• Title/Summary/Keyword: Modelling Experiment

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Design of the Mathematics Curriculum through Mathematical Modelling (수학적 모델링을 통한 교육과정의 구성원리)

  • 신현성
    • Journal of the Korean School Mathematics Society
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    • v.4 no.2
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    • pp.27-32
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    • 2001
  • The paper describes some principles how we design the mathematics curriculum through mathematical Modelling. since the motivation for modelling is that it give us a cheap and rapid method of answering illposed problem concerning the real world situations. The experiment was focussed on the possibility that they can involved in modelling problem sets and carry modelling process. The main principles could be described as follows. principle 1. we as a teacher should introduce the modelling problems which have many constraints at the begining situation, but later eliminate those constraints possibly. principle 2. we should avoid the modelling real situations which contain the huge data collection in the classroom, but those could be involved in the mathematics club and job oriented problem solving. principle 3. Analysis of modelling situations should be much emphasized in those process of mathematics curriculum principle 4. As a matter of decision, the teachers should have their own activities that do mathematics curriculum free. principle 5. New strategies appropriate in solving modelling problem could be developed, so that these could contain those of polya's heusistics

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Verification Experiment and Analysis for 6 kW Solar Water Heating System(Part 2 : Modelling and Simulation) (6 kW급 태양열 온수급탕 시스템의 실증실험 및 분석(제2보 모델링 및 시뮬레이션))

  • 최봉수;김진홍;강용태;홍희기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.6
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    • pp.556-565
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    • 2004
  • We have experimented an actual solar water heating system acquiring real data for one year period. On the basis of the operation data, it is necessary to predict the system performance such as collector efficiency and solar fraction, and to analyze the economical efficiency for system optimal design. To estimate the performance of actual systems through simulation, valid modelling for components consisting of the system should be accompanied. The present study is focused on the modelling for load patterns and operating control conditions. We proposed two load models: concentration model which gathers real loads as a meaningful group and distribution model which disperses real loads with time. If grouping of the load distribution is suitable, the predicted values by the concentration model approaches to those by the distribution model close to actual load pattern apparently. As a result, both of them are in good agreement with those by experiment.

Centrifuge Modelling of Bridge Abutment Foundation on the Sloped Ground (경사지반에 위치한 교대기초의 원심모델링)

  • Yoo, Nam-Jae;Jun, Sang-Hyun;Hong, Young-Kil
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.209-214
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    • 2007
  • This paper is the research result about centrifuge model experiments of investigating the behavior of bridge abutment on the sloped ground. Ground condition of the studied site was the bridge abutment with pile foundation adjacent to the slope. The pile foundations was supported on the soft rocks covered with the embankment. Evaluating the behavior of such a complicate ground and structure conditions was not easy so that the centrifuge modelling was performed to find the overall behavior of them. Layout of centrifuge model experiment was simplified to simulate easily the actual behavior of very complicate site condition. Construction process in field such as ground excavation for footing foundation, installation of piles, placement of footing and bridge abutment, backfilling and surcharge loading eas duplicated in the centrifuge model experiment. Consequently, the stability of the piled bridge abutment adjacent to the slope of embankment was evaluated throughout centrifuge modelling.

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The Modelling and Characteristic Analysis of Brushless Synchronous Motor with Sinusoidal back EMF (정현파 역기전력 특성을 갖는 브러시리스 동기전동기의 모델링 및 특성해석)

  • Kim, Il-Nam;Baek, Su-Hyeon;Kim, Cheol-Jin;Maeng, In-Jae;Yun, Sin-Yong
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.6
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    • pp.380-386
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    • 2000
  • This paper presents the mathematical modelling analysis of Brushless Synchronous Motor(BLSM). The dynamic and the steady state characteristics of BLSM are simulated and analyzed : electromagnetic torque, speed, line voltage, and current. We used mathematical modelling to model of BLSM with sinusoidal back EMF, namely the shaft transformation referencing rotor frame from a, b, c three to produce constant torque like synchronous motor. The experiment result has already similar to compare with simulation result : torque error about 7%, speed error about 5%. The validity of proposed modelling and analysis was confirmed by the experimental result.

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An Experimental Study of Forming Process Development in Large Nozzle-Shaped Product Using the Incremental Forging Method for Expanding (점진적 팽창단조법에 의한 대형 노즐형제품의 성형공정 개발에 관한 실험적 연구)

  • Park, C.Y.;Yang, D.Y.;Lee, K.H.;Eun, I.S.
    • Transactions of Materials Processing
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    • v.3 no.1
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    • pp.110-119
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    • 1994
  • In this paper, a new forming process of large-size forgings of converged nozzle-shape is developed by the experimental study using the incremental forging method and combined forming method. The development of the forming process is focused on the manufacturing of large-size forgings by the press with medium load capacity. Various related processes are proposed and modelling experiments using plasticine are carried out. Thus, the incremental forging method for expanding is recommanded from the study of formability and forming load, etc. The selected process is then subjected to modelling experiments of lead and the design parameters such as preform for final process, die-width of the upper die and reduction amount of each stroke are determined. In order to verify the effectiveness of the selected process, 1/7 scale prototype experiment of the real material is carried out. Forgings of converged nozzle shape can be produced by the developed process within the limit loads and with the simple tools.

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IMPLEMENTATION OF GIS BASED WATER QUALITY INDICES FOR WATER QUALITY MANAGEMENT

  • Song, Ta-O;Kim, Kye-Hyun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.612-615
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    • 2007
  • Water quality modelling is an ideal tool of simulating physical, chemical and biological changes occurring in water systems. It has been utilized in a number of GIS-based water quality management and analysis applications. However, there is a need of a decision making process to translate the modelling result into an understandable form thereby implement the modelling results to the real world. This paper outlines a new water quality index called the QUAL2E's water quality index (QWQI) based on the water quality modelling using QUAL2E. The development mainly includes four steps: variable selection, sub-index development, weight assignment and sub-index aggregation. An experiment of applying the index and GIS to the Sapgyo River in Korea was implemented. Different from other water quality indices for general water uses, the index is specifically used for the simulated water quality indicators. The index can provide a simple and easy-to-understand decision support. Furthermore, interfacing with GIS, the decision analysis can be performed within a spatial environment. However, more study needs to be made in the future including the improvement of aggregation function.

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Finite element modelling of GFRP reinforced concrete beams

  • Stoner, Joseph G.;Polak, Maria Anna
    • Computers and Concrete
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    • v.25 no.4
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    • pp.369-382
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    • 2020
  • This paper presents a discussion of the Finite Element Analysis (FEA) when applied for the analysis of concrete elements reinforced with glass fibre reinforced polymer (GFRP) bars. The purpose of such nonlinear FEA model development is to create a tool that can be used for numerical parametric studies which can be used to extend the existing (and limited) experiment database. The presented research focuses on the numerical analyses of concrete beams reinforced with GFRP longitudinal and shear reinforcements. FEA of concrete members reinforced with linear elastic brittle reinforcements (like GFRP) presents unique challenges when compared to the analysis of members reinforced with plastic (steel) reinforcements, which are discussed in the paper. Specifically, the behaviour and failure of GFRP reinforced members are strongly influenced by the compressive response of concrete and thus modelling of concrete behaviour is essential for proper analysis. FEA was performed using the commercial software ABAQUS. A damaged-plasticity model was utilized to simulate the concrete behaviour. The influence of tension, compression, dilatancy, mesh, and reinforcement modelling was studied to replicate experimental test data of beams previously tested at the University of Waterloo, Canada. Recommendations for the finite element modelling of beams reinforced with GFRP longitudinal and shear reinforcements are offered. The knowledge gained from this research allows for the development of a rational methodology for modelling GFRP reinforced concrete beams, which subsequently can be used for extensive parametric studies and the formation of informed recommendations to design standards.

A Study on the Torque Control Method of a Hydraulic Actuation System for Measuring the Dynamic Stiffness of Missile Fin Actuators (유도무기용 날개구동기의 동적 강성 측정을 위한 유압 구동장치의 토크제어 기법에 관한 연구)

  • Lee, Ho-Sung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.3
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    • pp.181-188
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    • 2007
  • This paper presents a torque control method of a hydraulic actuation system for measuring the dynamic stiffness of missile fin actuators. We propose a new control technique called Dual Dynamic Torque Feedback Control(DDTFC), which improves the stability of the torque control system and enables fast tracking of torque command. The developed control scheme is derived from the physical understanding based on mathematical modelling and analysis. The dynamics of hydraulic torque control servo-system is unravelled via physics-based modelling and nonparametric system identification. In order to verify the effectiveness of the method, the experiment is carried out with a test equipment for measuring the dynamic stiffness. The experiment and simulation results show that DDTFC gives stability improvement.

Laboratory experiment on the assessment of the ground strength with corestone (실내실험을 통한 핵석지반의 강도정수 산정연구)

  • 이수곤;김동은;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.95-102
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    • 2003
  • Corestone rock mass has complex characters because it is made up of stronger and stiffer corestone in a weaker and softer matrix. Physical model corestone rock mass made up of stiffer corestone in weaker matrix were tested in uniaxial compression and numercal modelling analysis The result of the uniaxial compression tests showed that increasing the corestone proportion generally increased the modulus of deformation. And the strength decreased in the lower corestone proportion, but it increased in the higher proportion(45%, 65% corestone by volume). The strength and the modulus of deformation were not affected by different size coretone on the same proportion. The result of the numerical modelling analysis showed similar trend compared with the result of the result of the uniaxial compression test. But though the result of th uniaxial compression test is similar to the result of the numerical modelling analysis, it's unreasonalble to apply the results of this paper to in situ corestone rock mass. So mere laboratory tests including triaxial test and the other numerical program analyses are necessary to apply the results to in situ corestone mass

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