• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.539-546
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• 2013

Surge phenomenon can be occurred in a compressor when compressor performance of turbofan engine for an aircraft is changed considerably in a short time on the cases like take-off phase and changing of RPM from idle to maximum, because performance of aircraft engine is changed suddenly. This study is aimed to avoid surge in a compressor. Dynamic simulation in a compressor is modeled by simulink in specific condition. Fuel flow is control input, rpm and air mass flow are expressed in terms of transfer function. Surge margin is obtained by using compressor performance map from NPSS. VIGV(Variable Inlet Guide Vane) is controlled by PD controller with difference between surge margin and reference. Finally this paper verifies IGV can prevent surge phenomenon in a compressor.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.4
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• pp.109-116
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• 1997

This paper describes the surge protective device combined with varistor and LC low pass filter on AC power circuits. Up to now varistors alone have been used as a surge protective device on AC power circuits, but it gives negative effects on the equipments to be protected due to the steep rise and high remnant voltage. Therefore in this work, for the purpose of improving the cutoff performance of surge protective device on AC power circuits, the hybrid-type surge protective device with varistor and LC filter was designed and prepared. And the experiments for operational characteristics and clamping performance of the surge protective device were carried out with an 1.2/50[$\mu$s] impulse generator. As a result, the proposed surge protective device with the combination of varistors and LC filter can limit the surge voltage to lower value and reduce the value of dV /dt to very small values. Also the attenuation of high-frequency voltages across the output port is effectively provided by LC filter. Therefore this result may be all the more helpful avoiding both damage and upset of electronic systems.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.2
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• pp.299-328
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• 2009

In this study, the present condition of 8 Open APIs for books, such as Naver, Daum, Aladdin, Amazon, Google, KERIS, LibraryThing, and OCLC, were compared and analyzed. In addition, the bibliographic records of 167 samples of visible 'light & paraphotic' (DDC 535) classifications were selected from the bibliographic records of the library of C university, and the effectiveness of the Open APIs were compared and analyzed. On the basis of the results of this analysis, 12 Open API application models, which were judged to be useful in expanding the function of the access point of the bibliographic records and enhancing the library catalog using Open API, were experimentally implemented. Various methods of augmenting access points of bibliographic records and expanded library catalogue were investigated using the unique identifier described in the KORMARC fields of 001, 010, 012, 020, 035, 246, 505, 520, 850, 856 for the integrated format for bibliographic data, and Open API. Finally, using Open API for the brief display and detailed display screen as a result of search of the OPAC of the sample bibliographic records, the devices for the expanding library catalog were implemented as examples.

• Journal of the Korean Society for Library and Information Science
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• v.36 no.3
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• pp.49-68
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• 2002

Througout the literature, various opinions and recommendations are presented concerning educational backgrounds for subject specialist librarianship. However, the Korean library and information science education is designed as the college program, and n, utilization of either minor or double major programs is regarded as the best to produce qualified subject specialist librarians. Nevertheless, the courses in the library and information science should be promoted first. Accordingly, this study starts with the assumption that the subject bibliography course in the library and information science is designed directly or indirectly to educate students as subject specialist librarians. For this, law and law firm library were explored as examples, and then, finally a law bibliography was provided for the training of the law specialist librarians.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.309-330
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• 2022

Intellectual structure analysis, which quantitatively identifies the structure, characteristics, and sub-domains of fields, has rapidly increased in recent years. Analysis techniques traditionally used to conduct intellectual structure analysis research include bibliographic coupling analysis, co-citation analysis, co-occurrence analysis, and author bibliographic coupling analysis. This study proposes a novel intellectual structure analysis method, Keyword Bibliographic Coupling Analysis (KBCA). The Keyword Bibliographic Coupling Analysis (KBCA) is a variation of the author bibliographic coupling analysis, which targets keywords instead of authors. It calculates the number of references shared by two keywords to the degree of coupling between the two keywords. A set of 1,366 articles in the field of 'Open Data' searched in the Web of Science were collected using the proposed KBCA technique. A total of 63 keywords that appeared more than 7 times, extracted from 1,366 article sets, were selected as core keywords in the open data field. The intellectual structure presented by the KBCA technique with 63 key keywords identified the main areas of open government and open science and 10 sub-areas. On the other hand, the intellectual structure network of co-occurrence word analysis was found to be insufficient in the overall structure and detailed domain structure. This result can be considered because the KBCA sufficiently measures the relationship between keywords using the degree of bibliographic coupling.

• Journal of the Korean Society for information Management
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• v.17 no.1
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• pp.7-20
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• 2000

The study attempts to propose a distributed bibliographic information retrieval system using distributed retrieval servers and distributed databases. CORBA and JAVA applications have been employed to solve both the bottleneck and the problems that simultaneous searches in distributed databases cannot deal with under the CGI or JAVA applications. The proposed distributed bibliographic retrieval system using two distributed servers with their distributed databases was successfully experimented. However, it is recommended that both heterogeneous information retrieval systems and databases are included in further studies.

• Journal of the Korean Society for information Management
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• v.7 no.1
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• pp.40-58
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• 1990

Many factors playa role in designing the interface for bibliographic data entry system in response to the various needs. Among the major variables to be considered are planning, record format, screen design, automatic generation of access points, error checking, download from bibliographic databases, character codes, card catalog production, and use of authority data.This paper described with examples how these design considerations can be implemented in empirical system.

• Journal of the Korean Society for information Management
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• v.13 no.1
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• pp.119-141
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• 1996

The purpose of this study is to seek how to effectively acquire a full-text using LHI(Loca1 Holdings Information) when we search bibliographic DB. For this study, the pre-investigation of LHI within Online and CD-ROM DB was made using local and overseas literature. The questionary survey was made of librarians and users who have used CD-ROM. The finding of this study is that LHI is not very widely used in libraries, thus more study on ,LHI within Online and CD-ROM DB is required to get high quality information service.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.2
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• pp.319-342
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• 2003

Catalog serves a dual purposes. One is finding function(or identifying function) that is identified and located specific items and the other is collocating function which is displayed specific author's all works and all related editions. This study is re-examined the functions of catalog. For catalog's effective serving this study is provided and overviewed the FRBR(Functional Requirements for Bibliographic Record) models as reference conceptual model for functions of catalog.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.279-306
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• 2023

This study analyzed bibliographic attributes related to the selection and use of reading materials based on data on books borrowed or purchased together in order to understand the properties of reading materials that have complex user needs from various perspectives. As a result of creating co-occurrence matrices of bibliographic attribute terms by dividing them into 26 sub-attribute units related to KDC main class, target reader, and user age, and performing network analyses, the details and prominent mediating role of bibliographic attributes of reading materials were identified. The results of this study will be helpful in designing facets of reading information systems, including library OPAC, in the future.