• Title/Summary/Keyword: 색인구성

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Prefetch R-tree: A Disk and Cache Optimized Multidimensional Index Structure (Prefetch R-tree: 디스크와 CPU 캐시에 최적화된 다차원 색인 구조)

  • Park Myung-Sun
    • The KIPS Transactions:PartD
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    • v.13D no.4 s.107
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    • pp.463-476
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    • 2006
  • R-trees have been traditionally optimized for the I/O performance with the disk page as the tree node. Recently, researchers have proposed cache-conscious variations of R-trees optimized for the CPU cache performance in main memory environments, where the node size is several cache lines wide and more entries are packed in a node by compressing MBR keys. However, because there is a big difference between the node sizes of two types of R-trees, disk-optimized R-trees show poor cache performance while cache-optimized R-trees exhibit poor disk performance. In this paper, we propose a cache and disk optimized R-tree, called the PR-tree (Prefetching R-tree). For the cache performance, the node size of the PR-tree is wider than a cache line, and the prefetch instruction is used to reduce the number of cache misses. For the I/O performance, the nodes of the PR-tree are fitted into one disk page. We represent the detailed analysis of cache misses for range queries, and enumerate all the reasonable in-page leaf and nonleaf node sizes, and heights of in-page trees to figure out tree parameters for best cache and I/O performance. The PR-tree that we propose achieves better cache performance than the disk-optimized R-tree: a factor of 3.5-15.1 improvement for one-by-one insertions, 6.5-15.1 improvement for deletions, 1.3-1.9 improvement for range queries, and 2.7-9.7 improvement for k-nearest neighbor queries. All experimental results do not show notable declines of the I/O performance.

A Study on the Automatic Detection of Railroad Power Lines Using LiDAR Data and RANSAC Algorithm (LiDAR 데이터와 RANSAC 알고리즘을 이용한 철도 전력선 자동탐지에 관한 연구)

  • Jeon, Wang Gyu;Choi, Byoung Gil
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.4
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    • pp.331-339
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    • 2013
  • LiDAR has been one of the widely used and important technologies for 3D modeling of ground surface and objects because of its ability to provide dense and accurate range measurement. The objective of this research is to develop a method for automatic detection and modeling of railroad power lines using high density LiDAR data and RANSAC algorithms. For detecting railroad power lines, multi-echoes properties of laser data and shape knowledge of railroad power lines were employed. Cuboid analysis for detecting seed line segments, tracking lines, connecting and labeling are the main processes. For modeling railroad power lines, iterative RANSAC and least square adjustment were carried out to estimate the lines parameters. The validation of the result is very challenging due to the difficulties in determining the actual references on the ground surface. Standard deviations of 8cm and 5cm for x-y and z coordinates, respectively are satisfactory outcomes. In case of completeness, the result of visual inspection shows that all the lines are detected and modeled well as compare with the original point clouds. The overall processes are fully automated and the methods manage any state of railroad wires efficiently.

k-Interest Places Search Algorithm for Location Search Map Service (위치 검색 지도 서비스를 위한 k관심지역 검색 기법)

  • Cho, Sunghwan;Lee, Gyoungju;Yu, Kiyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.4
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    • pp.259-267
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    • 2013
  • GIS-based web map service is all the more accessible to the public. Among others, location query services are most frequently utilized, which are currently restricted to only one keyword search. Although there increases the demand for the service for querying multiple keywords corresponding to sequential activities(banking, having lunch, watching movie, and other activities) in various locations POI, such service is yet to be provided. The objective of the paper is to develop the k-IPS algorithm for quickly and accurately querying multiple POIs that internet users input and locating the search outcomes on a web map. The algorithm is developed by utilizing hierarchical tree structure of $R^*$-tree indexing technique to produce overlapped geometric regions. By using recursive $R^*$-tree index based spatial join process, the performance of the current spatial join operation was improved. The performance of the algorithm is tested by applying 2, 3, and 4 multiple POIs for spatial query selected from 159 keyword set. About 90% of the test outcomes are produced within 0.1 second. The algorithm proposed in this paper is expected to be utilized for providing a variety of location-based query services, of which demand increases to conveniently support for citizens' daily activities.

Implementation of Annotation-Based and Content-Based Image Retrieval System using (영상의 에지 특징정보를 이용한 주석기반 및 내용기반 영상 검색 시스템의 구현)

  • Lee, Tae-Dong;Kim, Min-Koo
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.5
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    • pp.510-521
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    • 2001
  • Image retrieval system should be construct for searching fast, efficient image be extract the accurate feature information of image with more massive and more complex characteristics. Image retrieval system are essential differences between image databases and traditional databases. These differences lead to interesting new issues in searching of image, data modeling. So, cause us to consider new generation method of database, efficient retrieval method of image. In this paper, To extract feature information of edge using in searching from input image, we was performed to extract the edge by convolution Laplacian mask and input image, and we implemented the annotation-based and content-based image retrieval system for searching fast, efficient image by generation image database from extracting feature information of edge and metadata. We can improve the performance of the image contents retrieval, because the annotation-based and content-based image retrieval system is using image index which is made up of the content-based edge feature extract information represented in the low level of image and annotation-based edge feature information represented in the high level of image. As a conclusion, image retrieval system proposed in this paper is possible the accurate management of the accumulated information for the image contents and the information sharing and reuse of image because the proposed method do construct the image database by metadata.

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A Study on Functions and Present Situation of Subject Specialists for Information Services in Korean College and University Libraries (한국의 대학도서관 정보서비스에 있어서 주제전문사서의 현황과 기능에 관한 조사연구)

  • Han, Sang-Wan
    • Journal of the Korean Society for information Management
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    • v.3 no.2
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    • pp.42-74
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    • 1986
  • The objective of the study is to search for a theoretical and practical solution for the question "what is the most effective and Qualitative method of information service for the college and university libraries in Korea." Assuming the maximum service, or total service theory in information services, it needs the subject specialist who has highly qualified in his subject. This research adapted the survey method by questionnaire to the reference/information librarian who worked in college and university libraries, 159 librarians returned the questionnaires. By the analysis of this questionnaires, the following major results were found: 1. There were only 7.6% who could be called as subject specialist in Korean college and university libraries. 2. The subject specialist system is necessary to enhance the Information services in college and university libraries. 3. The major functions of subject specialists are information services In given subject fields; to prepare the bibliographies, guides, reading lists, indexes and abstracts; distribution of information and current awareness services; well balanced collection developments; liaison function between academic departments, students and faculty members; formal and informal lecture on the use of the library and the resources; and the cataloging and classification. 4. The best library and information education system is the graduate level study which is offering the M.L.S. or M.S. of library and information science with the emphasis on the study of subject background. 5. They will establish the faculty status for academic librarian by the development of subject specialist system in college and university libraries in Korea.

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A study on the event processing methods for ubiquitous sensor network (유비쿼터스 센서 네트워크를 위한 이벤트 처리 기법에 관한 연구)

  • Cho, Yang-Hyun;Park, Yong-Min;Kim, Hyeon-Gyu
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.1
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    • pp.137-147
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    • 2013
  • The RFID(Radio Frequency Identification) and the WSN(Wireless Sensor Network) have technical similarities and mutual effects, they have been recognized to be studied separately, and sufficient studies have not been conducted on the technical integration of the RFID and the WSN. Therefore, EPC global which realized the issue proposed the EPC(Electronic Produce Code) Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPC global network. The proposed EPC Sensor Network technology uses the Complex Event Processing method in the middleware to integrate data occurring through the RFID and the WSN in a single environment and to interoperate the events based on the EPC global network. However, as the EPC Sensor Network technology continuously performs its operation even in the case that the minimum conditions are not to be met to find complex events in the middleware, its operation cost rises. Therefore, to address the problems of the existing system, we defined the minimum conditions of the complex events to detect unnecessary complex events in the middleware, and proposed an algorithm that can extract complex events only when the minimum conditions are to be met. To examine the minimum conditions, a index and a query index are used to extract complex events. To evaluate the performance of the proposed methods, In the case of the method of extracting complex events based on a bitmap index, we used the existing extraction method and NS2 simulation to evaluate its performance and thus to show its good performance in terms of the number of operation and the processing time for the complex events.

AS B-tree: A study on the enhancement of the insertion performance of B-tree on SSD (AS B-트리: SSD를 사용한 B-트리에서 삽입 성능 향상에 관한 연구)

  • Kim, Sung-Ho;Roh, Hong-Chan;Lee, Dae-Wook;Park, Sang-Hyun
    • The KIPS Transactions:PartD
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    • v.18D no.3
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    • pp.157-168
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    • 2011
  • Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.

The Present State and Solutions for Archival Arrangement and Description of National Archives & Records Service of Korea (국가기록원의 기록물 정리기술의 현황과 개선방안)

  • Yoon, Ju-Bom
    • Journal of Korean Society of Archives and Records Management
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    • v.4 no.2
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    • pp.118-162
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    • 2004
  • Archival description in archives has an important role in document control and reference service. Archives has made an effort to do archival description. But we have some differences and problems about a theory and practical processes comparing with advanced countries. The serious difference in a theory is that a function classification, maintenance of an original order, arrangement of multi-level description are not reflected in practical process. they are arranged in shelves after they are arranged by registration order in a unit of a volume like an arrangement of book. In addition, there are problems in history of agency change or control of index. So these can cause inconvenience for users. For improving, in this study we introduced the meaning and importance of arrangement of description, the situation and problem of arrangement of description in The National Archives, and a description guideline in other foreign countries. The next is an example for ISAD(G). This paper has chapter 8, the chapter 1 is introduction, the chapter 2 is the meaning and importance of arrangement of description, excluding the chapter 8 is conclusion we can say like this from the chapter 3 to the chapter 7. In the chapter 3, we explain GOVT we are using now and description element category in situation and problem of arrangement of description in Archives. In the chapter 4, this is about guideline from Archives in U.S.A, England and Australia. 1. Lifecycle Date Requirement Guide from NARA is introduced and of the description field, the way of the description about just one title element is introduced. 2. This is about the guideline of the description from Public Record Office. That name is National Archives Cataloguing Guidelines Introduction. We are saying "PROCAT" from this guideline and the seven procedure of description. 3. This is about Commomon Record Series from National Archives of Australia. we studied Registration & description procedures for CRS system. In the chapter 5, This is about the example which applied ISAD to. Archives introduce description of documents produced from Appeals Commission in the Ministry of Government Administration. In the chapter 6, 7. These are about the problems we pointed after using ISAD, naming for the document at procedure section in every institution, the lack of description fields category, the sort or classification of the kind or form, the reference or identified number, the absence description rule about the details, function classification, multi-level description, input format, arrangement of book shelf, authority control. The plan for improving are that problems. The best way for arrangement and description in Archives is to examine the standard, guideline, manual from archives in the advanced countries. So we suggested we need many research and study about this in the academic field.

GWB: An integrated software system for Managing and Analyzing Genomic Sequences (GWB: 유전자 서열 데이터의 관리와 분석을 위한 통합 소프트웨어 시스템)

  • Kim In-Cheol;Jin Hoon
    • Journal of Internet Computing and Services
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    • v.5 no.5
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    • pp.1-15
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    • 2004
  • In this paper, we explain the design and implementation of GWB(Gene WorkBench), which is a web-based, integrated system for efficiently managing and analyzing genomic sequences, Most existing software systems handling genomic sequences rarely provide both managing facilities and analyzing facilities. The analysis programs also tend to be unit programs that include just single or some part of the required functions. Moreover, these programs are widely distributed over Internet and require different execution environments. As lots of manual and conversion works are required for using these programs together, many life science researchers suffer great inconveniences. in order to overcome the problems of existing systems and provide a more convenient one for helping genomic researches in effective ways, this paper integrates both managing facilities and analyzing facilities into a single system called GWB. Most important issues regarding the design of GWB are how to integrate many different analysis programs into a single software system, and how to provide data or databases of different formats required to run these programs. In order to address these issues, GWB integrates different analysis programs byusing common input/output interfaces called wrappers, suggests a common format of genomic sequence data, organizes local databases consisting of a relational database and an indexed sequential file, and provides facilities for converting data among several well-known different formats and exporting local databases into XML files.

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Research Trend and Futuristic Guideline of Platform-Based Business in Korea (플랫폼 기반 비즈니스에 대한 국내 연구동향 및 미래를 위한 가이드라인)

  • Namn, Su Hyeon
    • Management & Information Systems Review
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    • v.39 no.1
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    • pp.93-114
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    • 2020
  • Platform is considered as an alternative strategy to the traditional linear pipeline based business. Moreover, in the 4th industrial revolution period, efficiency driven pipeline business model needs to be changed to platform business. We have such success stories about platform as Apple, Google, Amazon, Uber, and so on. However, for those smaller corporations, it is not easy to find out the transformation strategy. The essence of platform business is to leverage network effect in management. Thus platform based management can be rephrased as network management across the business functions. Research on platform business is popular and related to diverse facets. But few scholars cover what the research trend of the domain is. The main purpose of this paper is to identify the research trend on platform business in Korea. To do that we first propose the analytical model for platform architecture whose components are consumers, suppliers, artifacts, and IT platform system. We conjecture that mapping of the research work on platform to the components of the model will make us understand the hidden domain of platform research. We propose three hypotheses regarding the characteristics of research and one proposition for the transitional path from pipeline to platform business model. The mapping is based on the research articles filtered from the Korea Citation Index, using keyword search. Research papers are searched through the keywords provided by authors using the word of "platform". The filtered articles are summarized in terms of the attributes such as major component of platform considered, platform type, main purpose of the research, and research method. Using the filtered data, we test the hypotheses in exploratory ways. The contribution of our research is as follows: First, based on the findings, scholars can find the areas of research on the domain: areas where research has been matured and territory where future research is actively sought. Second, the proposition provided can give business practitioners the guideline for changing their strategy from pipeline to platform oriented. This research needs to be considered as exploratory not inferential since subjective judgments are involved in data collection, classification, and interpretation of research articles.