• Title/Summary/Keyword: Semi-Join

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A Flexible Query Processing System for XML Regular Path Expressions (XML 정규 경로식을 위한 유연한 질의 처리 시스템)

  • 김대일;김기창;김유성
    • Journal of KIISE:Databases
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    • v.30 no.6
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    • pp.641-650
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    • 2003
  • The eXtensible Markup Language(XML) is emerging as a standard format of data representation and exchange on the Internet. There have been researches about storing and retrieving XML documents using the relational database which has techniques in full growth about large data processing, recovery, concurrency control and so on. Since in previous systems same structure information and fundamental operation are used for processing of various kinds of XML queries, only some specific query can be efficiently processed not all types of query. In this paper, we propose a flexible query processing system. To process query efficiently, the proposed system analyzes regular path expression queries, and uses $\theta$-join operation using region numbering values to check ancestor-descendent relationship and equi-join operation using parent's region start value to check parent-child relationship. Thus, the proposed system processes efficiently XML regular path expressions. From the experimental results, we show that proposed XML query processing system is more efficient than previous systems.

AUTOMATIC MULTITORCH WELDING SYSTEM WITH HIGH SPEED

  • Moon, H.S;Kim, J.S.;Jung, M.Y.;Kweon, H.J.;Kim, H.S.;Youn, J.G.
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.320-323
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    • 2002
  • This paper presents a new generation of system for pressure vessel and shipbuilding. Typical pressure vessel and ship building weld joint preparations are either traditional V, butt, fillet grooves or have narrow or semi narrow gap profiles. The fillet and U groove are prevalently used in heavy industries and shipbuilding to melt and join the parts. Since the wall thickness can be up to 6" or greater, welds must be made in many layers, each layer containing several passes. However, the welding time for the conventional processes such as SAW(Submerged Arc Welding) and FCAW(Flux Cored Arc Welding) can be many hours. Although SAW and FCAW are normally a mechanized process, pressure vessel and ship structures welding up to now have usually been controlled by a full time operator. The operator has typically been responsible for positioning each individual weld run, for setting weld process parameters, for maintaining flux and wire levels, for removing slag and so on. The aim of the system is to develop a high speed welding system with multitorch for increasing the production speed on the line and to remove the need for the operator so that the system can run automatically for the complete multi-torch multi-layer weld. To achieve this, a laser vision sensor, a rotating torch and an image processing algorithm have been made. Also, the multitorch welding system can be applicable for the fine grained steel because of the high welding speed and lower heat input compare to a conventional welding process.

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Applicability of Geo-spatial Processing Open Sources to Geographic Object-based Image Analysis (GEOBIA)

  • Lee, Ki-Won;Kang, Sang-Goo
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.379-388
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    • 2011
  • At present, GEOBIA (Geographic Object-based Image Analysis), heir of OBIA (Object-based Image Analysis), is regarded as an important methodology by object-oriented paradigm for remote sensing, dealing with geo-objects related to image segmentation and classification in the different view point of pixel-based processing. This also helps to directly link to GIS applications. Thus, GEOBIA software is on the booming. The main theme of this study is to look into the applicability of geo-spatial processing open source to GEOBIA. However, there is no few fully featured open source for GEOBIA which needs complicated schemes and algorithms, till It was carried out to implement a preliminary system for GEOBIA running an integrated and user-oriented environment. This work was performed by using various open sources such as OTB or PostgreSQL/PostGIS. Some points are different from the widely-used proprietary GEOBIA software. In this system, geo-objects are not file-based ones, but tightly linked with GIS layers in spatial database management system. The mean shift algorithm with parameters associated with spatial similarities or homogeneities is used for image segmentation. For classification process in this work, tree-based model of hierarchical network composing parent and child nodes is implemented by attribute join in the semi-automatic mode, unlike traditional image-based classification. Of course, this integrated GEOBIA system is on the progressing stage, and further works are necessary. It is expected that this approach helps to develop and to extend new applications such as urban mapping or change detection linked to GIS data sets using GEOBIA.

Building a Community of Practice of Research Data Curators: A Qualitative Study (연구데이터 큐레이터로 구성된 실천공동체 구축에 관한 질적 연구)

  • Han, Na-eun
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.3
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    • pp.119-152
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    • 2022
  • This study examined the activities of Community of Practice (CoP) of research data curators, including their community building and maintenance activities, by using activity theory as its main theoretical framework. The study used an embedded multiple-case study design for exploring the activities of three CoP of research data curators. The case study design used document analysis and semi-structured interviews to collect data. Besides the community building and maintenance activities, other activities were performed in the CoP of research data curators, which could be largely divided into curation activities, education activities, and communication activities. Membership was largely divided into institutional membership and individual membership, and the motives for members to join and contribute to the CoP vary from extrinsic to intrinsic motivations. Finally, we identified and categorized challenges and success indicators for CoP of research data curators as perceived by participants. In particular, we identified three types of challenges or contradictions the communities faced and 14 perceived indicators of success. This study informs the practice of research data curation by providing a knowledge base for building and maintaining a CoP of research data curators.

Subsistence Mode of Small Manufacturing Enterprises at the Industrial Community in Taegu City. (대도시 주공혼재지역의 영세제조업의 존립기반: 대구시 노원동을 사례로)

  • Lee, Chul-Woo;Park, Sahng-Min
    • Journal of the Korean association of regional geographers
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    • v.6 no.1
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    • pp.29-49
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    • 2000
  • The purposes of this study are to identify the characteristics of inner-city industrial community and to analyse the subsistence mode of small manufacturing enterprises in the industrial community in Taegu Metropolitan area. The case study area, Nowon 1. 2-ga dong, is the typical inner city industrial community, adjacent to old industrial complex, which was recently transformed from semi -industrial to semi-residential zoning district. Now there are many old one story housing, newly constructed multi stories housing and many small factories of metal and machinery products. The conflicts of between residents and small business owners are not serious but latent. The subsistence mode of small manufacturing enterprises in this area is characterized as the network production system. The main attributes of this mode are local integration, horizontal subcontracting and strong industrial linkages in production processes and transactions. These transactions are mainly made by face-to-face contacts. The small business owners' local social networks are seen as series of units which are interconnected through various types of social and business relations. They exchange business information as using social networks. In addition, the majority of them join local social clubs with their local business counterpartners. Finally, the locational advantages of inner-city industrial community are production network, different industrial linkages and characteristic industrial milieu such as social solidarity, informal labor market and incubator effects. But these advantages are being challenged from the contradiction between capital and laned property and the urban gentrification policy. Accordingly, there should be positive redevelopment policy considering the subsistence mode of small business in these areas.

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Comparison Analysis of Aromatic Compounds in the Aromatic Rice Germplasm by Gas Chromatography and Mass Spectrometry (Gas Chromatography-Mass Spectrometry에 의한 향미 유전자원의 방향성 화합물 비교분석)

  • Kim, Jeong-Soon;Cho, Jum-Rae;Gwag, Jae-Gyun;Kim, Tae-San;Ahn, Sang-Nag;Lee, Sok-Young
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.1
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    • pp.88-103
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    • 2009
  • The volatile and semi-volatile compounds of 5 accessions of domestic scented and 25 accessions of introduced scented were extracted by solid phase microextraction (SPME) and analyzed by gas chromatographymass spectrum (GC-MS). A total of 156 volatile and semivolatile compounds were identified from 30 accessions of aromatic rice, including 32 alcohols, 25 acids, 25 ketones, 21 hydrocarbon, 18 esters, 16 aldehydes, 4 ethers, 5 amines, 2 phenols, 2 bases, and 8 miscellaneous compounds. By UPGMA/Neighbor-join tree analysis, the thirty accessions of aromatic rice could be classified into seven groups according to the major odor or aroma compounds. Group I included indica type of Basmati varieties. Group II and Group IV included japonica type introduced scented. Group III consisted only Hyangmibyeo1ho in domestic scented. Group V and Group VII included indica type of Basmati and non-Basmati varities. Group VI included four of domestic scented of seven accessions excepted Basmati6129, Basmati 6311, and Seratus Malam.

A Revenue Allocation Model for the Integrated Urban Rail System in the Seoul Metropolitan (수도권 도시철도 수입금 정산 분석모형)

  • Shin, Seong-Il;Noh, Hyun-Soo;Cho, Chong-Suk
    • Journal of Korean Society of Transportation
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    • v.23 no.5 s.83
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    • pp.157-167
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    • 2005
  • Seoul metropolitan public transport reform results in the introduction of the semi-public operation and distance-based fare policies. With implementation of these policies, public transport revenue allocation has been (will be) evolved very complicated because the existing revenue allocation issues have not only been clearly solved, which is generated by the combined relationship among Korea Railroad Corporation (KRC). Seoul Metropolitan Subway Corporation (SMSC). Seoul Metropolitan Rapid Transit Corporation (SMRTC), and Incheon Rapid Transit Corporation (IRTC), but also the revenue allocation problem between bus and urban railroad-related organizations need to be considered in this combined framework. On top of that. based on the future plans such as the private sector's railroad construction plan(s), the light rail transit construction plans of several local governments and the join of remained bus lines of Seoul metropolitan areas, it is understood that the revenue allocation among public transport operating organization will become one of main issues of operation organization as well as local and central governments. As a basic approach for revenue allocation of public transport operation organizations, the purpose of this paper is to propose an integrated model applicable to estimate degree of service contribution in passenger carriage in the combined public transport network. With a hypothesis that the complete electronic card system is deployed, this paper supposes every passenger's loading and alighting stations is recordable. Thereby, this paper limits research scope as to Seoul metropolitan railroad area since used route(s) between origin and destination stations can not be traceded because transfer stations each passenger path through is not recorded. Each model proposed in the paper is as follows: 1. a generalized cost reflecting passenger's transfer behavior; 2.a K path model for determining similar routes between O-D; 3.an assignment model for loading O-D trips onto the detected similar routes using Logit Model.