• Title/Summary/Keyword: CNS Design

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Preliminary Design of GBAS Onboard Test Equipment

  • Jeong, Myeong-Sook;Ko, Wan-Jin;Bae, Joong Won;Jun, Hyang Sig
    • Journal of Positioning, Navigation, and Timing
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    • v.2 no.1
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    • pp.41-48
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    • 2013
  • When the ground subsystem of Ground Based Augmentation System(GBAS) is installed at the airport, the functions and performance of subsystem should be evaluated through ground and flight testing at the pre-commissioning phase. In the case of GBAS flight testing, it can be conducted by the existing flight check aircraft, but the GBAS ground testing requires the development of specially customized equipment to perform the ground testing. Therefore, this paper describes the preliminary design of GBAS onboard test equipment which can be independently used for the GBAS ground testing and flight testing on a car and an aircraft.

Development of Human Factors Evaluation System for Car Navigation System (자동차 항법장치의 인간공학 평가시스템 개발)

  • Cha, Doo-Won;Park, Peom
    • IE interfaces
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    • v.12 no.2
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    • pp.294-304
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    • 1999
  • This paper describes the theoretical background and detailed structure of Navi-HEGS (Navigation system Human factors Evaluation and Guideline System) which has been developed for the human factors and HMI(Human-Machine Interface) researches for a CNS (Car Navigation System) and a digital map. Navi-HEGS is and integrated system that consists of a digital map UIMS(User Interface Management System), a CNS simulator, various evaluation tools, and a design guideline system. If Navi-HEGS is properly applied and utilized, it is possible to extract the substantial users requirements and preferences of a CNS and a digital map and then, these requirements can be simulated and evaluated with various human factors evaluation techniques. Applications of Navi-HEGS can improve the CNS usability, drivers safety and performance that directly affect the success of ITS(Intelligent Transport System). Also, results can be used as the basic data to establish the standards and design guidelines for the driver-centered CNS design.

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INVESTIGATION OF THE CNS HOLE SHAPE AND A PROPOSED INSTALLATION METHOD FOR A VACUUM CHAMBER FOR THE HANARO REACTOR

  • Cho Yeong-Garp;Kim Young-Ki;Lee Kye-Hong;Choung Yun-Hang
    • Nuclear Engineering and Technology
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    • v.38 no.5
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    • pp.455-458
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    • 2006
  • The HANARO reactor has a vertical hole for a cold neutron source (CNS) in the heavy-water reflector tank, i.e., the CNS hole, which was considerably deformed during its welding to the horizontal cold neutron (CN) beam tube. This paper presents an investigation of the form of the CNS hole for the optimal design of the a vacuum chamber for the CNS. In addition, the installation method of the vacuum chamber into the CNS hole for minimizing the water thickness between the vacuum chamber and the nose of the CN beam tube is proposed.

Design Considerations on the Standby Cooling System for the integrity of the CNS-IPA

  • Choi, Jungwoon;Kim, Young-ki
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.104-104
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    • 2015
  • Due to the demand of the cold neutron flux in the neutron science and beam utilization technology, the cold neutron source (CNS) has been constructed and operating in the nuclear research reactor all over the world. The majority of the heat load removal scheme in the CNS is two-phase thermosiphon using the liquid hydrogen as a moderator. The CNS moderates thermal neutrons through a cryogenic moderator, liquid hydrogen, into cold neutrons with the generation of the nuclear heat load. The liquid hydrogen in a moderator cell is evaporated for the removal of the generated heat load from the neutron moderation and flows upward into a heat exchanger, where the hydrogen gas is liquefied by the cryogenic helium gas supplied from a helium refrigeration system. The liquefied hydrogen flows down to the moderator cell. To keep the required liquid hydrogen stable in the moderator cell, the CNS consists of an in-pool assembly (IPA) connected with the hydrogen system to handle the required hydrogen gas, the vacuum system to create the thermal insulation, and the helium refrigeration system to provide the cooling capacity. If one of systems is running out of order, the operating research reactor shall be tripped because the integrity of the CNS-IPA is not secured under the full power operation of the reactor. To prevent unscheduled reactor shutdown during a long time because the research reactor has been operating with the multi-purposes, the introduction of the standby cooling system (STS) can be a solution. In this presentation, the design considerations are considered how to design the STS satisfied with the following objectives: (a) to keep the moderator cell less than 350 K during the full power operation of the reactor under loss of the vacuum, loss of the cooling power, loss of common electrical power, or loss of instrument air cases; (b) to circulate smoothly helium gas in the STS circulation loop; (c) to re-start-up the reactor within 1 hour after its trip to avoid the Xenon build-up because more than certain concentration of Xenon makes that the reactor cannot start-up again; (d) to minimize the possibility of the hydrogen-oxygen reaction in the hydrogen boundary.

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The Analysis for the Ergonomic Design of the Topographical Objects Marking Method (인간공학적 설계를 위한 지형지물 명칭 표기에 대한 분석)

  • Moon, Hyung-Don;Cha, Doo-Won;Park, Peom
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.260-266
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    • 1997
  • The Navigation Streets Map that directly supplies information for a driver plays an important role in Car Navigation System(CNS). Therefore, cause the compatibility, preference, visibility, and readability of the navigation streets map will be hold sway over driver's information acquisition, safety, and performance in CNS, it is important that designer's requirements should be analyuzed for ergonomic design of navigation streets map. Especially, there are differences between the topographical objects marking method and that of the general map in a navigation streets map. Because much information is marked in a narrow space, it is important that the text information should be done in navigation streets map. Also, because it is a important factor to mark the text format for the marking method of the topographical objects, the design requirements will be drawn out through the factor analysis for the text marking method. And when ergonomic designers are doing, this result will be basic research for developing driving simulator of CNS and it will be a ergonomic guideline of navigation streets map.

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COLD NEUTRONS AT NIST

  • Kopetka P.A.;Rowe J.M.;William R.E.
    • Nuclear Engineering and Technology
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    • v.38 no.5
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    • pp.427-432
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    • 2006
  • The design process for the series of cold neutron sources installed at NIST is presented, with particular emphasis on the reason for the decisions and choices made. These developments are used to illustrate some of the general principles of CNS design.

Shielding design and analyses of the cold neutron guide hall for the KIPT neutron source facility

  • Zhong, Zhaopeng;Gohar, Yousry
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.989-995
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    • 2018
  • Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine, and its commissioning process is underway. The facility will be used for researches, producing medical isotopes, and training young nuclear specialists. The neutron source facility is designed with a provision to include a cryogenically cooled moderator system-a cold neutron source (CNS). This CNS provides low-energy neutrons, which will be used in the scattering experiment and material structures analysis. Cold neutron guides, coated with reflective material for the low-energy neutrons, will be used to transport the cold neutrons to the experimental site. The cold neutron guides would keep the cold neutrons within certain energy and angular space concentrated inside, while most of the gamma rays and high-energy neutrons are not affected by the cold neutron guides. For the KIPT design, the cold neutron guides need to extend several meters outside the main shield of the facility, and curved guides will also be used to remove the gamma and high-energy neutron. The neutron guides should be installed inside a shield structure to ensure an acceptable biological dose in the facility hall. Heavy concrete is the selected shielding material because of its acceptable performance and cost. Shield design analysis was carried out for the CNS guide hall. MCNPX was used as the major computation tool for the design analysis, with neutron and gamma dose calculated separately. Weight windows variance reduction technique was also used in the shield design. The goal of the shield design is to keep the total radiation dose below the $5.0{\mu}Sv/hr$ guideline outside the shield boundary. After a series of iterative MCNPX calculations, the shield configuration and parameters of CNS guide hall were determined and presented in this article.