• Title/Summary/Keyword: cellular-automata

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Climate and Land use Changes Impacts on Hydrology in a Rural Small Watershed (장래 기후변화와 토지이용 변화에 따른 농촌소유역의 수문 영향 분석)

  • Kim, Hak-Kwan;Kang, Moon-Seong;Lee, Eun-Jeong;Park, Seung-Woo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.6
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    • pp.75-84
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    • 2011
  • The objective of this study is to evaluate the hydrologic impacts of climate and land use changes in a rural small watershed. HadCM3 (Hadley Centre Coupled Model, ver.3) A2 scenario and LARS-WG (Long Ashton Research Station - Weather Generator) were used to generate future climatic data. Future land use data were also generated by the CA-Markov (Cellular Automata-Markov) method. The Soil and Water Assessment Tool (SWAT) model was used to evaluate hydrologic impacts. The SWAT model was calibrated and validated with stream flow measured at the Baran watershed in Korea. The SWAT model simulation results agreed well with observed values during the calibration and validation periods. In this study, hydrologic impacts were analyzed according to three scenarios: future climate change (Scenario I), future land use change (Scenario II), and both future climate and land use changes (Scenario III). For Scenario I, the comparison results between a 30-year baseline period (1997~2004) and a future 30-year period (2011~2040) indicated that the total runoff, surface runoff, lateral subsurface runoff, groundwater discharge, and evapotranspiration increased as precipitation and temperature for the future 30-year period increased. The monthly variation analysis results showed that the monthly runoff for all months except September increased compared to the baseline period. For Scenario II, both the total and surface runoff increased as the built-up area, including the impervious surface, increased, while the groundwater discharge and evapotranspiration decreased. The monthly variation analysis results indicated that the total runoff increased in the summer season, when the precipitation was concentrated. In Scenario III, the results showed a similar trend to that of Scenario II. The monthly runoff for all months except October increased compared to the baseline period.

The Simulation of Myocardium Conduction System using DEVCS and Discrete Time CAM (DEVCS 및 Discrete Time CAM을 이용한 심근 전도 시스템의 시뮬레이션)

  • Kim, K.N.;Nam, G.K.;Son, K.S.;Lee, Y.W.;Jun, K.R.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.150-155
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    • 1997
  • Modelling and Simulation of the activation process for the myocardium is meaningful to understand special excitation conduction system in the heart and to study cardiac functions. In this paper, we propose two dimensional cellular automata model for the activation process of the myocardium and simulated by means of discrete time and discrete event algorithm. In the model, cells are classified into anatomically similar characteristic parts of heart; SA node, internodal tracks, AV node, His bundle, bundle branch and four layers of the ventricular muscle, each of which has a set of cells with preassigned properties, that is, activation time, refractory duration and conduction time between neighbor cell. Each cell in this model has state variables to represent the state of the cell and has some simple state transition rules to change values of state variables executed by state transition function. Simulation results are as follows. First, simulation of the normal and abnormal activation process for the myocardium has been done with discrete time and discrete event formalism. Next, we show that the simulation results of discrete time and discrete event cell space model is the same. Finally, we compare the simulation time of discrete event myocardium model with discrete time myocardium models and show that the discrete event myocardium model spends much less simulation time than discrete time myocardium model and conclude the discrete event simulation method Is excellent in the simulation time aspect if the interval deviation of event time is large.

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Cell-based Discrete Event and Discrete Time Simulation for the Prediction of Oil Slick Movement and Spreading in Ocean Environment (해상에서의 원유 확산 과정 예측을 위한 격자 기반 이산 사건 및 이산 시간 시뮬레이션)

  • Ha, Sol;Cha, Ju-Hwan;Ku, Nam-Kug;Lee, Kyu-Yeul
    • Korean Journal of Computational Design and Engineering
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    • v.17 no.1
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    • pp.45-53
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    • 2012
  • In this paper, oil spreading simulation model is proposed for analyzing the oil spreading phenomenon rapidly when the ocean is polluted by the oil from a stranded ship. The space occupied by the ocean is converted into the latticed cell, and the each cell contains the information, such as the quantity of the oil, the temperature of the ocean, and the direction of current and wind. Two states, such as "clean" and "polluted" are defined in the each cell, and the oil in the cell spreads to the neighbor cells by the spreading rules. There are three spreading rules. First, the oil in the certain cell only spreads to the neighbor cells that contain larger oil than the certain cell. Second, the oil evaporates in proportion to the temperature of the ocean at the every time step. Third, the oil spreading property is affected by the direction and the speed of the current and the wind. The oil spreading simulation model of the each cell is defined by using the combined discrete event and discrete time simulation model architecture with the information and the spreading rules in the cell. The oil spreading simulation is performed when the oil of 10,000 kL is polluted in the ocean environment of 300 m by 300 m with various current and wind.

Analysis of Characteristics and Land Use Regulation of Urban Growth Potential Area in Busan Metropolitan City (부산권 도시성장 잠재지역의 특성 및 토지이용규제 실태 분석)

  • KIM, Ho-Yong;KIM, Ji-Sook
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.138-148
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    • 2018
  • Land use regulations introduced for rationalization of land use due to the diversification of socio-economic development, resulting in inconvenience to the people's economic life, have recently changed the paradigm due to deregulation. In this study, the potential areas for urban growth in the Busan area were derived by simulating using the CA model and spatial characteristics were analyzed along with land use regulated areas. The analysis examined whether the land use regulations were actually intended to curb urban growth and promote the efficiency of land use, or if there were other factors that could cause inconvenience to the people's lives. The analysis showed that the greenbelt zones in areas with high development pressure outside urban areas were acting as land use regulations, but there were multiple regulations on land use in many areas. Therefore, it is deemed that various approaches and reviews will be needed, including reconsideration of multiple regulations in areas with high urban growth potential, while maintaining the net function of land use regulations.

Color Image Encryption using MLCA and Transformation of Coordinates (MLCA와 좌표변환을 이용한 컬러 영상의 암호화)

  • Yun, Jae-Sik;Nam, Tae-Hee;Cho, Sung-Jin;Kim, Seok-Tae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1469-1475
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    • 2010
  • This paper presents a problem of existing encryption methods using pseudo-random numbers based on MLCA or complemented MLCA and proposes a method to resolve this problem. The existing encryption methods have a problem which the edge of original image appear on encrypted image because the image have color similarity of adjacent pixels. In this proposed method, we transform the value and spatial coordinates of all pixels by using pseudo-random numbers based on MLCA. This method can resolve the problem of existing methods and improve the level of encryption by encrypting pixel coordinates and pixel values of original image. The effectiveness of the proposed method is proved by conducting histogram and key space analysis.

Generation of Pattern Classifier using LFSRs (LFSR을 이용한 패턴분류기의 생성)

  • Kwon, Sook-Hee;Cho, Sung-Jin;Choi, Un-Sook;Kim, Han-Doo;Kim, Na-Roung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.6
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    • pp.673-679
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    • 2014
  • The important requirements of designing a pattern classifier are high throughput and low memory requirements, and low cost hardware implementation. A pattern classifier by using Multiple Attractor Cellular Automata(MACA) proposed by Maji et al. reduced the complexity of the classification algorithm from $O(n^3)$ to O(n) by using Dependency Vector(DV) and Dependency String(DS). In this paper, we generate a pattern classifier using LFSR to improve efficiently the space and time complexity and we propose a method for finding DV by using the 0-basic path. Also we investigate DV and the attractor of the generated pattern classifier. We can divide an n-bit DS by m number of $DV_i$ s and generate various pattern classifiers.

Design and Implementation of an Integrated CA-GIS System (CA-GIS 통합시스템의 설계와 구현)

  • 박수홍
    • Spatial Information Research
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    • v.9 no.2
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    • pp.185-206
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    • 2001
  • Cellular Automata(CA) have been investigated and utilized as a theoretical framework and/or methodology for analyzing and simulating the properties and behaviors of many complex systems in various physical science and engineering field. Due to the conceptual elegance and effectiveness of implementing spatio-temporal dynamic models and the compatibility with raster GISs, recently a variety of modeling works using both CA and GIS have been published in GIS fields Most of spatial dynamic models introduced in previous research, however, were very limited and furthermore integrated CA-GIS system for practical modeling purpose are not developed yet. This study aims to develop an integrated CA-GIS system in which a CA simulator is used as an analytical engine for GIS providing a multipurpose spatial dynamic modeling functionalities. This integrated CA-GIS system is anticipated radically enhancing the current lacking dynamic modeling functionalities of GIS and being utilized as an powerful and effective tool for practical spatial dynamic modeling research.

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The Effect of Spatial Scale and Resolution in the Prediction of Future Land Use using CA-Markov Technique (면적규모 및 공간해상도가 CA-Markov 기법에 의한 미래 토지이용 예측결과에 미치는 영향)

  • Kim, Seong-Joon;Lee, Yong-Jun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.2
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    • pp.58-70
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    • 2007
  • The purpose of this study is to predict future land use using Landsat images through assessing the effect of spatial scale and resolution in applying CA (Cellular Automata)-Markov technique. The scale for areas ranging from $31.26km^2$ to $84.48km^2$ showed about 11% difference of overall accuracies. Among the five spatial resolutions (10m, 30m, 50m, 100m, 150m), 30m resolution showed the best result in the prediction of area and spatial distribution of urban areas. Based on the results, the 2004 land use by CA-Markov was predicted using 1996 and 2001 land use data and compared with the 2004 land use by maximum likelihood classification. After that, future land uses of 2030, 2060 and 2090 were predicted and the results showed a tendency of gradual increase in urban area and high decrease in forest area.

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Color Image Encryption using MLCA and Bit-oriented operation (MLCA와 비트 단위 연산을 이용한 컬러 영상의 암호화)

  • Yun, Jae-Sik;Nam, Tae-Hee;Cho, Sung-Jin;Kim, Seok-Tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.141-143
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    • 2010
  • This paper presents a problem of the existing encryption method using MLCA or complemented MLCA and propose a method to resolve this problem. With the existing encryption methods, the result of encryption is affected by the original image because of spatial redundancy of adjacent pixels. In this proposed method, we transform spatial coordinates of all pixels into encrypted coordinates. We also encrypt color values of the original image by operating XOR with pseudo-random numbers. This can solve the problem of existing methods and improve the levels of encryption by randomly encrypting pixel coordinates and pixel values of original image. The effectiveness of the proposed method is proved by conducting histogram, key space analysis.

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Multi-directional Pedestrian Model Based on Cellular Automata (CA기반의 다방향 보행자 시뮬레이션 모형개발)

  • Lee, Jun;Bae, Yun-Kyung;Chung, Jin-Hyuk
    • International Journal of Highway Engineering
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    • v.12 no.4
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    • pp.11-16
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    • 2010
  • Various researches have been performed on the topic of pedestrian traffic flow. At the beginning, the modeling and simulation method for the vehicular traffic flow was simply applied to pedestrian traffic flow. Recently, CA based simulation models are frequently applied to pedestrian flow analysis. Initially, the square Lattice Model is a base model for applying to pedestrians of counterflow and then Hexagonal Lattice Model improves its network as a hexagonal cell for more realistic movement of the avoidance of pedestrian conflicts. However these lattice models express only one directional movement because they express only one directional movement. In this paper, MLPM (the Multi-Layer Pedestrian Model) is suggested to give various origins and destinations for more realistic pedestrian motion in some place.