• Title/Summary/Keyword: path-finder model

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Development of Path finder Model and Qualified Model of Coarse Sun Sensor Assembly for Low Earth Orbit Satellite (저궤도 위성용 저정밀 태양센서 선행모델 및 인증모델 개발)

  • Kim, Yong-Bok;Jo, Young-Jun;Yong, Ki-Lyuk;Woo, Hyung-Je
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.491-504
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    • 2008
  • CSSA (Coarse Sun Sensor Assembly) is the essential sensor for satellite attitude control. CSSA measures the direction of the sun's rays and determines whether the satellite is in the ellipse. The paper shows the development process and test results of Path-finder & Qualified Model CSSA as the preceding development in order to develop the CSSA for low earth orbit satellite. We needs the definite and precision procedure and lots of experience. This paper shows that we can improve those through the development of Path-finder and Qualified Model CSSA. Therefore, we can obtain the results to meet the functional requirement.

Verification for Multithreaded Java Code using Java Memory Model (자바 메모리 모델을 이용한 멀티 스레드 자바 코드 검증)

  • Lee, Min;Kwon, Gi-Hwon
    • The KIPS Transactions:PartD
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    • v.15D no.1
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    • pp.99-106
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    • 2008
  • Recently developed compilers perform some optimizations in order to speed up the execution time of source program. These optimizations require the reordering of the sequence of program statements. This reordering does not give any problems in a single-threaded program. However, the reordering gives some significant errors in a multi-threaded program. State-of-the-art model checkers such as JavaPathfinder do not consider the reordering resulted in the optimization step in a compiler since they just consider a single memory model. In this paper, we develop a new verification tool to verify Java source program based on Java Memory Model. And our tool is capable of handling the reordering in verifying Java programs. As a result, our tool finds an error in the test program which is not revealed with the traditional model checker JavaPathFinder.

The process of Indoor Space Combination Network Model based on object oriented CAD data and its application (CAD 객체 정보에 기초한 공간 정보 네트워크 모델의 구성 프로세스와 활용방안)

  • Oh, Jung-Woo;Kim, Kyung-Hwan;Lee, Yoon-Sun;Ahn, Byung-Ju;Kim, Jae-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.6
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    • pp.129-136
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    • 2008
  • There is a tremendous need for an effective indoor facility management since the building are tend to be built taller and bigger due to latest technology. Also, information that is continuously used and transferred during the design and construction phase is emerging due to 3D object-oriented CAD. Therefore, a system that will use such information for facility management should be developed. In this study, we have defined a process that will automatically create an spatial network model and also verified the usability by establishing an sample model. As a result, an effective spatial network has been generated and an evacuation path finder was found efficiently.

3D Terrain Reconstruction Using 2D Laser Range Finder and Camera Based on Cubic Grid for UGV Navigation (무인 차량의 자율 주행을 위한 2차원 레이저 거리 센서와 카메라를 이용한 입방형 격자 기반의 3차원 지형형상 복원)

  • Joung, Ji-Hoon;An, Kwang-Ho;Kang, Jung-Won;Kim, Woo-Hyun;Chung, Myung-Jin
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.6
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    • pp.26-34
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    • 2008
  • The information of traversability and path planning is essential for UGV(Unmanned Ground Vehicle) navigation. Such information can be obtained by analyzing 3D terrain. In this paper, we present the method of 3D terrain modeling with color information from a camera, precise distance information from a 2D Laser Range Finder(LRF) and wheel encoder information from mobile robot with less data. And also we present the method of 3B terrain modeling with the information from GPS/IMU and 2D LRF with less data. To fuse the color information from camera and distance information from 2D LRF, we obtain extrinsic parameters between a camera and LRF using planar pattern. We set up such a fused system on a mobile robot and make an experiment on indoor environment. And we make an experiment on outdoor environment to reconstruction 3D terrain with 2D LRF and GPS/IMU(Inertial Measurement Unit). The obtained 3D terrain model is based on points and requires large amount of data. To reduce the amount of data, we use cubic grid-based model instead of point-based model.