• 제목/요약/키워드: cross combination

검색결과 567건 처리시간 0.024초

Multigroup cross-sections generated using Monte-Carlo method with flux-moment homogenization technique for fast reactor analysis

  • Yiwei Wu;Qufei Song;Kuaiyuan Feng;Jean-Francois Vidal;Hanyang Gu;Hui Guo
    • Nuclear Engineering and Technology
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    • 제55권7호
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    • pp.2474-2482
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    • 2023
  • The development of fast reactors with complex designs and operation status requires more accurate and effective simulation. The Monte-Carlo method can generate multi-group cross-sections in arbitrary geometry without approximation on resonances treatment and leads to good results in combination with diffusion codes. However, in previous studies, the coupling of Monte-Carlo generated multi-group cross-sections (MC-MGXS) and transport solvers has shown relatively large biases in fast reactor problems. In this paper, the main contribution to the biases is proved to be the neglect of the angle-dependence of the total cross-sections. The flux-moment homogenization technique (MHT) is proposed to take into account this dependence. In this method, the angular dependence is attributed to the transfer cross-sections, keeping an independent form for the total sections. For the MET-1000 benchmark, the multi-group transport simulation results with MC-MGXS generated with MHT are improved by 700 pcm and an additional 120 pcm with higher order scattering. The factors that cause the residual bias are discussed. The core power distribution bias is also significantly reduced when MHT is used. It proves that the MCMGXS with MHT can be applicable with transport solvers in fast reactor analysis.

딸기 내저온성 품종육성에 적합한 교배조합 선발 (Selection of Cross Combination for Development New Cultivar of Low Temperature Tolerant in Strawberry)

  • 이선이;김승유;김대영;정호정;노일래
    • 농업생명과학연구
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    • 제50권2호
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    • pp.45-52
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    • 2016
  • 딸기의 내저온성 품종육성을 위한 우수 교배친 선발을 위해 '다홍', '감홍', '매향', '설향'을 자방친으로 이용하고 '다홍', '감홍', '매향', '설향', '수경', '선홍', '원교3111호' 등을 화분친으로 하여 24조합을 작성하고 조합능력 검정을 실시하였다. 그 결과, 자방친을 '다홍'으로 하였을 경우에는 전체조합에서 과중이 작아지는 경향이 있었고, '감홍'은 생존율이 낮아 두 품종은 자방친으로 적합하지 않은 것으로 나타났다. 화분친에 있어서도 '선홍'을 화분친으로 이용한 경우 경도가 낮아지는 경향이 있었고, '수경'은 기형과가 다소 발생하는 경향이 있어 화분친으로 적합하지 않았다. 그러나 '매향'과 '설향'을 자방친으로 이용할 경우 발아율과 생존율이 상대적으로 높았고, 과실품질이 우수하고 수량성도 높은 것으로 나타났다. 따라서 '매향'과' 설향'이 자방친으로 우수하였고, 화분친으로는'매향', '설향', ' 원교3111호' 등이 우수하였다. 특히, '매향' × '설향', '설향' × '매향', '설향' × '원교3111호' 조합은 당도, 과실크기, 경도, 수량성 측면에서 우수성이 인정되기 때문에 내저온성 교배조합으로 적합하다고 판단된다.

대장암 환자의 경구용 항암제 복용이행과 영향요인 (Influencing Factors on Medication Adherence in Colorectal Cancer Patients Receiving Oral Chemotherapy)

  • 김정혜
    • 종양간호연구
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    • 제12권3호
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    • pp.213-220
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    • 2012
  • Purpose: The purpose of this study was to identify factors that influence medication adherence in colorectal cancer patients receiving oral chemotherapy. Methods: One hundred and nine colorectal cancer patients receiving oral chemotherapy were recruited in the cross-sectional survey design. A survey including medication adherence, knowledge about chemotherapy, self-efficacy, depression and symptom experience were completed. Results: The level of medication adherence was $7.38{\pm}.80$. Medication adherence showed significant differences according to perceived health status and combination of IV chemotherapy. Medication adherence was significant correlated with self-efficacy, depression and symptom experience. On stepwise regression analysis, the most important factors related to the medication adherence were symptom experience, perceived health status and combination of IV chemotherapy. These variables explained 17% of medication adherence. Conclusion: The level of medication adherence in colorectal cancer patients receiving oral chemotherapy was relatively high. It is important to develop nursing intervention for medication adherence in colorectal cancer patients that focus on symptom experience and to consider about perceived health status and combination of IV chemotherapy.

자바-네이티브 조합모델을 이용한 실시간 임베디드 미들웨어 시스템에 관한 연구 (Real-time Embedded Middleware System using Java-Native Combination Model)

  • 김광수;정민수;정준영
    • 대한전기학회논문지:시스템및제어부문D
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    • 제54권3호
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    • pp.141-147
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    • 2005
  • In the field of electrical industry, embedded computing environment including hardware and software is getting more important as the industry shifts to the knowledge-based one. Java could play a great role as bridging technology in such a transition because it provides a lot of benefits like dynamic application download, compatibility of cross platform, and its own security solution. However, the Java technology has a limitation of real-time problem when it is applied to the embedded computing system of the electrical industry. To solve the problem, a novel java-native combination model has been proposed and designed to a firmware level. This scheme has been employed in four kinds of control boards. The result shows that the proposed model has great potential to implement the real-time processing in control of the devices.

Catalytic Dehydrocoupling of Bis(1-sila-3-butyl)benzene and 2-Phenyl-1,3-disilapropane by Zirconocene Catalysts

  • 우희권;송선정
    • Bulletin of the Korean Chemical Society
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    • 제17권11호
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    • pp.1040-1044
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    • 1996
  • The catalytic dehydrocoupling of bis(1-sila-3-butyl)benzene, 1 by Cp2ZrCl2/Red-Al and Cp2ZrCl2/n-BuLi combination catalysts yielded a mixture of oily and solid polymers. While the catalytic dehydrocoupling of 2-phenyl-l,3-disilapropane, 2 by Cp2ZrCl2/n-BuLi combination catalyst produced a mixture of oily and solid polymers, the catalytic redistribution/dehydrocoupling of 2 by Cp2ZrCl2/Red-Al combination catalyst gave oily polymer. The dehydrocoupling of 1 and 2, unless the prior silane redistribution occurs, seems to initially produce a low-molecular-weight polymer, which then undergoes an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble polymer.

Quantitative analysis of rutin content using silkworm genetic resources

  • Ju, Wan-Taek;Kim, Kee-Young;Sung, Gyoo-Byung;Kim, Yong-Soon
    • International Journal of Industrial Entomology and Biomaterials
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    • 제31권2호
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    • pp.56-61
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    • 2015
  • Rutin is an important bioflavonoid that is consumed in the daily diet. This study compared the functional components of rutin from various silkworm species using a gene database with those of rutin produced by silkworms selectively bred through cross-combinations. We made comparisons between the geographical origin and species of silkworm using a gene database and discovered that rutin activity was ranked in the following order by species, Chinese (C5)> miscellaneous varieties (Jamsaeng 1 Ho) >Japanese (Jam 115) > European (E58) >Korean (Sun 3 ho). However, rutin levels with respect to various genetic traits (blood color, silk color, and egg color) were consistent. In order to study rutin changes that occurred during the cross breeding of the silkworm gene, we bred cross-combinations utilizing Jam 115 and the 4051 silkworms. In conclusion, in order to provide information about the constituents of functional materials contained in silkworm powder, it is imperative that silkworm cross breeding occurs so that the database of functional materials extracted from silkworms will expand.

Quantitative Analysis of 1-Deoxynojirimycin Content Using Silkworm Genetic Resources

  • Ju, Wan-Taek;Kim, Kee-Young;Sung, Gyoo-Byung;Kim, Yong-Soon
    • International Journal of Industrial Entomology and Biomaterials
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    • 제29권2호
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    • pp.162-168
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    • 2014
  • 1-Deoxynojirimycin(1-DNJ or DNJ), a component in silkworm powder, prevents glucose from being absorbed into the bloodstream from the small intestine by inhibiting ${\alpha}$-glucosidase activity. This study compared the functional components of 1-DNJ from various silkworm species using a gene database with those of 1-DNJ produced by silkworms bred through cross-combinations. We utilized comparisons of geographical origins and species of silkworms using a gene database and discovered that 1-DNJ activity was ranked in the following order by species, Japanese (SK-1) > Chinese (C48) > European (Rock191). 1-DNJ constituted varying percentages of silkworm organs in the following order, blood > epithelial tissue > body fat > silk glands. With regard to sex, 1-DNJ, levels were higher in males than females. However, 1-DNJ levels with respect to various genetic traits (blood color, silk color, and egg color) were consistent. In order to study 1-DNJ changes that occurred during cross breeding of the silkworm gene, we bred cross-combinations utilizing SK-1 and C48 silkworms. In conclusion, in order to provide information about the constituents of functional materials contained in silkworm powder, it is imperative that silkworm cross breeding occurs so that the database of functional materials extracted from silkworms will expand.

자연환기와 복사냉방을 병용한 하이브리드 시스템의 제안 (A Proposal of Hybrid Cooling System Coupled with Radiation Panel Cooling and Natural Ventilation)

  • 송두삼
    • 설비공학논문집
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    • 제15권6호
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    • pp.543-550
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    • 2003
  • In order to saving the energy for HVAC system of buildings, utilization of wind-induced cross ventilation is thought to be promising. However, utilization of natural ventilation alone is not sufficient for maintaining the human thermal-comfort such as in hot and humid regions. A hybrid air conditioning system with a controlled natural ventilation system, or combination of natural ventilation with mechanical air conditioning is thought to overcome the deficiency of wind-driven cross ventilation and to have significant effects on energy reduction. This paper describes a concept of hybrid system and propose a new type of hybrid system using radiational cooling with wind-induced cross ventilation. Moreover, a radiational cooling system is compared with an all-air cooling system. The characteristics of the indoor environment will be examined through CFD (Computational Fluid Dynamics) simulation, which is coupled with a radiation heat transfer simulation and with HVAC control in which the PMV value for the human model in the center of the room is controlled to attain the target value.

Optimal Path Planning for UAVs to Reduce Radar Cross Section

  • Kim, Boo-Sung;Bang, Hyo-Choong
    • International Journal of Aeronautical and Space Sciences
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    • 제8권1호
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    • pp.54-65
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    • 2007
  • Parameter optimization technique is applied to planning UAVs(Unmanned Aerial Vehicles) path under artificial enemy radar threats. The ground enemy radar threats are characterized in terms of RCS(Radar Cross Section) parameter which is a measure of exposure to the radar threats. Mathematical model of the RCS parameter is constructed by a simple mathematical function in the three-dimensional space. The RCS model is directly linked to the UAVs attitude angles in generating a desired trajectory by reducing the RCS parameter. The RCS parameter is explicitly included in a performance index for optimization. The resultant UAVs trajectory satisfies geometrical boundary conditions while minimizing a weighted combination of the flight time and the measure of ground radar threat expressed in RCS.