• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.238-248
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• 2007

As the demand of employing various PC software on mobile embedded devices which have limited storages has been increased, software streaming services are needed. However it takes too much time to launch software on them because it is transferred through wireless networks. To address this problem, prefetch algorithms are needed. We examined 'Last successor (LS)' algorithm and PPM-based prefetch algorithm as prefetch algorithms for software streaming services. We present 'Probability-base Multi Successor (PMS)' algorithm which is contrived through analyzing evaluations of previous algorithms and characteristics of software streaming services. While LS has one successor per each block, PMS has N successors based on probability which is calculated by PPM-based prefetch algorithm. The hit rate of PMS is similar to that of PPM-base prefetch algorithm and the space overhead is similar to that of LS. We can get good efficiency at the point of memory usage when PMS is applied to software streaming services.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.666-669
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• 2010

여러 가지 지하시설물 중 국가 주요 자원의 수송망을 책임지는 주요구조물인 수도관, 가스관등의 배관구조물은 접근이 쉽지 않은 지하공간에 복잡하게 연결되어 있어 그 중요성에 비해 유지, 관리, 보수가 쉽지 않았다. 이러한 배관구조물을 균열, 조인트 풀림 등의 손상으로부터 보다 안전하고 효율적으로 관리하기 위하여 상시적 배관구조물 손상진단기법을 연구하였다. 이를 위해 배관 구조물 시험체에 볼트풀림, notch 등과 같은 손상에 대하여 대표적인 압전센서인 PZT와 MFC를 부착하고 임피던스기법 및 유도 초음파기법을 적용하여 볼트풀림개수, notch 손상개수 증가에 따른 출력신호를 반복 계측하였다. 객관적인 평가를 위해 계측된 신호를 신호처리기법인 웨이블렛 변환을 수행하고, RMSD 및 1-CC의 손상지수를 사용하여 구조물손상을 정량화 시켰으며 이를 토대로 구조물의 건전성의 기준이 되는 임계값을 설정함으로서 임피던스와 유도초음파 두 검색기법을 이용한 상시적 배관구조물 건전성 모니터링의 가능성을 살펴보았다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.411-411
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• 2010

Cavity mode Whistler wave를 사용하는 자화유도결합플라즈마 (Magnetized Inductively Coupled Plasma, MICP)의 제반 특성을 비등방성 수송계수를 가지는 Drift-Diffusion 근사, 에너지 보존 방정식 및 유도전자계를 self-consistent 하게 고려하여 계산하였다. 이러한 접근법은 비충돌성 전자가열현상을 고려하지 못하는 단점에도 불구하고, 반도체 장비설계에 필수적인 전자온도, 밀도, 플라즈마 전위, 시스템의 임피던스 특성에 대한 경향성 파악에 매우 유용하다. 뿐만 아니라 전자밀도분포가 공간내에 형성되는 R-wave mode에 미치는 영향을 분석할 수 있다. 직경 320 mm를 가지는 작은 반응기에서 시뮬레이션과 실험결과를 비교하여 본 모델링 방법의 타당성을 검증한 후, 450 mm wafer가공에 적합한 대면적 플라즈마 반응기에서 플라즈마 특성을 연구하였다. 수 mTorr의 공정압력에서 약 10 Gauss전후의 약한 자장이 인가됨으로서 반경방향의 전자밀도 균일성이 대폭 향상되었다. 플라즈마 및 안테나의 대면적화에 수반되는 높은 Q값이 자장의 인가로 큰 폭으로 감소함으로서 임피던스메칭의 안정성이 비약적으로 개선되었고 전력전달 효율 또한 크게 증가함을 알 수 있었다. 본 연구 결과는 차세대 450 mm 반도체 공정장비의 개발에 있어 자화유도결합플라즈마가 매우 유용하게 사용될 수 있음을 보여준다.

• Annual Conference of KIPS
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• 2012.11a
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• pp.1396-1398
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• 2012

본 논문에서는 데이터베이스 관리자를 대상으로 한 안드로이드용 SQL*Plus 원격접속 애플리케이션을 개발하였다. 기존의 PC를 이용해 DB에 접근할 수밖에 없었던 시간적, 공간적 제약을 극복하는데 목적이 있으며 직관적인 UI와 여러 기능을 통해 사용자에게 편의를 제공하고자 한다.

• Annual Conference of KIPS
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• 2004.05a
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• pp.1181-1184
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• 2004

최근 정보 시스템의 활용도가 높아지고 인터넷을 통한 공간의 제약 없이 네트워크를 통해 먼 거리의 컴퓨터에 원격으로 접속하고 상호간에 자유롭게 데이터를 공유하게 됨으로써 정보유출 위험성이 날로 증가하고 있다. 현재 정보 유출 방지를 위해 다양하고 효율적인 방법들이 연구되어 오면서, 수많은 정보 시스템들은 사용자 인증 및 암호화 기술을 사용하여 보안성이 크게 강화되었다. 그러나 여전히 내부관리자나 사용자에 의한 정보 유출에 대해서는 취약한 실정이다. 본 논문에서는 커버로스 인증 시스템 및 접근제어목록을 이용하여 대부분의 암호화 파일시스템에서 문제로 제기되는 파일 공유 문제를 해결하고, 사용자 단위로 관리할 필요가 없는 시스템수준의 키 관리를 하는 안전한 데이터 관리 시스템을 제안함으로써 내부자에 의한 정보 유출 방지 및 외부자 침입을 탐지할 수 있는 방안을 제시한다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.3
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• pp.47-58
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• 2023

This study was conducted through reviewing Aspects of Design and Construction in Entrance Space of the World Heritage Royal Tombs of the Joseon Dynasty, which is equipped with parking lots, ticket offices, toilets, exhibition halls, information boards, and rest facilities for the convenience of visitors and the purpose of this study was to propose a direction for improvement. The results of the study are as follows: First, the reduced area of Royal Tombs of the Joseon Dynasty was unable to fully accommodate the ritual movement line, and as a result, the location of the entrance space in the current royal tomb was decided to accommodate minimal convenience functions. In the meantime, the entrance space of the royal tombs has been relocated or renovated in order to achieve its integrity as a World Heritage Site, rational arrangement of movement lines and spatial utility. Second, the size of the entrance space ranges from 1,000 square meters in Jeongneung in Seoul to 16,000 square meters in Hongyuneung in Namyangju, and the number of annual users varies greatly from 12,000 in Onneung in Yangju to 410,000 in Seonjeongneung in Seoul. Considering the conditions of the 16 royal tombs, the entrance space should be provided at an appropriate scale, reflecting the surrounding land use and accessibility that affect the influx of users, the size of the site, and the king's awareness and preferences. Third, the location of the parking lot, the presence or absence of an outer courtyard and an internal courtyard bordering the ticket and check offices, and the location of the Historical and Cultural Museum made it possible to know the aspects of entrance space of the Joseon Royal Tombs, where the spatial configuration is determined Fourth, according to the royal tombs, it was found that the entrance space should have essential parking, access control, information, and convenience functions, and that support, exhibition, passage, and recess functions should be optional. At this time, the management office and the Historical and Cultural Center are in charge of support and exhibition functions. The function of passage can be a strategy that provides a sense of entry and the function of recess which has been introduced in only four royal tombs requires an appropriate location and landscape access.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1791-1798
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• 2010

This research predicted the change and characteristics of space structure by new residential area development through objective and quantitative analysis of urban spatial configuration using space syntax and associated the prediction with the city status statistics data and quantitative analysis, and the results are summarized as follows: (1) If large scale new residential area of Dongnae township proceeds to be developed according to present plan, accessibility to the new residential area will drop, and also as the outside space ripple effects by new residential area development also are anticipated small, the new residential area apprehensibly will not succeed to play the role of integrating the entire city structurally, but will cause structural problem, severing the city structure. (2) If the city planned road between existing urban center planned based on 2004 Chuncheon city plan overall drawing and main road which is the entrance road of the planned new residential area is developed together, the accessibility to the entire space of Chuncheon city and the new residential area will be easy, allowing the new residential area properly integrated into the entire space of Chuncheon city, consequently giving a prediction that classification of land use between the central part of Chuncheon city and surrounding residential area would become conspicuous.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.339-350
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• 2024

Purpose: This study analyzes accessibility of 10 hydrogen charging stations in Seoul and identifies areas that were difficult to access. The purpose is to re-analyze accessibility by adding a new location in terms of equity and safety of location placement, and then draw implications by comparing the improvement effects. Method: By applying the location-allocation model and the service area model based on network analysis of the ArcGIS program, areas with weak access were identified. The location selection method applied the 'Minimize Facilities' method in consideration of the need for rapid arrival to insufficient hydrogen charging stations. The limit distance for arrival within a specific time was analyzed by applying the average vehicle traffic speed(23.1km/h, Seoul Open Data Square) in 2022 to three categories: 3,850m(10minutes), 5,775m(15minutes), 7,700m(20minutes). In order to minimize conflicts over the installation of hydrogen charging stations, special standards of the Ministry of Trade, Industry and Energy applied to derive candidate sites for additional installation of hydrogen charging stations among existing gas stations and LPG/CNG charging stations. Result: As a result of the analysis, it was confirmed that accessibility was significantly improved by installing 5 new hydrogen charging stations at relatively safe gas stations and LPG/CNG charging stations in areas where access to the existing 10 hydrogen charging stations is weak within 20 minutes. Nevertheless, it was found that there are still areas where access remains difficult. Conclusion: The location allocation model is used to identify areas where access to hydrogen charging stations is difficult and prioritize installation, decision-making to select locations for hydrogen charging stations based on scientific evidence can be supported.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.4
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• pp.642-659
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• 2012

The main aim of this article is to examine theoretical issues on the 'global-local connectivity' of regional industrial cluster and regional innovation system which have been presented since the 2000s in terms of three different aspects. Firstly, the concept of 'geographical proximity' is discussed within the context of its importance for the regional industrial development by considering relationships of cluster, local buzz and global pipeline. Secondly, concepts on knowledge gatekeeper and temporary cluster are explored with respect to their role of a mediator in forming or transforming global-local connectivity. Finally, policy implications of the global-local connection are presented. Authors arguments are as follows; firstly, in order to improve regional industrial cluster on the basis of geographical proximity, relational proximity which is beyond different spatial scales has to be secured. It means that geographical convenience and inconvenience are required simultaneously for regional industrial development. Secondly, A base of the global-local connectivity is socal capital and embeddedness. Therefore, it needs to understand that relational proximity is embedded into different culture and habit at different spatial scales. Finally, within the context of the global-local connectivity, in order to overcome spatial hierarchy by the division of labor of firms, it needs to consider the complex system which is composed of vertical and horizontal hierarchy by the spatial division of labor by firms, openness and closeness of clusters, and the scope of policies' inclusion and exclusion by central and local governments.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.120-131
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• 2009

This study measured the centripetal force and effective scope of the population spread from urban center and subcenters in order to diagnose the urban spatial structure of the formation of a multicentric city structure in Busan. The study analyzed the variability of the determination coefficient value (R square) with a negative exponential function derived from the population density model by extending the circular region into 5-km units. The aim of this study was to measure changes in the effective scope of the population centripetal force of the urban center and subcenter in 5-year intervals from 1995 to 2005 using census data. The explanatory adequacy of the population density function was examined with the bias of the function to calculate the distance error between the real location of the urban center and the optimal location, according to the population density function. To summarize the results, the value for the area of Jungangdong showed a continuous reduction, whereas Seomyeon (Bujeondong) maintained explanatory adequacy without a large change. As a whole, Busan was in the process of continuous diversification, in spite of its reduced population. Therefore, it appears necessary to strengthen the function of the urban center and subcenter and to supply adequate dwelling zones close to downtown to form a more efficient urban spatial structure. The results of the present study will be utilized as basic data for the formulation of a political approach to the efficient reorganization of spatial structure by correlating concrete spatial information with the population variability of Busan's urban center and subcenter.