• 제목/요약/키워드: Spatial Pattern Evolution

검색결과 30건 처리시간 0.023초

혼잡교통류 관리를 위한 동적 용량의 개념 및 산정방법 (Dynamic Capacity Concept and its Determination for Managing Congested Flow)

  • 박은미
    • 대한교통학회지
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    • 제22권3호
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    • pp.159-166
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    • 2004
  • 도로용량편람에서 정의하고 있는 용량은 하류부에 용량을 제한하는 요소가 없다는 것을 가정한 정상교통류에 대한 용량 개념으로서, 이는 전통적으로 계획, 설계, 현재 및 장래 도로시설의 운영상태 분석 등에 사용되어 왔다. 실시간 제어는, 용량을 초과하지 않는 교통류를 유지시켜 혼잡교통류로의 전이를 막고, 물리적 여건이나 제반 확률적 요인으로 혼잡이 발생하였을 경우 조속히 용량이하로 교통량을 떨어뜨려 정상교통류로 회복시키는 데 목표를 둔다. 이러한 맥락에서 용량은 실시간 제어의 효과를 좌우하는 중요한 입력변수이며, 정상교통류 상태라면 혼잡으로 전이되지 않을 임계치로서의 용량 산정이 중요한 관건이다. 그러나 혼잡교통류 상태에서 정상교통류로 되도록 빨리 회복시켜 주기 위한 제어 기준으로서의 용량은, 하류부 혼잡의 시공간적 전개에 따라 변하는 값이어야 하며 이러한 동적 용량변화를 정확히 예측할 수 있는 방법론이 요구된다. 이에 본 연구에서는 기존의 용량 개념을 출력 개념의 용량으로 정의하고, 입력 개념의 용량을 최대가능처리량(Maximum Sustainable Throughput)으로 새롭게 정의하였다. 이 최대가능처리량은 혼잡의 시공간적 전개에 따라 결정되는 동적 용량이며, 이러한 혼잡의 시공간적 전개는 Newell의 단순화된 교통량-밀도 모형으로 예측할 것을 제안하였다.

EOF와 CSEOF를 이용한 한반도 강수의 변동성 분석 (Investigation of Korean Precipitation Variability using EOFs and Cyclostationary EOFs)

  • 김광섭;순밍동
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.1260-1264
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    • 2009
  • Precipitation time series is a mixture of complicate fluctuation and changes. The monthly precipitation data of 61 stations during 36 years (1973-2008) in Korea are comprehensively analyzed using the EOFs technique and CSEOFs technique respectively. The main motivation for employing this technique in the present study is to investigate the physical processes associated with the evolution of the precipitation from observation data. The twenty-five leading EOF modes account for 98.05% of the total monthly variance, and the first two modes account for 83.68% of total variation. The first mode exhibits traditional spatial pattern with annual cycle of corresponding PC time series and second mode shows strong North South gradient. In CSEOF analysis, the twenty-five leading CSEOF modes account for 98.58% of the total monthly variance, and the first two modes account for 78.69% of total variation, these first two patterns' spatial distribution show monthly spatial variation. The corresponding mode's PC time series reveals the annual cycle on a monthly time scale and long-term fluctuation and first mode's PC time series shows increasing linear trend which represents that spatial and temporal variability of first mode pattern has strengthened. Compared with the EOFs analysis, the CSEOFs analysis preferably exhibits the spatial distribution and temporal evolution characteristics and variability of Korean historical precipitation.

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Spatial Characteristics and Driving Forces of Cultivated Land Changes by Coupling Spatial Autocorrelation Model and Spatial-temporal Big Data

  • Hua, Wang;Yuxin, Zhu;Mengyu, Wang;Jiqiang, Niu;Xueye, Chen;Yang, Zhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권2호
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    • pp.767-785
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    • 2021
  • With the rapid development of information technology, it is now possible to analyze the spatial patterns of cultivated land and its evolution by combining GIS, geostatistical analysis models and spatiotemporal big data for the dynamic monitoring and management of cultivated land resources. The spatial pattern of cultivated land and its evolutionary patterns in Luoyang City, China from 2009 to 2019 were analyzed using spatial autocorrelation and spatial autoregressive models on the basis of GIS technology. It was found that: (1) the area of cultivated land in Luoyang decreased then increased between 2009 and 2019, with an overall increase of 0.43% in 2019 compared to 2009, with cultivated land being dominant in the overall landscape of Luoyang; (2) cultivated land holdings in Luoyang are highly spatially autocorrelated, with the 'high-high'-type area being concentrated in the border area directly north and northeast of Luoyang, while the 'low-low'-type area is concentrated in the south and in the municipal area of Luoyang, and being heavily influenced by topography and urbanization. The expansion determined during the study period mainly took place in the Luoyang City, with most of it being transferred from the 'high-low'-type area; (3) elevation, slope and industrial output values from analysis of the bivariate spatial autocorrelation and spatial autoregressive models of the drivers all had significant effects on the amount of cultivated land holdings, with elevation having a positive effect, and slope and industrial output having a negative effect.

서울 영상산업 클러스터의 공간적 특성: 영화산업과 방송산업의 성장과 집적지 변화 (Spatial Characteristics of Media Cluster in Seoul: Co-Evolution and Changes in Film and Broadcast TV Production)

  • 이경원;서우석
    • 한국경제지리학회지
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    • 제26권3호
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    • pp.202-222
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    • 2023
  • 본 연구는 서울의 영화산업과 방송산업 공간분포를 분석하고 집적지 변화에 작용하는 산업 성장과 도시 특성에 주목하여 서울 영상산업 클러스터의 공간적 특성을 파악하고자 한다. 1994년, 2004년, 2014년, 2021년의 서울시 사업체 조사를 분석자료로, 산업의 성장을 확인하고 공간적 자기상관성 분석(Moran's I와 LISA분석)을 수행해 영상산업의 공간분포와 집적지 변화를 확인했다. 또한 현직 종사자 인터뷰의 질적자료 수집과 분석으로 영상산업의 현황과 집적지 형성 요인 등을 파악하여 종합적인 분석을 시도했다. 분석 결과 영화산업과 방송산업 집적지는 서울에 분산되어 다핵형태로 성장하고 있다. 1994년에 영화산업 집적지는 충무로와 강남, 방송산업은 여의도로 집적지 구분이 뚜렷했던 반면, 2021년에는 마포와 강남이 영화산업과 방송산업의 공통 집적지로 나타났다. 그 외 여의도, 강서-영등포 일대의 방송산업 집적지와 성수 일대의 영화산업 집적지가 확인되었다. 끝으로 본 연구에서는 서울의 영상산업 성장과 공간적 분포 변화에 작용한 요인들을 영상산업의 특성과 도시환경의 변화와 연관시켜 제시하였다.

MAGNETIC RECONNECTION IN SHEARED SOLAR MAGNETIC ARCADES

  • CHOE G. S.
    • 천문학회지
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    • 제29권spc1호
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    • pp.303-305
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    • 1996
  • The evolution of solar magnetic arcades is investigated with the use of MHD simulations imposing resistivity on sheared magnetic fields. It is found that there is a critical amount of shear, over which magnetic reconnection can take place ill an arcade-like field geometry to create a magnetic island. The process leading to reconnect ion cannot. be solely attributed to a tearing instability, but rather to a reactive evolution of the magnetic arcade under resistivity. The natures of the arcade reconnection are governed by the spatial pattern of resistivity. A fast reconnection with a small shock angle can only be achieved when the diffusion region is localized. In this case. a highly collimated reconnect ion outflow can tear the plasmoid into a pair, and most of principal features in solar eruptive processes are reproduced.

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Enhancement of Surface Diffusivity for Waviness Evolution on Heteroepitaxial Thin Films

  • Kim, Yun Young
    • 한국표면공학회지
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    • 제47권6호
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    • pp.287-292
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    • 2014
  • The present study deals with a numerical analysis on the island growth of heteroepitaxial thin-films through local surface diffusivity enhancement. A non-linear governing equation for the surface waviness evolution in lattice-mismatched material systems is developed for the case of spatially-varying surface diffusivity. Results show that a flat film that is stable under constant diffusivity conditions evolves to form nanostructures upon externally-induced spatial diffusivity modulation. The periodicity of waviness can be controlled by changing the modulation parameters, which allows for generation of pattern arrays. The present study therefore points towards a post-deposition treatment technique that achieves controllability and order in the structure formation process for applications in nanoelectronics and thin-film devices.

동아시아 여름몬순 지수의 자기조직화지도(SOM)에 의한 강수량의 계절 내 진동 분류 (Classification of Intraseasonal Oscillation in Precipitation using Self-Organizing Map for the East Asian Summer Monsoon)

  • 추정은;하경자
    • 대기
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    • 제21권3호
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    • pp.221-228
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    • 2011
  • The nonlinear characteristics of summer monsoon intraseasonal oscillation (ISO) in precipitation, which is manifested as fluctuations in convection and circulation, is one of the major difficulty on the prediction of East Asian summer monsoon (EASM). The present study aims to identify the spatial distribution and time evolution of nonlinear phases of monsoon ISO. In order to classify the different phases of monsoon ISO, Self-Organizing Map(SOM) known as a nonlinear pattern recognition technique is used. SOM has a great attractiveness detecting self-similarity among data elements by grouping and clustering such self-similar components. The four important patterns are demonstrated as Meiyu-Baiu, Changma, post-Changma, and dry-spell modes. It is found that SOM well captured the formation of East Asian monsoon trough during early summer and its northward migration together with enhanced convection over subtropical western Pacific and regionally intensive precipitation including Meiyu, Changma and Baiu. The classification of fundamental large scale spatial pattern and evolutionary history of nonlinear phases of monsoon ISO provides the source of predictability for extended-range forecast of summer precipitation.

Nonequilibrium Domain Configurations Undergoing Large Angle Rotations in Mesoscopic Magnetic Thin Film Elements (retracted)

  • Choi, B.C.;Hong, Y.K.;Rudge J.;Donohoe G.;Xiao Q.F.
    • Journal of Magnetics
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    • 제11권2호
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    • pp.61-65
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    • 2006
  • The physical origin of complex dynamic domain configuration in nonequilibrium magnetic systems with mesoscopic length scales has been studied. An increasing complexity in the spatial feature of the evolution is found to accompany the increasing reversal speed, when a ferromagnetic element is driven by progressively faster switching fields applied antiparallel to the initial magnetization direction. As reversal rates approach the characteristic precession frequencies of spin fluctuations, the thermal energy can boost the magnetization into local configurations which are completely different from those experienced during quasistatic reversal. The sensitive dependence of the spatial pattern on switching speed can be understood in terms of a dynamic exchange interaction of thermally excited spins; the coherent modulation of the spins is strongly dependent on the rise time of switching pulses.

함경도 출신 조선족 농촌주거의 공간적 특성과 변천에 관한 실태조사연구 (A Research on The Spatial Characteristics and Changes in Farmhouses of Ethnic Korean Chinese Origined From Ham-kyeong do)

  • 김일학;장위쿤
    • 한국주거학회논문집
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    • 제27권1호
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    • pp.13-20
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    • 2016
  • The paper takes the rural housings of the Chaoxian nationality of Ham-kyeongdo in the three provinces in Northeast China as research object, to discuss the spatial form andthe characteristic of the change in the housing. The research result shows that the dwellings' plane forms in the Tumen River, the coast of Yalu River and the Sino Russian border are mainly traditional "Jeong-ji central type (J)", while in Heilongjiang are mainly "Jeong-ji and corridor central type (J-C)". In the evolution of living space and behavior patterns, there appears sliding door and partition between Jeongjibang and kitchen in the former, and Badang space in the front of the Kang and the behavior pattern remains its original seat-type lifestyle mainly. While there forms Dikang space and living space in the process of different cultures blend and modernization in the later and appears some upright-type behavior patterns. There is distinct characteristic in regional changes in both.

교외개발의 재조명: 도시의 진화와 계획으로의 함의 (Revisiting Suburban Developments: Urban Evolution and Its Implication to Planning)

  • 강상준
    • 환경영향평가
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    • 제31권3호
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    • pp.161-172
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    • 2022
  • 본 연구는 현대도시 문제점 중 하나인 교외개발 사례를 통해 도시의 진화성을 이해해 보려는 시론적 연구이다. 방법론으로 (1) 국내 9개(1980-2010), 미국 49개 도시(1992-2019년)의 도시확장강도지수(UEII) 산출, (2) 2019년 시카고 대도시권 도시지역을 대상으로 형태학적 공간패턴(MSP)과 엔트로피(Entropy) 분석이다. 주요결과는 (1) 도시확산 현상은 보편적인 도시변화 특성으로 이해할 수 있다, (2) 전체지역의 특성은 하위단위 도시들의 특성과 다른 방향으로 나타날 수 있다. 연구함의는 (1) 교외 도시확산현상은 도시에게 부여된 여러 기능에 부합하는 도시변화 현상으로 이해할 수 있으며 하위단위 도시·생활권의 기능이 큰 의미를 갖는다, (2) 진화론적 관점에서의 도시는 기존의 발달성장 논의와 큰 차이가 있다. 이 연구는 도시의 부분적 특성을 사례로 삼고 있다는 한계를 보이며 향후 도시의 진화하는 속성을 이해하기 위한 폭넓은 실증연구가 필요하다.