• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data scalable growth and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for suports snapshots and reorganizations.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.520-532
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• 2002

A new architecture called the Storage Area Network(SAN) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use SAN more efficiently, most SAN operating systems support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually. A logical volume manager plays a key role in storage virtualization. In order for mapping managers to process snap-shots and reorganizations, an efficient freespace manager is required, and it affects the overall performance of logical volume. In this thesis, we design and implement a freespace manager for logical volume manager. The freespace manager efficiently allocates physical blocks for logical blocks. Also, it processes space allocation requests for supports snapshots and reorganizations.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.58-64
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• 2011

Objective: The 3-dimensional reconstruction method with resolution recovery modeling has advantages of high spatial resolution and contrast because of its precise modeling of spatial blurring according to the distance from detector plane. The aim of this study was to evaluate one of the resolution recovery reconstruction methods (Astonish, Philips Medical), compare it to other iterative reconstructions, and verify its clinical usefulness. Materials and Methods: NEMA IEC PET body phantom and Flanges Jaszczak ECT phantom (Data Spectrum Corp., USA) studies were performed using Skylight SPECT (Philips) system under four different conditions; short or long (2 times of short) radius, and half or full (40 kcts/frame) acquisition counts. Astonish reconstruction method was compared with two other iterative reconstructions; MLEM and 3D-OSEM which vendor supplied. For quantitative analysis, the contrast ratios obtained from IEC phantom test were compared. Reconstruction parameters were determined by optimization study using graph of contrast ratio versus background variability. The qualitative comparison was performed with Jaszczak ECT phantom and human myocardial data. Results: The overall contrast ratio was higher with Astonish than the others. For the largest hot sphere of 37 mm diameter, Astonish showed about 27.1% and 17.4% higher contrast ratio than MLEM and 3D-OSEM, in short radius study. For long radius, Astonish showed about 40.5% and 32.6% higher contrast ratio than MLEM and 3D-OSEM. The effect of acquired counts was insignificant. In the qualitative studies with Jaszczak phantom and human myocardial data, Astonish showed the best image quality. Conclusion: In this study, we have found out that Astonish can provide more reliable clinical results by better image quality compared to other iterative reconstruction methods. Although further clinical studies are required, Astonish would be used in clinics with confidence for enhancement of images.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.193-196
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• 2011

공간적으로 다양하게 재구성되며 이동하는 분산/이동/실시간 시스템을 명세 및 분석하기 위한 기존의 프로세스 대수들은 명세/분석 과정에서 텍스트 기반의 명세 언어를 사용한다. 이로 인하여 프로세스 사이의 이동성과 프로세스들의 공간적 분포를 대한 명세 및 분석 방법은 매우 큰 복잡도가 존재한다. 이를 극복하기 위하여 일반 프로세스 대수를 시각적인 형태로 표현하는 다양한 기법들이 제안되었다. 이러한 시각화 언어들은 시스템의 특정 상태를 명세하거나, 시스템의 속성을 공간적 분포와 링크정보로 분리하는 방법들이 사용되었지만, 명세하고자 하는 시스템의 전체 행위에 대한 효율적인 명세 방법이 존재하지 않고, 시각화 언어임에도 불구하고 텍스트기반의 프로세스 대수와 병행되어 사용되어야만 하는 제약들이 존재한다. 이러한 제약들을 극복하기 위한 하나의 방법으로 본 논문에서는 프로세스 대수를 위한 새로운 시각화 언어인 Onion Visual Language를 제안한다. Onion Visual Language는 프로세스 사이에서 발생하는 이동과 상호작용 등의 전체 행위를 원형의 양파껍질과 같은 형태로 표현하며, 각 프로세스들 사이에서 발생하는 행위들의 관계를 액션으로 표현한다. 또한, 계층화된 프로세스 구조, 프로세스의 상태정보, 프로세스의 미래 행위 정보, 비결정적 행위정보를 포함하여 매우 복잡한 시스템의 특징을 효율적으로 명세/분석 가능하도록 하였다.

• Journal of Korean Library and Information Science Society
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• v.48 no.1
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• pp.1-20
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• 2017

Public library is the most well-used cultural infrastructure, life-long learning space, and social facility within local community. In order to respond to the multi-purpose identities, space structure of many public libraries is changed or reconstructed to open-concept, multi-functional and interconnected areas. Accordingly, the noise issue in public libraries has emerged as one of key environmental parameters and noise management is bound to be considered as a scale for determining whether a user-friendly library. This study measured the noise level of the public libraries in Daegu city, analyzed measurement results on the basis of national and international standards, and suggested the various reduction plans.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.1519-1522
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• 2003

기존의 웹 문서나 컨텐츠들의 표현적 한계를 극복하기 위한 방안으로 메타 데이터에 관한 다양한 연구가 수행되어졌고 그 결과의 산물중에 가장 대표적인 것으로 XML을 들 수 있다. XML은 문서의 내용뿐 아니라 구조까지도 기술할 수 있는 장점을 통해 향후 정보 교환에 핵심적인 역할을 할 것으로 기대되어지고 있으며 이에 따라 XML 문서를 효율적으로 저장하고 검색하기 위한 다양한 연구가 진행되고 있다. BitCube는 Bit-wise 연산이 가능한 3차원 비트맵 인덱싱을 사용하여 XML 문서들의 구조적 유사성에 따라 클러스터링하고 사용자의 질의에 대한 처리를 수행하는 인덱싱 기법으로 그것의 빠른 성능을 입증하였다. 그러나 BitCube의 클러스터링은 XML 문서의 경로에 중점을 둔 것이므로 클러스터와 경로가 담고 있는 실제 단어들간에는 연관성이 없으므로 3차원 비트맵 인덱스는 하나의 평면을 제외한 모든 평면이 굉장히 높은 공간 사용량을 갖는 회소행렬이 된다. 본 논문에서는 늘어나는 방대한 문서의 양으로 인한 시스템의 성능 저하를 막고 안정적인 성능을 유지할 수 있도록 기존 연산의 성능을 저하시키지 않으면서 공간을 최소화 할 수 있는 연결 리스트틀 설계하고 3차원 비트맵 인덱스를 연결 리스트로 재구성하는 방법을 제시한다.

• Journal of the Korean Geographical Society
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• v.49 no.2
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• pp.139-159
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• 2014

This study problematizes the dominance of developmental state theory and its negative influences in the field of Korean studies, in particular, dealing with the industrialization during the developmental era, 1960s~70s. As is generally known, the theory has been in a position of unchallenged authority on the industrialization experience of East Asian countries, including South Korea. However, at the same time, it has also misled us into overlooking strategic relations that had articulated the state forms at multiple scales. This study aims to reconstruct the historical contexts by the theorizing prompted by recent work on state space. I shed light on the multiscalar strategic relations that had shaped the Ulsan refinery plant as a representative state space of the South Korean industrialization during two decades after liberation. Specifically, the study illustrates the features and roles of Cold War networks and multiscalar agnets such as Nam Goong-Yeon. By identifying the plant as a result of sequential articulations between Ulsan and other scales, this study concludes by suggesting to reframing the strategic relational spaces, beyond the view of methodological nationalism, in the perspective of multiscalar approach.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.907-914
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• 2014

A heuristic search algorithm is proposed to plan a collision free path for robots in an indoor environment. The proposed algorithm is to find a collision free path in the gridded configuration space by proposed heuristic graph search algorithm. The proposed algorithm largely consists of two parts : tunnel searching and path searching in the tunnel. The tunnel searching algorithm finds a thicker path from start grid to goal grid in grid configuration space. The tunnel is constructed with large grid defined as a connected several minimum size grids in grid-based configuration space. The path searching algorithm then searches a path in the tunnel with minimum grids. The computational time of the proposed algorithm is less than the other graph search algorithm and we analysis the time complexity. To show the validity of the proposed algorithm, some numerical examples are illustrated for robot.

• Journal of the Korean association of regional geographers
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• v.13 no.1
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• pp.82-103
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• 2007

Neoliberalism can be seen as a path-dependent, hybrid and contradictory project that operates actually (not just ideologically) through intervention of the state that has been not weakened in its strength but different in its strategies, especially through neoliberal policies of remaking urban space. This paper seeks to characterize the development of neoliberalism and urban policies in S. Korea, by examining the trajectory of neoliberalism generated in its contextually specific way since the late 1980s, by illuminating the intersection between new neoliberal programs and the existing developmentalism of the state and changes in spatial policy with its effects, which can be divided into two phases: the first from the late 1980s to the economic crisis in 1997, and the second from the crisis to the present. This paper finally identifies several paths in which the state and the market would be interrelated, and argues that the vision of national development and spatial policy should be welfare(i.e. human)-oriented, not industry(i.e. capital)-oriented.

• Spatial Information Research
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• v.19 no.1
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• pp.107-116
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• 2011

Due to development of environment of wireless Internet, location based services on the basis of spatial data have been increased such as real time traffic information as well as CNS(Car Navigation System) to provide mobile user with route guidance to the destination. However, the current application adopting the file-based system has limitation of managing and storing the huge amount of spatial data. In order to supplement this challenge, research which is capable of managing large amounts of spatial data based on embedded database system is surely demanded. For this reason, this study aims to suggest the lossless compression technique by using the hybrid approach of BytePacking and Lempel-Ziv which can be applicable in DBMS so as to save a mass spatial data efficiently. We apply the proposed compression technique to actual the Seoul and Inchcon metropolitan area and compared the existing method with suggested one using the same data through analyzing the query processing duration until the reconstruction. As a result of comparison, we have come to the conclusion that suggested technique is far more performance on spatial data demanding high location accuracy than the previous techniques.