• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.27-35
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• 2011

Multicarrier-Direct Sequence/Code Division Multiple Access(MC-DS/ CDMA) which is a combination of Orthogonal Frequency Division Multiplexing(OFDM) and DS/CDMA has been of significant interest as a means to take such advantages as bandwidth efficiency, high bit rate and robustness against multipath fading. In this paper we study a reduced-complexity multiuser detection aided multirate MC-DS/CDMA with time(T)-domain and frequency(F)-domain spreading. The one- dimensional orthogonal variable spreading factor(1D OVSF) code extracted from 2D OVSF code are used as a spreading code in T/F-domain. The proposed system will use code grouping interference cancellation(CGIC) receiver to reduce Multiuser Interference(MUI). The CGIC receiver uses code grouping by the correlation properties of 1D OVSF code and dose not requires the code information and activity of other user. The multiuser detector with CGIC receiver will be analyzed in Time- and Frequency-domain separately(jointly). The system performance is analytically derived in Additive White Gaussian Noise(AWGN) channel and we also compare the system performance between proposed system and T/F spreaded single(multi) rate multiuser MC-DS/CDMA system. In the computer simulation results, the proposed receiver of demonstrated huge performance improvement over conventional matched filter receiver.

• Journal of the Korean Geographical Society
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• v.48 no.5
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• pp.686-708
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• 2013

The goal of this investigation is to examine the matter as to how various cyberpolitical activities such as on-line civic participation, cyber parties, development and movement of civil society networks are appeared in cyberspace; and how political activities in cyberspace are associated with offline environment. This research was based on in-depth and open-ended interviews centering around 20s (32 interviewees) and the major results are as in the following. First, in terms of on-line civic participation, searching political issues occur in places, where internet users can access information easily relatively, and creating or reconstructing political information is identified in places giving stability or affinity to the public society. Second, even though each party's homepage for the channel of cyber parties has enough capacity as bridgespace, which takes charge of supporting f lows of people, goods, capital, and ideas, most of them don't play a role to establish virtual or real networks. Exceptively, cyber parties contribute to make temporalized places, where nobody takes the responsibility, somewhat. Third, the development and movement of civil society networks is divided into several segments according to political interests and tendency in online; furthermore, such a cyberpolitical activity influences human networks and the decision of major places for political activities in offline.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.55-65
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• 2008

At these information age when the importance of news is of particular emphasis, the field of image-production for the news are being made rapid progressive by high-tech like multi-media, multi-channel digital system. Even experts who have engaged in the work of broadcasting in th field for a long time are perplexed with rapid development in Broadcasting equipments and expression techniques. The field of TV is characterized by the speed of change and the desire of viewers for new and interesting video images. The image expression system applying image line has ever existed as one of conventional image expression methods. Obsolete and old image expressions are paling into significance for viewers who want to access more information in a short time. but The change of image expression systems due to the progressive stream of time has forced existing imaginary to be changed constantly to accommodate the changing interests and expectations of the viewers. Therefore, in this treatise, we need a broad interpretation about the direction of this imaginary line for TV news image in that existing systems of image producing haven’t also been changed and adapted to the stream of time. In these days, image is defined as not only video, but also audio. also We need to reduce the confusion concerning the imaginary line and contribute to a correct understanding images of TV news for not only customers but also producer by extending and applying the concept of imaginary line to image producing.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.33-40
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• 2020

This work tackles the problem of conventional reinforcement learning scheme which has a relatively long training time to reduce energy consumption in underwater network. The enhanced scheme adjusts the learning range of reinforcement learning based on distance estimation. It can be reduce the scope of learning. To take account the fact that the distance estimation may not be accurate due to the underwater wireless network characteristics. this research added noise in consideration of the underwater environment. In simulation result, the proposed AQ-NAV scheme has completed learning much faster than existing method. AQ-NAV can finish the training process within less than 40 episodes. But the existing method requires more than 120 episodes. The result show that learning is possible with fewer attempts than the previous one. If AQ-NAV will be applied in Underwater Networks, It will affect energy efficiency. and It will be expected to relieved existing problem and increase network efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1A
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• pp.33-43
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• 2010

Recently, users want to use real-time multimedia services, such as internet, VoIP, etc., using their IEEE 802.11 wireless lan mobile stations. In order to provide such services, a handoff among access points is essential to support the mobility of a node, in such an wide area. However, the legacy handoff methods of IEEE 802.11 technology are easy to lose connections. Also, the recognition of a disconnection and channel re-searching time make the major delay of the next AP to connect. In addition, because IEEE 802.11 decides the selection of an AP depending only on received signal strength, regardless of a node direction, position, etc., it cannot guarantee a stable bandwidth for communication. Therefore, in order to provide a real-time multimedia service, a node must reduce the disconnection time and needs an appropriate algorithm to support a sufficient communication bandwidth. In this paper, we suggest an algorithm which predicts a handoff point of a moving node by using GPS location information, and guarantees a high transmission bandwidth according to the signal strength and the distance. We implemented the suggested algorithm, and confirmed the superiority of our algorithm by reducing around 3.7ms of the layer-2 disconnection time, and guaranteed 24.8% of the communication bandwidth.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.67-74
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• 2006

We have developed a control electronics system for an infrared detector array of KASINICS (KASI Near Infrared Camera System), which is a new ground-based instrument of the Korea Astronomy and Space science Institute (KASI). Equipped with a $512{\times}512$ InSb array (ALADDIN III Quadrant, manufactured by Raytheon) sensitive from 1 to $5{\mu}m$, KASINICS will be used at J, H, Ks, and L-bands. The controller consists of DSP(Digital Signal Processor), Bias, Clock, and Video boards which are installed on a single VME-bus backplane. TMS320C6713DSP, FPGA(Field Programmable Gate Array), and 384-MB SDRAM(Synchronous Dynamic Random Access Memory) are included in the DSP board. DSP board manages entire electronics system, generates digital clock patterns and communicates with a PC using USB 2.0 interface. The clock patterns are downloaded from a PC and stored on the FPGA. UART is used for the communication with peripherals. Video board has 4 channel ADC which converts video signal into 16-bit digital numbers. Two video boards are installed on the controller for ALADDIN array. The Bias board provides 16 dc bias voltages and the Clock board has 15 clock channels. We have also coded a DSP firmware and a test version of control software in C-language. The controller is flexible enough to operate a wide range of IR array and CCD. Operational tests of the controller have been successfully finished using a test ROIC (Read-Out Integrated Circuit).

• Journal of the Korean Society for information Management
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• v.26 no.1
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• pp.321-350
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• 2009

The purpose of this study is to find methods for utilizing digital room in public library and its efficient operation by analyzing the status quo of the digital rooms in public libraries, which had been built nation-widely about 5 years ago. It is found that it is urgent to supplement and improve the infrastructure of them. It is also required to build multi-functional digital rooms and an integrated operational system for digital rooms. Implementation of an integrated operational system, first of all, for applicable sections of digital room may be the best alternative. The multi-functional digital rooms can be built, which, in addition to its traditional function, can include a variety of original information resources and function of information creation using application programs, as well as functions such as education, information services, online/offline community creation, and activating information sharing. In the future, the digital rooms in public libraries must play a significant role as online/offline spaces, which are not the places for use and access to internet information resource, but for information/knowledge sharing and collaborative activities. It also must provide a communication channel between librarians and users as well as among users themselves.

• Archives of design research
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• v.17 no.1
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• pp.153-162
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• 2004

This paper focused on the effect of Kansei design on the web in branding as well as its influence factors. As a key of this research, it classified web users' Kansei into five categories; 1) functional Kansei, 2) sensoryKansei, 3) psychological Kansei, 4) relational Kansei and 5) cultural Kansei, and organized relevant factors. Online surveys were conducted on seven websites of the fast food brands in Korea (Lotteria, Mcdonald, BurgerKing, Popeyes, KFC, Pizza Hut, Domino's) which are targeting 463 male and females in 20s. As a result, an average of 58% responded that they had a positive Kansei experience and could enhanceits brand preference. Of the sensory Kansei, visual design factors were the one that gave the greatest effect on brand preference enhancement. Regarding the functional Kansei satisfaction, such as user convenience and access speed were also one of the most crucial variables for the whole Kansei satisfaction. Moreover, the preference enhancement brought not only a positive effect on its reliability but also its brand image and consumers' purchasing desire. Based on the survey results, the additional FGI (Focus Group Interview) had been conducted and determined \circled1 what kind of major Kansei that users wanted to have satisfied, \circled2 what type of design can give strong Kansei appeal to its users, and \circled3what design factors gave an effect on sensory emotion. In the course of this research, Itried to renew the awareness of the web importance as a major channel in non-mass interactive marketing, and suggest the effect and its possibility of emotional branding through Kansei design in the web as well as design principles of strategic Kansei design.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.456-467
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• 2016

Wireless Access in Vehicular Environments (WAVE) communication technology, which provides vehicleto-vehicle and vehicle-to-infrastructure communication and offers safe and convenient service, has been developed for application to an Intelligent Transport System (ITS). This paper provides field test results on a study of the feasibility of WAVE technology application to railway communication systems. A test railway communication system based on WAVE technology has been built along the Daebul line and a newly developed EMU. Field tests have been carried out according to the communication function requirements for LTE - R. The test results show that the railway communication system based on WAVE technology meets the functional requirements: maximum transmission length is 730m, maximum transfer delay is 5.69ms, and maximum interruption time is 1.36s; other tests including throughput test, video data transmission test, VoIP data test, and channel switching test also produced results that meets the functional requirements. These results suggest that WAVE technology can be applied to the railway communication system, enabling Vehicle-to-Wayside communication.

• Smart Media Journal
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• v.8 no.3
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• pp.23-30
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• 2019

With the popularization of the Internet and smartphone uses, people in the modern era are living in a multi-channel environment in which they access the information system freely through various methods and media. In the process of utilizing such services, users must authenticate themselves, the typical of which is ID & password authentication. It is considered the most convenient method as it can be authenticated only through the keyboard after remembering its own credentials. On the other hand, modern web services only allow passwords to be set with high complexity by different combinations. Passwords consisting of these complex strings also increase proportionally, since the more services users want to use, the more user authentication information they need to remember is recommended periodically to prevent personal information leakage. It is difficult for the blind, the disabled, or the elderly to remember the authentication information of users with such high entropy values and to use it through keyboard input. Therefore, this paper proposes a user authentication method using Google Assistant, MFCC and DTW algorithms and speaker authentication to provide the handicapped users with an easy user authentication method in the login process.