• Title/Summary/Keyword: model update

Search Result 649, Processing Time 0.026 seconds

Model Updating of a Car Body Structure Using a Generalized Free-Interface Mode Sensitivity Method (일반화 자유경계 모드 감도법을 이용한 차체구조물의 모델개선)

  • Jang, Gyeong-Jin;Park, Yeong-Pil
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.24 no.5 s.176
    • /
    • pp.1133-1145
    • /
    • 2000
  • It is necessary to develop an efficient analysis method to identify the dynamic characteristics of a large mechanical structure and update its finite element model. That is because these processes need the huge computation of a large structure and iterative estimation due to the use of the first- order sensitivity. To efficiently carry out these processes, a new method, called the generalized free-interface mode sensitivity method, has been proposed in the authors' preceeding paper. This method is based on substructuring approach such as a free-interface method and a generalized synthesis algorithm. In this paper, the proposed method is applied to the model updating of a car body structure to verify its accuracy and reliability for a large mechanical structure.

Advanced Process Control of the Critical Dimension in Photolithography

  • Wu, Chien-Feng;Hung, Chih-Ming;Chen, Juhn-Horng;Lee, An-Chen
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.9 no.1
    • /
    • pp.12-18
    • /
    • 2008
  • This paper describes two run-to-run controllers, a nonlinear multiple exponential-weight moving-average (NMEWMA) controller and a dynamic model-tuning minimum-variance (DMTMV) controller, for photolithography processes. The relationships between the input recipes (exposure dose and focus) and output variables (critical dimensions) were formed using an experimental design method, and the photolithography process model was built using a multiple regression analysis. Both the NMEWMA and DMTMV controllers could update the process model and obtain the optimal recipes for the next run. Quantified improvements were obtained from simulations and real photolithography processes.

Experimental Modal Analysis for Understanding Dynamic Characteristics of Bus Full BIW Assembly (버스차체 동특성 파악을 위한 실험 모드해석)

  • Lee, Joon-Ho;Kim, Gyeong-Ho;Park, Mi-You;Kim, Kyoung-Won;Song, Kyoung-Ho;Park, Youn-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2002.11a
    • /
    • pp.314.2-314
    • /
    • 2002
  • It is necessary first to understand dynamic characteristics of a bus full BIW assembly for fatigue endurance analysis. FE model has been used usually for analyzing the dynamic behavior of structures. A lot of experience and effort, however, is necessary to make a credible FE model. Experimental modal analysis of structures has been performed to verify the credibility of initial FE model and to update the model. (omitted)

  • PDF

The Ground Vibration Test on an Aircraft and FE Model Update (항공기 지상 진동 시험 및 동특성 모델의 개선)

  • 유홍주;변관화;박금룡
    • Journal of KSNVE
    • /
    • v.8 no.4
    • /
    • pp.690-699
    • /
    • 1998
  • This paper discusses the techniques, procedures and the results of the ground vibration test(GVT) performed on the development aircraft and the simple procedure of FE model updating technique from the GVT results. The GVT was carried out using random excitation technique with MIMO(Multi-Input-Multi-Output) data acquistion method, and taking full advantage of poly-reference global parameter estimation technique to identify the vibration modes. In dynamic FE modeling, the aircraft was represented by beam elements and all dynamic analysis was performed using MSC/NASTRAN for this model. In updating procedure, the stiffness of the beam model was adjusted iteratively so as to get the natural frequencies and mode shapes close to the GVT results.

  • PDF

SOx Process Simulation, Monitoring, and Pattern Classification in a Power Plant (발전소에서의 SOx 공정 모사, 모니터링 및 패턴 분류)

  • 최상욱;유창규;이인범
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.8 no.10
    • /
    • pp.827-832
    • /
    • 2002
  • We propose a prediction method of the pollutant and a synchronous classification of the current state of SOx emission in the power plant. We use the auto-regressive with exogeneous (ARX) model as a predictor of SOx emission and use a radial basis function network (RBFN) as a pattem classifier. The ARX modeling scheme is implemented using recursive least squares (RLS) method to update the model parameters adaptively. The capability of SOx emission monitoring is utilized with the application of the RBFN classifier. Experimental results show that the ARX model can predict the SOx emission concentration well and ARX modeling parameters can be a good feature for the state monitoring. in addition, its validity has been verified through the power spectrum analysis. Consequently, the RBFN classifier in combination with ARX model is shown to be quite adequate for monitoring the state of SOx emission.

Design and Application of Term Project Model for Game Mathematics in Flipped Learning Environments (플립드러닝 환경에서 게임수학 텀프로젝트 모형 설계 및 적용)

  • Choi, Youngmee
    • Journal of Korea Multimedia Society
    • /
    • v.20 no.7
    • /
    • pp.1102-1112
    • /
    • 2017
  • The purpose of this study is to design and application of term project model for Game Math in flipped learning environment. In the term project self study model, students interacts with multi-instruction materials and multi-tutors on flipped learning. We develop a case for game update term project and implement it to a real Game Math classroom. As a result, we show the positive learning experiences focused on effects of technology and human relation through survey.

Multi-Objective Optimization Using Kriging Model and Data Mining

  • Jeong, Shin-Kyu;Obayashi, Shigeru
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.7 no.1
    • /
    • pp.1-12
    • /
    • 2006
  • In this study, a surrogate model is applied to multi-objective aerodynamic optimization design. For the balanced exploration and exploitation, each objective function is converted into the Expected Improvement (EI) and this value is used as fitness value in the multi-objective optimization instead of the objective function itself. Among the non-dominated solutions about EIs, additional sample points for the update of the Kriging model are selected. The present method was applied to a transonic airfoil design. Design results showed the validity of the present method. In order to obtain the information about design space, two data mining techniques are applied to design results: Analysis of Variance (ANOVA) and the Self-Organizing Map (SOM).

Developing a Model to Explain the Process of Technology Transfer at Entrepreneurial University

  • Soleimani, Mohsen;Tabriz, Akbar Alem;Shavarini, Sohrab Khalili
    • Industrial Engineering and Management Systems
    • /
    • v.15 no.4
    • /
    • pp.298-306
    • /
    • 2016
  • The gap between universities, scientific centers and industrial-production units is one of higher education concerns. In academic entrepreneurship, the university work simultaneously in education, research and entrepreneurship. The universities play a key and important role in providing educational opportunities in economic development. This research aims to develop and expand science as well as help managers to explain the process of technology transfer in entrepreneurial university. This research is applied-developmental type and on the other hand, data driven theories have been used in this study. Current model is generally tried to meanwhile compensate previous shortcomings, include some strengths such as considering domestic factors of Iran as well as update effective factors on the process of technology transfer. Finally the suggested model has been compared with existing well-known models that each one of those models have some drawbacks which have been tried to be minimized in suggested model as much as possible.

Sequential Adaptation Algorithm Based on Transformation Space Model for Speech Recognition (음성인식을 위한 변환 공간 모델에 근거한 순차 적응기법)

  • Kim, Dong-Kook;Chang, Joo-Hyuk;Kim, Nam-Soo
    • Speech Sciences
    • /
    • v.11 no.4
    • /
    • pp.75-88
    • /
    • 2004
  • In this paper, we propose a new approach to sequential linear regression adaptation of continuous density hidden Markov models (CDHMMs) based on transformation space model (TSM). The proposed TSM which characterizes the a priori knowledge of the training speakers associated with maximum likelihood linear regression (MLLR) matrix parameters is effectively described in terms of the latent variable models. The TSM provides various sources of information such as the correlation information, the prior distribution, and the prior knowledge of the regression parameters that are very useful for rapid adaptation. The quasi-Bayes (QB) estimation algorithm is formulated to incrementally update the hyperparameters of the TSM and regression matrices simultaneously. Experimental results showed that the proposed TSM approach is better than that of the conventional quasi-Bayes linear regression (QBLR) algorithm for a small amount of adaptation data.

  • PDF

Analysis of Vibration and Electromagnetic Forces on a Generator End-winding for 500 MW Fossil Power Plant (500MW 급 대형 발전기 권선단부의 전자기력과 동특성 해석)

  • 김철홍;주영호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.11b
    • /
    • pp.826-831
    • /
    • 2001
  • Electromagnetic forces generate vibrations in the end-winding of large generators. A finite element analysis using a commercial S/W is performed to calculate electromagnetic force of end-winding in two pole generator for 500 MW fossil power plant. Also, this paper presents analytical and experimental modal analysis results of generator end- winding. Using validated FE model, 3D electromagnetic model which computes the forces on the end-winding is coupled with a 3D mechanical model which calculates the dynamic displacement and stress under electromagnetic forces. These results will be used to evaluate reliability of end-winding and applied to update model.

  • PDF