• 제목/요약/키워드: Spatial Clusters

검색결과 284건 처리시간 0.027초

Social Media and Popular Places: The Case of Chicago

  • Al-Kodmany, Kheir
    • 국제초고층학회논문집
    • /
    • 제8권2호
    • /
    • pp.125-136
    • /
    • 2019
  • This paper offers new ways to learn about popular places in the city. Using locational data from Social Media platforms platforms, including Twitter, Facebook, and Instagram, along with participatory field visits and combining insights from architecture and urban design literature, this study reveals popular socio-spatial clusters in the City of Chicago. Locational data of photographs were visualized by using Geographic Information Systems and helped in producing heat maps that showed the spatial distribution of posted photographs. Geo-intensity of photographs illustrated areas that are most popularly visited in the city. The study's results indicate that the city's skyscrapers along open spaces are major elements of image formation. Findings also elucidate that Social Media plays an important role in promoting places; and thereby, sustaining a greater interest and stream of visitors. Consequently, planners should tap into public's digital engagement in city places to improve tourism and economy.

Salient Object Detection Based on Regional Contrast and Relative Spatial Compactness

  • Xu, Dan;Tang, Zhenmin;Xu, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제7권11호
    • /
    • pp.2737-2753
    • /
    • 2013
  • In this study, we propose a novel salient object detection strategy based on regional contrast and relative spatial compactness. Our algorithm consists of four basic steps. First, we learn color names offline using the probabilistic latent semantic analysis (PLSA) model to find the mapping between basic color names and pixel values. The color names can be used for image segmentation and region description. Second, image pixels are assigned to special color names according to their values, forming different color clusters. The saliency measure for every cluster is evaluated by its spatial compactness relative to other clusters rather than by the intra variance of the cluster alone. Third, every cluster is divided into local regions that are described with color name descriptors. The regional contrast is evaluated by computing the color distance between different regions in the entire image. Last, the final saliency map is constructed by incorporating the color cluster's spatial compactness measure and the corresponding regional contrast. Experiments show that our algorithm outperforms several existing salient object detection methods with higher precision and better recall rates when evaluated using public datasets.

무선 센서 네트워크에서 동적 클러스터 유지 관리 방법을 이용한 에너지 효율적인 주기적 데이터 수집 (An Energy-Efficient Periodic Data Collection using Dynamic Cluster Management Method in Wireless Sensor Network)

  • 윤상훈;조행래
    • 대한임베디드공학회논문지
    • /
    • 제5권4호
    • /
    • pp.206-216
    • /
    • 2010
  • Wireless sensor networks (WSNs) are used to collect various data in environment monitoring applications. A spatial clustering may reduce energy consumption of data collection by partitioning the WSN into a set of spatial clusters with similar sensing data. For each cluster, only a few sensor nodes (samplers) report their sensing data to a base station (BS). The BS may predict the missed data of non-samplers using the spatial correlations between sensor nodes. ASAP is a representative data collection algorithm using the spatial clustering. It periodically reconstructs the entire network into new clusters to accommodate to the change of spatial correlations, which results in high message overhead. In this paper, we propose a new data collection algorithm, name EPDC (Energy-efficient Periodic Data Collection). Unlike ASAP, EPDC identifies a specific cluster consisting of many dissimilar sensor nodes. Then it reconstructs only the cluster into subclusters each of which includes strongly correlated sensor nodes. EPDC also tries to reduce the message overhead by incorporating a judicious probabilistic model transfer method. We evaluate the performance of EPDC and ASAP using a simulation model. The experiment results show that the performance improvement of EPDC is up to 84% compared to ASAP.

The Spatial Performance of Multi-Level Shopping Clusters A Case Study of Nanshan Commercial Cultural District

  • Haofeng, Wang;Yupeng, Zhang;Xiaojun, Rao
    • 국제초고층학회논문집
    • /
    • 제6권2호
    • /
    • pp.149-163
    • /
    • 2017
  • With the intensification of urban development in Chinese cities, mixed land use in urban centers extends vertically into 3-D and expands its scale from a single building to commercial clusters. The multi-level pedestrian system in city centers also changed its role from one of traffic isolation to spatial integration, where transit nodes, street sidewalks, squares, building entrances, atriums, and corridors are interconnected, both horizontally and vertically, into a whole spatial system, within which pedestrian flows are guided and shopping facilities are arranged. This paper uses spatial configuration analysis of space syntax to examine the impacts of spatial patterns on movement distribution and the business performance of tenant mix in the multi-level commercial system of the Nanshan Commercial Cultural District in Shenzhen, China. The key objective is to better understand the interactions between the socio-economic variables and spatial design parameters of a shopping complex. The research findings point to the importance of multiplicity between syntactic variables and other spatial variables in influencing the pedestrian flows, business performance and tenant mix in highly complex commercial systems. Particularly noteworthy is the relationship between spatial accessibility measures and the location of escalators, and the ways in which individual commercial buildings are embedded into the overall spatial system. The study suggests that this may lead to the preliminary identification of the spatial qualities of effective vertical extensions of mixed land use in a high-density urban settings.

Spectroscopic Confirmation of Galaxy Clusters at z~0.92

  • Kim, Jae-Woo;Im, Myungshin;Lee, Seong-Kook;Hyun, Minhee
    • 천문학회보
    • /
    • 제40권1호
    • /
    • pp.45.1-45.1
    • /
    • 2015
  • Galaxy clusters have provided important information to understand the evolution of the universe, since the number density and mass of clusters are tightly related to the cosmological parameters. In addition, galaxy clusters are an excellent laboratory to investigate the galaxy evolution in dense environments. However, finding galaxy clusters at high redshift ($z{\geq}1$) still remains as a main subject in astronomy due to their rareness and difficulty in identifying such objects from optical imaging data alone. Here, we report a spectroscopic follow-up observation of distant galaxy cluster candidates identified by a deep optical-NIR dataset of Infrared Medium-deep Survey. Through the galaxy spectra taken with the IMACS instrument on the Magellan telescope, we confirm at least 3 massive clusters at z~0.92. Interestingly, the maximum spatial separation between these clusters is ~8Mpc, which implies that this system is a new supercluster in the distant universe. We also discuss properties of galaxies in these clusters based on multi-wavelength photometric data.

  • PDF

Identifying Cluster Candidates in CFHTLS W2 Field

  • Paek, Insu;Im, Myungshin;Kim, Jae-Woo
    • 천문학회보
    • /
    • 제43권1호
    • /
    • pp.59.2-59.2
    • /
    • 2018
  • Recent studies of galaxy clusters have shown that the galaxy clusters in dense environment tend to have lower star formation rate in local universe with z < 1. However, this correlation is not significant in galaxy clusters with z > 1. The study of galaxy clusters around z=1 can yield insight into cosmological galaxy evolution. Nevertheless, the identification of galaxy clusters beyond the scope of immediate local universe requires wide field data in optical and near-infrared bands. By incorporating data from Canada-France-Hawaii Telescope Legacy Survey(CFHTLS) and Infrared Medium-Deep Survey(IMS), the photometric redshifts of galaxies in CFHTLS W2 field were calculated. Using spatial distribution and photometric redshifts, the galaxies in the field were divided into redshift bins. The image of each redshift bin was analyzed by measuring the number density within proper distance of 1Mpc. By comparing high density regions in consecutive redshift bins, we identified the cluster candidates and mapped the large-scale structure within the CFHTLS W2 field.

  • PDF

Identifying Cosmic Voids using Clusters as the Antipode

  • 심준섭;박창범;김주한
    • 천문학회보
    • /
    • 제44권2호
    • /
    • pp.40.1-40.1
    • /
    • 2019
  • We report progress on identifying cosmic voids using cluster halos as the antipode. According to the standard scenario of structure formation, clusters are expected to form at peaks of the initial density field, whereas cosmic voids form at troughs. Then, a cluster would be a void if the sign of the initial density fluctuation of the universe were inverted. To study the relevance of anti-structures of clusters to cosmic voids, we use a pair of simulations whose initial density fields are sign inverted versions to each other. By examining the spatial distribution and environment of the particles in inverted simulation, which are the member particles of clusters in the other simulation, we discuss the characteristics of the antipode structures of clusters including their size, density, internal structure, and redshift evolution as well.

  • PDF

Space Syntax 기법을 이용한 교과교실제 과목영역별 공간계획에 관한 연구 - 일본 시민중학교 계획사례를 중심으로 - (Study on Spatial Planning of Subject-centered Clusters Using Space Syntax Methodology - Focused on the Spatial Planning of Shimin Junior School, Japan -)

  • 이재홍;이현희
    • 교육시설 논문지
    • /
    • 제24권4호
    • /
    • pp.15-24
    • /
    • 2017
  • This paper aims to investigate in what extent subject-centered clusters are different from one another in terms of message system, which is composed of curriculum, pedagogy and evaluation. For this, Bernstein's pedagogic transmission code(i.e., classification and framing) and school typology(i.e., open-type or close-type) have been explored, and then applied into Shimin Junior School, Japan, in order to find out substantial characteristics between subject-centered clusters. In this case study, VGA(visibility graph analysis), as one of syntactical methodologies in space syntax theory, has been used to measure to what degree they are actually different. Throughout in-depth investigation of spatial configurations, it can be said that the square of clusters is strongly connected and integrated very well, so that it acts as an anchor place for school life within a cluster. However, it works in different ways according to message systems. In the subjects like Japanese and Science whose message system are characterized by strong classification and strong framing, integration values are relatively low, and this means that it is hard to expect cross-referencing activities through the subject squares. On the contrary, the subject of Social Studies defined by weak classification and weak framing shows the highest mean integration values, and this can be expected that there are inter-changeable learning activities in the square.

연령별 인구이동 특성에 대한 탐색적 공간 데이터 분석 (ESDA) : 대구시를 사례로 (Exploratory Spatial Data Analysis (ESDA) for Age-Specific Migration Characteristics : A Case Study on Daegu Metropolitan City)

  • 김감영
    • 한국지역지리학회지
    • /
    • 제16권5호
    • /
    • pp.590-609
    • /
    • 2010
  • 본 연구의 목적은 연령별 인구이동의 구조와 공간적 패턴에 대한 이해를 향상시킬 수 있는 다양한 탐색적 공간 데이터 분석(Exploratory Spatial Data Analysis: ESDA) 기법들을 제시하는데 있다. ESDA 기법의 하나로 지역의 연령별 이동성향과 이동구조를 파악하기 위한 도구로 인구이동 피라미드를 고안하였다. 인구이동 피라미드는 연령별 전입, 전출, 순이동 정보를 이용하여 작성되는 그래픽 도구이다. 또한 연령별 인구이동의 공간적 패턴을 파악하기 위하여 다양한 국지적 연관성 측정 지표인 Local Moran's $I_i$, Getis-Ord's ${G_i}^*$와 이를 응용한 AMOEBA 기법을 이용하였다. 사례 분석 결과, 제시한 ESDA 기법들을 이용하여 연령별 인구이동 구조, 연령별 이동의 연관성, 연령별 순이동률의 공간 군집 패턴 등을 확인할 수 있었으며, 연령별 공간 군집 사이의 상응관계를 탐색할 수 있었다. 이러한 정보는 인구이동 현상에 대한 상세한 이해뿐만 아니라 인구이동을 유발하는 지역의 특성을 유추하는데 도움을 준다.

  • PDF

The Formation of Innovative Clusters in Kazakhstan: Analysis and Methods for Identifying Specialization

  • Kireyeva, Anel A.;Nurlanova, Nailya K.
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제1권1호
    • /
    • pp.23-30
    • /
    • 2014
  • The aim of this research is theoretical and methodological approaches to the necessity of formation of innovation clusters as growth poles on the basis of statistical analysis and identification of specialization. In this research, we used methods, which will allow to analyze of innovative processes and to identify of prospective branches of specialization of the formation of innovative clusters in the spatial context. Keeping with the previous literature, the present study is determined by the novelty of the problem, concerning the formation and development of innovative clusters as growth poles, as well as large specifics of problems in our country in the framework of use of innovative clusters. An analysis was showed that Kazakhstan's regions have substantial differences in the groups of regions for most of the indicators have presented form a tightly located clusters and in the ratings of innovative susceptibility and innovative activity. This research has some practical implications, which have proved that innovative clusters become platforms as growth poles for introduction of advanced technologies, development of innovative companies, thereby providing a certain stability of the economy of the regions.