• Journal of KIISE:Computing Practices and Letters
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• v.15 no.9
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• pp.685-689
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• 2009

Flash memory has several features such as low~power consumption and fast access so that there has been various research on using flash memory as new storage. Especially the Solid State Disk which is composed of flash memory chips has recently replaced the hard disk. At present, SSD adopts the multi-channel and multi-way architecture to exploit advantages of parallel access. In this architecture, data are written on SSD in a unit of a superblock which is composed of multiple blocks in which some blocks are put together. This paper proposes two schemes of selecting, segmenting and re-composing victim superblocks to optimize concurrent processing when a buffer flush occurs. The experimental results show that 35% of superblock- based write operations is reduced by selecting victims and additional 9% by composition of superblock.

• Construction Engineering and Management
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• v.23 no.3
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• pp.17-22
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• 2022

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.949-952
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• 2000

공유 저장장치에 접근할 수 있는 경로를 다중화함으로써 클러스터 파일시스템 내 한 노드에서 발생하는 결함을 허용할 수 있다. 공유 저장장치의 다중접근은 파일 이동과 파일 중복으로 이루어진다. 본 논문에서는 전역 파일 시스템의 평균 응답 시간을 줄이기 위해 파일 자원의 접근률에 따라 우선 순위를 두어 파일이동과 과일 중복 시 발생할 수 있는 클러스터 파일 시스템의 성능 저하 및 서비스 중단을 막기 위한 방법을 제안한다. 파일 자원의 접근률은 파일 처리 시에 사용되는 블록, 아이노드(mode), 슈퍼블록과 같은 자원 사용 빈도를 통해 얻어질 수 있다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.2
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• pp.3-12
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• 2001

Currently, the superscalar architecture dominates todays microprocessor marketplase. As, more transistors are integrated onto larger die, however, an on-chip multiprocessor is regarded as a promising alternative to the superscalar microprocessor. This paper examines the behavior of the next generation block encryption algorithms RC6 and Rijndael on the on-chip multiprocessing microprocessor. Based on the simulation results by using a program-driven simulator, the on-chip multiprocessor can exploit thread level parallelism effectively and overcome the limitation of instruction level parallelism in the next generation block encryption algorithms.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.10
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• pp.71-82
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• 2019

This study tried to prove why a low-rise residential block is more vitalized than in a superblock consisted of an apartment housing complex. To do this, two adjacent superblocks in Yeoksam 2-dong were selected as a case study among superblocks of residential area in Gangnam, Seoul. It adopted the concept of 'complexity', 'Osmosis', 'Vitality' and 'Permeability' for evaluation indexes to measure street vitality. As a result, four indexes were clearly higher in low-density residential superblocks than apartment housing complex superblocks. First, the superblocks for apartment housing complexes showed a lower 'complexity' because large-scale parcels for an apartment housing complex reduces a possibility for various land uses. Second, smaller blocks improved "osmosis" compared to larger blocks, and the larger the block, the less likely it is that buildings and streets penetrate activity. Third, as the apartment complex block became larger, the number of accesses decreased. Thus, it did not provide vitality to the streets. Fourth, high permeability was shown in the low-density superblocks, while that of the superblock consisted of apartment housing complexes was very low because the entrance of the complexes entrance is closed to the public. The results of this study demonstrated that an apartment housing complex may hamper street vitality and deteriorate the quality of urban environments.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.16-18
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• 2021

최근 베어메탈 시스템에 스케줄러 시스템 기반 인프라 시스템에서 벗어나 사용자 맞춤형 클라우드 인프라가 관심을 받고 있다. KI Cloud 플랫폼은 고성능 컴퓨팅(HPC) 사용자를 위한 클라우드 기반 IaaS, PaaS 통합 플랫폼이다. 본 논문에서는 KI Cloud를 위한 데이터 저장소 설계 및 구현에 대해 기술한다. 오픈 소스 Ceph 분산 스토리지 시스템을 기반으로 구축하였고, 프로젝트의 목적에 맞게 블록 스토리지, 오브젝트 스토리지, 파일 스토리지 방식으로 구현하였다. Openstack 기반의 서비스와 Kubernetes 기반의 서비스가 하나의 스토리지를 통해 다양한 타입의 서비스를 제공할 수 있도록 개발하였다.

• The KIPS Transactions:PartD
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• v.17D no.6
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• pp.383-394
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• 2010

Flash memory based SSDs are currently being considered as a promising candidate for replacing hard disks due to several superior features such as shorter access time, lower power consumption and better shock resistance. However, SSDs have different characteristics from hard disk such as difference of unit and time for read, write and erase operation and impossibility for over-writing. Because of these reasons, SSDs have disadvantages on hard disk based systems, so FTL(Flash Translation Layer) is designed to increase SSDs' efficiency. In this paper, we propose an advanced logical address mapping method for increasing SSDs' performance, which is named HAMM(Hybrid Address Mapping Method). HAMM addresses drawbacks of previous block-mapping method and super-block-mapping method and takes advantages of them. We experimented our method on our own SSDs simulator. In the experiments, we confirmed that HAMM uses storage area more efficiently than super-block-mapping method, given the same buffer size. In addition, HAMM used smaller memory than block-mapping method to construct mapping table, demonstrating almost same performance.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.140-154
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• 2011

Through this thesis, I intended to analyze superhero action thriller through that achieved in art and box office after the film release. I would to access about it centering around directing viewpoint. of Christoper Nolan is evaluate as 'upgraded excellent action thriller'that have remarkable theme and excellent visual. Analysis of directing'll classify both contents and form. See about contents... theme of existential dilemma about the good and the evel, characters who is grew more powerful, and deeper than Batman series in old times. the fifth plot, especially dramatic plot by Joker's game, and various irony and motif. About form... efficient use of IMAX camera, prominence of action directing about car chase and fighting... better editing and music and art than former super hero series. The most important merit of is it's a philosophical theme. It is dipicted very seriously and successfully. First of all, the film has more advanced technique power and new directing style.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.536-541
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• 2008

이차적인 저장공간으로 사용되는 하드디스크의 용량은 기술의 발전으로 나날이 커져가고 있다. 이렇게 디스크 용량이 증가함에 따라 파일 시스템의 단편화 현상은 더더욱 심화되며, 전체적인 시스템의 성능을 떨어뜨리는 주원인이 되고 있다. 우리는 단편화 현상 해결을 위한 첫 단계로 자동적이고 지속적인 단편화 측정을 위한 자동적인 레이아웃 스코어링(Autonomic Layout Scoring)기법을 제안한다. ALS 기법을 활용하면 파일 시스템이 생성된 후, 계속해서 단편화 현상의 정도를 측정하게 되며 이를 토대로 단편화 현상을 제거하기 위한 기법을 적용할 수 있다. 본 논문에서는 ALS 기법을 설계하고 리눅스 2.6 버전의 EXT2 파일 시스템에 구현하였다. 그리고 실제 파일 시스템을 수행하면서 단편화 현상을 측정하는 과정과 아이노드, 블록 그룹, 슈퍼 블록이 각각 노화되는 정도를 측정한 결과를 보인다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5385-5392
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• 2014

Super typhoons develop as a result of meteorological changes. In 2012, Typhoons Bolaven and Denba reached Korea. The maximum instantaneous wind speed of the typhoons reached 60 m/sec. Harbor structures including sofa block sustained damage and loss by the abnormally high waves. In Korea, tetrapod blocks were installed the most for wave dissipating. Nevertheless, a structural evaluation of the tetrapod block has not been performed. This study examined the structural mechanism and weakness part of the tetrapod block under a range of boundary conditions. The block has weakness against a tensile force because it is plain concrete. The joint part of the legs is the most vulnerable to tensile stress. The weakest part can be reduced if the joint part is reinforced as a hunch.