• 제목/요약/키워드: Post-Net

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Ecological Studies on the Vegetation of Castanea crenata Community and Both Sides

  • Huh, Man-Kyu;Cho, Joo-Soo;Jang, Gi-Bong
    • 한국환경과학회지
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    • 제17권1호
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    • pp.1-6
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    • 2008
  • The characters of Castanea crenata community which is associated with human activities recently extended around the field of Saengbiryang-myeon at Sanseong-gun in Gyeongsangnam-do. The C. crenata community and its outskirts were investigated for several ecological parameters and the results can be summarized as fellows. C. crenata is prevailing in the plantation area, whereas Pinus densiflora and Quercus mongolica are prevailing in its outskirts. The mean species diversity of plantation was lower than that of natural forests. In stratification of investigated areas, overstory tree layer was dominant in the zone of plantation and dominant layers in the natural forest were understory tree layer, shrub, and herb. Plant biomass and net production which estimated from degree of green naturality were much higher in natural forests than those of the plantation community. Least significant differences (LSD) post hoc analysis revealed that P. densiflora and Q. mongolica community had significantly greater than densities than C. crenata community.

사출성형의 보압과정에 관한 연구

  • 이호상;전형환;한진현;설권;한창훈
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 추계학술대회 논문집
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    • pp.46-50
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    • 2001
  • Due to its ability in producing a net-shape product to high precision in a very shot cycle time, injection molding has become one of the most important polymer-processings in the industry today. Recently the CAE applications in the field of injection molding have provided significant contributions to the mold design and process optimization. As a part of such an application the packing process has been studied using C-PARK. The prediction of pressure variations during post-filling stage for amorphous material has been compared with an experimental observation for a simple rectangular geometry of uniform thickness. And the optimal packing processes were calculated using the cavity pressure curve near the gate. As a case study, a warpage simulation was carried out for a DY-HOLDER with the variable number of gates.

OVERVIEW OF CONTAINMENT FILTERED VENT UNDER SEVERE ACCIDENT CONDITIONS AT WOLSONG NPP UNIT 1

  • Song, Y.M.;Jeong, H.S.;Park, S.Y.;Kim, D.H.;Song, J.H.
    • Nuclear Engineering and Technology
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    • 제45권5호
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    • pp.597-604
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    • 2013
  • Containment Filtered Vent Systems (CFVSs) have been mainly equipped in nuclear power plants in Europe and Canada for the controlled depressurization of the containment atmosphere under severe accident conditions. This is to keep the containment integrity against overpressure during the course of a severe accident, in which the radioactive gas-steam mixture from the containment is discharged into a system designed to remove the radionuclides. In Korea, a CFVS was first introduced in the Wolsong unit-1 nuclear power plant as a mitigation measure to deal with the threat of over pressurization, following post-Fukushima action items. In this paper, the overall features of a CFVS installation such as risk assessments, an evaluation of the performance requirements, and a determination of the optimal operating strategies are analyzed for the Wolsong unit 1 nuclear power plant using a severe accident analysis computer code, ISAAC.

INFLUENCE OF FUEL-MATRIX INTERACTION ON THE BREAKAWAY SWELLING OF U-MO DISPERSION FUEL IN AL

  • Ryu, Ho Jin;Kim, Yeon Soo
    • Nuclear Engineering and Technology
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    • 제46권2호
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    • pp.159-168
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    • 2014
  • In order to advance understanding of the breakaway swelling behavior of U-Mo/Al dispersion fuel under a high-power irradiation condition, the effects of fuel-matrix interaction on the fuel performance of U-Mo/Al dispersion fuel were investigated. Fission gas release into large interfacial pores between interaction layers and the Al matrix was analyzed using both mechanistic models and observations of the post-irradiation examination results of U-Mo dispersion fuels. Using the model predictions, advantageous fuel design parameters are recommended to prevent breakaway swelling.

Post-Fukushima challenges for the mitigation of severe accident consequences

  • Song, JinHo;An, SangMo;Kim, Taewoon;Ha, KwangSoon
    • Nuclear Engineering and Technology
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    • 제52권11호
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    • pp.2511-2521
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    • 2020
  • The Fukushima accident is characterized by the fact that three reactors at the same site experienced reactor vessel failure and the accident resulted in significant radiological release to the environment, which was about 1/10 of the Chernobyl releases. The safe removal of fuel debris in the reactor vessel and Primary Containment Vessel (PCV) and treatment of huge amount of contaminated water are the major issues for the decommissioning in coming decades. Discussions on the new researches efforts being carried out in the area of investigation of the end state of fuel debris and Boling Water reactor (BWR) specific core melt progression, development of technologies for the mitigation of radiological releases to comply with the strengthened safety requirement set after the Fukushima accident are discussed.

실시간 우편물류 운영시스템 설계에 관한 연구 (Design for Real-Time Postal Logistics Operational System)

  • 이기백;김완석;박종흥
    • 산업공학
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    • 제20권4호
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    • pp.547-559
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    • 2007
  • In this paper, we design Real-Time Postal Logistics Operational Model and System as a to-be system. Current postal logistics information system, named PostNet, is a basic infra system designed for an end-to-end IT-driven process, from mail acceptance to delivery, linked with internal and external systems. Recent competing circumstances drive demand for more intelligent information system. So we design real-time postal logistics operational system focused on site operations. we analyze postal logistics operation and interview field workers and establish real-time postal logistics operational model to solve operational issues. Finally we suggest system specifications.

Damages, Human Behaviour and Recovery of Urban Residents in the 2005 West off Fukuoka Earthquake

  • Murakami, H.
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.13-18
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    • 2008
  • The 2005 west off Fukuoka earthquake with Mjma 7.0 occurred in the vicinity of Fukuoka city with 1.4 million populations, which had been regarded as rather seismically inactive in Japan. The strong motion records by K-net indicated PGV of 64 cm/s in Fukuoka city and some condominium buildings sustained extensive non-structural damages. In this study, we conducted a questionnaire survey for residents of 8 condominium buildings located in the downtown area of Fukuoka city after the earthquake. The results indicate that damaged nonstructural walls and distorted doors disrupted evacuation route for many occupants, and furniture and content damage on upper floors became severer resulting in higher rates of human casualty. Earthquake preparedness for indoor safety was raised after the earthquake, though further safety measures can be advised. In the phase of post-earthquake emergency and restoration period, residents' management organizations play important roles, so that neighborhood activities to promote communication networks are important in urban environment with aging population.

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THE DEVELOPMENT OF A SAFETY ASSESSMENT APPROACH AND ITS IMPLICATION ON THE ADVANCED NUCLEAR FUEL CYCLE

  • Hwang, Yong-Soo;Kang, Chul-Hyung
    • Nuclear Engineering and Technology
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    • 제42권1호
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    • pp.37-46
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    • 2010
  • The development of advanced nuclear fuel cycle(ANFC) technology is essential to meet the national mission for energy independence via a nuclear option in Korea. The action target is to develop environmentally friendly, cost-effective measures to reduce the burden of long term disposal. The proper scenarios regarding potential radionuclide release from a repository have been developed in this study based on the advanced korean Reference Disposal System(A-KRS). To predict safety for the various scenarios, a new assessment code based on the GoldSim software has also been developed. Deterministic analysis indicates an environmental benefit from the ANFC as long as the solid waster from the ANFC act as a proper barrier.

Impact of hydrogen on rupture behaviour of Zircaloy-4 nuclear fuel cladding during loss-of-coolant accident: a novel observation of failure at multiple locations

  • Suman, Siddharth
    • Nuclear Engineering and Technology
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    • 제53권2호
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    • pp.474-483
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    • 2021
  • To establish the exclusive role of hydrogen on burst behaviour of Zircaloy-4 during loss-of-coolant accident transients, an extensive single-rod burst tests were conducted on both unirradiated as-received and hydrogenated Zircaloy-4 cladding tubes at different heating rates and internal overpressures. The visual observations of cladding tubes during bursting as well as post-burst are presented in detail to understand the effect of hydrogen concentration, heating rate, and internal pressure. Impact of hydrogen on burst parameters-burst stress, burst strain, burst temperature-during loss-of-coolant accident transients are compared and discussed. Rupture at multiple locations for hydrogenated cladding at lower internal pressure and higher heating rate is reported for the very first time. A novel burst criterion accounting hydrogen concentration in nuclear fuel cladding is proposed.