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Determination of Optimum Batch Size and Fuel Enrichment for OPR1000 NPP Based on Nuclear Fuel Cycle Cost Analysis (OPR1000 발전소의 핵연료 주기비분석을 통한 최적 배취 크기와 핵연료 농축도 결정)

  • Cho, Sung Ju;Hah, Chang Joo
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.256-262
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    • 2014
  • Cycle length of domestic nuclear power plants is determined by the demand-supply plan of utility company. The target cycle length is achieved by adjusting the number of feed fuel assembly and fuel enrichment. Traditionally, utility company first select the number of feed fuel assembly and then find out the fuel enrichment to achieve the special cycle length. But it is difficult to find out if this method is most economical than any other combinations of the enrichment and batch size satisfying the same cycle length. In this paper, core depletion calculation is performed to find out the optimum combination of the enrichment and batch size for given target cycle length in terms of fuel cycle cost using commercial core design code; CASMO/MASTER code. To minimize the uncertainty resulting from transition core analysis, levelized fuel cycle cost analysis was applied to the equilibrium cycle core in order to determine the optimum combination. The sensitivity study of discount rate was also carried out to analyze the levelized fuel cycle cost applicable to countries with different discount rates. From the levelized fuel cycle cost analysis results, the combination with smaller batch size and higher fuel enrichment becomes more economical as the discount rate becomes lower. On the other hand, the combination with higher batch size and lower fuel enrichment becomes more economical as the discount rate becomes higher.

The Clinicopathologic Features and Prognosis of Multiple Early Gastric Cancer (다발성 조기위암의 임상적 특징과 예후)

  • Ahn, Young-Jae;Oh, Sung-Jin;Song, Jye-Won;Kang, Wook-Ho;Hyung, Woo-Jin;Choi, Seung-Ho;Noh, Sung-Hoon
    • Journal of Gastric Cancer
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    • v.8 no.4
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    • pp.198-203
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    • 2008
  • Purpose: Multiple early gastric cancer (MEGC) accounts for between 4.5% and 11.7% of all early gastric cancers (EGC). We investigated the treatment of MEGC from the viewpoint of the clinicopathologic features of the disease. Materials and Methods: 2,281 patients with EGC underwent gastric resection at the Department of Surgery, Severance Hospital during the 11 years between January 1994 and December 2004 and we carried out a retrospective analysis of these patients. Results: There were 91 cases of synchronous MEGC (4.0%) according to the diagnostic criteria of Moertel: there were 81 double, 9 triple and 1 quadruple lesions. Of the 102 accessory lesions, 64 (62.7%) were less than 10 mm in diameter and 83 (81.4%) were located in the same region as the main lesion. The most frequent histologic type of main lesion was a well differentiated adenocarcinoma, which was found in 52 cases (57.1%). There were 49 mucosal main lesions and 42 submucosal main lesions. Lymph node metastasis was detected in 6 cases (6.6%): 1 in mucosal lesions and 5 in submucosal main lesions Conclusion: Solitary EGC and MEGC had very similar clinopathological features and a similar prognosis. Therefore, we believe that the general EGC treatment guidelines can be applied for multiple EGC. It is important to evaluate the whole stomach before and during the operation and then after examining the resected specimen.

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Characteristics of Night Specialized Traffic Accident Hotspot Using Continuous Risk Profile (CRP) Analysis (CRP (Continuous Risk Profile) 분석을 이용한 야간 특화 교통사고 다발구간의 특성)

  • Kim, Heesoo;Oh, Heungun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.1
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    • pp.49-56
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    • 2021
  • The purpose of this study is to develop a methodology to select a cluster of night traffic accidents using CRP (Continuous Risk Profile) analysis. the other purpose of this study is to present the characteristics of the traffic accident cluster section selected at night using CRP analysis. The CRP analysis was performed considering traffic volume of target routes through traffic accident data. In addition, variables were set according to the freeway sections. the method of subtracting the daytime CRP from the nighttime CRP was used to analyze the nighttime traffic accident. As a result, Using the CRP analysis, the sections of hotspot were identified and plotted based on traffic accidents. Also, the sections where traffic accidents are frequent were those where IC or Tunnels were installed, and there was a deviation from the general section. In conclusion, CRP analysis could be used to calculate the frequent section of specialized traffic accidents at night, and it was selected as a point in need of improvement due to the frequent occurrence of specialized traffic accidents at night in the section where IC or tunnel facilities are installed. In addition, it is inferred that the number of specialized traffic accidents at night in the section where IC or tunnel facilities are installed is a factor in the problem of night visibility due to lighting facilities.

Hereditary Multiple Exostosis at Distal Tip of Distal Phalanx -A Case Report- (수부 원위지골 원위부 조갑하에 발생한 유전성 다발성 외골종 - 1례 보고-)

  • Han, Chung-Soo;Jeong, Bi-O;Kim, Man-Ho
    • The Journal of the Korean bone and joint tumor society
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    • v.10 no.2
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    • pp.138-141
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    • 2004
  • Osteochomdromas, which are uncommon in the hand, are encountered most frequently with hereditary multiple exostosis. They can occur away from the epiphyseal plate region at the distal end of the proximal and middle phalanges. But little has been written about exostosis that occur at the distal end of the distal phalnges. We report one case of hereditary multiple exostosis that arose at the distal end of the distal phalnges. Complete excision was done and the patient was disease-free of 4 years follow-up.

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Multiple Low-grade Osteosarcoma in Children - A Case Report - (소아에서 다발성으로 나타난 저등급 골육종 - 1예 보고 -)

  • Kim, Tai-Seung;Park, Yong-Wook
    • The Journal of the Korean bone and joint tumor society
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    • v.15 no.2
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    • pp.171-177
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    • 2009
  • Low grade central osteosarcoma is an rare variant of conventional osteosarcoma and generally occurs in older age than conventional. We experienced a case of low grade osteosarcoma occurred in a 12 years old female. Moreover, it occurred multifocally in left tibia, left femoral neck and midshaft, and left acetabulum. We could not sure whether it was from synchronous or metachronous metastasis. Usually the low grade osteosarcoma progresses very slowly. But, despite this case was low grade osteosarcoma with very indolent progression, furthermore, it showed synchronous or metachronous metastasis. So we report this unusual case with review of literature.

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An Investigation of Pressure Drop Characteristics of Finned Rod Bundles (핀 봉다발의 압력강하 특성 연구)

  • Chung, Moo-Ki;Chung, Chang-Hwan;Chung, Heung-June;Song, Chul-Hwa;Yang, Sun-Kyu
    • Nuclear Engineering and Technology
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    • v.23 no.3
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    • pp.328-339
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    • 1991
  • A multi-purpose research reactor called KMRR has been developed by Korea Atomic Energy Research Institute(KAERI) to generate a maximum thermal output of 30 MW. As a part of thermal hydraulics study, pressure drop characteristics of the longitudinally finned fuel rod bundles were experimentally investigated in a recirculating water test loop. The present study is focused on the investigation of fin effects on pressure drop and the development of pressure drop correlation for the finned rod bundles in a wide range of flow conditions. Friction factor correlations for each design of the finned rod bundles are developed. The value of friction factor for the finned rod bundles was higher than the analytical solution (64/Re) of laminar circular channel new but became lower than the Blasius equation as Reynolds number was increased.

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A Statistical Study of Effective Properties due to Fiber Tow Misalignment and Thickness Change for Plain Weave Textile Composites (섬유다발 배열 및 적층수에 따른 평직복합재료 등가물성치의 변화에 관한 통계적 연구)

  • 우경식;서영욱
    • Composites Research
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    • v.13 no.6
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    • pp.63-72
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    • 2000
  • In this paper, statistical treatments of effective properties for plain weave textile composites were presented. Configurations up to 32 layers with varied stacking phase shifts were considered. Effective properties were calculated by numerical simulation in which uni-axial tensile and shear load were applied at unit cell. Sample analysis was utilized to consider the inherent randomness in the phase shift and the results were treated statistically. It was found that effective properties were dependent on stacking phase shifts for thin plain weave textile composites. The distribution of $E_{xx}$ and $V_{xy}$ were skewed and the range of possible values was relatively large. As the number of layers increased, however, the distribution width became narrower and mean values converged. In contrast, $G_{xy}$ was not affected by phase shifts and thickness changes.

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Ascending Aortic Dissection Late After Aortic Valve Replacement (대동맥 판막 치환술 후 만기에 발생한 상행 대동맥 박리증)

  • 오정훈;이동협;이정철;정태은;이장훈;한승세
    • Journal of Chest Surgery
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    • v.34 no.8
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    • pp.630-633
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    • 2001
  • Central anticholinergic syndrome is defined as an absolute or relative reduction in cholinergic activity in the central nervous system and has a wide variety of manifestations. It is associated with almost any drug given during anesthesia, except neuromuscular relaxants, and treated with the cholinesterase inhibitor physostigmine. The diagnosis of central anticholinergic syndrome is often made when symptoms resolve promptly after the administration of physostigmine. We present a case of a central anticholinergic syndrome diagnosed by treatment with physostigmine, in a patient who received closure of patent foramen ovale associated with stroke.

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Crimp Angle Dependence of Effective Properties for 3-D Weave Composite (굴곡각에 따른 3차원 평직 복합재료의 등가 물성치 예측)

  • Choi, Yun-Sun;Woo, Kyeongsik
    • Composites Research
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    • v.29 no.1
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    • pp.33-39
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    • 2016
  • In this study, geometric modeling and finite element analysis of 3-dimensional plain weave composite unit cell consisting of 3 interlaced fiber tows and resin pocket were performed to predict effective properties. First, tow properties were obtained from micro-mechanics finite element unit cell analysis, which were then used in the meso-mechanics analysis. The effective properties were obtained from a series of unit cell analyses simulating uniaxial tensile and shear tests. Analysis results were compared to the analysis and experimental results in the literature. Various crimp angles were considered and the effect on the effective properties was investigated. Initial failure strengths and failure sequence were also examined.

Seismic Performance of Special Reinforced Concrete Coupling Beams with Different Reinforcement Details (보강상세에 따른 특수전단벽 연결보의 내진성능)

  • Chun, Young-Soo;Park, Ji-Young
    • Land and Housing Review
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    • v.6 no.1
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    • pp.21-29
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    • 2015
  • Coupling beams posses proper strength, stiffness and ductility capacities to resist efficiently under seismic loads. The strength, stiffness and ductility capacities for special diagonally reinforced concrete coupling beam with a span-to-depth ratio 2.0 or less is higher than those of coupling beam with conventionally reinforced concrete coupling beam. However, diagonally reinforced detailing creates major construction problem. In this study, design alternatives for diagonally reinforced concrete coupling beams were experimentally investigated. The results show that angle reinforced coupling beam(specimen SA) exhibited a better stable behavior in comparison with non-diagonally coupling beams(specimens SB-series) and sustained corresponding drift ratio, peak-to-peak stiffness and cumulative dissipated energy in comparison to diagonally coupling beam(specimen CA).