• Title/Summary/Keyword: data modelling

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Optimum chemicals dosing control for water treatment (상수처리 수질제어를 위한 약품주입 자동연산)

  • 하대원;고택범;황희수;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.772-777
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    • 1993
  • This paper presents a neuro-fuzzy modelling method that determines chemicals dosing model based on historical operation data for effective water quality control in water treatment system and calculates automatically the amount of optimum chemicals dosing against the changes of raw water qualities and flow rate. The structure identification in the modelling by means of neuro-fuzzy reasing is performed by Genetic Algorithm(GA) and Complex Method in which the numbers of hidden layer and its hidden nodes, learning rate and connection pattern between input layer and output layer are identified. The learning network is implemented utilizing Back Propagation(BP) algorithm. The effectiveness of the proposed modelling scheme and the feasibility of the acquired neuro-fuzzy network is evaluated through computer simulation for chemicals dosing control in water treatment system.

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Investigation of Concrete Flaw Using Seismic First Arrival (탄성파 초동주시를 이용한 콘크리트 구조물의 결함 탐지)

  • 서백수;장선웅;김석현;서정희
    • Tunnel and Underground Space
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    • v.11 no.2
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    • pp.120-121
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    • 2001
  • The purpose of this study is to investigate concrete flaw using seismic first arrival and various inversion method. Seismic wave propagation was calculated using finite element method in theoretical modelling and tomogram was made using various inversion methods in theoretical and experimental modelling. Five steps of seismic first arrival were selected from FEM results and these data were used to calculate seismic velocity section. According to the results, exact seismic first arrival picking method was proposed and experimental modelling was conducted.

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The AC Power System Development For the Big Wind Farm (대형 풍력 농장에 대한 AC 전력시스템 모델링 개발)

  • Zang, Shuai;Choi, Joon-Ho;Sun, Qitao;Cho, Jung-Sub
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.300-302
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    • 2008
  • This paper will discuss the steps in building a wind farm and the modelling of AC power system for wind power generation. And take the JeJu island for an example, with its good wind power energy resource, the most important factor for a wind farm is a good power system interconnection to decrease the power loss including the transmission loss as less as possible. So in this paper, after the JEJU wind energy analysis, we will mainly discuss the development of the modelling on JEJU AC power system by using PSCAD. And also for using the real data of the wind power in the simulation, the modelling of the JeJu power system in 2011 will also be presented in this paper.

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Performance analysis of a detailed FE modelling strategy to simulate the behaviour of masonry-infilled RC frames under cyclic loading

  • Mohamed, Hossameldeen M.;Romao, Xavier
    • Earthquakes and Structures
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    • v.14 no.6
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    • pp.551-565
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    • 2018
  • Experimental testing is considered the most realistic approach to obtain a detailed representation of the nonlinear behaviour of masonry-infilled reinforced concrete (RC) structures. Among other applications, these tests can be used to calibrate the properties of numerical models such as simplified macro-models (e.g., strut-type models) representing the masonry infill behaviour. Since the significant cost of experimental tests limits their widespread use, alternative approaches need to be established to obtain adequate data to validate the referred simplified models. The proposed paper introduces a detailed finite element modelling strategy that can be used as an alternative to experimental tests to represent the behaviour of masonry-infilled RC frames under earthquake loading. Several examples of RC infilled frames with different infill configurations and properties subjected to cyclic loading are analysed using the proposed modelling approach. The comparison between numerical and experimental results shows that the numerical models capture the overall nonlinear behaviour of the physical specimens with adequate accuracy, predicting their monotonic stiffness, strength and several failure mechanisms.

On the intra-granular behaviour of a cocktail of inert gases in oxide nuclear fuel: Methodological recommendation for accelerated experimental investigation

  • Romano, M.;Pizzocri, D.;Luzzi, L.
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1929-1934
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    • 2022
  • Besides recent progresses in the physics-based modelling of fission gas and helium behaviour, the scarcity of experimental data concerning their combined behaviour (i.e., cocktail) hinders further model developments. For this reason, in this work, we propose a modelling methodology aimed at providing recommendations for accelerated experimental investigations. By exploring a wide range of annealing temperatures and cocktail compositions with a physics-based modelling approach we identify the most interesting conditions to be targeted by future experiments. To corroborate the recommendations arising from the proposed methodology, we include a sensitivity analysis quantifying the impact of the model parameters on fission gas and helium release, in conditions representative of high and low burnup.

Study of nonlinear hysteretic modelling and performance evaluation for piezoelectric actuators based on activation functions

  • Xingyang Xie;Yuguo Cui;Yang Yu
    • Smart Structures and Systems
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    • v.33 no.2
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    • pp.133-143
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    • 2024
  • Piezoelectric (PZT) actuators have been widely used in precision positioning fields for their excellent displacement resolution. However, due to the inherent characteristics of piezoelectric actuators, hysteresis has been proven to greatly reduce positioning performance. In this paper, five mathematical hysteretic models based on activation function are proposed to characterize the nonlinear hysteresis characteristics of piezoelectric actuators. Then the performance of the proposed models is verified by particle swarm optimization (PSO) algorithm and the experiment data. Thirdly, the fitting performance of the proposed models is compared with the classical Bouc-Wen model. Finally, the performance of the five proposed models in modelling hysteresis nonlinearity of piezoelectric drivers is compared, in terms of RMSE, MAPE, SAPE and operation efficiency, and relevant suggestions are given.

PRACTICAL MODELLING OF STONE-COLUMN REINFORCED GROUND

  • Tan By S.A.;Tjahyono S.
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.10a
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    • pp.291-311
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    • 2006
  • The acceleration of consolidation by stone columns was mostly analysed within the framework of a basic unit cell model (i.e. a cylindrical soil body around a column). A method of converting the axisymmetric unit cell into the equivalent plane-strain model would be required for two-dimensional numerical modelling of multi-column field applications. This paper proposes two practical simplified conversion methods to obtain the equivalent plane-strain model of the unit cell, and investigates their applicability to multi-column reinforced ground. In the first conversion method, the soil permeability is matched according to an analytical equation, whereas in the second method, the column width is matched based on the equivalence of column area. The validity of these methods is tested by comparison with the numerical results of unit-cell simulations and with the field data from an embankment case history. The results show that for the case of linear-elastic material modelling, both methods produce reasonably accurate long-term consolidation settlements, whereas for the case of elasto-plastic material modelling, the second method is preferable as the first one gives erroneously lower long-term settlements, where plastic yielding of stone column are ignored.

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Traffic Emission Modelling Using LiDAR Derived Parameters and Integrated Geospatial Model

  • Azeez, Omer Saud;Pradhan, Biswajeet;Jena, Ratiranjan;Jung, Hyung-Sup;Ahmed, Ahmed Abdulkareem
    • Korean Journal of Remote Sensing
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    • v.35 no.1
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    • pp.137-149
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    • 2019
  • Traffic emissions are the main cause of environmental pollution in cities and respiratory problems amongst people. This study developed a model based on an integration of support vector regression (SVR) algorithm and geographic information system (GIS) to map traffic carbon monoxide (CO) concentrations and produce prediction maps from micro level to macro level at a particular time gap in a day in a very densely populated area (Utara-Selatan Expressway-NKVE, Kuala Lumpur, Malaysia). The proposed model comprised two models: the first model was implemented to estimate traffic CO concentrations using the SVR model, and the second model was applied to create prediction maps at different times a day using the GIS approach. The parameters for analysis were collected from field survey and remote sensing data sources such as very-high-resolution aerial photos and light detection and ranging point clouds. The correlation coefficient was 0.97, the mean absolute error was 1.401 ppm and the root mean square error was 2.45 ppm. The proposed models can be effectively implemented as decision-making tools to find a suitable solution for mitigating traffic jams near tollgates, highways and road networks.

Improved Radial Sweep Algorithm for 3-dimensional Terrain Modelling (3차원 지형 모델링을 위한 개선된 Radial Sweep 알고리즘)

  • Ryoo, Seung-Taek;Ahn, Chung-Hyun;Yoon, Kyung-Hyun
    • Journal of Korean Society for Geospatial Information Science
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    • v.5 no.2 s.10
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    • pp.77-85
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    • 1997
  • Researches in the field of Computer Graphics and Geographical Information Systems(GIS) have extensively studied the method of photo-realistic landscape modelling, because it have become a commom requirement in applications such as flight simulators, mission rehearsal, and construction planning. A common approach to the display of terrain uses a Digital Elevation Model(DEM). DEM is an evenly spaced array of the terrain elevation data and can be obtained from stereo satellite data. With the DEM data, the process of 3D terrain modelling consists of three steps. The first step is to extract the meaningful data (such as peak, pit, passes...) from DEM data based on LOD(Level Of Detail) criteria. The second is to construct the 3D surface by TIN, which represents a surface as a set of non-overlapping continuous triangular facets of irregular size and shape. The third is a rendering of 3D terrain model. The goal of this research is a construction of 3D terrain with TIN. To do this, we are going to app]y Radial Sweep Algorithm. Radial Sweep Algorithm for generating TIN works quickly and efficiently. However, it does not solve the problem caused by the approximated nature of triangulated surface. To solve this problem, this research derive improved radial sweep algorithms with the optimal triangle definition.

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Fuzzy Modelling and Fuzzy Controller Design with Step Input Responses and GA for Nonlinear Systems (비선형 시스템의 계단 입력 응답과 GA를 이용한 퍼지 모델링과 퍼지 제어기 설계)

  • Lee, Wonchang;Kang, Geuntaek
    • Journal of the Korean Institute of Intelligent Systems
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    • v.27 no.1
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    • pp.50-58
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    • 2017
  • For nonlinear control system design, there are many studies based on TSK fuzzy model. However, TSK fuzzy modelling needs nonlinear dynamic equations of the object system or a data set fully distributed in input-output space. This paper proposes an modelling technique using only step input response data. The technique uses also the genetic algorithm. The object systems in this paper are nonlinear to control input variable or output variable. In the case of nonlinear to control input, response data obtained with several step input values are used. In the case of nonlinear to output, step input response data and zero input response data are used. This paper also presents a fuzzy controller design technique from TSK fuzzy model. The effectiveness of the proposed techniques is verified with numerical examples.