• Title/Summary/Keyword: spatial representation

Search Result 405, Processing Time 0.029 seconds

The Processing of Spatial Joins using a Bit-map Approximation (비트맵 근사 표현을 이용한 효율적인 공간 조인)

  • 홍남희;김희수
    • Journal of the Korea Computer Industry Society
    • /
    • v.2 no.2
    • /
    • pp.157-164
    • /
    • 2001
  • This paper studies on the processing of spatial joins. The spatial join operation is divided into filters and refinement steps in general. The processing of spatial joins can be greatly improved by the use of filters that reduce the polygons in order to find the intersecting ones. As a result, three possible sets of answers are identified: the positive one, the negative one and the inconclusive one. To identify all the interesting pairs of polygons with inconclusive answers, it is necessary to have access to the representation of polygons so that an exact geometry test can take place. We introduce a bit-map approximation technique to drastically reduce the computation required by the refinement step during refinement processing. Bit-map representation are used for the description of the internal, the external and the boundary regions of the polygon objects. The proposed scheme increases the chance of trivial acceptance and rejection of data objects, and reduces unnecessary disk accesses in query processing. It has been shown that the reference to the object data file can be cut down by as much as 60%.

  • PDF

Representation Method of Viewpoint-based Directional Relationship for 3-Dimensional Graphic Databases (3차원 그래픽 데이타베이스를 위한 시점기반의 방향관계 표현 기법)

  • 황종하;백중환;황수찬
    • Journal of KIISE:Databases
    • /
    • v.30 no.2
    • /
    • pp.157-167
    • /
    • 2003
  • Spatial relations among objects we one of the most frequently used searching criteria for a query based on the contents of 3-D images. However, the existing researches have mainly focused only the absolute directional relations based on a fixed viewpoint in 2-D images. So, this paper presents a representation method of viewpoint based directional relations that enables spatial relations among objects to be retrieved based on a viewpoint of an observer. The retrieval technique based on our method is a]so described. In this paper, the notion of 3D string is defined to express the spatial relations in a 3-D space. A retrieval method based on relative directional relations among objects from a viewpoint of an observer is also presented. The proposed method simplifies the retrieval of viewpoint-based directional relations because 2D+1D scheme reduces the dimension.

Converting Triangulated 3D Indoor Mesh Data to OGC IndooGML (삼각분할된 3차원 실내공간데이터를 OGC IndoorGML로 변환하는 방법)

  • Li, Ki-Joune;Kim, Dong Min
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.36 no.6
    • /
    • pp.499-505
    • /
    • 2018
  • Most of 3D indoor spatial data recently constructed by many projects merely focus on the visualization rather than geospatial information applications. The 3D indoor data for visualization in 3DS or COLLADA format are based on triangular mesh representation. In order to implement meaningful applications, we need however more meaningful information in 3D indoor spatial data than visualization data in triangular meshes. For this reason, an OGC (Open Geospatial Consortium) standard, called IndoorGML(Indoor Geographic Markup Language) was published to meet the requirements on 3D indoor spatial data for several geospatial applications for indoor space more than simple visualization. It means that it becomes a critical functional requirement to convert triangular mesh representation in 3DS or COLLADA to IndoorGML. In this paper we propose a framework of the conversion, which consists of geometric, topological, and semantic construction of data from triangular meshes. An experiment carried out to validate the proposed framework is also presented in the paper.

The Archi-Semiotic Characteristics of Spatial Modality in Interactive Space - Focus on Gilbert Simondon's Information of Technology - (상호작용 공간 모달리티의 건축기호적 특징 - 질베르 시몽동의 기술의 정보·형태화 관점 -)

  • Suh, Juneho
    • Korean Institute of Interior Design Journal
    • /
    • v.22 no.1
    • /
    • pp.75-84
    • /
    • 2013
  • This study focuses on Gilbert Simondon's individuation theory, a core concept of his technological philosophy, and spatial modality in interactive space as the schema of interactive operation. The study examines spatial modality as the technology of an interaction-enabler that has archi-semiotic characteristics in the designed space by aspects of examples. They are based on ideas and properties of a combined environment and the concept of information, which form Simondon's individuation theory. In the process of technological individuation, spatial modality has the characteristics of archi-semiotics from a combined environment and information. The first of the three properties is representation through semiosis and the information surface. Second is the context by relation works and perception, and third are the symbolic aspects, which could create Placeness by meaning. Combining meaningful constructive and deconstructive spaces could result in space for interactive communication. Spatial modality makes it possible to interact with users and spaces. In fact, it could have a particular semiotic mode of address and become a semiotic and contextual base. As a basic investigation of spatial modality, this study will contribute to interactive space design research.

Theoretical Background for Data-driven Integration of Raster-based Geological Information (격자형 지질정보의 자료유도 통합을 위한 이론적 배경)

  • Lee, Ki-Won;Chi, Kwang-Hoon
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.3 no.1 s.5
    • /
    • pp.115-121
    • /
    • 1995
  • Recently, spatial integration for mineral exploration is regarded as an important task of various geological applications of GIS. Therefore, theoretical bases of data representation and reasoning concerned with Dempster-Shafer theory and Fuzzy theory were systematically as the data-driven integration methodologies for raster-based geoinformation; they are distinguished from target-driven methodology based on statistical background. According to previous actual applications of these methods to mineral exploration, they have been proven to provide useful information related to hidden target mineral deposits, and it is thought that some suggestions in this study are helpful to further real applications including representation, reasoning, and interpretation stages in order to obtain a decision-supporting layer.

  • PDF

Day / Night Cycle Spatial Representation of Elementary Students of Urban and Rural Area from an Earth- and a Space-based Perspective (도심 지역 및 도서 지역 초등학생들의 낮과 밤에 대한 지구 기반 관점과 우주 기반 관점의 공간표상)

  • Shin, Myeong-Kyeong;Kim, Jong-Young
    • Journal of Korean Elementary Science Education
    • /
    • v.37 no.3
    • /
    • pp.309-322
    • /
    • 2018
  • There is no doubt that science -and, therefore, science education- is central to the lives of all (NGSS, 2013). This manuscript focuses on ideas in astronomy that are at the foundation of elementary students' understanding of the discipline: the apparent motion of the sun explaining the day / night cycle on Earth. According to prior research demonstrating that neither children nor adults hold a scientific understanding of the big ideas of astronomy (NRC, 1996), understanding of concepts may base students' progress towards more advanced understanding in the domain of astronomy. We have analyzed the logic of the domain and synthesized prior research assessing children's spatial representation from an earth- and a space based perspective to develop a set of learning trajectories that describe how students' initial ideas about apparent celestial motion as they take school science can be build upon. In this study elementary students' representations were compared by their resident context including urban and rural. This study may present a first look at the use of a learning progression framework in analyzing the structure of astronomy education. We discuss how this work may eventually lead towards the development and empirical testing of how children learn to describe and explain apparent patterns of celestial motion.

A Study on the Edge Enhancement of X-ray Images Generated by a Gas Electron Multiplier Chamber

  • Moon, B.S.;Coster, Dan
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.4 no.2
    • /
    • pp.155-160
    • /
    • 2004
  • In this paper, we describe the results of a study on the edge enhancement of X-ray images by using their fuzzy system representation. A set of gray scale X-ray images was generated using the EGS4 computer code. An aluminum plate or a lead plate with three parallel strips taken out has been used as the object with the thickness and the width of the plate, and the gap between the two strips varied. We started with a comparative study on a set of the fuzzy sets for their applicability as the input fuzzy sets for the fuzzy system representation of the gray scale images. Then we describe how the fuzzy system is used to sharpen the edges. Our algorithm is based on adding the magnitude of the gradient not to the pixel value of concern but rather to the nearest neighboring pixel in the direction of the gradient. We show that this algorithm is better in maintaining the spatial resolution of the original image after the edge enhancement.

Functional neuroanatomy of the vestibular cortex and vestibular stimulation methods for neuroimaging studies

  • Seung-Keun Lee;Eek-Sung Lee
    • Annals of Clinical Neurophysiology
    • /
    • v.26 no.1
    • /
    • pp.1-7
    • /
    • 2024
  • The vestibular cortex is a distributed network of multisensory areas that plays a crucial role in balance, posture, and spatial orientation. The core region of the vestibular cortex is the parietoinsular vestibular cortex (PIVC), which is located at the junction between the posterior insula, parietal operculum, and retroinsular region. The PIVC is connected to other vestibular areas, the primary and secondary somatosensory cortices, and the premotor and posterior parietal cortices. It also sends projections to the vestibular nuclei in the brainstem. The PIVC is a multisensory region that integrates vestibular, visual, and somatosensory information to create a representation of head-in-space motion, which is used to control eye movements, posture, and balance. Other regions of the vestibular cortex include the primary somatosensory, posterior parietal, and frontal cortices. The primary somatosensory cortex is involved in processing information about touch and body position. The posterior parietal cortex is involved in integrating vestibular, visual, and somatosensory information to create a representation of spatial orientation. The frontal cortex is involved in controlling posture, and eye movements. The various methods used to stimulate the vestibular receptors in neuroimaging studies include caloric vestibular stimulation (CVS), galvanic vestibular stimulation (GVS), and auditory vestibular stimulation (AVS). CVS uses warm or cold water or air to stimulate the semicircular canals, GVS uses a weak electrical current to stimulate the vestibular nerve, and AVS uses high-intensity clicks or short tone bursts to stimulate the otolithic receptors.

Residents' Preference for Spatial Features in Sitting Areas at Assisted Living Facilities - Focused on direct or indirect social interaction for older adults -

  • Lee, Min-Ah;Rodiek, Susan D.
    • International Journal of Human Ecology
    • /
    • v.14 no.1
    • /
    • pp.87-102
    • /
    • 2013
  • This study investigated residents' preferences for spatial features of sitting areas in assisted living facilities, and provides recommendations for planning sitting areas to support residents' spatial preferences and social interaction. The study participants were 69 residents of eight assisted living facilities (30+ resident capacity), located in south central Texas. A photographic comparison method was used, in which residents were shown 20 matched pairs of photos, with a single feature digitally modified in each pair, and asked to select which environmental representation they preferred. The hypothesized spatial characteristics were identified in practice based literature as those that may encourage usage of sitting areas: viewability, variety, homelikeness, and privacy. Most of the hypothesized features were preferred by participants, with the highest preference found for non-institutional furniture arrangements and naturalness, followed by increasing enclosure and variety of seating. Preference was less significant for domestic cues such as carpeted floors, divided light windows, and boundaries defined by different colored material or columns, possibly due to their physical impairments or preference for visual openness. Participants' level of mobility assistance was significantly related to their preference for some features, such as seating with people-watching capability, and carpeted floors. The findings have implications for facility architects and administrators engaged in resident-oriented spatial planning.

A Generation Method of Spatially Encoded Video Data for Geographic Information Systems

  • Joo, In-Hak;Hwang, Tae-Hyun;Choi, Kyoung-Ho;Jang, Byung-Tae
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.801-803
    • /
    • 2003
  • In this paper, we present a method for generating and providing spatially encoded video data that can be effectively used by GIS applications. We collect the video data by a mobile mapping system called 4S-Van that is equipped by GPS, INS, CCD camera, and DVR system. The information about spatial object appearing in video, such as occupied region in each frame, attribute value, and geo-coordinate, are generated and encoded. We suggest methods that can generate such data for each frame in semi-automatic manner. We adopt standard MPEG-7 metadata format for representation of the spatially encoded video data to be generally used by GIS application. The spatial and attribute information encoded to each video frame can make visual browsing between map and video possible. The generated video data can be provided and applied to various GIS applications where location and visual data are both important.

  • PDF