• Title/Summary/Keyword: Space Objects

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Map recognition using the relation between line segments (선분들간의 관계를 이용한 인식)

  • 장경식;김재희
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.10
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    • pp.89-97
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    • 1997
  • Because a map consists of many lines, a process of recognizing an object in a map is one to group lines that are consistent with the structure of the object. Therefore, it is important to establish an efficient method for finding lines which constitute objects. In this paper, a novel method for recognizing roads and districts in a land register map is proposed. In this method, lines that constitute objects are searched in a reduced search space by defining some relations between lines, and objects are recognized by using the structural information of the objects. As a result, the search space is reduced effetively, and even objects that embody the broken lines and the crossed lines are recognized.

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CHEMICAL EVOLUTION IN VeLLOs

  • Lee, Jeong-Eun
    • Journal of The Korean Astronomical Society
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    • v.40 no.4
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    • pp.83-89
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    • 2007
  • A new type of object called "Very Low Luminosity Objects (VeLLOs)" has been discovered by the Spitzer Space Telescope. VeLLOs might be substellar objects forming by accretion. However, some VeLLOs are associated with strong outflows, indicating the previous existence of massive accretion. The thermal history, which significantly affects the chemistry, between substellar objects with a continuous low accretion rate and objects in a quiescent phase after massive accretion (outburst) must be greatly different. In this study, the chemical evolution has been calculated in an episodic accretion model to show that CO and $N_2H^+$ have a relation different from starless cores or Class 0/I objects. Furthermore, the $CO_2$ ice feature at $15.2{\mu}m$ will be a good tracer of the thermal process in VeLLOs.

Development of a Software for Re-Entry Prediction of Space Objects for Space Situational Awareness (우주상황인식을 위한 인공우주물체 추락 예측 소프트웨어 개발)

  • Choi, Eun-Jung
    • Journal of Space Technology and Applications
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    • v.1 no.1
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    • pp.23-32
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    • 2021
  • The high-level Space Situational Awareness (SSA) objective is to provide to the users dependable, accurate and timely information in order to support risk management on orbit and during re-entry and support safe and secure operation of space assets and related services. Therefore the risk assessment for the re-entry of space objects should be managed nationally. In this research, the Software for Re-Entry Prediction of space objects (SREP) was developed for national SSA system. In particular, the rate of change of the drag coefficient is estimated through a newly proposed Drag Scale Factor Estimation (DSFE), and is used for high-precision orbit propagator (HPOP) up to an altitude of 100 km to predict the re-entry time and position of the space object. The effectiveness of this re-entry prediction is shown through the re-entry time window and ground track of space objects falling in real events, Grace-1, Grace-2, Tiangong-1, and Chang Zheng-5B Rocket body. As a result, through analysis 12 hours before the final re-entry time, it is shown that the re-entry time window and crash time can be accurately predicted with an error of less than 20 minutes.

GPU-based Image-space Collision Detection among Closed Objects (GPU를 이용한 이미지 공간 충돌 검사 기법)

  • Jang, Han-Young;Jeong, Taek-Sang;Han, Jung-Hyun
    • Journal of the HCI Society of Korea
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    • v.1 no.1
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    • pp.45-52
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    • 2006
  • This paper presents an image-space algorithm to real-time collision detection, which is run completely by GPU. For a single object or for multiple objects with no collision, the front and back faces appear alternately along the view direction. However, such alternation is violated when objects collide. Based on these observations, the algorithm propose the depth peeling method which renders the minimal surface of objects, not whole surface, to find colliding. The Depth peeling method utilizes the state-of-the-art functionalities of GPU such as framebuffer object, vertexbuffer object, and occlusion query. Combining these functions, multi-pass rendering and context switch can be done with low overhead. Therefore proposed approach has less rendering times and rendering overhead than previous image-space collision detection. The algorithm can handle deformable objects and complex objects, and its precision is governed by the resolution of the render-target-texture. The experimental results show the feasibility of GPU-based collision detection and its performance gain in real-time applications such as 3D games.

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A Study of IndoorGML Automatic Generation using IFC - Focus on Primal Space - (IFC를 이용한 IndoorGML 데이터 자동 생성에 관한 연구 - Primal Space를 중심으로 -)

  • Nam, Sang Kwan;Jang, Hanme;Kang, Hye Young;Choi, Hyun Sang;Lee, Ji Yeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.6
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    • pp.623-633
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    • 2020
  • As the time spent in indoor space has increased, the demand for services targeting indoor spaces also continues to increase. To provide indoor spatial information services, the construction of indoor spatial information should be done first. In the study, a method of generation IndoorGML, which is the international standard data format for Indoor space, from existing BIM data. The characteristics of IFC objects were investigated, and objects that need to be converted to IndoorGML were selected and classified into objects that restrict the expression of Indoor space and internal passages. Using the proposed method, a part of data set provided by the BIMserver github and the IFC model of the 21st Century Building in University of Seoul were used to perform experiments to generate PrimalSpaceFeatures of IndoorGML. As a result of the experiments, the geometric information of IFC objects was represented completely as IndoorGML, and it was shown that NavigableBoundary, one of major features of PrimalSpaceFeatures in IndoorGML, was accurately generated. In the future, the proposed method will improve to generate various types of objects such as IfcStair, and additional method for automatically generating MultiLayeredGraph of IndoorGML using PrimalSpaceFeatures should be developed to be sure of completeness of IndoorGML.

The Representation of 3-D Objects Using Ray Tracing and Space Subdivision (광선 추적법과 공간 분할을 이용한 입체 도형의 표현)

  • Kim, Y.I.;Cho, D.U.;Choi, B.U.
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1073-1076
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    • 1987
  • In this paper, a new ray tracing algorithm which uses space subdivision method is introduced. In order to reduce huge number of ray-surface intersection calculation, the space is subdivided as lattice that contains minimum number of objects. With lattice structure, the process that calculates unnecessary ray-surface intersection is eliminated.

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AN EXTENSION OF A RELIABLE WAVELENGTH COVERAGE OF THE AKARI NG GRISM MODE

  • Baba, Shunsuke;Nakagawa, Takao;Isobe, Naoki;Shirahata, Mai;Ohyama, Youichi;Yano, Kenichi;Kochi, Chihiro
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.45-47
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    • 2017
  • The Infrared Camera onboard the AKARI satellite carried out spectroscopic observations with a grism mode named NG, whose wavelength coverage was $2.5-5.0{\mu}m$. We reinvestigate the current flux calibration for the NG grism mode, with which calculated flux density implausibly decreases at $4.9{\mu}m$ especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the first-and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.

A Study on the Placement of Game Objects using Space Syntax (3차원 공간 상에서 Space Syntax를 이용한 게임 객체 배치 연구)

  • Choi, Seung-Kwan;Kim, Dong-Hyun;Kim, Young-Ook
    • Journal of Korea Game Society
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    • v.12 no.5
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    • pp.43-56
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    • 2012
  • The purpose of this research is to provide the rationality of placement of game objects using the space analysis for game map so that the game designers can find out the proper position for each object in the map. The significance of this research is beyond the limitations of the existing research using Space Syntax theory is confined to the analysis of the behavior of players in the map, this research suggest the method of the efficient placement of game objects in level design step. This paper as the worth of the industry is expected to be able to reduce the repetitive tasks that may occur during game level design steps. Through this, it is also expected by reducing game development period and development costs in accordance with the reasonable placement of game objects.

A Study on the Typological Characteristics of a Section form of Exhibition Space -A basic Study on the Environmental Design of museum(3)- (단위 전시공간의 단면형태 특성에 관한 고찰 -박물관 환경디자인에 관한 기초적 연구(3)-)

  • 임채진;하미정
    • Korean Institute of Interior Design Journal
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    • no.16
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    • pp.190-201
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    • 1998
  • The purpose of this study is to consider the correlational factors of space sections based on the fact the exhibition space plays an important role as a medium of displaying art works. And an another purpose is to investigate the characteristics of various types of exhibition unite space from which In intend to suggest basic sources of exhibition design. I classified domestic and foreign museum which are chosen as objects of study according to form and shape of a section plan. Then comparing exhibition space's form and scale exhibited genre lighting system layout composition display and its correlation with an already established thesis on museum architecture I will infer the characteristics of each type of a space. From these studies proper display conditions requested at the museum are different from the genre and property of the exhibited objects. And lighting system display angel of view and appreciation type affect the exhibition area. The shape of space classifies types of section which cause space's characteristics.

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DESIGN AND STRUCTURAL ANALYSIS OF DOME ENCLOSURE FOR TRACKING ARTIFICIAL SPACE OBJECTS (인공우주물체 추적용 완전 개폐형 돔의 설계 및 구조해석)

  • Seol, K.H.;Kim, S.J.;Jang, M.;Min, S.W.;Mun, B.S.;Baek, K.M.
    • Publications of The Korean Astronomical Society
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    • v.22 no.4
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    • pp.211-217
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    • 2007
  • We have been making dual dome enclosures which are useful to track artificial space objects at SSNT (Space Science and Technology Lab.) Kyung Hee University. We verified the safety of the dome enclosures using basic design and structure analyses before manufacturing them, and then performed an optimization analysis for economic and safe systems. The dome enclosure has a fully-open type structure to smoothly operate a telescope made in the style of altazimuth mount with very fast tracking. It is also designed to be safe against extreme weather conditions. The general structure of the observatory system consists of the dual dome enclosures at the top of a container. For the structural analyses, we consider the following two methods: (1) gravitational sustain analysis - how the structure supporting the dome withstand the weight of the dome, and (2) wind load analysis that considers the effect of the wind velocity at the region where the observatory is located. The result of overall deformation is found to be less than 0.551mm and the result of equivalent stress is found to be 20.293Mpa, indicating that the dual dome system is reasonably designed. This means structurally to be safe.