• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3803-3810
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• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1801-1810
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• 2016

The OpenDaylight controller has been receiving significant attention as one of the enabling open source framework for SDN, and this paper analyzes the architecture and procedure of OpenDaylight based controller cluster. The OpenDaylight controller cluster uses shard based distributed datastore and Raft algorithm to maintain consistency among controllers inside a cluster. The performance evaluation analyzes the leader re-election time as well as latencies of CRUD and Routed RPC according to cluster size, shard role, and sharding strategy, and we discuss the optimal operation strategy for OpenDaylight controller cluster.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.382-386
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• 2007

Objective : Various techniques of cervical laminoplasty have been developed to decompress the spinal canal in patients with multilevel cervical spondylotic myelopathy. This study compared the early surgical outcomes between unilateral open-door laminoplasty and midline splitting cervical laminoplasty. Materials and Methods : From March 2004 to August 2005, we performed cervical laminoplasty in 34 patients with cervical myelopathy. Of these patients, 24 were treated by unilateral open-door laminoplasty [open-door group] and 10 by midline splitting cervical laminoplasty [splitting group]. The mean duration of follow up was 9.2 months in the open-door group and 15.8 months in the splitting group. We retrospectively analyzed neurological outcomes using the Japanese Orthopedic Association [JOA] score, and compared the radiological changes between the two groups. Results : Postoperative JOA score and recovery rate were $13.29{\pm}4.01$ and $56.28{\pm}44.91%$ in the open-door group and $15.75{\pm}0.88$ and $72.69{\pm}19.99%$ in the splitting group. There was no statistical difference between the two groups [p>0.05]. Regarding the radiological assessment, the increase of postoperative axial canal area was $63.23{\pm}23.24%$ in the open-door group and $42.30{\pm}14.96%$ in the splitting group [p<0,05]. Conclusion : There was no statistical difference in the neurological outcome when the early surgical outcomes of the open-door group and the splitting group were compared. However, the open-door group showed wider cervical spinal canal areas than the splitting group.

• Proceedings of the KSCN Conference
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• 2005.04a
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• pp.118-119
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• 2005

• International Journal of Knowledge Content Development & Technology
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• v.6 no.1
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• pp.85-103
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• 2016

The Directory of Open Access Books (DOAB) provides a searchable index peer-reviewed monographs and edited volumes published under an Open Access business model, with links to the full texts of the publications at the publisher's website or repository. This paper discusses a global analysis of open access books, which are available in the Directory of Open Access Books (DOAB). The data was collected from the open access directory at http://www.doabooks.org/ on $20^{th}$ October 2015. In total 3379 books are listed as available on the directory; the first and second books were published in 1866 and 1867 respectively. After 1962, the publication of books, increased gradually and the greatest number of books more than 300, was published in 2010, 2012, 2013 and 2014. Nearly 47 percent of the books (1584) were published in the English language only.

• Research in Mathematical Education
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• v.3 no.1
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• pp.9-21
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• 1999

In mid 1980s, open education arrived in Korea. It was influenced by the educational reforms implemented in American primary schools. Currently, the Ministry of Education is appealing to teachers for their active involvement in educational reform by using open education methodology. Often teachers in Korea complain that they do not know what to do or how to change in order to practice the open education. It is time to review the state of open education in Korea and the United States. This paper contains the following segments: 0) Introduction, 1) Beginning of open education, 2) A brief history of open education in Korea, 3) The current status of open education in the United States, 4) A glance at open mathematics classroom in Korea, 5) Lessons from the review, and 6) Conclusion.

• Knowledge Management Research
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• v.11 no.4
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• pp.1-19
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• 2010

With the increasing importance of ecosystem in a business environment, the value of open innovation is receiving great attention. Under open innovation, companies open their knowledge, capital, and other resources to cooperating companies; on the other hand, under closed innovation companies depend solely on their own resources. In this paper, we compare closed and open innovation using the simulation method, and confirm that in terms of total capital and production of the industry, open innovation provides greater opportunities to the entire ecosystem. Moreover, Schumpeterian competition, which is a dynamic of closed innovation, functions even under open innovation. Our findings highlight that not only small but also large companies can receive the benefit of an enlarged industry under open innovation.

• Knowledge Management Research
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• v.9 no.4
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• pp.17-33
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• 2008

This study proposes University 2.0 as a model case of open, flexible, and distributed learning environment for higher education based on theoretical foundations and perspectives. As web 2.0 technologies emerge into the field of education, ways of generating and disseminating information and knowledge have been drastically changed. Professors are no longer the only source of knowledge. Students using internet often become prosumers of knowledge who search and access information through the web as well as publish their own knowledge using the web. A concept and framework of University 2.0 is introduced for implementing the new interactive learning paradigm with an open, flexible and distributed learning environment for higher education. University 2.0 incorporates online and offline learning environments with various educational media. Furthermore, it employs various learning strategies and integrates formal and informal learning through learning communities. Both instructors and students in University 2.0 environment are expected to be active knowledge generators as well as creative designers of their own learning and teaching.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.215-217
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• 2003

본 논문에서는 음악이나 동영상과 같은 디지털 미디어 컨텐츠의 유통과 보안을 위하여 개인 사용자의 접속 권한을 부여하고 제한을 가할 수 있는 OpenIPMP에 대하여 살펴본다. 그리고 본 논문은 디지털 미디어 컨텐츠의 저작권보호와 복제 방제를 위해 워터마킹 기술을 OpenIPMP에 연동시켰다. 아울러 디지털 미디어 권한에 대하여 표현하고 처리하고자 하는 목적으로 MPEG-21 REL을 역시 OpenIPMP에 연동시켰다.

• Journal of the Korea Society of Computer and Information
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• v.21 no.1
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• pp.65-72
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• 2016

Network virtualization is an emerging technology for solving the rigidity of the physical network infrastructure. The innovative technique virtualizes all resources in the network, including the network links and nodes, and provides a number of virtual networks on a single network infrastructure. In order to realize a virtual network, a thorough and complete monitoring of all resources in the network should be performed firstly. OpenFlow is an open source stack for network virtualization. However, it is impossible to apply OpenFlow to AP-based legacy wireless LAN environment because OpenFlow targets ethernet-based LAN environment. In this paper, we implement an adaptor-styled virtual switch for AP-based wireless LAN through customizing the Open vSwitch which is a virtual switch of OpenFlow. The evaluation test results show that the implemented OpenFlow stack operates successfully. The implemented OpenFlow stack can now be plugged immediately in existing AP-based wireless LAN environment and plays network resource monitoring. In the future, we can develop wireless LAN virtualization applications on the wireless OpenFlow stack.