• Title/Summary/Keyword: Spatial Operators

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Aerial Triangulation with 3D Linear Features and Arc-Length Parameterization

  • Lee, Won-Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.3
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    • pp.115-120
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    • 2009
  • Point-based methods with experienced human operators are processed well in traditional photogrammetric activities but not the autonomous environment of digital photogrammetry. To develop more robust and accurate techniques, higher level objects of straight linear features accommodating element other than points are adopted instead of points in aerial triangulation. Even though recent advanced algorithms provide accurate and reliable linear feature extraction, extracting linear features is more difficult than extracting a discrete set of points which can consist of any form of curves. Control points which are the initial input data and break points which are end points of piecewise curves are easily obtained with manual digitizing, edge operators or interest operators. Employing high level features increase the feasibility of geometric information and provide the analytical and suitable solution for the advanced computer technology.

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Representation and History Management of Spatio-Temporal Objects using a Gothic GIS Tool (고딕 GIS 도구를 이용한 시공간 객체의 표현과 이력관리)

  • Paik, Ju-Yeon;Lee, Seong-Jong;Ryu, Keun-Ho
    • Journal of KIISE:Databases
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    • v.27 no.1
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    • pp.101-112
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    • 2000
  • In Geographic Information System, spatial object can be changed in the attribute information, spatial location and the topological relation between them with the change of time. However traditional GIS deletes the old value of aspatial information and replaces them with new value. Therefore. it is difficult to manage thc history of changed spatial object and can not support the spatio-temporal queries including temporal queries. In this paper, we propose a spatio-temporal objected model to solve this problem. We implement the proposed model with spatio-temporal class using Gothic GIS tool. The historical information of an object is stored into the object itself for the effective history management. And, in order to provide the queries for the history of an object and spatio-temporal relationship, we add temporal operators, spatio-temporal operators, and spatio-temporal query operations into Gothic, and improve the facility of the Gothic.

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A Design of Filtering Technique on LBSNS using Spatial Join (LBSNS에서의 공간조인을 이용한 필터링 기법의 설계)

  • Lee, Eun-Sik;Cho, Dae-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.230-232
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    • 2011
  • Owing to the advent of digital devices which equipped with GPS, such as smartphone and tablet pc, a number of LBSNS applications have been released and even SNS applications serve various Location-Based Services. In twitter's case, the news of interesting area is provided to user not by being subscribed them automatically, but by being searched on web-site. This paper describes the system designed for users want to subscribe the local news without procedure like searching using operators. This system uses PBSM(Partition Based Spatial-Merge Join) which has no index for batch processing and against a massive query. The results from Spatial Join are stored in Materialized View then provided to user.

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Spatial Changes in Work Capacity for Occupations Vulnerable to Heat Stress: Potential Regional Impacts From Global Climate Change

  • Kim, Donghyun;Lee, Junbeom
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.1-9
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    • 2020
  • Background: As the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea. Methods: The data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis. Results: Our findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea. Conclusion: Although previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

Indoor Spatial Awareness Project and Indoor Spatial Data Model

  • Li, Ki-Joune
    • Spatial Information Research
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    • v.16 no.4
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    • pp.441-453
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    • 2008
  • With the rapid progress of location based services, GIS, and ubiquitous computing technologies, the space that we are dealing with is no longer limited to outdoor space but being extended to indoor space. Indoor space has some differences from outdoor space, therefore to provide integrated spaces and seamless services, it is required to establish new theories, data models, and systems. For this reason, ambitious project has been launched last year to establish a theoretical background, develop a core technologies and systems, and provide services of indoor spatial awareness. In this paper, we present an overall sketch on the project and major research topics. First, we present the ISA (indoor spatial awareness) project with its goal and research topics. Second, a simplified 3D spatial model, called prism model, is proposed as a basic data types and operators of indoor spatial DBMS. Third, a indoor feature data model, developed T. Kolbe et al. who is a member of this project team, is introduced in this paper. This model provides a basis for the integration of different spaces.

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Shipyard Spatial Scheduling Solution using Genetic Algorithms

  • Yoon Duck Young;Ranjan Varghese
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.35-39
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    • 2004
  • In a shipyard, there exist various critical decision making components pertaining to various production hindrances. The most prominent one is best-fit spatial arrangement for the minimal spatial occupancy with better pick-ability for the erection of the ship in the dock. During the present research, a concept have been conceived to evade the gap between the identification oj inter-relationships among a set of blocks to be included on a pre-erection area, and a detailed graphical layout of their positions, is called an Optimal Block Relationship Diagram A research has been performed on generation of optimal (or near Optimal) that is, with minimal scrap area. An effort has been made in the generation of optimal (or near-optimal) Optimal Block Relationship Diagram with the Goldberg's Genetic Algorithms with a representation and a set of operators are 'trained' specifically for this application. The expected result to date predicts very good solutions to test problems involving innumerable different blocks to place. The suggested algorithm could accept input from an erection sequence generator program which assists the user in defining the nature and strength of the relationships among blocks, and could produce input suitable for use in a detailed layout stage.

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OQL/Geo : An object- oriented spatial query language for Geographic Information Systems (OQL/Geo : 지리 정보 시스템을 위한 객체지향 공간 질의어)

  • 김양희;김명선;권석형;정창성
    • Spatial Information Research
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    • v.3 no.2
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    • pp.191-204
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    • 1995
  • The data model is a system model which abstracts the spatial and nonspatial fea¬tures of the real world. A system defines through its data model a framework for the inner rep¬resentation of and connections with the outside world. The spatial query language is one of the most efficent framework for defining connection with outside world in the GIS. Existing GIS uses a spatial data model based on relational data model. Therefore, it has some difficulties in data abstraction and representing complex objects through inheritance. In this paper, we pro-pose an object oriented data model-Topological Object Model(TOM). TOM combines object model in ODMG and the planer topological object. Based on this model, we present an object-oriented spatial query language-OQL/Geo. OQL/Geo extends OQL in ODMG and represents TOM effectively. It also provides several operators such as geometric, topological and visible ope-rators. Moreover, it represents with diverse flexivility the request for complex spatial analysis and presentation of query results.

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A Study on 3Dimensional Automatic Boundaries Detection on Medical Images or Radiation Therapy Planning (방사선 치료 계획 장치를 위한 의료 영상의 3차원적 자동 경계선 검출에 관한 연구)

  • Choi, Eun-Jin;Suh, Doug-Young
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.172-175
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    • 1997
  • Outline contour is detected firstly to simulate dose distribution in radiation therapy planning system. In this paper, we developed automatic contour detection system using temporal and spatial relationships of image sequences. The low level image analysis involves the use of directional gradient edge operators and Laplacian operator. The High level portion of algorithm uses a knowledge-based strategy that incorporates fuzzy resoning method.

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Measurement of Spatial Dose Distribution for evaluation operator dose during Neuro-interventional Procedures (두경부 질환의 인터벤션 시술 시 시술자의 피폭선량평가를 위한 공간선량측정에 관한 연구)

  • Han, Su-Chul;Hong, Dong-Hee
    • Journal of radiological science and technology
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    • v.39 no.3
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    • pp.323-328
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    • 2016
  • The spatial dose distribution was measured with ionization chamber as preliminary study to evaluate operator dose and to study dose reduction during neuro-interventional procedures. The zone of operators was divided into four area (45, 135, 225, and 315 degree).We supposed that operator exist on the four area and indicated location of critical organs(eyes, breast, gonad). The spatial doses were measured depending on distance( 80, 100, 120, and 140 cm) and location of critical organs. The spatial doses of area of 225 degree were 114.5 mR/h (eyes location), 143.1 mR/h (breast location) and 147 mR/h (gonad location) in 80 cm. When changed location of x-ray generator, spatial dose increased in $18.1{\pm}10.5%$, averagely. We certified spatial dose in the operator locations, Using the results of this study, It is feasible to protect operator from radiation in neuro-interventional procedures.

A Design of Spatio-Temporal Data Model for Simple Fuzzy Regions

  • Vu Thi Hong Nhan;Chi, Jeong-Hee;Nam, Kwang-Woo;Ryu, Keun-Ho
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.384-387
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    • 2003
  • Most of the real world phenomena change over time. The ability to represent and to reason geographic data becomes crucial. A large amount of non-standard applications are dealing with data characterized by spatial, temporal and/or uncertainty features. Non-standard data like spatial and temporal data have an inner complex structure requiring sophisticated data representation, and their operations necessitate sophisticated and efficient algorithms. Current GIS technology is inefficient to model and to handle complex geographic phenomena, which involve space, time and uncertainty dimensions. This paper concentrates on developing a fuzzy spatio-temporal data model based on fuzzy set theory and relational data models. Fuzzy spatio-temporal operators are also provided to support dynamic query.

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