• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.673-677
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• 2010

Recently, NAND flash memory has been widely used in embedded systems, personal computers, and server systems because of its attractive features, such as non-volatility, fast access speed, shock resistance, and low power consumption. Due to its hardware characteristics, specifically its 'erase-before-write' feature, Flash Translation Layer is required for using flash memory like hard disk drive. Many FTL schemes have been proposed, but conventional FTL schemes have problems such as block thrashing and block associativity problem. The KAST scheme tried to solve these problems by limiting the number of associations between data block and log block to K. But it has also block thrashing problem in random access I/O pattern. In this paper, we proposed a new FTL scheme, UDA-LBAST. Like KAST, the proposed scheme also limits the log block association, but does not limit data block association. So we could minimize the cost of merge operations, and reduce merge costs by using a new block reclaim scheme, log block garbage collection.

• The Journal of the Korea Contents Association
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• v.6 no.3
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• pp.46-54
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• 2006

Various schemes for mobility are currently studied in ITU-T, 3GPP, IETF, and so on. Mobility support in NGN for seamless service is necessarily required. Currently proposed mechanisms are MIPV6,0, Q.MMF, and IMS. However the performance comparison of all existing schemes is not examined as yet. That is, the existing methods need to be compared according to each performance parameter. So, in this paper, we investigate and compare the performances of MIPv6,0, Q.MMF, IMS to location registration. In addition, this paper presents the performance comparison of handover latency times. For this, we use NS-2 simulator. As a result of analysis, Q.MMF shown the best performance as it is measured the minimum time and cost. And it has low handover latency time in comparison with other mechanisms.

• Journal of the Korean housing association
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• v.19 no.1
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• pp.57-66
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• 2008

In the past, strong social bands, which had spontaneous communities, existed in Korean traditional society. However, while it's developing through industrialization; monolithic apartment houses were introduced which causes less interaction between neighbors. With the growing attention to the higher living quality, various schemes to revitalize the community spirits have been groped, including to improve in hardhearted neighborhood relationships and to cope with the dreariness in the city. With the development of the internet and the spread of 'digital home', the communities in cyber space have been especially revitalized since the information-oriented society. In a move to strengthen the communities in apartment complexes, this study tries to find the revitalization scheme for virtual communities in apartment complexes by analyzing the contents of its web sites and understanding the world of virtual community. These are compared and analyzed. The related virtual communities ("cafe" or "blogs") are also analyzed. The results are as follows. 1) There are some differences among the contents provided by apartment virtual community developing companies, still, it could be categorized into four types; "apartment complex introduction and management information" "community revitalization" "living guide" "individual services" 2) The contents provided by self-organized communities of residents neither require additional charge nor special membership for information while the formation is not systematized. 3) In the comparison of apartment virtual community developing companies with residents self-organized communities, "apartment complex introduction and management information" on freeboard, notice, request and Q&A, and "community revitalization" on communication board are both provided throughout the web sites. 4) The contents provided by apartment virtual community developing companies makes the information available in a wide range with managers, on the other hand, self-organized communities emphasize on showing attachment and concern of residents and requiring communications between neighborhoods.

• Journal of the Korean association of regional geographers
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• v.21 no.2
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• pp.342-354
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• 2015

We suggested definition and classification scheme of uninhabited islands in Taeanhaean National Park for efficient management. Islands (seom) and reefs (yeo) were classified based on approximate HHW. Uninhabited islands were categorized into vegetated islands and rocky islands depending on presence of woody vegetation cover for physical geographic and ecological value and importance. Reefs were also divided into an underwater reef and a reef which covers and uncovers based on approximate LLW. We excluded those areas which are not separated from main land by waterbody even though it is in approx. HHW from islands. We considered several divided areas which adjoin geographically and ecologically one another under the condition of approx. LLW as an island. By using above schemes, we categorized 50 uninhabited islands in Taeanhaean National Park into three groups; 24 vegetated islands, 14 rocky islands, and 12 reefs. If the public institutions adopt these schemes as national standards, it will be useful in managing uninhabited islands nationwide.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.97-108
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• 2005

In this paper a method of reconstructing a desired image through the geometrical transformation and the interpolation techniques is presented by comparing different interpolation schemes. Several different interpolation schemes are compared with respect to the amount of error that is the difference between the original and the reverse-projective transformed images. Higher ordered B-spline interpolation turned to be superior to other techniques in reconstructing the image which is desired to be close to the unskewed image as much as possible. In the results, this paper demonstrates that the reverse projection using the higher ordered B-spline interpolation is superior to those conventional interpolation methods, linear, cubic spline for reconstructing image. In experiments, the error decreases as the order of B-spline increases. The proposed technique is useful for various practical and theoretical applications in the area of satellite, medical, and commercial image processing.

• Journal of Korea Port Economic Association
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• v.19 no.2
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• pp.87-109
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• 2003

Localization is one of the typical phenomena of this age in Korea. Localization of Port is on the beginning in this Country as the introduction of Port Authority in the Port of Busan and Incheon. As the condition of world trade has been changed, the level of Competition among Ports is severer than before, especially in the East Asia Area. Since many experts of Port say that centralized control system of Port has many Problems, some other Port Control system has been studied and suggested for long time. One of the Countermeasures of these Port Problems is Port Authority System which aims the balance of central and local development. Port Authority System does not want to achieve only Public Duty or Utility but also Commerciality which is fundamentally very important for the survival of Port. In this Paper, the necessities of Port Authority Introduction in Korea was explained. And Port Authority System will be introduced 2004 year in Busan Port firstly and Incheon Port, secondly. The Main Contents of Port Authority System was suggested , in this Paper and some Problems which shall be considered for better operation of Port Authority System was investigated. I suggested some countermeasures, endeavoring the competitive advantage of Port and higher Port Performance, in terms of 3 Dimensions. One is in the side of basic Policy Directions, the other is the activation schemes of functional department which composed of many activities of Port Authority System and the third is in the side of operation body. As this paper, however, has some limitations and Port Authority System is just beginning stage, future research shall be continued in real and concrete level.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.134-143
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• 2021

Recently, with the development of mobile devices and social media services, contents recommendation schemes have been studied. They are typically applied to the job curation systems. Most existing university education content recommendation schemes only recommend the most frequently taken subjects based on the student's school and major. Therefore, they do not consider the type or field of employment that each student wants. In this paper, we propose a university educational contents recommendation scheme for job curation services. The proposed scheme extracts companies that a user is interested in by analyzing his/her activities in the job curation system. The proposed scheme selects graduates or mentors based on the reliability and similarity of graduates who have been employed at the companies of interest. The proposed scheme recommends customized subjects, comparative subjects, and autonomous activity lists to users through collaborative filtering.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4703-4723
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• 2018

In recent years, dense small cell network has been deployed to address the challenge that has resulted from the unprecendented growth of mobile data traffic and users. It has proven to be a cost efficeient solution to offload traffic from macro-cells. Software defined heterogeneous wireless network can decouple the control plane from the data plane. The control signal goes through the macro-cell while the data traffic can be offloaded by small cells. In this paper, we propose a framework for cell virtualization and user association in order to satisfy versatile requirements of multiple tenants. In the proposed framework, we propose an interference graph partioning based virtual-cell association and customized physical-cell association for multi-homed users in a software defined small cell network. The proposed user association scheme includes 3 steps: initialization, virtual-cell association and physical-cell association. Simulation results show that the proposed virtual-cell association outperforms the other schemes. For physical-cell association, the results on resource utilization and user fairness are examined for mobile users and infrastructure providers.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.238-241
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• 2006

지난 10년 동안 인터넷은 빠른 속도로 모든 분야에 확산되어 왔으면 이와 비슷한 현상으로 최근 몇 년 동안 무선 네트워크의 확산 역시 타른 속도로 보급되고 있는 추세이다. 그리고 무선 네트워크 침입의 형태와 기술 또한 시간과 비례하여 그 다양성이 점차 증가되고 있으며 공격 시도 및 침입에 성공하는 공격의 횟수도 증가하고 있다. 기존 무선 보안 시스템인 Wireless-IDS는 사고 대응 계획이 설계되고 기획되지 않으면, 보안성을 거의 제공하지 않는다. 그리고 이벤트를 감시하고 사고에 대응하기 위한 인적 요소 비용이 크게 소요되는 단점을 가지고 있다. 기존의 TMS는 필요에 따라 자동화되고 능동적인 대응 수단을 제공하기도 하지만, 새롭게 생성되는 많은 무선 위협의 경우 사람이 막아야 하는 현실을 고려하고 있다. 그리하여 본 연구에서는 무선 상에서의 위협을 자동적으로 관리하는 Wireless-TMS의 효율적인 관리를 위해 수많은 무선 트래픽 중에 위협을 어떻게 분류할 것인가에 초점을 맞추어 연구를 진행한다.

• Journal of the Korean housing association
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• v.13 no.6
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• pp.79-88
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• 2002

The intent of this study is to investigate the feasibility of small-scale developments in residential blocks in the city, and to propose development strategies and models. This research is done on the premises that large housing developments ignore the urban structure of its own quality, whitens on-lot-based multi-unit housing developments fail to maintain amenity and livability in residential blocks. For solving these shortcomings, this research proposes the possibility of small-scale housing development models as an alternative development system. And some residential blocks were selected as case sites and analyzed into typical block types, to support the proposal of pertinent development types. Each type was investigated and discussed in terms of development feasibility and proper development strategies. Finally, three development schemes are proposed as prototypical models for the best application in residential blocks.