• Kyungpook Mathematical Journal
• /
• 제32권1호
• /
• pp.21-30
• /
• 1992

• Nuclear Engineering and Technology
• /
• 제54권10호
• /
• pp.3803-3810
• /
• 2022

OpenMC is a community-driven open-source Monte Carlo neutron and photon transport simulation code. The Weight Window Mesh (WWM) function and an automatic Global Variance Reduction (GVR) method was recently developed and implemented in a developmental branch of OpenMC. This WWM function and GVR method broaden OpenMC's usage in general purposes deep penetration shielding calculations. However, the Local Variance Reduction (LVR) method, which suits the source-detector problem, is still missing in OpenMC. In this work, the Weight Window Generator (WWG) function has been developed and benchmarked for the same branch. This WWG function allows OpenMC to generate the WWM for the source-detector problem on its own. Single-material cases with varying shielding and sources were used to benchmark the WWG function and investigate how to set up the particle histories utilized in WWG-run and WWM-run. Results show that there is a maximum improvement of WWM generated by WWG. Based on the above results, instructions on determining the particle histories utilized in WWG-run and WWM-run for optimal computation efficiency are given and tested with a few multi-material cases. These benchmarks demonstrate the ability of the OpenMC WWG function and the above instructions for the source-detector problem. This developmental branch will be released and merged into the main distribution in the future.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 춘계학술대회논문집
• /
• pp.176-179
• /
• 2008

In a numerical simulation of open channel turbulent flows, the determination of wall roughness height for wall function was studied. The roughness constant, based on the law-of-the -wall for flow on rough walls, obtained by experimental works for pipe flows is employed in general wall functions. However, this constant of wall function is the function of Froude number in open channel flows. Thus, the wall roughness should be determined by taking into account the effect of Froude number. In addition, the wall roughness should be corresponding to Manning's roughness coefficient widely used for open channels. In this study, the relation between wall roughness height as an input condition and Manning's roughness coefficient was investigated, and an equation for effective wall roughness height considering the characteristics of numerical models was proposed as a function of Manning's roughness coefficient.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.121-124
• /
• 2003

The conventional CNC(Computerized Numerical Controller) of machine tool, which is dependent to CNC maker, was a closed architecture type. Therefore, it is impossible to implement a special user-define function to CNC. But recently, CNC is changed to OAC(Open Architecture Controller) type increasingly and the general function of CNC can be upgrade efficiently. This paper describes web service application for remote monitoring regarding the faults or machine tool with open architecture CNC. The major faults of CNC machine tool can be defined to the operational faults to be charged over 70%. Those faults are unpredictable because of being occurred without any warning. To generalize the fault diagnosis efficiently. two diagnosis models such as SF(Switching Function) and SSF(Step Switching Function) are proposed and the function of fault diagnosis is implemented to internal function of OAC. Also, to service remotely the faults of CNC machine tool. the suitable web environment is proposed and practical function is programmed to evaluate its operation on web.

• 천문학회지
• /
• 제35권2호
• /
• pp.87-95
• /
• 2002

We have conducted VI CCD photometry of the open cluster NGC 6819 in order to understand the effects of dynamical evolution in old open clusters. Our photometry covers 18' $\times$ 18' on the sky, centered on the cluster, which seems to cover the whole cluster field. Our photometry reaches down to V $\approx$ 20.5, which allows us to analyze the luminosity function and spatial distribution of stars brighter than Mv $\approx$ 8.5. There is a clear evidence for mass segregation in NGC 6819, i.e., the giants and upper main-sequence stars are concentrated in the inner regions, whereas the lower main-sequence stars distribute almost uniformly throughout the cluster. The luminosity function of the main-sequence stars of NGC 6819 is almost flat. The flat luminosity function indicates that a large number of low mass stars has escaped from the cluster unless its initial mass function is much different from the Salpeter type (${\phi}(m){\propto} m^{-(1+x)},x = 1.35$).

• 대한통합의학회지
• /
• 제5권3호
• /
• pp.49-55
• /
• 2017

Purpose: The purpose of this study was to investigate effect of open kinetic chain exercise on the motor function of the lower limb in middle school soccer players. Method: The subjects consisted of 14 soccer players who attend middle school in Gwangju. All subjects received open kinetic chain exercise for 3 weeks. The muscle strength of the ankle was measured by a commander muscle tester. Postural control ability was measured using a hopping test. All measurements for each subject were conducted pre-intervention and 3 weeks post-intervention. Result: There were significant differences post-intervention in the muscle strength and-the postural control ability of the open kinetic chain exercise group(p<.05). Conclusion: Open kinetic chain exercise had a significant positive effect on the motor function of the lower limb in soccer players. Therefore, open kinetic chain exercise may prevent and resolve injury with careful management while soccer players are training or playing games. It could be helpful to extend the lives of athletes and improve their records.

• 천문학회지
• /
• 제21권1호
• /
• pp.37-55
• /
• 1988

Combining the luminosity functions of main sequence stars in 3 associations and 22 open clusters, the initial luminosity function and mass function for these clusters are derived. For stars of m > $0.6m_{\odot}$, they are well consistent with those for the field stars.

• Kyungpook Mathematical Journal
• /
• 제32권1호
• /
• pp.31-43
• /
• 1992

• 한국문헌정보학회지
• /
• 제54권3호
• /
• pp.187-208
• /
• 2020

오픈 에듀케이션이란 디지털 기술을 기반으로 교육 장벽을 해소하기 위해 전세계적으로 진행되고 있는 운동이다. 점차 확산되고 있는 오픈 에듀케이션 환경에서 도서관의 교육적 기능을 어떻게 수행할 것인가에 대한 논의가 필요하다. 이 연구에서는 오픈 에듀케이션의 개념과 구성요소를 고찰하고, 오픈 에듀케이션 환경에서 도서관이 어떻게 교육적 기능을 수행할 것인지 그 접근 방안을 제안하고자 한다. 이 연구의 결과는 도서관의 교육적 기능의 관점에서 도서관이 오픈 에듀케이션의 실행과 확산의 주체가 되고, 이를 위한 역할과 방향을 설정하는 데 있어 지침이 될 것이다.

• 한국초등수학교육학회지
• /
• 제14권3호
• /
• pp.723-744
• /
• 2010

오늘날 사회에서는 다양하고, 유연한 사고능력을 가진 창의적인 인재 육성을 필요로 하고 있다. 이에 개방형 문제는 다양한 답을 찾는 과정에서 학습자의 창의력 계발에 효과적인 학습방법으로 생각된다. 이러한 개방형 문제는 두뇌 발달에 어떠한 영향을 미칠 것인가? 최근 두뇌 기능 상태를 고려한 교수-학습 활동 개발의 필요성이 제안되면서 이를 위한 기초 연구로 학습자의 뇌파 측정 및 뇌파를 통한 교육 효과 검증 등이 시도되고 있다. 본 연구에서는 개방형 문제가 수학적 창의력에 미치는 영향과 함께 뇌파 측정을 통해 뇌기능 발달에 미치는 효과를 파악하고자 하였다. 연구 결과 개방형 문제는 학습자의 수학적 창의력과 두뇌 각성, 긍정적인 학습 성향, 두뇌 활동의 효율성을 높이는데 효과적인 문제 유형이었다. 따라서 개방형 문제가 꾸준히 개발되어 학생들에게 다양한 답을 찾는 문제 해결 경험을 제공해야 한다. 또한 개방형 문제를 활용한 수업에도 적극 활용될 필요가 있다. 특히 개방형 문제 해결이 뇌기능에 미치는 긍정적인 효과를 고려해 볼 때, 주의가 낮고, 수학 학습에 소극적인 학습자에게 개방형 문제를 제시하고, 꾸준한 학습 경험을 제공할 필요가 있다.