• Nuclear Engineering and Technology
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• 제54권3호
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• pp.811-816
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• 2022

This work presents the methodology used to expand the capabilities of the Monte Carlo code OpenMC for the calculation of reactor kinetic parameters: effective delayed neutron fraction β_eff and neutron generation time L. The modified code, OpenMC(Time-Dependent) or OpenMC(TD), was then used to calculate the effective delayed neutron fraction by using the prompt method, while the neutron generation time was estimated using the pulsed method, fitting Λ to the decay of the neutron population. OpenMC(TD) is intended to serve as an alternative for the estimation of kinetic parameters when licensed codes are not available. The results obtained are compared to experimental data and MCNP calculated values for 18 benchmark configurations.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1593-1603
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• 2023

In deterministic and Monte Carlo transport codes, b-delayed emission is included using a group structure where all of the precursors are grouped together in 6 groups or families, but given the increase in computational power, nowadays there is no reason to keep this structure. Furthermore, there have been recent efforts to compile and evaluate all the available b-delayed neutron emission data and to measure new and improved data on individual precursors. In order to be able to perform a transient Monte Carlo simulation, data from individual precursors needs to be implemented in a transport code. This work is the first step towards the development of a tool to explore the effect of individual precursors in a fissile system. In concrete, individual precursor data is included by expanding the capabilities of the open source Monte Carlo code OpenMC. In the modified code - named Time Dependent OpenMC or OpenMC(TD)- time dependency related to β-delayed neutron emission was handled by using forced decay of precursors and combing of the particle population. The data for continuous energy neutron cross-sections was taken from JEFF-3.1.1 library. Regarding the data needed to include the individual precursors, cumulative yields were taken from JEFF-3.1.1 and delayed neutron emission probabilities and delayed neutron spectra were taken from ENDF-B/VIII.0. OpenMC(TD) was tested in a monoenergetic system, an energy dependent unmoderated system where the precursors were taken individually or in a group structure, and in a light-water moderated energy dependent system, using 6-groups, 50 and 40 individual precursors. Neutron flux as a function of time was obtained for each of the systems studied. These results show the potential of OpenMC(TD) as a tool to study the impact of individual precursor data on fissile systems, thus motivating further research to simulate more complex fissile systems.

• 지식경영연구
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• 제11권4호
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• pp.21-39
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• 2010

Recommender system is a core component of e-commerce. Correspondingly, metrics to evaluate the system performance have been developed and applied. However, even though we have lots of applications that have tried to adopt recommender systems, the dearth of successfully installed recommender systems for more than a decade leads us to a skeptical thinking that current metrics do not sufficiently indicate the recommender system success in business viability point of view. Hence, the purpose of this paper is to reconfigure measures for recommender system success. Adopting DeLone and McLean's amended model of information system success as the underlying framework, content analysis with intellectual properties on recommender systems was conducted to modify the currently used metrics. Then a model of recommender system success is proposed based on the newly identified metrics are compared with traditional metrics.

• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.128-132
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• 2019

This paper is to explore the success factors of the online public grievance redressal system in the Nepal. It empirically tests the conceptual path model developed by DeLone and McLean which consists of six social perception variables with regard to citizen's intention to use the system. The estimates from 577 respondents support all the 13 hypotheses generated from D&L model. People's attitude and social norms are the two most important factors on the continuous usage of the system. It is suggested that the social factors are as much important as technological aspects when it comes to the e-government implementation. It is also suggested that the government should pay more attention to human factors in upgrading the design and development of e-grievance system in the foreseeable future.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2000년도 한국우주과학회보 제9권2호
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• pp.40-40
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• 2000

No Abstract, See Full Text

• Journal of Microbiology
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• 제44권6호
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• pp.591-599
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• 2006

To address the diversity of cyclodextrin-producing P. graminis strains isolated from wheat roots and rhizospheres of maize and sorghum sown in Australia, Brazil, and France, restriction fragment length polymorphism analysis of part of genes encoding RNA polymerase (rpoB-RFLP) and DNA gyrase subunit B (gyrB-RFLP) was used to produce genetic fingerprints. A phylogenetic tree based on rpoB gene sequences was also constructed. The isolates originated from Brazil could be separated from those from Australia and France, when data from the rpoB-based phylogenetic tree or gyrB-RFLP were considered. These analyses also allowed the separation of all P. graminis strains studied here into four clusters; one group formed by the strains GJK201 and $RSA19^T$, second group formed by the strains MC22.02 and MC04.21, third group formed by the strains TOD61, TOD 221, TOD302, and TOD111, and forth group formed by all strains isolated from plants sown in Cerrado soil, Brazil. As this last group was formed by strains isolated from sorghum and maize sown in the same soil (Cerrado) in Brazil, our results suggest that the diversity of these P. graminis strains is more affected by the soil type than the plant from where they have been isolated.

• 천문학회보
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• 제25권2호
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• pp.40-40
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• 2000

• The Korean Journal of Pain
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• 제34권2호
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• pp.139-155
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• 2021

The quality of subgroup analyses (SGAs) in chronic non-cancer pain trials is uncertain. The purpose of this study was to address this issue. We conducted a comprehensive search in MEDLINE and EMBASE from January 2012 to September 2018 to identify eligible trials. Two pairs of reviewers assessed the quality of the SGAs and the credibility of subgroup claims using the 10 criteria developed by Sun et al. in 2012. The associations between the quality of the SGAs and the studies' characteristics including risk of bias, funding sources, sample size, and the latest impact factor, were assessed using multivariable logistic regression. Our search retrieved 3,401 articles of which 66 were eligible. The total number of SGAs was 177 of which 52 (29.4%) made a subgroup claim. Of these, only 15 (8.5%) were evaluated as being of high quality. Among the 30 SGAs that claimed subgroup effects using an appropriate method of performing interaction tests, the credibility of only 5 were assessed as high. None of the subgroup claims met all the credibility criteria. No significant association was found between the quality of SGAs and the studies' characteristics. The quality of the SGAs performed in chronic pain trials was poor. To enhance the quality of SGAs, scholars should consider the developed criteria when designing and conducting trials, particularly those which need to be specified a priori.

• 대한전자공학회논문지SP
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• 제46권6호
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• pp.102-111
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• 2009

본 논문에서는 움직임 보상 결과의 신뢰도를 바탕으로 움직임 보상 순차주사화 알고리즘의 결과와 움직임 보상 수직-시간 필터의 결과를 결합하는 순차주사화 알고리즘을 제안한다. 움직임 보상 순차주사화 알고리즘은 높은 공간 해상도를 가진 고화질 영상을 생성하지만 움직임 벡터가 잘못 추정되었을 경우 눈에 띄는 에러를 발생시킨다. 반면에 움직임 보상 수직-시간 필터는 높은 공간 해상도를 제공하지는 못하지만 움직임 벡터의 에러에 강건한 특성을 가지고 있기 때문에 전체적으로 자연스러운 영상을 제공한다. 제안하는 순차주사화 알고리즘은 추정된 움직임 벡터와 움직임 보상 순차주사화 알고리즘의 결과를 분석하여 움직임 보상의 신뢰도를 추정한 후, 움직임 보상 신뢰도에 기반 한 가중치를 바탕으로 두 가지 방법의 장점을 결합한다. 제안된 방법은 움직임 보상의 신뢰도가 높은 영역에서는 높은 공간 해상도를 제공하는 움직임 보상 순차주사화 알고리즘을 적용하고 움직임 보상의 신뢰도가 낮은 영역에 대해서는 움직임 보상 수직-시간 필터를 적용하여 눈에 띄는 에러 없이 높은 공간 해상도를 가지는 영상을 생성한다. 실험 결과에서는 제안된 알고리즘이 기존의 알고리즘에 비해 시각적 및 수치적인 면에서 뛰어난 결과를 보임을 확인할 수 있다.

• 만화애니메이션 연구
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• 통권49호
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• pp.87-112
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• 2017

중첩은 복수의 이미지들을 겹쳐 놓는 것으로 여러 가지 표현의 목적을 위해 사용된다. 중첩 가운데, 특히 움직임을 표현하기 위한 중첩은 운동의 과정을 분석, 종합하면서 예술의 여러 분야에서 활용되어 왔다. 이러한 움직임을 표현하는 중첩을 '동체중첩'이라고 명명하고, '하나의 화면에 단일 동체의 운동을 동시에 나열해 움직임을 표현하는 기법'으로 정의한다. 동체중첩은 회화와 사진과 같은 평면 예술에서 시작되었는데 이를 '정적인 동체중첩'으로 분류하고, 이를 이어서 영화와 애니메이션과 같은 영상예술로 발전한 동체중첩은 '동적인 동체중첩'으로 분류한다. 이러한 동체중첩의 중심에는 무엇보다도 동체중첩의 독자적인 예술성과 미학을 구현한 노먼 맥라렌의 작품 <빠 드 되>가 위치하며, 이 작품을 중심으로 동체중첩의 핵심 개념을 분석하고 그 선후에 대한 연구를 통해 동체중첩의 맥락과 예술적 성취를 확인한다. 그리고 오늘날 동체중첩은 디지털 테크놀로지의 발달에 힘입어 기술과 차원을 더욱 확장시키고 있다. 신기술을 활용한 새로운 동체중첩의 작업들은 <빠 드 되>를 매체적으로, 그리고 개념적으로 재해석해 동체중첩의 새로운 가능성을 보여 주는데 이러한 동체중첩의 경향과 전망에 관해 살펴본다. 이와 같이 <빠 드 되>를 중심으로 한 동체중첩에 관한 논의는 궁극적으로 동체중첩이 이룬 예술적 성취를 확인하고 그 의미와 새로운 가능성에 대해 고찰하는 계기를 제공한다.