• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.911-920
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• 2004

Intensive studies have been made in the area of VOD server. Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Bu11er size and disk bandwidth. we propose a efficient user-grouping policy for multi-casting services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and QOS change of proposed scheme are about 23% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.243-250
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• 2012

This study proposes new protocol protecting patients' personal record more safely as well as solving medical dispute smoothly by storing the record not into a computer server in hospitals but into the National Health Insurance Corporation computer server. The new protocol for electronic medical record is designed using RSA public key algorithm and DSA digital signature. In addition, electronic medical record systems are built up with more safety and reliability through certificate authority. The proposed medical information systems can strengthen trust between doctors and patients. If medical malpractice occurs, the systems can also provide evidence. Furthermore, the systems can be helpful to reduce medical accidents. The systems could be also utilized efficiently in various applied areas.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.860-863
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• 2008

플래시 메모리는 우리 생활에 널리 사용되고 있는 휴대용 저장장치 중의 하나이다. 빠른 입출력 속도와 저전력, 무소음, 작은 크기 등의 장점을 가지나 덮어쓰기가 불가능하고 읽기/쓰기의 속도에 비해 소거 연산의 속도가 매우 느리다는 단점이 있다. 이를 보완하기 위해, 호스트와 플래시 메모리 사이에 버퍼 캐시를 두어 사용하고 있으며, 버퍼 캐시에 사용되는 교체 정책에 따라 플래시 메모리 장치의 성능이 크게 영향을 받는다. 본 논문에서는 블록 단위의 LRU 기법의 단점을 개선한 HPLRU 기법을 제안한다. HPLRU 기법은 최근에 자주 참조되었던 페이지인 핫 페이지 들을 모아 리스트를 만들어 관리하고, 이를 통해 페이지 적중률을 향상시키고 다른 페이지들로 인해 핫 페이지들이 소거되는 현상을 개선하였다. 이 알고리즘은 임의 데이터 패턴에 좋은 성능을 보이며 쓰기 발생 횟수를 많이 감소시키는 결과를 보였다.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.53-66
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• 2008

The construction technologies for development and urbanization diversely effect on the water qualities, hydraulics and aquatic ecosystems in watershed areas. Usually, the landuse changes in watershed areas by human activities are known as the main sources of pollutants to aquatic ecosystems. Therefore, in order to protect the aquatic ecosystems and to improve the water quality, the construction technologies should be improved with environmental technologies. In this paper, several applicable technologies for construction projects and protection of aquatic ecosystem will be summarized, which are the low impact developments (LID), buffer zones, watershed management practices, etc. Also the 21st sustainable environmental policies concerning watershed management will be discussed for watershed managers.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.617-643
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• 2019

The Demilitarized Zone(DMZ) is a buffer zone set between the southern and northern limit lines established after the 1953 Armistice Agreement. It is an important natural environment conservation area where wild species of animals and plants live. On the other hand, the development pressure on the DMZ will increase when the inter-Korean economic cooperation is activated in the future. As a result, DMZ development should consider not only the economic cost-benefit aspects, but also how to assess and conserve the biodiversity of the DMZ, as well as the recovery costs and budget. This paper develope a sustainable DMZ management model under biodiversity uncertainly by using real option approach. The model is also designed to reflect the political risk and regional specificity of the DMZ. Through empirical analysis, I derive the biodiversity threshold (b^*) that can secure the DMZ investment economy under uncertainty. In addition, through the sensitivity analysis, I derive the factors influencing the biodiversity threshold, and suggest the policy implications for sustainable management of DMZ.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.7
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• pp.209-216
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• 2023

Modern HPC systems are equipped with many-core CPUs with dozens of cores. When performing parallel I/O in such a system, there is a limit to scalability due to the problem of the LRU lock management policy of the Linux system. The study proposes an improved FinerLRU to solve this problem. Our new FinerLRU improves the parallel write performance of file systems using the buffer cache through granular lock management by increasing the number of LRU locks upto the maximum number of cores. The proposed method was implemented in Linux 5.18.11, and the performance was measured on two types of CPUs, Intel Icelake Xeon and Intel Knights landing, with different characteristics, and it was found that a performance improvement of about two times can be obtained in both types of systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.22-33
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• 2018

Recently domestic manufacturing companies have been experiencing worsening profitability and stunted growth due to the long-term economic recession and the rapid rise of developing countries such as China and Southeast Asia. These difficulties force many companies to concentrate their core competencies on new value creation and innovation in order to gain momentum for new growth. Enterprise Resource Planning (ERP) has been considered as one of viable solutions. Among the various modules in ERP, shop floor control function in the production management module is rather limited. In order to overcome this problem, Manufacturing Execution System (MES) has been used as a subsystem which has a strong information gathering power and flexibility. Both systems interact closely with each other. In particular, ERP requires fast, accurate shop floor information at MES. This paper describes how to synchronize relevant information between ERP and MES with theory of constraints (TOC). The processing time information transmitted from the MES workplace is received at the ERP workplace. In the process, the received processing time is causing information distortion in ERP, when the information gathering standard of MES is different from the ERP information interpretation standard. The Drum-Buffer-Rope theory of TOC was applied to resolve this problem, therefore, information synchronization between both systems was made. As a precondition, the standard time of the upper ERP system was rearranged according to the capacity constraints resource. As a result, standard time restructuring has affected changes in labor costs. Standard labor costs have come close to actual ones, and information synchronization of MES transmission data has improved the reliability of standard product costs, such that it enabled various company-wide restructuring actions to be much more effective.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.3
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• pp.82-91
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• 2007

Rural areas dominate country landscape, where the population is rich in traditional and natural heritage. Dangsan forests and Rural community forests (RCF) have been maintained by local residents for hundreds of years. However, many of these forests have been disturbed, and only small amount of Dangsan forests and the RCF remain due to the efforts of local residents. Recently, the remnants of Dangsan forests and RCF have been regarded as living traditional landscapes representing the cultural and rural background of Korea. But the value of Dangsan forests and the RCFs has not been recognized by many. This study aims to understand the characteristics and management status of Dangsan forests in Sungnam-ri, Wonju. Sungnam-ri has four villages, each of which is bordered by a Dangsan forest at the riparian buffer. Sungnam-ri has been selsected as a site for a rural village development project by the Ministry of Agriculture & Forestry of Korea. Sunghwanglim (the Upper Dangsan forest) is designated as Natural Monument No.93 and entrance is limited in this area. The size of Sunghwanglim is $21,133m^2$, and the major tree species are Kalopanax pictus (Dangsan tree, Divine tree), Pinus densiflora, Abies holophylla, Acer triflorum, Ulmus davidiana, Fraxinus rhynchophylla and Quercus serrata. In total, 124 trees with more than 40 cm in DBH are at this site. As for cultural activities, the Dangsan festival is held on April 8th and September 9th of the lunar calendar at shrines in the forests. Although other Dangsan forests are smaller than Sunghwanglim, they also have similar cultural activities. The landscape of the Dangsan forests have been managed for several hundred years by the local people, and they intend to continue maintaining the Dangsan forests for the purpose of festivals and other cultural activities. The findings in this study suggest that Dangsan forests have the potential for the development of rural villages and for the improvement of cultural and natural landscapes in Korea.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.327-341
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• 2021

The riparian eco-belt is an efficient technique that can reduce non-point pollution sources in the basin and improve ecological connectivity and health. In Korea, a legal system for the construction and management of riparian eco-belts is in operation. However, it is currently excluded that rivers and floodplains in dam reservoir that are advantageous for buffer functions such as control of non-point pollutants and ecological habitats. Accordingly, this study presented and analyzed a plan to select a site for an integrated riparian ecol-belt that comprehensively evaluates the water quality and ecosystem characteristics of each dam floodplain and riparian zone for the Daecheong Dam basin in Geum River watershed. First, the Daecheong Dam basin was divided into 138 sub-basin with GIS, and the riparian zone adjacent to the dam floodplain was analyzed. Sixteen evaluation factors related to the ecosystem and water quality impact that affect the selection of integrated riparian eco-belt were decided, and weights for the importance of each factor were set through AHP analysis. The priority of site suitability was derived by conducting an integrated evaluation by applying weights to sub-basin by floodplains and riparian zone factors. In order to determine whether the sites derived through GIS site analysis are sutiable for actual implementation, five sites were inspected according to three factors: land use, pollution sources, and ecological connectivity. As a result, it was confirmed that all sites were appropriate to apply integrated riparian ecol-belt. It is judged that the riparian eco-belt site analysis technique proposed through this study can be applied as a useful tool when establishing an integrated riparian zone management policy in the future. However, it might be necessary to experiment various evaluation factors and weights for each item according to the characteristics and issues of each dam. Additional research need to be conducted on elaborated conservation and restoration strategies considering the Green-Blue Network aspect, evaluation of ecosystem services, and interconnection between related laws and policy and its improvements.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.35-53
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• 2021

Over the past 20 years, Korea's number of international passengers and freight transportation records has increased by 8.6% per year, respectively. However, despite the development of sea lanes and increased voyages, there have been constant calls for improving the inefficient management of international passenger ports. Hence, this paper presents improvements and further directions for international passenger port management. Focusing on the Incheon International passenger port as a representative case study, the main results show that the most important, urgent, possible measures for improving the port management include (i) the expansion of customs personnel and implementation of a 24-hours customs clearance system in operation, (ii) installation of buffer facilities between the ferry and ferry cargo and establishment of hinterland specialized in car ferry freight in a facility, and (iii) clear standards for cost-bearing subjects and limitation of high cost related to terminal use in institution. These results imply the need for government policy access and investment reflecting stakeholder opinions at various levels, such as operation, facilities, institution, and so forth, for efficient management of international passenger ports.