• Title/Summary/Keyword: Automatic Modelling

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Development of a General-Purpose Program for Automatic Finite-Element Modelling with Quadrilateral Finite Elements (사각형 유한요소 해석모델의 자동생성 프로그램의 개발)

  • Joun, M.S.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.1
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    • pp.157-165
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    • 1994
  • A general-purpose program for automatic two-dimensional finite-element modelling with quadrilateral elements was developed in this research. The conventional looping method employed in the program was introduced with emphasis on a new splitting criterion and a splitting scheme developed for improving the method. Some application examples were given, which show versatility and applicability of the developed program.

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Parameter Optimization of QUAL2K Using Influence Coefficient Algorithm and Genetic Algorithm (영향계수법과 유전알고리즘을 이용한 QUAL2K 모형의 매개변수 최적화)

  • Cho, Jae-Heon;Lee, Chang-Hun
    • Journal of Environmental Impact Assessment
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    • v.18 no.2
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    • pp.99-109
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    • 2009
  • In general, manual calibration is commonly used for the stream water quality modelling. Because the manual calibration depends upon the subjectivity and experience of the researcher, it has a problem with the objectivity of the modelling. Thus, the interest about the automatic calibration by the optimization technique is deeply increased. In this study, Influence coefficient algorithm and Genetic algorithm are introduced to develop an automatic calibration model for the QUAL2K that are the latest version of the QUAL2E. Genetic algorithm, used in this study, is very simple and easy to understand but also applicable to any complicated mathematical problem, and it can find out the global optimum solution effectively. The developed automatic calibration model is applied to the Gangneung Namdaecheon. The calibration results about the 11 water quality variables show the good correspondence between the calculated and observed water quality values.

An Approach for the Automatic Box-Jenkins Modelling

  • Park, Sung-Joo;Hong, Chang-Soo;Jeon, Tae-Joon
    • Journal of Korean Institute of Industrial Engineers
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    • v.10 no.1
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    • pp.17-25
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    • 1984
  • The use of Box-Jenkins technique is still very limited due to the high level of knowledge required in comprehending the technique and the cumbersome iterative procedure which requires a large amount of cost and time. This paper proposes a method of automating the univariate Box-Jekins modelling to overcome the limitations of subjective identification in iterative procedure by using Variate Difference method, D-statistic and Pattern Recognition algorithm combined with Akaike's Information Criterion. The results of the application to real data show that the average performance of automatic modelling procedure is better or not worse, at least, than those of the existing models which have been manually set up and reported in the literature.

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궤도차량용 자동변속기의 변속조향동특성 해석

  • 송창섭
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1996.03a
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    • pp.67-71
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    • 1996
  • The dynamic equation is built by the mathematical modelling. The modelling is composed of various components used for the automatic transmission of tracked vehicles. When the transmission is shifting, the shock occurs in the drivetrain. The transient torques affect the durability and reliability of the vehicle. The factor and design point are analyzed for the transmission.

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Extension of the VSACF for Modelling Seasonal Time Series (계절적 시계열 모형화를 위한 VSACF 의 확장)

  • 전태준
    • Journal of the Korean Operations Research and Management Science Society
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    • v.16 no.1
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    • pp.68-75
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    • 1991
  • The purpose of this thesis is to develop the new technique for the analysis of seasonal time series by extending the vector sample auto-correlation function(VSACF), which was developed for ARMA modelling procedure. After the problems of VSACF for modelling seasonal time series are investigated, the adjacent variance is defined and used for decomposing the seasonal factor from the seasonal time series. The seasonal indices are calculated and the VSACF is applied to the transformed series. The automatic procedure for modelling seasonal time series is suggested and applied to the real data, the international airline passenger travel.

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An Artificial Neural Networks Application for the Automatic Detection of Severity of Stator Inter Coil Fault in Three Phase Induction Motor

  • Rajamany, Gayatridevi;Srinivasan, Sekar
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2219-2226
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    • 2017
  • This paper deals with artificial neural network approach for automatic detection of severity level of stator winding fault in induction motor. The problem is faced through modelling and simulation of induction motor with inter coil shorting in stator winding. The sum of the absolute values of difference in the peak values of phase currents from each half cycle has been chosen as the main input to the classifier. Sample values from workspace of Simulink model, which are verified with experiment setup practically, have been imported to neural network architecture. Consideration of a single input extracted from time domain simplifies and advances the fault detection technique. The output of the feed forward back propagation neural network classifies the short circuit fault level of the stator winding.

A study on An Application for Ensuring Safety of Computer Based Automatic Train Control System (컴퓨터기반 자동열차제어장치의 안전성 확보에 관한 연구)

  • Lee jongwoo;SHIN jongwoo
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.54 no.6
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    • pp.261-268
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    • 2005
  • This paper propose the safety design of automatic train control system which is used for controlling and monitoring train speed not to excess a permitted speed. Safety activities are shown for the computerized system to achieve a required safety requirement. The safety activities are composed of system dynamic modelling to identify potential hazards contained in the target system, to analyze sub system faults to provoke the hazards. Risks analysis are carried out to estimate losses caused from the hazards to allocate safety requirement. We Proposed design solutions for sub system to meet safety requirement.

A study on the control strategy for automatic adjustment of ITC(Integrated Tube Components) (ITC 자동조정을 위한 제어기법에 관한 연구)

  • 김성락;이종운;변증남;장태규
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.935-938
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    • 1991
  • We are developing an automatic adjusting system for ITC. ITC(Integrated Tube Components) has a large set-by-set variability in its characteristics. And it also has nonlinearities. It requires not only a fast vision process but also an efficient control algorithm to meet the need for high productivity. In this paper, the description of an adjusting system and the modelling of ITC will be presented. And also the concept of a new rule based hierarchical algorithmic approaches will be suggested.

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Comparison of the fit of automatic milking system and test-day records with the use of lactation curves

  • Sitkowska, B.;Kolenda, M.;Piwczynski, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.3
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    • pp.408-415
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    • 2020
  • Objective: The aim of the paper was to compare the fit of data derived from daily automatic milking systems (AMS) and monthly test-day records with the use of lactation curves; data was analysed separately for primiparas and multiparas. Methods: The study was carried out on three Polish Holstein-Friesians (PHF) dairy herds. The farms were equipped with an automatic milking system which provided information on milking performance throughout lactation. Once a month cows were also subjected to test-day milkings (method A4). Most studies described in the literature are based on test-day data; therefore, we aimed to compare models based on both test-day and AMS data to determine which mathematical model (Wood or Wilmink) would be the better fit. Results: Results show that lactation curves constructed from data derived from the AMS were better adjusted to the actual milk yield (MY) data regardless of the lactation number and model. Also, we found that the Wilmink model may be a better fit for modelling the lactation curve of PHF cows milked by an AMS as it had the lowest values of Akaike information criterion, Bayesian information criterion, mean square error, the highest coefficient of determination values, and was more accurate in estimating MY than the Wood model. Although both models underestimated peak MY, mean, and total MY, the Wilmink model was closer to the real values. Conclusion: Models of lactation curves may have an economic impact and may be helpful in terms of herd management and decision-making as they assist in forecasting MY at any moment of lactation. Also, data obtained from modelling can help with monitoring milk performance of each cow, diet planning, as well as monitoring the health of the cow.

A Study on the Evaluation of Automatic Steering System of Ships in Folowing Seas (추사파중을 항행하는 선박의 자동조타 시스템 평가에 관한 연구)

  • 이경우;손경호
    • Journal of the Korean Institute of Navigation
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    • v.25 no.4
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    • pp.407-415
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    • 2001
  • In the present study, irregular disturbances to ship dynamics is proposed, where irregular disturbances implying irregular wave and the fluctuating component of wind for the evaluation of automatic steering system of ship in following seas. Prediction method based on the principle of linear superposition. Irregular wave disturbances in following seas is calculated by frequency variation method. The mathematical model of each element of an automatic steering system is derived, which takes account of a few non-linear mechanisms. PD(Proportional-Derivative) controller and low-pass filter with a weather adjustment are adopted to modelling the characteristics of an autopilot. Performance index is introduced from the viewpoint of energy saving, which derived from the concept of energy loss on ship propulsion. Finally, the present methods are applied to two typical types of ship ; an ore carrier and a fishing boat. The various effects of control constants of autopilot on propulsive energy loss are investigated

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