• Journal of Positioning, Navigation, and Timing
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• v.5 no.1
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• pp.21-28
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• 2016

The Wide Area Differential Global Positioning System (WADGPS) that uses a number of Global Navigation Satellite System (GNSS) reference stations are implemented with various types and provide services as it can service a wide range of areas relatively. This paper discusses a constellation design of reference stations and performance analysis of the WADGPS. It presented performance results of static and dynamic users when wide area correction algorithm was applied using eight reference stations.

• Journal of Korean Library and Information Science Society
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• v.32 no.1
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• pp.1-31
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• 2001

University libraries need the development of a common Internet-based reference request system in order to prevent duplicated investment and provide interoperability among them. This paper proposes a standard of Internet-based reference recluest system that serves reference request-responses and that provides reference source sites on the world wide web. Using this system, university libraries can cooperate other libraries with reference databases and may perform tasks of reference service efficiently.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.172-177
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• 2007

Reference linking based on a identification system is being widely used both domestically and overseas. National R&D information contains all information related to the R&D programs such as the output and equipment information resulting from the participant and project information. The reference linking service enables the user to freely look up output of a certain program, participant of a project, equipment information from the project or participant and all other information that originates from a R&D project without having to search for it. The reference linking service in the area of national R&D will enable the linking of heterogeneous information produced at different sources.

• Korean Journal of Materials Research
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• v.13 no.10
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• pp.651-657
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• 2003

Ultrasonic microscope has been used to detect the defects on surface or inner solid. Conventionally, it has used at a single operating frequency. The resolution and quality of the measured images are determined by a characteristic of the transducer of the ultrasonic microscope. The conventional ultrasonic microscope has been used envelope detector to detect the amplitude of reflected signal, but the changes in amplitude is not sensitive enough for specimen with microstructure that in phase. In this paper, we have studied multi-frequency depth resolution enhancement with ultrasonic reflection microscope for the reflectors of a stainless steel reference specimen and a reference calibration block to be used as the material in nuclear power plants for ISI, PSI. Increased depth resolution can be obtained by taking two, three-dimensional images at more that one frequency and numerically combining the results. As results of the experiment, we could get enhanced images with the rate of contrast in proportion and high quality signal distribution for the image to the changing rate of depth for the reflectors of the two kinds of specimens.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.12 no.1
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• pp.101-115
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• 2001

The library information service which uses a web is active. But users feel difficulty to use library homepage's content, because many content are accumulated in the library homepage very rapidly. So users want to be customized and personalized the various content which it provides from library home page. The MyLibrary is founded in customization and personalization of library's content. This MyLibrary is suitable for large library. But the MyLibrary can be used as the tool for digital reference service.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3196-3198
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• 1999

In this paper, we are proposed ATM AAL 1 source clock recovery methods for CBR service. The proposed method compute the difference between network clock level and the reference level by inspecting the variation of a buffer. Also it is the service clock recovery method that control local clock using the look-up table defined clock dividing rate of the difference in advance. It can be applicable to both SDH network and PDH network which has no common reference clock between its ends, it has an important mean in view of the internetworking between existing networks for the integrated service chased by B_ISDN.

• Journal of the Korean Society for information Management
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• v.22 no.3 s.57
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• pp.327-350
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• 2005

Second, the necessity of adopting subject divisional plan is to secure enough subject librarians and large space These necessities must be fulfilled prior to adopting the subject divisional plan. Third subject divisional plan model for efficient reference service of university library is 'wide-area subject divisional plan model'. 1) In the case of central library, the space model of wide-area subject divisional plan is programmed as undergraduate library for the undergraduate students. And each subject libraries is operated as research library for the professors and graduate students. 2) In central library, the collection model of wide-area subject divisional plan is practiced as offering reference and general education centered data for undergraduate students 'study. And each subject libraries is furnished with research papers, recent journals, and various major-related data. 3) The human resource model of wide-area subject divisional plan is applicated by arranging appropriate librarians at the right place. In the case of central library, the reference librarians and librarians who educate the users and take charge of function are set in to help undergraduate students with their study. Subject library needs to secure subject librarians, librarians who take charge of function, and graduate students who are related to the subject as student assistant. Then it is possible to discriminate reference service by subjects and users.

• Journal of Korean Library and Information Science Society
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• v.40 no.4
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• pp.177-198
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• 2009

The domestic libraries offered users computer environment early to adapt in information age. However, the computer environment is generalized today, so it is needed to change about the role of electronic information room in this point. The author investigated use experience by 78 students who are student in library and information science. They experienced electronic information room and wrote their experience. As a result, they felt most inconvenience in information service of librarians, facilities and equipment and space. To improve the service of electronic information room, it is needed to develop the mission and service policy of electronic information room. And also the librarian must think the room as modern reference room that has digital and analog materials and information technology.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.3
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• pp.221-228
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• 2011

For service-area-widening and commercialization of DGNSS service, Ministry of Land, Transport and Maritime Affairs is developing a DGNSS service based on VRS using T-DMB. In this study, three PRC generation algorithms are developed for VRS DGNSS and their accuracies were evaluated. Three DGNSS correction generation algorithms are based on inverse distance weighting, 1st- and 2nd- multiple linear regression, and their positioning accuracies were compared in terms of the number of reference stations used for network composition and the algorithm type. As a result, the positioning accuracy of the case of using 16 sites is better than that of 6 sites. And the algorithm using the multiple linear regression showed the best performance. When the positioning accuracy of VRS DGNSS was compared with the traditional single-reference DGNSS, the improvement ratio was 20-23% and 20-36% for the horizontal and vertical directions, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.40-47
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• 2009

Recently, dynamic proxy caching has been proposed on the distributed environment so that media objects by user's requests can be served directly from the proxy without contacting the server. However, it makes caching challenging due to multimedia large sizes, low latency and continuous streaming demands of media objects. To solve the problems caused by streaming demands of media objects, this paper has been proposed the grouping scheme with fuzzy filtering based on partition and mapping. For partition and mapping, this paper divides media block segments into fixed partition reference block(R$_f$P) and variable partition reference block(R$_v$P). For semantic relationship, it makes fuzzy relationship to performs according to the fixed partition temporal synchronization(T$_f$) and variable partition temporal synchronization(T$_v$). Simulation results show that the proposed scheme makes streaming service efficiently with a high average request response time rate and cache hit rate and with a low delayed startup ratio compared with other schemes.