• Journal of Digital Contents Society
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• v.3 no.1
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• pp.89-99
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• 2002

Saturation routing algorithm is known to be an effective routing mechanism for tactical application and packet radio networks, since it minimizes the call set-up time and does not have to maintain routing tables. But, it is known that it has significant drawbacks with respect to the network efficiency, the overhead on the control messages [1]. We consider a tactical circuit-switched grid network with a maximum of tour links and two priority classes of voice traffic. Using the minimum first-derivative length (MFDL) path, we improve the blocking probability performance of a circuit-switched network without increasing the call set-up time and processor loading of the algorithm.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.679-686
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• 2008

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay model that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.1
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• pp.183-196
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• 2015

With widespread use of smart phones, SNS has been growing rapidly. Companies are required to do its utilization and a preemptive response. However, taking advantage of SNS is still insignificant in the companies. Compared with traditional marketing, people still consider the SNS marketing unfamiliar. This study is aimed at widening the breadth of understanding of marketing activity using SNS and inquiring into its effective applications. In an effort to achieve this research objective, first, this study analyzed the aspect of real applications by reviewing diverse practical business cases. Second, this study provided the momentum of the understanding of SNS marketing-based knowledge. The effective method of producing consumer-intimate products and services lies in customers' participation in development and production. SNS marketing is the very communication and gives ear to a customer's voice. Earnest and creative SNS marketing will play a role as a stepping-stone for businesses to move much closer to a customer.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.58-62
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• 1999

Previously, laryngectomized patients can achieve speech with tracheoesophageal device. Tracheoesophageal speech is currently one of the best methods of postlaryngectomy voice rehabilitation. But, tracheoesophageal speakers have some troublesome with digital occlusion of tracheostoma in every speaking time. Therefore, the tracheostoma valve has been introduced since 1982, and this valve could eliminate the need of tracheostoma digital occlusion. Currently, couple of tracheostoma valves has been introduced and developed. In this article, we introduced the 3 representative tracheostoma valves. Also, we discussed their use and characteristics. Traditionally the tracheostoma valve is used in total laryngectomized patients. We introduced one case using a tracheostoma valve after near total laryngectomy. Advantage and disadvantage of Blom-Singer valve and BIVONA II valve during using in this patients are discussed.

• Journal of the Korean Professional Engineers Association
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• v.24 no.1
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• pp.95-103
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• 1991

The communication transmission engineering plays the most important role in electrical communications engineering. Recently, it has been making remarkable progress as an infrastructure supporting informationaged society. Specially, the start of television conference and service of high speed digital transmission can be said it is announcing a raising curtain of high speed broad band age. Together with high speed broad band service needs a capacity as much as several or several hundred times of telephone with one circuit, various kinds of service forms are anticipated to emerge, it is anticipated to give a big impact to the way of future communications newtork. At present, telecommunication network is transforming telephone voice information by analog technology into a flexible higher system disposable of a variety of information such as pictures or data other than telephone by the introduction of digital technology. Consequently, the development of hereafter for the following respective technologies is desired.

• Journal of the Korean Professional Engineers Association
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• v.24 no.2
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• pp.127-136
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• 1991

The communication transmission engineering plays the most important role in electrical communications engineering. Recently, it has been making remarkable progress as an infrastructure supporting informationaged society. Specially, the start of television conference and service of high speed digital transmission can be said it is announcing a raising curtain of high speed broad band age. Together with high speed broad band service needs a capacity as much as several or several hundred times of telephone with one circuit, various kinds of service forms are anticipated to emerge, it is anticipated to give a big impact to the way of future communications network. At present, telecommunication network is transforming telephone voice information by analog technology into a flexible higher system disposable of a variety of information such as pictures or data other than telephone by the introduction of digital technology. Consequently, the development of the hereafter for the following respective technologies is desired.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.131-138
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• 2014

This paper is on a stereo acoustic echo canceller with the blind signal separation for post processing. The convergence speed of the stereo acoustic echo canceller is deteriorated due to mixing two residual signals which are update signals of each echo canceller. To solve this problem, we are to use the blind signal separation(BSS) method separating the mixed signals after the echo cancellers. The blind signal separation method can extracts the source signals by means of the iterative computations with two input signals. We had verified performances of the proposed acoustic echo canceller for stereo through simulations. The results of simulations show that the acoustic echo canceller for stereo using this algorithm operates stably without divergence in the normal state. And, when the speech signals were inputted, this echo canceller achieved about 2dB higher ERLE with the BSS post processing method than without this method. This stereo echo canceller showed the best performance in the case of inputting the real voice signal.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.199-200
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• 2006

In this paper, we deal with suggestion of effective traffic information transfer methods using voice broadcasting when traffic information are transferred by Digital Multimedia Broadcasting TPEG service. We apply TPEG service, which is used for collecting real-time traffic information, also we implement the GPS for identifying the drivers spot. We suggested traffic information selection method by distance and a weighted traffic information with their testing algorithm.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.388-396
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• 2010

Generally, flight information is transmitted by voice signal over legacy UHF radio in ground to air communication system. In this paper, we have implemented the transceiver of TDL(tactical data link) which transmits tactical information, such as flight information, using digital signal. For transmitting digital information over radio path, we have designed data modem that is processing CPFSK modulation, and TDMA(Time Division Multiple Access) network for Synchronization among multi user(platform). By simulating aeronautical propagation modeling with the environment of Korea terrain, it is predicted the maximum performance of communication range of the transceiver. As result of the transceiver's aviational boarding test, it is proved that the transceiver of TDL over legacy UHF radio transmits and receives the tactical information in TDMA network within communication range of 160km.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1618-1634
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• 2000

ISDN, the beginning of broadband and multimedia service, is a digital network that provides integrated end-to-end digital telecommunication services for transmissions of different kinds of information, from voice and facsimiles to data and images. In Japan, Britain and U. S there has been shown the demand of ISDN is considerable and ISDN technology is becoming quite stable. Furthermore,their ISDN service experience helps them to set up and carry out the marketing strategies for Internet access services such as ADSL, Cable Modem and WLL, etc. This paper examines and compares services, charge and discount scheme of ISDN across 14 telecommunication carriers. It can be utilize as a reference for diffusing ISDN as well as developing Internet access services and marketing strategies.