에 대한 수치해석)

  • Park, J.K.;Kang, K.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.155-158
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    • 2009
  • We developed a numerical method to analyze the contact-line problems, incorporating a dynamic contact angle model. We used level set method to capture free surface. The method is applied to the analysis of dynamic behavior of a droplet in DC electrowetting. The result is compared with an experimental data and result of perturbation method.

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Dynamic Response Analysis of Cylindrical Shell with Axisymmetric Loading (축대칭 하중을 받는 원통형 셸의 동적응답 해석)

  • Choi, Myung-Soo;Yeo, Dong-Jun
    • Journal of Power System Engineering
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    • v.17 no.6
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    • pp.33-39
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    • 2013
  • It is very important to analyze the dynamic responses of the shell structures from the viewpoint of the design of shell structures with a variety of axisymmetric loadings. In this paper, the computational algorithm for the dynamic response analysis of an cylindrical shell with axisymmetric loading is formulated by the transfer mass coefficient method based on the transfer of mass coefficient. After the computational programs for obtaining the dynamic responses of cylindrical shells with axisymmetric loading are made by the transfer mass coefficient method and the finite element method, the computational results by both methods are compared. From the computational results, we can confirm that the transfer mass coefficient method has the effectiveness in the dynamic response analyses of cylindrical shells with a variety of axisymmetric loadings.

Development of Transfer Function Separation Method for Experimental Dynamic Modification of Mounted System (마운트계의 실험적 설계변경을 위한 전달함수분리법의 개발)

  • 정의봉;조영희
    • Journal of KSNVE
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    • v.7 no.5
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    • pp.847-852
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    • 1997
  • Many investigations about the dynamic analysis of the structural system based on the BBA(Building Block Approach) method which predict dynamic characteristics of synthesized structures from each structure. But it is actually sometimes difficult to remove mounts from structures. In this paper, TFSM(The Transfer Function Separation Method) is developed which can predict dynamic characteristics of separated structures from the data of vibrational experiment of the synthesized structures. By combining TFSM with BBA, this paper also proposes the method which can predict dynamic characteristics of mount-modified structure without removing mounts from structures. And the proposed method is verified by the experimental data of plates.

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REVIEW OF VARIOUS DYNAMIC MODELING METHODS AND DEVELOPMENT OF AN INTUITIVE MODELING METHOD FOR DYNAMIC SYSTEMS

  • Shin, Seung-Ki;Seong, Poong-Hyun
    • Nuclear Engineering and Technology
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    • v.40 no.5
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    • pp.375-386
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    • 2008
  • Conventional static reliability analysis methods are inadequate for modeling dynamic interactions between components of a system. Various techniques such as dynamic fault tree, dynamic Bayesian networks, and dynamic reliability block diagrams have been proposed for modeling dynamic systems based on improvement of the conventional modeling methods. In this paper, we review these methods briefly and introduce dynamic nodes to the existing reliability graph with general gates (RGGG) as an intuitive modeling method to model dynamic systems. For a quantitative analysis, we use a discrete-time method to convert an RGGG to an equivalent Bayesian network and develop a software tool for generation of probability tables.

Dynamic analysis of non-symmetric FG cylindrical shell under shock loading by using MLPG method

  • Ferezghi, Yaser Sadeghi;Sohrabi, Mohamad R.;MosaviNezhad, Seyed M.
    • Structural Engineering and Mechanics
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    • v.67 no.6
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    • pp.659-669
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    • 2018
  • The Dynamic equations in the polar coordinates are drawn out using the MLPG method for the non-symmetric FG cylindrical shell. To simulate the mechanical properties of FGM, the nonlinear volume fractions for radial direction are used. The shape function applied in this paper is a form of the radial basis functions, by using this function all the requirements for an effective and suitable shape function are established. Hence in this study, the multiquadrics (MQ) radial basis functions are exploited as the shape function governing the problem. The MLPG method is combined with the the Newmark time approximation scheme to solve dynamic equations in the time domain. The obtained results by the MLPG method to be verified are compared with the analytical solution and the FEM. The obtained results through the MLPG method show a good agreement in comparison to other results and the MLPG method has high accuracy for dynamic analysis of the non-symmetric FG cylindrical shell. To demonstrate the capability of the present method to dynamic analysis of the non-symmetric FG cylindrical shell, it is analyzed dynamically with different volume fraction exponents under harmonic and rectangular shock loading. The present method shows high accuracy, efficiency and capability to dynamic analysis of the non-symmetric FG cylindrical shell with nonlinear grading patterns.

An Effective Frequency Allocation Plan for Symmetric 10MDSL Systems (양방향 10MDSL을 위한 VDSL 시스템의 주파수할당 계획)

  • Kil, Jung-Su;Kwon, Ho-Yeol
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.169-173
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    • 2002
  • In this paper, we discussed an effective VDSL frequency plan for symmetric 10MDSL service. The frequency plan 998 and plan 997 for asymmetric VDSL services have been not optimally designed for 10MDSL services. To obtain the reaches and data rates of 10MDSL, we proposed two frequency allocation schemes : Static method and dynamic method. We can select frequency bands with their fixed boundaries in static method while with their variable boundaries in dynamic method. To show the effectiveness of our proposed methods, we performed some simulations about plan 997 and plan 998, new static method, and new dynamic method. According to the simulation results, the proposed dynamic method can provide the best data rates and reaches for 10 Mbps symmetric VDSL services.

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A Study on the Analysis of Stochastic Nonlinear Dynamic System (확률적 비선형 동적계의 해석에 관한 연구)

  • 남성현;김호룡
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.3
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    • pp.697-704
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    • 1995
  • The dynamic characteristics of a system can be critically influenced by system uncertainty, so the dynamic system must be analyzed stochastically in consideration of system uncertainty. This study presents the stochastic model of a nonlinear dynamic system with uncertain parameters under nonstationary stochastic inputs. And this stochastic system is analyzed by a new stochastic process closure method and moment equation method. The first moment equation is numerically evaluated by Runge-Kutta method and the second moment equation is numerically evaluated by stochastic process closure method, 4th cumulant neglect closure method and Runge-Kutta method. But the first and the second moment equations are coupled each other, so this equations are approximately evaluated by a iterative method. Finally the accuracy of the present method is verified by Monte Carlo simulation.

A Study on Dynamic Behaviors of Steel Plate Girder bridge with Applying External Post-Tensioning Method (외부 후긴장 공법 적용에 따른 무도상 판형교의 동적거동 분석)

  • Choi, Dong-Ho;Choi, Jung-Youl;Choi, Jun-Hyeok;Park, Yong-Gul
    • Journal of the Korean Society for Railway
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    • v.9 no.2 s.33
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    • pp.160-168
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    • 2006
  • The major objective of this study is to investigate the effects and application of external post-tensioning method far steel plate girder bridge. It analyzed the mechanical behaviors of steel plate girder bridge with applying external post-tensioning on the finite element analysis, field test and laboratory test fur the lateral dynamic characteristics. As a result, the reinforcement of steel plate girder bridge the external post-tensioning method are obviously effective for the lateral dynamic response which is non-reinforced. The analytical and experimental study are carried out to investigate the post-tension force decrease lateral acceleration and deflection on steel plate girder bridge for serviceability. And the external post-tensioning method reduce dynamic maximum displacement(about $10{\sim}24%$), the increase of dynamic safety is predicted by adopting external post-tensioning method. From the dynamic test results of the servicing steel plate girder bridge, it is investigated that the change degree of natural frequency is very low with applying the external post-tensioning method The servicing steel plate girder bridge with external post-tensioning has need of the reasonable reinforcement measures which could be reducing the effect of lateral dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.