• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.610-617
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• 1987

This thesis is concerned with fault-tolerance of a B-net (Beta-network) which is a kind of interconnection network in the multicomputer system. In this paper, a method for obtaining Maximal Tolerable Fault Set(MTFS) of link line connecting switching elements in the arbitrary B-net is presented. Using this method, it is seen that testing of DFA capability is possible when s-a-faults of link line occur, and criterion for determining degree of fault- tolerance of a B-net in terms of link line is introduced.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.103-104
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• 2006

In this paper, we analyze the UAV datalink design with calculating link budget of long-distance (200 km) Ku-band LOS wireless link. We calculate C/N of the real system and compare it with the required C/N, using the CCIR reports. In the rainy day of summer on the Korean peninsula, to maintain percent reliability 90% and BER 10^(-5) together, link budget of uplink of the system has a lot of margin at 200 km, link budget of downlink using the block turbo code is enough for distance 200 km.

• Journal of the Ergonomics Society of Korea
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• v.12 no.1
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• pp.75-86
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• 1993

Hypermedia systems allow the retrieval and representation of multimedia in- formation such as text, graphics, image and voice/sound using navigation and browsing mechanisms. In this study we developed a hypermedia system which provides hierarchical group, local map and cluster view for effective navigation in hyperspace. The system also supports hot link, reference link, move-to link and multiple link to browse the multimedia information space effectively. This system has been designed to integrate the navigation, browsing and searching function of the hypermedia system in hyman factor perspective and provides the user-friendly user interface mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2484-2498
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• 2017

Various types of social media make the people share their personal experience in different ways. In some social networking sites. Some users post their reviews, some users can support these reviews with comments, and some users just rate the reviews as kind of support or not. Unfortunately, there is rare explicit negative comments towards other reviews. This means if there is a link between two users, it must be positive link. Apparently, the negative link is invisible in these social network. Or in other word, the negative links are redundant to positive links. In this work, we first discuss the feature extraction from social media data and propose new method to compute the distance between each pair of comments or reviews on social media. Then we investigate whether we can predict negative links via regression analysis when only positive links are manifested from social media data. In particular, we provide a principled way to mathematically incorporate multi-facet data in a novel framework, Constructing Negative Links, CsNL to predict negative links for discovering the hidden information. Additionally, we investigate the ways of solution to general negative link predication problems with CsNL and its extension. Experiments are performed on real-world data and results show that negative links is predictable with multi-facet of social media data by the proposed framework CsNL. Essentially, high prediction accuracy suggests that negative links are redundant to positive links. Further experiments are performed to evaluate coefficients on different kernels. The results show that user generated content dominates the prediction performance of CsNL.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.397-404
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• 2010

Recently, there is on-going research about tactical data link system based on the legacy radio. Tactical data link based on legacy radio is operated mostly in narrow bandwidth under 25khz. Communicating traffics in nodes participated at network need to be minimized for distributing tactical data in narrow bandwidth. In addition, the data distributing structure is necessary for distributing tactical informations such as a situation awareness and so on to war fighters. However, conventional server-client system wastes a lot of time to obtain information for war fighters as user uses pull system to gather necessary information by seeking it one by one. Especially, the fighter pilot is supposed to dedicate into a situation awareness and fight mission in every seconds but seeking information of a user terminal while aircraft maneuvering affects as obstacle to concentrate engaging hostiles. therefore, push technology, the tactical data distributing system, is necessary for war fighters to receive fixed tactical data automatically without putting attention to it. This paper propose the UMPC tactical data link push framework. the UMPC tactical data link is a tactical data link system based on the legacy radio. Proposed push framework is verified by composing experiment environment and testing.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.135-143
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• 2019

Purpose of this study is enhancing usability of online video platform by analyze link-depth and advertisement frequency. In this study, researcher checked market share of video platform which publishing web-drama, and compare their link-depth and advertisement frequency. As a result, access to the latest content has two to three link-depth. So it does not worsen usability. but, if contents doesn't show on main page or search result, it requires more than five to six steps. Image advertisement show up more than twice on every platform. 'Youtube' and 'Naver TV' show up pre-roll video advertisement in video player before offering contents. In this video platform information structure, directory searching needs high link-depth level and advertisement frequency. It will increase user's bounce rate and decrease return visit rate. So researcher suggests prototype using drop-down menu to reduce link-depth and enhance information structure.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.2
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• pp.227-234
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• 2014

A transceiver for a high-speed inductive-coupling link is proposed. The bi-phase modulation (BPM) signaling scheme is used due to its good noise immunity. The transmitter utilizes a complementary switching method to remove glitches in transmitted data. To increase the timing margin on the receiver side, an integrating receiver with a pre-charging equalizer is employed. The proposed transceiver was implemented via a 130-nm CMOS process. The measured timing window for a $10^{-12}$ bit error rate (BER) at 1.8 Gb/s was 0.33 UI.

• Journal of Communications and Networks
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• v.4 no.2
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• pp.136-147
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• 2002

In this paper, the maximal capacity of the data network link has attempted to be exploited by using the dynamic allocation strategy. We propose a new methodology based on the economic models for competing traffic classes (classes of sessions) in packet networks. As the demand for network services accelerates, users' satisfaction to the service level might decrease due to the congestion at the network nodes. To prevent this, efficient allocation of a networks resources, such as available bandwidth and switch capacity, is needed. By using the so-called user profile as well as the utility (e.g., data rate) functions, it is possible to allocate data rates and other utilities using the arbitrary number of QoS classes, say $0.01,...,$10.

• Journal of Astronomy and Space Sciences
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• v.37 no.2
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• pp.117-129
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• 2020

In a Satellite communication system, a link budget analysis is the detailed investigation of signal gains and losses moving through a channel from a sender to receiver. It inspects the fading of passed on data signal waves due to the process of spreading or propagation, including transmitter and receiver antenna gains, feeder cables, and related losses. The extent of the proposed tool is to make an effective, efficient, and user-friendly approach to calculate link budget analysis. It is also related to the satellite communication correlation framework by building up a graphical interface link analysis tool utilizing STK^® software with the interface of C# programming. It provides better kinds of graphical display techniques, exporting and importing data files, printing link information, access data, azimuth-elevation-range (AER), and simulation is also possible at once. The components of the link budget analysis tool include transmitter gain, effective isotropic radiated power (EIRP), free space loss, propagation loss, frequency Doppler shift, flux density, link margin, elevation plot, etc. This tool can be useful for amateur users (e.g., CubeSat developers in the universities) or nanosat developers who may not know about the RF communication system of the satellite and the orbital mechanics (e.g., orbit propagators) principle used in the satellite link analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.202-210
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• 2018

The modern battlefield is being developed as a network-centric warfare where priority is given to rapid status grasp and power deployment through scientification and modernization. Therefore, tactical data link has been continuously improving the network speed, and recently, security technology is required for wireless communication with the UAV and various devices for reconnaissance. In addition, the future information warfare will utilize advanced IT technology positively. Efforts are needed to integrate various systems and networks. However, these efforts are meaningful only when they can assume sufficient security in a newly changing information and communication environment. In this paper, we propose a new cryptographic synchronization for link encryption suitable for tactical data links. The proposed cryptographic synchronization is useful for T4 UAV link encryption, and it is also adaptable for lower BER, then we analyze the performances analysis of that.