• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.23-26
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• 2006

최근 대부분의 이러닝(E-Learning)을 교육하는 사이트는 학습 콘텐츠를 검색하는 방법이 단순한 리스트의 나열과 택스트 매칭(Text matching)방법을 사용하는 단점이 있다. 이를 보완하기 위해 좀 더 컴퓨터가 정보 데이터의 의미를 분석하여 검색이 가능하도록 개념 네트워크인 시맨틱웹(Semantic Web)이 등장하였다. 본 논문에서는 이러한 시맨틱웹의 온톨로지(Ontology) 언어 중에 토픽맵(Topic Maps)을 사용하여 많은 양의 학습 정보 데이터를 쉽고도 정확하게 연결 지어 학습 콘텐츠에 대한 정보를 표현하고, 구조화할 수 있는 방법을 모색해 보고자 한다. 학습자의 관심분야 정보, 학습객체의 학습 권장자의 정보와 함께 학습 경험과 검색 빈도수를 분석한 협력 필터링과 학습 에이전트의 개인화 기법을 동시에 사용하여 선호도를 분석한다. 이 선호도를 가지고 학습자의 메타데이터를 생성하고, 로그 데이터를 따로 데이터베이스에 저장한다. 이러한 학습자의 정보와 학습 콘텐츠간의 정보를 상호 연결하여, 그 토픽맵을 사용하여 연관관계를 정의해 줌으로써 학업성취도를 높이고, 학습자 개개인의 성향에 가장 알맞은 학습 콘텐츠를 탐색해가는 네비게이터(Navigator)를 설계하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.249-251
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• 2012

Augmented Reality (AR) enables the enhanced realism and interaction by providing the overlaid digital information on the user's view of the physical world. In this paper, we propose an AR-based ship design visualization system for presenting ship 3D model in smart phones or table PCs. The proposed system compute corner points and feature points by contour finding method and harris corner detector, and build a ship-design drawing database. By using SURF algorithm, key feature points are extracted from ship-design drawing image which is obtained by mobile camera. Then ship-design drawing image is recognized by matching the feature points stored in DB and extracted key feature points. 3D ship structures are visualized by overlaying the ship-design drawing image on the smart phone or table PC's screen. Compared to conventional 2D ship-design, proposed system helps to easily understand the structures of the ship and reduce the business design period. Thus, Enhanced competitiveness of business is expected.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.1
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• pp.97-110
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• 1996

The purpose of this study is to evaluate the urban land used by the Urban Land Use Information System (ULIS) which can supply the micro-level land usc information for the understanding of micro-level urban spatial structure and district-level planning and managements(such as urban design, redevelopment planning and district-level transportation planning, etc.). The study evaluates the current situation of urban land use database and suggests the prototype of urban land use database using GIS. The planning and management of post-modern city which has characterized by diversity and the mixture of land use, need more detail and quantitative information about land use. Recent redevelopment and reconstruction of existing physical condition are increasing the density of activity. It raises urban problems such as the shortage of infrastructure and traffic congestion, etc. In this process we need to construct information system which monitors current land use situation.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.947-957
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• 2016

KCI is a database for the citations of journals and papers published in Korea. Classification of a journal listed in KCI was mainly determined by the publisher who registered the journal at the time of application for the journal. However, journal classification in KCI was known for not properly representing the quoting rate between journals. In this study, we extracted communities of the journals registerd in KCI based on quoting relationship using various network clustering algorithms. Among them, the infomap algorithm turned out to give a classification more being alike to the current KCI's in the aspect of the modular structure.

• Database Research
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• v.34 no.3
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• pp.14-27
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• 2018

Recently, to alleviate the memory bottleneck problme occurred in Symmetric Multiprocessing (SMP) architecture, Non-Uniform Memory Access (NUMA) architecture was proposed. In addition, since an aggregation operator is an important operator providing properties and summary of data, the efficiency of the aggregation operator is crucial to overall performance of a system. Thus, in this paper, we propose an efficient aggregation processing technique on NUMA architecture. Our proposed technique consists of partition phase and merge phase. In the partition phase, the target relation is partitioned into several partial relations according to grouping attribute. Thus, since each thread can process aggregation operator on partial relation independently, we prevent the remote memory access during the merge phase. Furthermore, at the merge phase, we improve the performance of the aggregation processing by letting each thread compute aggregation with a local hash table as well as avoiding lock contention to merge aggregation results generated by all threads into one.

• Journal of IKEEE
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• v.24 no.2
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• pp.392-402
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• 2020

This paper proposes a solar tracking system without photo-sensors. The system can be classified into four modules: Solar Tracking, MPPT, ESS, and Real-Time Monitoring. Nine solar panels, as a basic unit, are adopted with grid structures of different heights to reduce wind influence and to enable solar tracking without photo-sensors. The low-cost MCU implements MPPT method which generates PWM switching signal for boost converter. The unit of ESS consists of three-series and four-parallel lithium-ion batteries in order to enable monitoring for abnormalities in temperature and electrical characteristics of battery. Four MCUs used in the system consists of two AVR Atmega128, and two Raspberry PI, and they exchanges operation informations. Experimental results of the proposed system show the solar tracking performance, the possibility of on-site and remote monitoring and the convenience of maintenance based on IoT technology.

• Journal of Digital Contents Society
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• v.14 no.1
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• pp.15-23
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• 2013

In response to the demands of large-scale data processing with low-power and new application, a storage system using SSD (Solid State Disk/Drive) with fast input-output performance instead of hard disc has appeared as storage device. Studies on methods to overcome specific problems of SSD such as various processing data units, out-place-update and limited delete count have been actively conducted. However, declining performance and stability have not been resolved yet when storing case specific data with small scale that causes frequent random write in hard disc or SSD. This thesis suggests a system structure that stores index requesting frequent random write in NVRAM capable of byte access by using characteristics such as byte unit fast read / write of NVRAM, non-volatile and smaller size of actual changed data size in index page than block size.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.328-332
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• 2006

환경모델링 기법은 비선형 오염유출현상을 구조화하여 배출특성 규명 및 정책대안의 영향예측 도구로서 활용도가 증가하고 있다. 반면 복잡한 입력 파라미터의 구성은 모형운영에 있어 비정량적 수치를 적용할 수 있는 가능성을 내포하고 있다. 이러한 한계성을 극복하기 위해 최근 들어 GIS와 정보기술의 연계를 통한 자료관리 및 모형 매개변수 산출을 위한 연구들이 활발히 진행 중에 있다. GIS-모델링 분야의 기술적 성장에도 불구하고 정보구축의 시점, 주기, 구축 형태 등의 통일화가 이루어지지 않았다. 따라서 BASINS과 같은 기 구축된 정보 분석체계를 사용하고자 할 때 단위사업별로 구축된 공간정보의 구조해석을 다시 수행해야 하는 문제를 지니고 있다. 이는 구축된 정보를 사용하여 해석하고자 하는 주체가 분명하지 않고, 분석모델에서 요구하는 입력 자료의 구조를 명확하게 해석할 수 있는 정보기술과 분석기술의 연계부족으로 발생한 문제이다. 이에 본 연구의 목적은 NGIS사업을 통해 축척된 지형공간 데이터베이스와 GIS의 공간분석기능을 연계하여 유역 오염원 기상 공간정보의 관리, 유역 오염유출모형인 HSPF(Hydrologic Simulation Program-Fortran)의 운영정보 생성을 지원하는 지능형 정보관리시스템을 개발하는데 있다. 주 연구내용은 시스템 분석 및 설계, 기초 데이터 수집과 DB 구축, 지형 매개변수 산정을 위한 GIS-HSPF의 통합 인터페이스 구축이다. 개발된 KBASIN-HSPF는 EPA에 의해 개발된 BASIN의 유역분할, 하천망생성, 지형특성계수 산정 기능과 함께 우리나라의 지형.오염원.기상정보의 저장구조를 고려한 데이터 모델링, Tissen망에 준한 강우자료 생성 그리고 HSPF 모형운영정보 산정 및 전환기능을 포함하고 있다. KBASIN-HSPF는 유역기반 점.비점오염원 정보를 통합 관리하고자 하는 오염총량관리제의 기술적 정보관리 환경으로 활용가능하며, 기존의 오염유출모델링을 위해 자료준비부터 정보연계, 모형운영까지 분산된 환경에서 수행되었던 것을 통합환경하에서 진행함으로써 정보의 질적보장과 정보전환의 표준화방안을 제시하는 정보분석시스템이다.

• Journal of KIISE:Databases
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• v.31 no.1
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• pp.13-22
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• 2004

With the proliferation of multimedia data, there is an increasing need to support the indexing and retrieval of high-dimensional image data. Although there have been many efforts, the performance of existing multidimensional indexing methods is not satisfactory in high dimensions. Thus the dimensionality reduction and the approximate solution methods were tried to deal with the so-called dimensionality curse. But these methods are inevitably accompanied by the loss of precision of query results. Therefore, recently, the vector approximation-based methods such as the VA- file and the LPC-file were developed to preserve the precision of query results. However, the performance of the vector approximation-based methods depend largely on the size of the approximation file and they lose the advantages of the multidimensional indexing methods that prune much search space. In this paper, we propose a new index structure called the GC-tree for efficient similarity search in image databases. The GC-tree is based on a special subspace partitioning strategy which is optimized for clustered high-dimensional images. It adaptively partitions the data space based on a density function and dynamically constructs an index structure. The resultant index structure adapts well to the strongly clustered distribution of high-dimensional images.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.614-621
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• 2004

At present, the electronic document is being processed in WYSWYG mode. For this, a document is structured by the logical structure and the physical structure, and is presented by the markup language. After XML is announced, an application scope of the electronic document is extended from interchanging to searching. However, in point of output quality, a XML document image on a browser has lower quality than a general document image on desktop publishing. The reason is which output function of a browser has not capability for high quality printing. The W3C developed XSL-FO(XSL-formatting Object) for style sheet formatting and PDL(Page Description Language) as like Postscript is already developed and used widely. In this paper, we designed the Postscript-Converter to get a high quality document image by converting XSL-FO into Postscript format.