• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.828-834
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• 2008

This paper presents high-spread (HS) random interleavers based interleave-division multiple access (IDMA) scheme for the 4th generation mobile radio system. High-spread feature of a random interleaver offers high-spread characteristics to interleavers and thus produces extrinsic values with low correlation. As interleavers are key components for user separation in the IDMA, the HS interleavers with this feature are employed and analyzed in the IDMA for performance improvement. In addition, by replacing random interleavers with the HS interleavers in the IDMA, bandwidth efficiency is achieved by means of reducing the length of the repetition code. Performance evaluation shows that the proposed scheme of the IDMA with the HS interleavers provides superior BER performance and improved bandwidth efficiency.

• Korean Journal of Human Ecology
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• v.9 no.3
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• pp.349-362
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• 2000

The purpose of this study was to identify the factors affected on the perception of appropriateness and the evaluation of physical state in the public community facilities. The sample of the study were consisted of 381 middle-aged and the aged who were participated in the leisure programs of the public community facilities and were living in Seoul and Daegu. Frequencies, means, one-way ANOVA, and multiple regression were employed for the analysis. The results of the study were as follows: The perception of appropriateness and the evaluation of the physical state in the public community facilities were differed by the type of facilities. The factors affected on the perception of appropriateness of the public community facilities were region, the access of transportation, and leisure attitude of the middle-aged and the aged. The factors had effects on the evaluation of the physical state of the facilities were educational attainment, health status, region, the access of transportation and the leisure participation.

• The Korean Journal of Archival Studies
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• no.49
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• pp.277-297
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• 2016

Access re-review is a process to reclassify the non-disclosure documents to open accessible documents, and it has to be performed in every five years. However, current procedures of the access re-review in many archives have not been properly working, due to the shortage of the available archivists for providing enough access re-review. Although many difficult situation for the re-review such as enormous amount of re-review documents and lack of archivists, access re-review was included in the administrative evaluation list, of which it makes the re-review for just evaluating process. In this study, the access re-review of Seoul Metropolitan Office of Education, which have performed by external service companies as well as the other institutions' progresses were summarized for improving access re-review process. Although Seoul Metropolitan Office of Education processed 610,000 re-review with 100,000,000 won budget for 4 years, the project has been failed to get more budget support because of the claim for the budget efficiency. The other institutions also could not focus on the actual access re-review. Considering all the points, current access re-review process is clearly required to be improved.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.61-66
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• 2010

The objective of this paper is to study the usability of the ingress/egress of elderly people, and analyze the physiological workload electromyography (EMG). We investigated the factors of discomfort while the elderly people are using the ingress/egress. Experiments were performed using a seating buck with 22 elderly participants (over 65 years old). The results showed that different muscles are activated during ingress and egress. A system called "easy access" was found which helps to access easily when a driver gets into a car. The current easy access was compared a newly proposed one. It was found that elderly people use less muscle during in/egress in the new easy access system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.965-972
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• 2005

We propose a new resource management scheme, Distributed Channel Allocation Protocol (DCAP), for multimedia Ad Hoc Wireless LANs (AWLANS). This scheme implements a Qualify-of-Service (QoS) providing distributed resource management on the Orthogonal Frequency Division Multiplexing-Code Division Multiple Access (OFDM-CDMA) channel architecture. According to the performance evaluation results for MPEG traffic sources, DCAP can be a good choice of resource management scheme for AWLANs supporting multimedia services on the Broadband Wireless Access(BWA)-type physical layer.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.4
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• pp.5-16
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• 2003

We have analyzed the performance of optical matched filters in the fiber-optic code division multiple access (FO-CDMA) system based on optical parallel coupler access encoder (PCAE) and parallel coupler access decoder (PCAD) by experiment. In previous studies, the performance evaluation of the FO-CDMA system using SCAE and SCAD was not sufficiently accurate because they analyzed system performance only considering the first order signals. Since optical SCAE and SCAD intrinsically have high order signals of various patterns as the number of coupler increases, they change auto- and cross-correlation intensities. Thus, it is necessary to investigate properties of the PCAE and PCAD so that we may analyze the exact performance of system. In this paper, it is found that the peak to sidelobe ratio using the PCAE and PCAD increases as $\alpha$ (coupling coefficient) value increases. Also, we found that the proposed PCAE and PCAD are superior to SCAE and SCAD in performance improvement.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.24 no.2
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• pp.247-268
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• 2013

The purpose of this study was to provide suggestions for the effective management of e-journals in academic libraries. Existing literatures were reviewed, web sites were examined, and informal interviews with librarians were conducted. This study comprehensively discussed various aspects of e-journal management, including 1) user behavior, 2) selection, acquisition, and evaluation, 3) access and search, 4) user education and its promotion, 5) archiving, 6) open access, 7) collection development policy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.8
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• pp.928-941
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• 2016

Energy consumption of today's wired data networks is driven by access networks. Today, green networking has become a issue to reduce energy wastes and $CO_2$ emission by adding energy managing mechanism to wired data networks. However, energy consumption and environmental impacts of wired access networks are largely unknown. In addition, there is a lack of general and quantitative valuation basis of energy use of large-scale access networks and $CO_2$ emissions from them. This paper compared and analyzed limits of existing models estimating energy consumption of access networks and it proposed a model to estimate energy consumption of large-scale access networks by top-down approach. In addition, this work presented models that assess environmental(anti-greening) impacts of access networks using results from our models. The performance evaluation of the proposed models are achieved by comparing with previous models based on existing investigated materials and actual measured values in accordance with real cases.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.113-120
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• 2009

XML can supply the standard data type in information exchange format on a lot of data generated in running database or applied programs for a company by using the advantage that it can describe meaningful information directly. Therefore, as it becomes more and more necessary to manage and protect massive XML data in an efficient way, the development of safe XML access control techniques needs a new method. In this study access authorization policies are defined to design access control systems. The findings demonstrated that algorithm suggested in this study improved system performance which was low due to the complex authorization evaluation process in the existing access control techniques. It is consequently proved that the safe XML access control policy presented in this study is in an improved form as compared with the existing access control methods.

• The Journal of the Acoustical Society of Korea
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• v.34 no.6
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• pp.463-469
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• 2015

In this paper, we propose an underwater propagation delay-aware medium access control protocol and evaluate the performance of the proposed protocol. In the proposed propagation delay-aware medium access control protocol, a sink node can restore the received RTS frames that are not piled up in a slot time. We analyze and compare the performance of the proposed underwater propagation delay-aware medium access control protocol with that of the conventional medium access control protocol in various environments.