• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.630-636
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• 2016

In this paper, a novel triple-mode cavity structure, designed for compactness and operating at 850 MHz, is analyzed. A cylindrical dielectric resonator is loaded into a metallic cylindrical cavity. Previous study has been focused on the analysis of the cylindrical dielectric resonator, but in this paper, the effect of the cylindrical metallic cavity has been analyzed. Enclosing the dielectric resonator inside the metallic cavity increases the resonant frequency of the dielectric resonator; however, this increases the quality factor and introduces the possibility of installing coupling screws. The principle of generation of triple-mode was investigated by parametric analysis. The generated triple-mode is TE011 mode and two orthogonally generated HEM121 modes. By adjusting the radius of the dielectric resonator, the height of the dielectric resonator, or the radius of the cylindrical metallic cavity, three modes could be coincided. However, the height of the metallic cavity keeps three modes separated. The mode characteristics of the proposed cavity are analyzed using a full-wave electromagnetic (EM) simulation. The proposed triple-mode cavity could be developed to triple-mode filter using a coupling screw, and the commercial application for the miniaturized filter below 1 GHz could be expected.

• Journal of the Korean Society for information Management
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• v.17 no.1
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• pp.129-148
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• 2000

Experiments were performed on three subsets of a Korean test collection in order to determine whether 2-Poisson model's Z value is a good measure for selecting subject words from a document to be indexed. It was found that subject word selection based on the Z value was effective for only one subset with short texts, i.e., the Science and Technology subset. Correlation analyses between 2-Poisson model's Z and TF.IDF weight for the three subsets showed that the correlation was relatively high for two test subsets with short texts, i.e., the Science and Technology subset and the Newspaper subset.

• Journal of Internet Computing and Services
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• v.12 no.3
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• pp.111-117
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• 2011

In this paper, the BER(Bit Error Rate) performance of a DVB-T2(Second Generation Digital Terrestrial Television Broadcasting System) in MISO(Multiple Input Single Output) transmission mode is evaluated by the computer simulation. In the DVB-T2 receiver, an IDD(Iterative Demapping and Decoder) technique is employed that exchanges extrinsic information between the demapper and the LDPC decoder. Simulation results show that the IDD-based DVB-T2 receiver in MISO transmission mode provides 2dB gain at BER of $10^{-4}$ but suffer from the frequency offsets between transmit antennas.

• Journal of Korean Library and Information Science Society
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• v.36 no.1
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• pp.237-268
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• 2005

This study scrutinize the occupational socialization process of school library media specialists through ethnographic materials with special reference to newly appointed in Daegu and Gyeongsangbukdo area. For the study researcher took in-depth interview with 38 media specialists and analyzed everyday life records appeared on the cyber communities of media specialists. The results show that most media specialist often experience discord with the institutional systems and have difficulties doing their jobs. The culture of school society is often full of conflict and many media specialists do not have firm identification with their jobs.

• Journal of the Korean Society for information Management
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• v.22 no.2 s.56
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• pp.57-85
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• 2005

Bliss stated that one of the purposes of the classification was to demonstrate that a coherent and comprehensive system, based on the logical principles of classification and consistent with the systems of science and education, may be available to services in libraries, to aid revision of long established classifications and to provide an adaptable, efficient and economical classification, notation and index. A fundamental principle is the idea of subordination each specific subject is subordinated to the appropriate general one. The full scheme followed the publication of two massive theoretical works on the organization of knowledge. Its main feature was the carefully designed maul class order. reflecting Comte principle of gradation in speciality.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.3
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• pp.63-73
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• 1993

For a systematic approach to rural settlement planning, socio-economic and land use potentialities were analysed in 10 villages("Ri", the lowest-order administrative unit in Korea)of Izuk-myun, Anseong-gun, Kyeonggi province, the model area in this study. Socio-economic potentialities, sub-grouped into rural and urban related ones, were analysed by the principal component analysis technique, while land use potentialities by the land suitability system of which the physical analysis is based on geographical information system. The principal component of rurality is strongly related with 5 key variables such as annual increasing rate of farm households, ratio of over 1ha-households, ratio of full-time farmers, ratio of animal rearing households and the principal component of urbanity with 6 key ones such as population density, number of schools, number of shops and servicing facilities, number of daily bus routes, number of non-farm households, percentage of area of housing sites. The analysis procedure of land suitability using the geographical information system were generalized and the results of analysis on village sites and paddy and upland fields were presented. The whole land use planning was presented by the criteria of the land suitability rank and the priority order of land use. land use.

• Journal of the Korean Society for information Management
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• v.19 no.4
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• pp.384-399
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• 2002

The ownership of scholarly communication, i.e. copyright is very important to solve the problem of access to many academic journals in network environment. The purpose of this article is to give a conceptual model for the open access based scholarly communication. The main point of this model is for the authors of research paper to retain copyright on their works and to license the work whenever it is reproduced or redistributed for non-profit use with academic purpose. And library have to construct full text journal databases under this open access license.

• Journal of the Korean Society for information Management
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• v.26 no.4
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• pp.7-34
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• 2009

Structures of stories, paragraphs, and sentences and inferences applied to indexing and searching were studied to construct the full-text and sentence retrieval system for storytelling. The system designed the database of stories, paragraphs, and sentences and the knowledge-base of inference rules to aid to write the story. The Knowledge-base comprised the files of story frames, paragraph scripts, and sentence logics made by mark-up languages like SWRL etc. able to operate in semantic web. It is necessary to establish more precise indexing language represented the sentences and to create a mark-up languages able to construct more accurate inference rules.

• Journal of Korean Library and Information Science Society
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• v.36 no.3
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• pp.65-83
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• 2005

Researches on the actual condition of the management of reading circles at 1991, 1999 and the third 2004 are analyzed and compared mutually in order to observe the process of development of reading circles because the management of reading circles in public libraries play an important role in activating reading activity. Public libraries increase twice in number than first research and take interest in the management of reading circles to activate reading activity, so public libraries are in full activity to organize and manage reading circles by themself, secure a budget for reading circles and supply spaces for reading activity constructively. However, development of the reading activity program and positioning of experts in management of reading circles have been remained as non solved problems.

• Bulletin of the Korean Mathematical Society
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• v.46 no.4
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• pp.743-769
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• 2009

An ID-based DNF signature scheme is an ID-based signature scheme with an access structure which is expressed as a disjunctive normal form (DNF) with literals of signer identities. ID-based DNF signature schemes are useful to achieve not only signer-privacy but also a multi-user access control. In this paper, we formally define a notion of a (non-interactive) ID-based DNF signature and propose the first noninteractive ID-based DNF signature schemes that are secure under the computational Diffie-Hellman and subgroup decision assumptions. Our first scheme uses random oracles, and our second one is designed without random oracles. To construct the second one, we use a novel technique that converts a non-interactive witness indistinguishable proof system of encryption of one bit into a corresponding proof system of encryption of a bit-string. This technique may be of independent interest. The second scheme straightforwardly yields the first ID-based ring signature that achieves anonymity against full key exposure without random oracles. We finally present two extensions of the proposed ID-based DNF signature schemes to support multiple KGCs and different messages.