• Title/Summary/Keyword: Computer experiments

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Distributed Simulator for General Control System in CEMTool

  • Lee, Tai-Ri;Lee, Young-Sam;Lee, Kwan-Ho;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2230-2234
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    • 2003
  • This paper proposes a distributed simulator for general control system in CEMTool. Systems can be described by SIMTool likes the simulink in Matlab. For distributed simulation, we can seperate any system into several parallel subsystems in SIMTool. The number of parallel subsystem can be determined by the system's property. After seperation, parallel simulator will do initialization, one-step-ahead simulation, block-distribution and ordering and so on. Finally, simulator will create independent C codes and executive files for each subsystem. The whole system is fulfilled by several PCs, and each PC executes one subsystem. There are communications among these subsystem using reflective memory or ethernet. We have made several experiments, and the 5-stand cold rolling mill control system is our main target. The result of parallel simulation has shown effective speedup in comparison with one pc simulation.

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Extension of Fast Level Set Method with Relationship Matrix, Modified Chan-Vese Criterion and Noise Reduction Filter

  • Vu, Dang-Tran;Kim, Jin-Young;Choi, Seung-Ho;Na, Seung-You
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.3E
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    • pp.118-135
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    • 2009
  • The level set based approach is one of active methods for contour extraction in image segmentation. Since Osher and Sethian introduced the level set framework in 1988, the method has made the great impact on image segmentation. However, there are some problems to be solved; such as multi-objects segmentation, noise filtering and much calculation amount. In this paper we address the drawbacks of the previous level set methods and propose an extension of the traditional fast level set to cope with the limitations. We introduce a relationship matrix, a new split-and-merge criterion, a modified Chan-Vese criterion and a novel filtering criterion into the traditional fast level set approach. With the segmentation experiments we evaluate the proposed method and show the promising results of the proposed method.

An Improved Saliency Detection for Different Light Conditions

  • Ren, Yongfeng;Zhou, Jingbo;Wang, Zhijian;Yan, Yunyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.3
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    • pp.1155-1172
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    • 2015
  • In this paper, we propose a novel saliency detection framework based on illumination invariant features to improve the accuracy of the saliency detection under the different light conditions. The proposed algorithm is divided into three steps. First, we extract the illuminant invariant features to reduce the effect of the illumination based on the local sensitive histograms. Second, a preliminary saliency map is obtained in the CIE Lab color space. Last, we use the region growing method to fuse the illuminant invariant features and the preliminary saliency map into a new framework. In addition, we integrate the information of spatial distinctness since the saliency objects are usually compact. The experiments on the benchmark dataset show that the proposed saliency detection framework outperforms the state-of-the-art algorithms in terms of different illuminants in the images.

Wine Quality Assessment Using a Decision Tree with the Features Recommended by the Sequential Forward Selection

  • Lee, Seunghan;Kang, Kyungtae;Noh, Dong Kun
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.2
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    • pp.81-87
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    • 2017
  • Nowadays wine is increasingly enjoyed by a wider range of consumers, and wine certification and quality assessment are key elements in supporting the wine industry to develop new technologies for both wine making and selling processes. There have been many attempts to construct a more methodical approach to the assessment of wines, but most of them rely on objective decision rather than subjective judgement. In this paper, we propose a data mining approach to predict human wine taste preferences that is based on easily available analytical tests at the certification step. We used sequential forward selection and decision tree for this purpose. Experiments with the wine quality dataset from the UC Irvine Machine Learning Repository demonstrate the accuracies of 76.7% and 78.7% for red and white wines respectively.

Tank Level Control using Fuzzy Inference Technique (퍼지추론기법을 이용한 탱크 레벨 제어)

  • Ji, Seok-Jun;Jeon, Pu-Chan;Park, Doo-Hwan;Lee, Joon-Tark
    • Proceedings of the KIEE Conference
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    • 1997.07b
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    • pp.724-727
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    • 1997
  • This paper describes a control method of tank level using Fuzzy Inference Technique. In General, to control tank level without a dangerous overflow and with a high accuracy is difficult because of high order time delay and nonlinearity. None the less, the hardware controller using 80586 Microprocessor with DT-2801 board in this paper was successfully implemented, through a series of simulations and experiments, the superiority of the proposed fuzzy controller ta a conventional PID one was investigated.

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Comparison of Image Classification Performance by Activation Functions in Convolutional Neural Networks (컨벌루션 신경망에서 활성 함수가 미치는 영상 분류 성능 비교)

  • Park, Sung-Wook;Kim, Do-Yeon
    • Journal of Korea Multimedia Society
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    • v.21 no.10
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    • pp.1142-1149
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    • 2018
  • Recently, computer vision application is increasing by using CNN which is one of the deep learning algorithms. However, CNN does not provide perfect classification performance due to gradient vanishing problem. Most of CNN algorithms use an activation function called ReLU to mitigate the gradient vanishing problem. In this study, four activation functions that can replace ReLU were applied to four different structural networks. Experimental results show that ReLU has the lowest performance in accuracy, loss rate, and speed of initial learning convergence from 20 experiments. It is concluded that the optimal activation function varied from network to network but the four activation functions were higher than ReLU.

Unsupervised Segmentation of Images Based on Shuffled Frog-Leaping Algorithm

  • Tehami, Amel;Fizazi, Hadria
    • Journal of Information Processing Systems
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    • v.13 no.2
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    • pp.370-384
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    • 2017
  • The image segmentation is the most important operation in an image processing system. It is located at the joint between the processing and analysis of the images. Unsupervised segmentation aims to automatically separate the image into natural clusters. However, because of its complexity several methods have been proposed, specifically methods of optimization. In our work we are interested to the technique SFLA (Shuffled Frog-Leaping Algorithm). It's a memetic meta-heuristic algorithm that is based on frog populations in nature searching for food. This paper proposes a new approach of unsupervised image segmentation based on SFLA method. It is implemented and applied to different types of images. To validate the performances of our approach, we performed experiments which were compared to the method of K-means.

The effects of Germanium concentration and Hydrogen loading time on the growth of fiber Bragg grating (Ge 도핑농도와 수소처리시간 변화가 광섬유격자 형성에 미치는 영향)

  • Song, J.H.;Lee, J.H.;Song, J.T.;Lee, K.S.;Lee, Y.S.;Jeon, C.O.;Jeon, K.I.
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.993-995
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    • 1998
  • We fabricated fiber gratings with three different Ge-doped fibers exposed to 60atm pressure of Hz gas at 90"C for different times and studied the effects of Ge-doping concentration and $H_2$ loading time on the growth of gratings. According to experiments. the growing effect of hydrogen loading on high Ge-doped fiber was great.

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Normalization Framework of BCI-based Facial Interface

  • Sung, Yunsick;Gong, Suhyun
    • Journal of Multimedia Information System
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    • v.2 no.3
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    • pp.275-280
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    • 2015
  • Recently brainwaves are utilized diversely in the field of medicine, entertainment, education and so on. In the case of medicine, brainwaves are analyzed to estimate patients' diseases. However, the applications for entertainments usually utilize brainwaves as control signal without figuring out the characters of the brainwaves. Given that users' brainwaves are different each other, a normalization method is essential. The traditional brainwave normalization approaches utilize normal distribution. However, those approaches assume that brainwaves are collected enough to conduct normal distribution. When the few amounts of brainwaves are measured, the accuracy of the control signal based on the measured brainwaves becomes low. In this paper, we propose a normalization framework of BCI-based facial interfaces for novel volume controllers, which can normalizes the few amounts of brainwaves and then generates the control signals of BCI-based facial interfaces. In the experiments, two subjects were involved to validate the proposed framework and then the normalization processes were introduced.

Computer simulation for the performance analysis of automobile air conditioning system (자동차용 에어컨 시스템의 성능해석을 위한 컴퓨터 시뮬레이션)

  • 이건호;유정열;정종대;최규환
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.2
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    • pp.202-216
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    • 1998
  • A computer simulation for the performance analysis of automobile air conditioning components is carried out for the various operating conditions. The automobile air conditioning system consists of laminated type evaporator, swash plate type compressor, parallel flow type condenser, externally equalized thermostatic expansion valve and receiver drier. The overall heat transfer coefficient and the pressure drop in laminated type evaporator were obtained through experiments. In parallel flow type condenser, the performance analysis computer program using the empirical equation for heat transfer coefficient has been developed and the results are compared with experimental results. A model for matching the performance analysis programs of respective components .of automobile air conditioning system is introduced. Further, the effects of varying condenser size and refrigerant charge on the performance of automobile air conditioning system are discussed clearly.

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