• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.74-80
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• 2000

In this paper, we proposed the MAC protocol and analyzed the performance for CATV/LAN network which was based upon HFC(hybrid optic coaxial) increased abruptly as alternative method of high speed network. Upstream channel which analyzed very deeply for CATV/LAN network have the preferential access property depending upon that position and unidirectional property. To solve this fairness problem, we propose the CSMA-CD/U/P protocol that transm it as $P_i$ probability although data packets is immediately transmitted when it was occurred. As the analytic result and simulation, we obtained $P_i$ value and its average delay time. Also, we get its variance value and queue length distribution. The mean delay time and queue length increase as the load and number of stations increase in the CATV/LAN network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1522-1536
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• 2011

Due to the advance of broadband communication networks including the Internet, the release of diverse media, and the busy life cycle of modern people, it became difficult to watch TV programs strictly according to the program schedule. Instead, demand to download and watch the programs at any time on TV is increasing. In order to meet the demand, terrestrial DTV broadcasters developed a TV service which provides various on-demand contents by integrating terrestrial DTV network and the Internet without enforcing viewers to subscribe broadcasting services such as IPTV or CableTV, and standardized it as OHTV(Open Hybrid TV). In this paper, we explain the current status of OHTV standard and worldwide hybrid TV services and their technical standards. We also provide a strategy for the next version of OHTV standard in order to enhance the value of OHTV.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.61-67
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• 2004

This paper describes the importance of the network equipment markets and the necessity of the testing and the verification for the network equipments and the effective system for network equipment test. With the rapid internet service development, the demands of the network equipments(for example, router, switching equipment etc.) are expanded. The network equipments request the high love technologies, so the foreign network equipments are prevailed in the domestic market. But the development of the network equipments in korea is in the beginning stage. To deploy the network equipments into the real network the network equipments should be tested and verified by the certified test labs. To get the verification from the foreign test lab, it takes a lot of expenses and times. For the competitiveness of our products in the international markets, the technique of the test and verification on the network equipments should be level-up. This paper investigates the network equipments market condition and the network equipments test condition in Korea. For the competitiveness of our commodities in the international markets, this paper proposes the testing strategy for network equipments.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.120-125
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• 1999

This paper is a study on the cyber education center, OpenEdu, developing on internet. The conventional cyber university is allowed for ID user only, but OpenEdu is opened all internet user for open education and it has a various content. free of charge and high quality. Also. in this system, we support the various 500 contents, other efficiently services and it is a self-learning(asynchronous) distance education application(HTML, PDF. Front Page) on cyber-space using the information super highway It will make the cyber education center from new paradigm of distance education. The purpose of OPenEdu provides a async. distance education service, free of charge to obtain many various contents on internet. The future study is enhanced user interface and upgraded content quality.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.139-148
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• 2006

This study is intended to propose quality criteria and Web metrics for usability quality evaluation of multimedia Web sites. Recently, applications of the Web sites are not limited to the area of industry and operating as it integrates the new technology. Also as information super highway becomes common with development or network technology, multimedia Web site is on the rise due to various use of multimedia attributes. Therefore this study expands to apply HTML based Web site quality evaluation studied in Software engineering, HCI, Hypermedia to multimedia Web site, and suggests new metrics by integrating flash usability which is expanding its portion in multimedia Web site lately. The Web metrics proposed in this study are verified by heuristic evaluation from a group of expert. It analyses the results of quantitative and qualitative qualify evaluation on Web Award Korea by comparing the award-winning, high-quality Web site with non-winning Web sites. This study can be used to establish guideline for high-quality multimedia Web site development in the future.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.251-266
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• 1996

In this paper, we design MHEG engine that can generate MHEG objects and present It to the users in Multimedia/Hypermedia Applications In the MHEG engine, the transmitted MHEG objects decoded into internal format. For the easy interpretation of MHEG objects, we define internal format as to be matched for each MHEG object. We easily processobjectinformation using the tree data structure because object inheritance and possession can be represented in tree structure. Object inheritance and possession must be represented in the internal format because they used in resolving the reference to external objector data file. The presentation synchronization extracts the synchronization information from MHEG composite objects, representing and controlling heterogencous media associated to spatio- temporal relation. In order to exactly represent the spatio-temporal synchronization included into MHEG composite object, we propose the algorithm that processes synchronization using the message of the synchronization module and the internal objects. MHEG engine proposed in this paper may be basic technology fro multimedia application area using Korea New Net.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.639-644
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• 2011

By the development of the information superhighway, the current data communication system can be exchanged data quickly and precisely between subscribers. In this paper, LVTTL(Low Voltage Transistor Transistor Logic), Using the fundamental one logic at several kinds of used in communication systems, the LVTTL transmission characteristics were measured by according to the change data transfer rate and the transmission line length. Because the transmission line length required on the current system is 30cm, We analysed LVTTL data transfer characteristics according to the transmission line length required on the current system. The amplitude level of LVTTL at 10Mbps is 3V and 50Mbps is 2.2V and 100Mbps is 2V and 125Mbps is 1.5V and 150Mbps is 1.4V. The length of transmission line 30cm was stable state up to 100Mbps data transfer rate.

• Journal of Digital Contents Society
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• v.15 no.1
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• pp.11-18
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• 2014

The strength of our country is based on high-speed networks to build a nationwide health information network to improve the quality of health care is needed. However, nature of the medical services in the hospital medical record form, so that all departments characterize each medical department, a common format that can be used for all disease is a very difficult challenge. This study is one of the ways to improve this priority issue on health information sharing medical information system(PACS/HIS) information linkage between the problem of information, compatibility and security issues derived. The problem is derived from the requirements of theorem 3 to 6 items. This is effective in order to improve sharing of medical information for the purpose of designing the software system. Sharing of medical information software system design are derived from stakeholders, requirements analysis, architecture design, software framework, configuration, architecture evaluation process. This study is based on the medical information standardization environmental diagnosis of a medical information system design. Software design philosophy is based on a new framework for deriving the function and mechanism made up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1369-1375
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• 2007

The recent, a large capacity of telecommunication networks is required in order to it is in proportion to capacity of information communication increase and to satisfy a demand because of the demand about Internet, a multimedia service of internet, Video of internet protocol(VoIP), Audio/Video streaming. As a result, DWDM(Dense Wavelength Division Multiplexing)technologies are emerging to be a prevailing the method of solving it without additional optical fiber network building and high-speed equipment. Therefore this thesis proposed the optical filter of fiber/multilayer slab coupled structure combining it to multilayer slab waveguide by polishing the cladding of one side of fiber to design the optical filter having these functions. When a separation distance of fiber and slab was $3{\mu}m$, The optical filter proposed as the simulation result was satisfied with a DWDM filter characteristic with FWHM of 0.1nm on TM mode and TE mode as 32nm polarization independence in a communication window of $1.3{\mu}m$ when center wavelength was each ${\lambda}_0=1.274755{\mu}m$ and ${\lambda}_0=1.30591{\mu}m$.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.729-741
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• 1999

ATM networks are widely deployed as the network that is capable of supporting multimedia services efficiently now. To date, a large portion of ATM connections, particularly in the WAN environment, have been of a permanent virtual circuits-requiring management intervention for set-up and tear-down. However, switched virtual circuits are required to support a range of desired characteristics on demand, to a reachable end user. To establish, maintain and release on-demand call/connections, the user-network interface(UNI) and node-node interface(NNI) signalling capabilities are required. Two protocols have been specified for NNI signalling within a public network: the broadband integrated-services user part(B-ISUP) protocol specified by the ITU-T, and the private network-network interface(PNNI) protocol specified by the ATM Forum. PNNI offers different type of internetwork or internodal interface from the traditional B-ISUP approach favored to date public network operators. In spite of its name, PNNI may find its place in network service provide networks as well as in private networks. Thus many public network operators and ATM equipment manufacturers are still unable to choose the NNI interface architecture of their system. In this paper, we survey the characteristics of the B-ISUP and PNNI protocols, and investigate the applicability issue of these specifications to the ATM-based Information Infra-Network of Korea. Analyzing the characteristics of the two protocols and clarifying the NNi requirements of the ATM-based Information Infra-Network of Korea, we propose that the B-ISUP protocol is more suitable than PNNI.