• Title/Summary/Keyword: core capability

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Counter-Current Flow Limit in Narrow Gap (간극에서의 역방향 유동 제한 현상 연구)

  • Kim, Yong-Hoon;Suh, Kune-Y.
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.706-712
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    • 1998
  • Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

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Counter-Current Flow Limit in Narrow Gap (간극에서의 역방향 유동 제한 현상 연구)

  • Kim, Yong-Hoon;Suh, Kune-Y.
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.386-392
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    • 1998
  • Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the Maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

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Development of Portable Conversation-Type English Leaner (대화식 휴대용 영어학습기 개발)

  • Yoo, Jae-Tack;Yoon, Tae-Seob
    • Proceedings of the KIEE Conference
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    • 2004.05a
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    • pp.147-149
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    • 2004
  • Although most of the people have studied English for a long time, their English conversation capability is low. When we provide them portable conversational-type English learners by the application of computer and information process technology, such portable learners can be used to enhance their English conversation capability by their conventional conversation exercises. The core technology to develop such learner is the development of a voice recognition and synthesis module under an embedded environment. This paper deals with voice recognition and synthesis, prototype of the learner module using a DSP(Digital Signal Processing) chip for voice processing, voice playback function, flash memory file system, PC download function using USB ports, English conversation text function by the use of SMC(Smart Media Card) flash memory, LCD display function, MP3 music listening function, etc. Application areas of the prototype equipped with such various functions are vast, i.e. portable language learners, amusement devices, kids toy, control by voice, security by the use of voice, etc.

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Reactivity feedback effect on loss of flow accident in PWR

  • Foad, Basma;Abdel-Latif, Salwa H.;Takeda, Toshikazu
    • Nuclear Engineering and Technology
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    • v.50 no.8
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    • pp.1277-1288
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    • 2018
  • In this work, the reactor kinetics capability is used to compute the design safety parameters in a PWR due to complete loss of coolant flow during protected and unprotected accidents. A thermal-hydraulic code coupled with a point reactor kinetic model are used for these calculations; where kinetics parameters have been developed from the neutronic SRAC code to provide inputs to RELAP5-3D code to calculate parameters related to safety and guarantee that they meet the regulatory requirements. In RELAP5-3D the reactivity feedback is computed by both separable and tabular models. The results show the importance of the reactivity feedback on calculating the power which is the key parameter that controls the clad and fuel temperatures to maintain them below their melting point and therefore prevent core melt. In addition, extending modeling capability from separable to tabular model has nonremarkable influence on calculated safety parameters.

An investigative study of enrichment reduction impact on the neutron flux in the in-core flux-trap facility of MTR research reactors

  • Xoubi, Ned;Darda, Sharif Abu;Soliman, Abdelfattah Y.;Abulfaraj, Tareq
    • Nuclear Engineering and Technology
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    • v.52 no.3
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    • pp.469-476
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    • 2020
  • Research reactors in-core experimental facilities are designed to provide the highest steady state flux for user's irradiation requirements. However, fuel conversion from highly enriched uranium (HEU) to low enriched uranium (LEU) driven by the ongoing effort to diminish proliferation risk, will impact reactor physics parameters. Preserving the reactor capability to produce the needed flux to perform its intended research functions, determines the conversion feasibility. This study investigates the neutron flux in the central experimental facility of two material test reactors (MTR), the IAEA generic10 MW benchmark reactor and the 22 MW s Egyptian Test and Research Reactor (ETRR-2). A 3D full core model with three uranium enrichment of 93%, 45%, and 20% was constructed utilizing the OpenMC particle transport Monte Carlo code. Neutronics calculations were performed for fresh fuel, the beginning of life cycle (BOL) and end of life cycle (EOL) for each of the three enrichments for both the IAEA 10 MW generic reactor and core 1/98 of the ETRR-2 reactor. Criticality calculations of the effective multiplication factor (Keff) were executed for each of the twelve cases; results show a reasonable agreement with published benchmark values for both reactors. The thermal, epithermal and fast neutron fluxes were tallied across the core, utilizing the mesh tally capability of the code and are presented here. The axial flux in the central experimental facility was tallied at 1 cm intervals, for each of the cases; results for IAEA 10 MW show a maximum reduction of 14.32% in the thermal flux of LEU to that of the HEU, at EOL. The reduction of the thermal flux for fresh fuel was between 5.81% and 9.62%, with an average drop of 8.1%. At the BOL the thermal flux showed a larger reduction range of 6.92%-13.58% with an average drop of 10.73%. Furthermore, the fission reaction rate was calculated, results showed an increase in the peak fission rate of the LEU case compared to the HEU case. Results for the ETRR-2 reactor show an average increase of 62.31% in the thermal flux of LEU to that of the HEU due to the effect of spectrum hardening. The fission rate density increased with enrichment, resulting in 34% maximum increase in the HEU case compared to the LEU case at the assemblies surrounding the flux trap.

The Improvement on Proposal Evaluation System of National Defense Core Technology R&D Projects (국방핵심기술 연구개발과제의 선정평가 개선 연구)

  • Kim, Chan-Soo;Cho, Kyu-Kab
    • Journal of Technology Innovation
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    • v.15 no.2
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    • pp.123-152
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    • 2007
  • The striking characteristic of the contemporary global security environment is that the nature of threats has become diverse and complex. For example, transnational and non-military threats including terrorism and proliferation of weapon of mass destruction has increased. In this security environment, Advanced countries funnel their investments for defense budgets into the assurance of key force capability and R&D of cutting-edge core technologies, in consideration of future battlefield environments so as to get an edge on not only defense science and technology but also intelligence capabilities. As shown by past practices of the korea's defense acquisition, the ministry of national defense has tried to enhance its force capabilities in the short-term by purchasing foreign weapon systems rather than by investing in domestic R&D. Accordingly, the technological gaps between the korea and advanced countries were widened due to both insufficient investment in development of domestic technologies and avoidance of technological transfer by advanced countries. Thus, for the effective execution of the R&D budget and the successful performance of the projects, the importance of selection, management and evaluation of the R&D projects is emphasized. So, The objective of this study is that the analysis of the proposal-selection evaluation system for the realization of the successful defense core technology R&D projects. This study focused on the improvement of the proposal-selection evaluation model which can be applicable to the national defense core R&D projects. Using the improved proposal-selection evaluation system, we propose a model to enhance the reliability of the national defense core technology R&D project evaluation system.

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CHARACTERISTICS OF SELF-LEVELING BEHAVIOR OF DEBRIS BEDS IN A SERIES OF EXPERIMENTS

  • Cheng, Songbai;Yamano, Hidemasa;Suzuki, TYohru;Tobita, Yoshiharu;Nakamura, Yuya;Zhang, Bin;Matsumoto, Tatsuya;Morita, Koji
    • Nuclear Engineering and Technology
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    • v.45 no.3
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    • pp.323-334
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    • 2013
  • During a hypothetical core-disruptive accident (CDA) in a sodium-cooled fast reactor (SFR), degraded core materials can form roughly conically-shaped debris beds over the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of the core material pool. However, coolant boiling may ultimately lead to leveling of the debris bed, which is crucial to the relocation of the molten core and heat-removal capability of the debris bed. To clarify the mechanisms underlying this self-leveling behavior, a large number of experiments were performed within a variety of conditions in recent years, under the constructive collaboration between the Japan Atomic Energy Agency (JAEA) and Kyushu University (Japan). The present contribution synthesizes and gives detailed comparative analyses of those experiments. Effects of various experimental parameters that may have potential influence on the leveling process, such as boiling mode, particle size, particle density, particle shape, bubbling rate, water depth and column geometry, were investigated, thus giving a large palette of favorable data for the better understanding of CDAs, and improved verifications of computer models developed in advanced fast reactor safety analysis codes.

A Study of the Impacts of Strategic Orientation on the Performance in Technology-based Start-ups (기술창업시 전략적 지향성이 창업성과에 미치는 영향)

  • Jang, Dong-Kwan;Song, In-Am;Hwang, Hee-Joong
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.37-45
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    • 2013
  • Purpose - Appropriate response to the fast changing economic environment determines SMEs' competiveness in the era of globalization and open market and, therefore, government policies to strengthen SME's competitiveness will be very important in the future. It is time to investigate the element of strategic orientation that is necessary for strengthening the competitiveness of SMEs, and its effect on the success of a business start-up. This study analyzes the network orientation in addition to existing strategic orientation, and focuses on price and quality management capability as mediators for strategic orientation and outcomes of business start-ups. Research design/data/methodology - The orientations of technology-based business founders were classified into market, technology, network, and entrepreneurial orientation. We then investigated the effect of these orientations on product price and quality management capability, as well as the influence of price and quality management capability on the outcome of a business start-up. This study is based on the nation-wide survey of the founders and members of technology-based business establishments. The survey was administered to 300 selected companies via email for a period of one month, at the end of which 175 companies replied with valid answers. Further, for effective and objective research, we used SPSS 14.0 and Amos 7.0 for structural equation modeling assumptions and hypothesis verification. Results - Except for entrepreneurial orientation, the other three orientations, namely, technology, market, and network orientations, affect the price management capability according to our results. The price management capability relates significantly with the sales and customer satisfaction. Especially, technology orientation is the core competency of start-ups that affects price and quality management capabilities. However, technology and entrepreneurial orientation do not influence the outcome of business start-ups, but affect their quality management capabilities. Conclusions - This study confirms that the strategic orientation affects product price as well as quality management capabilities, to introduce new products and achieve successful outcomes. In conclusion, new business founders face the dilemma of trade-off between price and quality in the planning stage of new product development. In particular, price management capability directly affects the outcome. Therefore, price management is more important for a successful start-up than quality management. Especially, during the initial stages of starting up a new business, price management capability entails following the market-leading company, or price penetration strategy. In this stage, price management is dependent on the information from outside rather than on the founder's decision, and it directly affects sales performance and customer satisfaction. In contrast, quality management capability is directly related to the technology capability and market experience of founders. In this case, subjective and proactive decision making is required for differentiation and development of demand in the niche market, which does not directly influence the sales performance and customer satisfaction.

A Study on the Relationships among ICT Capability, Global Orientation and Export Marketing in Korean SMEs (중소기업의 ICT 역량, 글로벌지향성 및 수출마케팅의 관계에 대한 연구)

  • Rhee, Yang-Pok
    • Korea Trade Review
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    • v.42 no.2
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    • pp.251-276
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    • 2017
  • The utilization of Digital and Social Network has become be a key success factor in business operations as information technologies evolve rapidly. This study is to identity the relationship between ICT & digital utilization, global orientation and export marketing capability in Korean SMEs. Survey data of Korean SMEs in south regional areas was collected and analyzed for empirical hypothesis test by PLS structural equation method. The key findings are as follows. First, ICT utilization such as SNS, homepage and online portal does not impact directly on export marketing capability. It means that SMEs would not still take advantage of utilization of social network availability. Second, ICT utilization has positive influences on global market orientation and global network orientation. Finally, both global market orientation and network have significant impacts on export marketing capability. In conclusion, global orientation has full-mediation effects on relationship between ICT capability and global marketing. This study provides evidences and some practical insights that digital utilization have indirect influences on global marketing through global markets and network orientation in Korean SMEs. In information technology era, ICT utilization will play an important role in the process of SMEs' internationalization. Therefore, for sustainable growth and survival SMEs should manage and intensify ICT capability more strategically as one of core competence. The value of ICT capability in SMEs would be depended on their strategic perspectives toward digitalization. Additional empirical research about digital capability based on larger sample will be needed.

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An Effective Project risk Management Based on Systems Engineering (시스템엔지니어링에 기반한 효과적인 리스크 관리)

  • Kang, Top;Kim, Sung-Cheol;Oh, Jung-Taek
    • Journal of the Korean Society of Systems Engineering
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    • v.7 no.1
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    • pp.43-51
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    • 2011
  • SE generally defines approaching ways of conducting identification, verification and integration of an optimized product and process solution to meet customer's needs by leveraging organizational competency in engineering and management. To successfully develop a new product under mass production contract, it is important to efficiently carry out the program by ensuring that three major competencies are secured; core technology, system integration, and program management. For successful implementation of tasks in the three areas, systematic execution is called for, which requires identifying risk factors in advance. In particular, comprehensive risk management role and responsibility is required for program management. Success of a development program is determined by complex elements of human resources, organization culture, and overall competency of an organization in technology and program management, including capability of the program manager. In this paper, a risk management solution is suggested to lead a program to success with a more efficient way through actual risk management by the concept of SE around the above three areas.