• Title/Summary/Keyword: Critical Science Research

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Monte Carlo Analysis of the Accelerator-Driven System at Kyoto University Research Reactor Institute

  • Kim, Wonkyeong;Lee, Hyun Chul;Pyeon, Cheol Ho;Shin, Ho Cheol;Lee, Deokjung
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.304-317
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    • 2016
  • An accelerator-driven system consists of a subcritical reactor and a controllable external neutron source. The reactor in an accelerator-driven system can sustain fission reactions in a subcritical state using an external neutron source, which is an intrinsic safety feature of the system. The system can provide efficient transmutations of nuclear wastes such as minor actinides and long-lived fission products and generate electricity. Recently at Kyoto University Research Reactor Institute (KURRI; Kyoto, Japan), a series of reactor physics experiments was conducted with the Kyoto University Critical Assembly and a Cockcrofte-Walton type accelerator, which generates the external neutron source by deuteriu-metritium reactions. In this paper, neutronic analyses of a series of experiments have been re-estimated by using the latest Monte Carlo code and nuclear data libraries. This feasibility study is presented through the comparison of Monte Carlo simulation results with measurements.

Production of Fe-Si-Cr Ferro Alloy by Using Mixed Silicothermic and Carbothermic Reduction (실리콘 및 탄소 복합 열환원 반응을 이용한 페로실리크롬 합금철의 제조)

  • Kim, Jong Ho;Jung, Eun Jin;Lee, Go-Gi;Jung, Woo-Gwang;Yu, Seon Jun;Chang, Young Chul
    • Korean Journal of Materials Research
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    • v.27 no.5
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    • pp.263-269
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    • 2017
  • Fe-Si-Cr ferroalloy is predominantly produced by carbothermic reduction. In this study, silicothermic and carbothermic mixed reduction of chromite ore to produce Fe-Si-Cr alloy is suggested. As reductants, silicon and silicon carbide are evaluated by thermochemical calculations, which prove that silicon carbide can be applied as a raw material. Considering the critical temperature of the change from the carbide to the metallic form of chromium, thereduction experiments were carried out. In these high temperature reactions, silicon and silicon carbide act as effective reductants to produce Fe-Si-Cr ferroalloy. However, at temperatures lower than the critical temperature, silicon carbide shows a slow reaction rate for reducing chromite ore. For the proper implementation of a commercial process that uses silicon carbide reductants, the operation temperature should be kept above the critical temperature. Using equilibrium calculations for chromite ore reduction with silicon and silicon carbide, the compositions of reacted metal and slag were successfully predicted. Therefore, the mass balance of the silicothermic and carbothermic mixed reduction of chromite ore can be proposed based on the calculations and the experimental results.

A Survey of QoS Based Routing Protocols for Wireless Sensor Networks

  • Sumathi, R.;Srinivas, M.G.
    • Journal of Information Processing Systems
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    • v.8 no.4
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    • pp.589-602
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    • 2012
  • With the increasing demand for real time applications in the Wireless Senor Network (WSN), real time critical events anticipate an efficient quality-of-service (QoS) based routing for data delivery from the network infrastructure. Designing such QoS based routing protocol to meet the reliability and delay guarantee of critical events while preserving the energy efficiency is a challenging task. Considerable research has been focused on developing robust energy efficient QoS based routing protocols. In this paper, we present the state of the research by summarizing the work on QoS based routing protocols that has already been published and by highlighting the QoS issues that are being addressed. The performance comparison of QoS based routing protocols such as SAR, MMSPEED, MCMP, MCBR, and EQSR has also been analyzed using ns-2 for various parameters.

A Study on Critical Success Factor Analysis and its Usage : An Aplication Study to the Steel Industry in Korea (주요성과요인분석과 그 활용방안에 관한 연구 :한국 철강산업에의 적용사례)

  • 문태수;신영종
    • Korean Management Science Review
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    • v.8 no.1
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    • pp.13-25
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    • 1991
  • Over the past few years, there has been a growing interest in using information technology for competitive advantage. A sustainable advantage is the key to the survival and growth of a firm. The successful implementation of information technology is dependent on efficient information systems planning. But the correct and complete information, requirements for effective information systems planning are frequently very difficult to obtain. In this paper the Critical Success Factors(CSF) method was employed as a means of managerial information requirements analysis for information systems planning in Korea's steel industry. CSFs are one of the few areas of activity that must go well to ensure the success of an organization. This paper addresses the concept and hierarchy of CSF analysis as a methodology in identifying corporate information needs and concludes with the use and benefit of results of CSF analysis.

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A Feminist Approach to Theory Evaluation

  • Im, Eun-Ok
    • Perspectives in Nursing Science
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    • v.1 no.1
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    • pp.50-65
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    • 2004
  • Despite the new wave of diverse philosophical thoughts in nursing, the criteria for theory evaluation rarely incorporate the new thoughts in its realm. Especially, feminist thoughts, which have contributed to the development of nursing knowledge through incorporating diversities and complexities of nursing phenomenon and reflecting social, cultural, and historical contexts surrounding nursing encounters, were rarely incorporated into the evaluation criteria. In this paper, a feminist approach to theory evaluation is proposed based on a critical analysis of the existing evaluation criteria. First, a historical review of feminist thoughts is provided, and feminist principles across diverse groups of thinking within feminism are discussed. Then, theory evaluation criteria are historically analyzed and critiqued while considering the feminist principles. The critical points found in the currently available theory evaluation criteria include: (a) the evaluation criteria are based on objectivity, (b) they are ignoring gender differences; (c) cultural differences tend not to be seriously considered; and (d) contexts surrounding nursing phenomenon are rarely considered. Based on the critical points, four additional components for theory evaluation are proposed. The components are: (a) respect for subjectivity; (b) historical and sociopolitical contextual considerations; (c) gender sensitivity; (d) cultural competence; and (e) blueprint for action.

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A Study regarding the Customer Loyalty of Korean-Style Food Restaurant (외식업체 한식 레스토랑의 고객 충성도에 관한 연구)

  • Jung, Young-Joo;Choi, Duck-Joo
    • Culinary science and hospitality research
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    • v.10 no.1
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    • pp.46-63
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    • 2004
  • The service quality factors which causes an effect in restaurant selections appeared with gain and loss factors of essence and the customers. The restaurant recommendation factor was appeared with shedding of blood characteristics. The research which sees Korean-style food party's decision making is difficult with the plan of the security and loyalty of customers presented. The marketing strategy for the customer loyalty of Korean-style food party will be able to be overcome. The critical point of the research which sees for the security of the loyalty customer selects a target market, and the strategy which invades intensively is necessary. The Korean-style food party decision may cause the customer fractionation anger which follows in market fractionation anger. It does not become accomplished from the research which sees but with the critical point of research to appear, the research of creation of the loyalty customer who applies a market fractionation anger necessity will be becomes feed with hereafter research subject.

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Stress Expression by the Maternally Transferred Xenobiotic Pollutants in the Reproductive Outputs of the Pacific Oyster, Crassostrea gigas

  • Jo, Qtae;Choy, Eun-Jung;Lee, Su-Jeong;Cho, Yong-Chul;Lee, Chu;Kim, Yoon
    • Journal of Aquaculture
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    • v.18 no.3
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    • pp.200-206
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    • 2005
  • We previously pointed out that the polluted sediment elutriate manifestly affected the early events of reproductive outputs in the Pacific oysters, Crassostrea gigas. A serial dilution of priority xenobiotic sediment elutriates determined by gas chromatography/mass spectrometry (GC/MS) were exposed to gametes of the oyster with different stress burdens to detail the maternal stress transfer to its reproductive outputs. There was an apparent critical concentration over which survival and morphogenesis were significantly affected with more profound damage in morphogenesis. The critical concentration which drives mortality and abnormal morphogenesis of the larvae corresponded to a dilution between 10 and 20% of our elutriate. The adverse effects of the early lives by the xenobiotic exposure over the critical concentration were magnified by the maternal stress from the exposed benzo(a)pyrene (BaP), one of the priority polyaromatic hydrocarbons (PAHs) during the maturation condition. These results indicate that maternal transfer of the xenobiotic compounds from oysters living in the contaminated location might represent a significant adverse effect to their larval population of wild seeds.