• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.338-339
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• 2018

최근 분산전원 시스템 개발로 인해 계통연계 인버터의 사용이 증가해 왔다. 계통연계 인버터의 주요한 역할은 계통연계 환경에서의 안정적인 운전과 계통 사고 시 중요 부하에 대한 연속적인 전력을 공급하기 위한 독립운전에 있다. 각 모드 전환시의 출력전압의 변동성과 과도응답 특성을 개선하기 위해 최근 다중 루프 및 간접 전류 제어 방식이 계통연계 인버터에 적용되었다. 하지만 이러한 제어 방식은 캐패시터 전압 및 인버터 전류의 측정이 요구되어 시스템의 비용 및 복잡성을 증가시키게 된다. 본 논문에서는 이산시간 상태공간에서의 전상태 관측기를 설계하여 무순단 절체 동작 시 제어기가 요구하는 변수를 추정하고 이를 궤환신호로 사용하여 시스템의 설계 비용 및 복잡성을 줄인다. 또한 계통연계 시 계통유입 고조파 전류를 억제하기 위해 일반적으로 사용되는 기존 공진형 제어기의 과도 응답을 개선하기 위해 이산시간에서 슬라이딩 모드와 공진제어기가 결합된 새로운 제어기 구조를 제안한다. 제안된 기법의 타당성은 PSIM 시뮬레이션을 통하여 입증된다.

• Spatial Information Research
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• v.21 no.6
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• pp.1-9
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• 2013

Recently, Construction information is being changed from CAD to BIM, and GIS is extending from outdoor to indoor information. In these circumstances, the needs of continuous use of construction information linked with GIS are growing constantly in stages of maintenance, operation and service as well as planning, design and construction. To this end, it is essential element to represent 3-dimensional large object efficiently in establishing BIM-GIS interoperability platform by combination of construction and spatial information. In this study, we design spatial data LOD for making spatial object and texture by level, and develop weight lightening algorithm of large spatial object.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.91-104
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• 2008

In tunnels, safety factor concept has been suggested to estimate their stability quantitatively. It is merely limited in the framework of mechanical analysis. However safety factor concept has not been applied in hydro-mechanical coupled analyses due to their modelling complexity. Recently studies on this topic are being actively made. In this study, induced drainage modelling methods for hydro-mechanical coupled analyses are compared and analyzed to estimate safety factor of a subsea tunnel exactly. To this end, methods both controlling hydraulic characteristic of shotcrete and using a drainage well are considered. Sensitivity analysis were carried out on rock class, thickness of shotcrete, and hydraulic properties of rock mass. As the results of this study, it turned out that the induced drainage modelling using a drainage well would give more reliable results than that of controlling hydraulic characteristic of shotcrete in estimating tunnel stability in hydro-mechanical coupled analyses.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.189-196
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• 2010

광역도시계획은 전략계획, 정책계획, 지침계획의 성격을 지니는 공간계획으로 청사진 계획으로 운용되어 온 기존의 광역개발계획 및 도시기본계획과 구분된다. 광역도시계획이 정하는 사항은 도시기본계획 및 관련 하위계획에서 기본적 취지를 검토하여 집행됨으로써 이들 계획에 대하여 지침 (guideline)적 성격을 가지나, 직접적으로 개별 개발행위나 토지이용행위를 구속하지는 않는다. 행정중심복합도시 광역도시계획에 대한 전략환경평가는 국토해양부 시행지침에서 제시한 절차를 준용하되, 계획수립 여건을 고려하여 평가계획 수립, 항목과 범위 설정(scoping), 환경성평가, 보고서 작성, 보고서 검토, 모니터링 및 사후평가의 6단계로 진행하였다. 전략환경평가 시 구체적인 항목과 범위, 평가방법 등은 계획의 범위와 성격, 내용 등에 대해 대안의 비교 검토가 가능하도록 4가지 사항을 중점적으로 고려하였다. 즉, 정책목표 달성방법의 환경 적 적정성, 대안의 설정, 자원과 에너지 이용의 효율성, 계획이 지구환경에 미치는 영향 등이다. 계획의 환경성 제고를 위해 설정한 항목은 인구, 토지이용계획, 교통계획, 녹지관리 등 4가지이며, 평가과정에서 반복 및 환류를 통하여 계획과 평가간의 연계성을 도모하였다. 이 과정에서 공간구조 변화는 행정중심복합도시를 정점으로 하고 주변 연결거점을 3개로 늘려 조정하였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.59-71
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• 2022

This study considered regional differences in the university-industry collaboration of Korean universities and performed cluster analysis to identify the spatial range with high university-industry collaboration connectivity. By university establishment type, it was found that the university-industry collaboration capacity of the major national university was superior overall, especially in the technology transfer & commercialization sector and the infrastructure sector, compared to private universities and general national universities. The spatial pattern of university-industry collaboration capacity showed relatively clear differences by city and province. In terms of university-industry collaboration capacity by sector, it was confirmed that the regional gap was not large in the talent training sector and the infrastructure sector, but the regional gap was relatively large in the technology transfer & commercialization sector and the start-up sector. As a result of the cluster analysis to identify a spatial range with high connectivity in terms of similarity and spatial proximity of university-industry collaboration patterns, it is divided into 15 clusters. It is found that most of major national universities are included in one of 15 clusters where all sectors of university-industry collaboration are strong. Therefore, as a policy measure to achieve regional innovative growth through enhancing the effectiveness of university-industry collaboration, we propose the establishment of a hub & spoke network-type collaboration system in which a major national university acts as a hub and nearby local universities play a spoke role.

• Journal of Information Technology and Architecture
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• v.11 no.4
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• pp.441-448
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• 2014

The application of spatial information has drawn significant attention from a wide range of industries. Railway spatial information facilitates the cooperation among related parties and improves the efficiency of asset management and operations. This study proposes the structure of Railway Object IDentifier(ROID) on railway spatial information. Current facility management and train operation are based on relative positioning system. Despite many advantages, relative positioning system causes serious problems such as the entire reconfiguration of positioning in the case of line change. Another major concern is the interface compatibility between individual facilities with different relative positioning. ROID based on absolute positioning addresses these issues, allowing the information exchange and convergence between independent parties. This study proposes ROID based on OID standard with object IDentifier and service object-oriented reference system. Our ROID employs the absolute positioning and the unique identifier, maintaining the compatibility with existing management system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.137-146
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• 2001

Route selection needs the analysis function of GSIS to analyze and manipulate a lot of spatial information efficiently. Therefore, it needs the linkage of system requiring the knowledge and the experience of experts as a method that can estimate each quantitative route for an efficient route selection. In this study, the route selection model through construction and analysis procedure of position information using GSIS were presented, and route selection system linked with expert system was developed. This system is easy to be used and managed for presenting route alignment according to conditions as a graphic user interface environmental window system by applying three tiers based object-oriented method. Using GSIS, the various information required for route selections in database was constructed, the characteristics of subject area by executing three-dimensional terrain analysis was grasped effectively, and the control point through buffering, overlay and location operation was extracted. Three alternative routes between a beginning point and an end point inputted by route selection system were selected. Therefore, the applications of the route selection system are presented by applying this system to the real study area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.373-383
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• 2015

Spatial information has been widely used for efficient land use and management, disaster management, environment management, infrastructure management, corporate marketing, and cultural assets management, and the need for spatial information is expected to be increased. For this reason, central government, local government and public institutions must establish a National Spatial Information System (Fifteen systems related to spatial information managed by National Spatial Data Infrastructure Policy office, NSIS) framework that guarantees high accuracy and quality. The NSIS will provide convenience usage of spatial information in the field of decision-making or civil support. However the current National Spatial Information System is mainly established with separate processes, which causes data redundancy, deterioration of information, passive opening, and sharing of the spatial data. This study suggests 4 standards, which has been derived by applying value-chain model to NSIS data flow, and they are ‘Production and Establishment’, ‘Integration and Sharing’, ‘Application and Fusion’ and ‘Release and Opening’. Based on these standards, the 15 NSIS were analyzed to draw out implications and reforming directions were suggested. By following these suggestions we expect more recent, consist, accurate, and connected National Spatial Information Service which will be more open to public and then satisfy the demands.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.1
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• pp.1-17
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• 2019

The purpose of this paper is to examine the spatial characteristics of the medical device industry in accordance with the promotion of regional industrial policy. For this aim, I suggest a research methodology that can examine the productivity of production activity and the profitability of sales activity by the government. As the government's large-scale support is localized by the 'selective support' method, the spatial characteristics of the productivity and profitability of the industry are different. In this context, the results of the review of the government's regional industrial policy in three aspects are as follows. First, the government's support did not come down to increased productivity and profitability. Second, high productivity at the regional level did not necessarily lead to high profitability. Finally, the high market share in terms of profitability did not guarantee high profits. Therefore, it is necessary for the government to reconsider the direction of regional industrial policy so that the link between productivity and profitability can be secured in the examination of the achievement of industrial specificity and policy support.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.1
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• pp.425-446
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• 2018

As makerspaces continue to be introduced in academic libraries in Korea, this study explores potential operating strategies of, and long-term justifications for, makerspaces as digital literacy eduational spaces and services at academic libraries. By examining related literature reviews and case studies of makerspaces, this study analyzes various programs and their respective creation, funding, development, and outcomes, including educational value and library-specific goals such as digital literacy and lifelong learning. This study also considers the perspectives of librarians at academic libraries in Korea who were asked about the purpose, impact, and limitations of makerspaces. Certain common themes appear: for example, it is necessary for makerspaces to resolve challenges related to stable funding, as well as staffing and training of professional librarians assisting with the on-the-ground operation of makerspaces. This study proposes that designing makerspaces for an academic library setting goes deeper than providing a collaborative environment with access to new technologies like 3D printers and laser cutters, and it may be uniquely appropriate to draw connections to libraries' objectives to provide digital literacy education and universities' mission to foster innovation and creativity among students.