• Title/Summary/Keyword: System modelling

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Seismic Response Analysis of Bridges Using Equivalent Linear Soil/Foundation Spring Model (등가선형 지반스프링모델을 사용한 교량의 지진응답해석)

  • 박형기
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.372-380
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    • 2000
  • Seismic forces for member design of bridges may be determined by modifying elastic member forces induced by design earthquakes using appropriate response modification factors according to national design code of bridges. Modeling of soil/foundation system is one of the critical parameter in the process of elastic seismic analysis of bridge system which greatly affects on the analysis results. In this paper, a simplified modelling procedure of soil/foundation system which gives practically reasonable results is presented and its applicability has been validated through example bridge. Based on the results, it has been shown that the procedure is acceptable in modelling soil/foundation system for practical seismic analysis of bridges.

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Simulations of the Performance Factors on Vacuum System

  • Kim, Hyung-Taek
    • International journal of advanced smart convergence
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    • v.6 no.4
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    • pp.1-8
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    • 2017
  • In this work, the effects of fairly influential factors on performance of vacuum system, such as constant pressure and outgassing effect were simulated to propose the optimum design factors. Outgassing effects of selected vacuum materials on the vacuum characteristics were simulated by the $VacSim^{Multi}$ simulation tool. This investigation examined the feasibility of reliably simulating the outgassing characteristics of common vacuum chamber materials (aluminum, copper, stainless steel, nickel plated steel, Viton A). The optimum design factors for vacuum systems were suggested based on the simulation results. And, the effects of throttle valve applications on vacuum characteristics were also simulated to obtain the optimum design model of variable conductance on high vacuum system. Simulated vacuum characteristics of the proposed modelling were agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve were schematized as the modelling of throttle valve for the constant process-pressure. Simulation results were plotted as pump-down curve of chamber and variable conductance of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably.

Video Data Modeling for Supporting Structural and Semantic Retrieval (구조 및 의미 검색을 지원하는 비디오 데이타의 모델링)

  • 복경수;유재수;조기형
    • Journal of KIISE:Databases
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    • v.30 no.3
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    • pp.237-251
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    • 2003
  • In this paper, we propose a video retrieval system to search logical structure and semantic contents of video data efficiently. The proposed system employs a layered modelling method that orBanifes video data in raw data layer, content layer and key frame layer. The layered modelling of the proposed system represents logical structures and semantic contents of video data in content layer. Also, the proposed system supports various types of searches such as text search, visual feature based similarity search, spatio-temporal relationship based similarity search and semantic contents search.

Theoretical Analysis in an Automotive Engine Cooling System (자동차용 엔진 냉각시스템의 이론적 해석)

  • Youn, Jong-Gap;Song, Seung-Hoon;Won, Sung-Pil
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.213-219
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    • 2000
  • In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, city-drive mode, and hill-climb mode by theoretical modeling of each component and numerical analysis. The modelling components are engine, radiator, heater, thermostat, water-pump, and cooling-fan. And also it has been developed the simulation program that can be used in case of design and system configuration changes. The comparison has not been made to verify the results of this work with experimental data, but the overall tendencies were agreed well with those of actual situation in four modes.

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Mode analysis of end-milling process by recursive parametric modelling (순환 파라메트릭 모델링에 의한 엔드밀 시스템의 모드 분석)

  • Kim, T.H.;Kim, J.D.
    • Journal of the Korean Society of Mechanical Technology
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    • v.13 no.3
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    • pp.73-79
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    • 2011
  • In this study, an analytical realization of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive least square modelling algorithm and the natural mode for real part and imaginary one was discussed. This recursive approach (RLSM) can be adopted for on-line end-milling identification. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF (Frequency response function) and mode analysis. Also the FRF was analysed for the prediction of a end-milling system using recursive algorithm.

The Effects of Tasks Setting for Mathematical Modelling in the Complex Real Situation (실세계 상황에서 수학적 모델링 과제설정 효과)

  • Shin, Hyun-Sung;Lee, Myeong-Hwa
    • Journal of the Korean School Mathematics Society
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    • v.14 no.4
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    • pp.423-442
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    • 2011
  • The purpose of this study was to examine the effects of tasks setting for mathematical modelling in the complex real situations. The tasks setting(MMa, MeA) in mathematical modelling was so important that we can't ignore its effects to develop meaning and integrate mathematical ideas. The experimental setting were two groups ($N_1=103$, $N_2=103$) at public high school and non-experimental setting was one group($N_3=103$). In mathematical achievement, we found meaningful improvement for MeA group on modelling tasks, but no meaningful effect on information processing tasks. The statistical method used was ACONOVA analysis. Beside their achievement, we were much concerned about their modelling approach that TSG21 had suggested in Category "Educational & cognitive Midelling". Subjects who involved in experimental works showed very interesting approach as Exploration, analysis in some situation ${\Rightarrow}$ Math. questions ${\Rightarrow}$ Setting models ${\Rightarrow}$ Problem solution ${\Rightarrow}$ Extension, generalization, but MeA group spent a lot of time on step: Exploration, analysis and MMa group on step, Setting models. Both groups integrated actively many heuristics that schoenfeld defined. Specially, Drawing and Modified Simple Strategy were the most powerful on approach step 1,2,3. It was very encouraging that those experimental setting was improved positively more than the non-experimental setting on mathematical belief and interest. In our school system, teaching math. modelling could be a answer about what kind of educational action or environment we should provide for them. That is, mathematical learning.

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A Study on the Development of Computer Aided Design System for Fixed Offshore Structures (고정식 해양구조물의 전산기 지원 설계시스템 개발에 관한 연구)

  • Sin, Hyeon-Gyeong;Park, Gyu-Won
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.83-88
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    • 1995
  • In this paper, the solid modeller suitable for PC was developed for Top-down 3-D representation and analysis of fixed offshore structures. Also solid modelling and hidden line removal were conducted in order to visualize the offshore structures based on the scan line z-buffer algorithm.

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Neural Network Modelling and Computer Simulation of the Local Circuits of the Outer Plexiform Layer in a Vertebrate Retina (망막 외망층의 국부회로에 대한 신경망 모델 및 컴퓨터 모의실험)

  • 이일병
    • Journal of Biomedical Engineering Research
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    • v.9 no.1
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    • pp.17-24
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    • 1988
  • This paper describes a neural network modelling of a vertebrate retina using a discrete-time and discrete-space approach based on neuro-anatomical data, and the computer simulations of the model which approximate the frog/amphibian negro-physiological data. It then compares them and describes how such a model can be beneficially used for confirming the hypothesis of a given neural system and further predict yet unknown experimental data.

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GA-based Fuzzy Modelling of Nonlinear Systems (비선형시스템의 유전알고리즘에 기초한 퍼지 모델링)

  • 이현식;진강규
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.10a
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    • pp.368-373
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    • 1998
  • This paper presents a GA-based fuzzy modelling scheme of nonlinear systems. The fuzzy model is a type of the Sugeno-Tagaki's fuzzy model whose consequence parts are described by a linear continuous dynamic equation as subsystem of a nonlinear system. The centers and width of the membership functions of the fuzzy sets defined over the input space and the orders and parameters of subsystems in the consequence parts are adjusted by a genetic algorithm. The effectiveness of the proposed method is verified

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A STUDY ON THE DIMENSIONAL ACCURACY OF MODELS USING 3-DIMENSIONAL COMPUTER TOMOGRAPHY AND 2 RAPID PROTOTYPING METHODS

  • Cho Lee-Ra;Park Chan-Jin;Park In-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.39 no.6
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    • pp.633-640
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    • 2001
  • Statement of problem. Relatively low success rate of root analogue implant system was supposed to be due to the time duration between extraction and implant installation. The use of three-dimensional computer tomography and the reconstruction of objects using rapid prototyping methods would be helpful to shorten this time. Purpose. This aim of this study was to evaluate the application possibility of the 3-dimensional computer tomography and the rapid prototyping to root analogue implants. Material and methods. Ten single rooted teeth were prepared. Width and height of the teeth were measured by the marking points. This was followed by CT scanning, data conversion and rapid prototyping model fabrication. 2 methods were used; fused deposition modelling and stereolithography. Same width and height of this models were measured and compared to the original tooth. Results. Fused deposition modelling showed an enlarged width and reduced height. The stereolithography showed more exact data compared with the fused deposition modelling. Smaller standard deviation were recorded in the stereolithographic method. Overall width error from tooth to rapid prototyping was 7.15% in fused deposition modelling and 0.2% in stereolithography. Overall height showed the tendency of reducing dimensions. Conclusion. From the results of this study, stereolithography seems to be very predictable method of fabricating root analogue implant.

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