• Journal of Multimedia Information System
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• v.4 no.4
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• pp.179-188
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• 2017

The Internet Video Coding (IVC) standard is due to be published by Moving Picture Experts Group (MPEG) for various Internet applications such as internet broadcast streaming. IVC aims at three things fundamentally: 1) forming IVC patents under a free of charge license, 2) reaching comparable compression performance to AVC/H.264 constrained Baseline Profile (cBP), and 3) maintaining computational complexity for feasible implementation of real-time encoding and decoding. MPEG experts have worked diligently on the intellectual property rights issues for IVC, and they reported that IVC already achieved the second goal (compression performance) and even showed comparable performance to even AVC/H.264 High Profile (HP). For the complexity issue, however, there has not been thorough analysis on IVC decoder. In this paper, we analyze the IVC decoder in view of the time complexity by evaluating running time. Through the experimental results, IVC is 3.6 times and 3.1 times more complex than AVC/H.264 cBP under constrained set (CS) 1 and CS2, respectively. Compared to AVC/H.264 HP, IVC is 2.8 times and 2.9 times slower in decoding time under CS1 and CS2, respectively. The most critical tool to be improved for lightweight IVC decoder is motion compensation process containing a resolution-adaptive interpolation filtering process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1059-1068
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• 1993

We will put the emphasis on the analysis of arbitrarily shaped microstrip antennas. The most general and rigorous treatment of microstrip antennas is given by the electric field integral equation(EFIE), usally formulated in the spectral domain. In this paper, we use a modification of EFIE, called the mixed potential integral equation(MPIE) , and we solve it in the space domain. This technique uses Green's functions associated with the scalar and vector potential which are calculated by using stratified media theory and are expressed as Sommerfeld integrals. The integral equation is solved by a moment's method using rooftop subsectional basis function. Thus, microstrip patches of any shape can be analysed at any frequency and for any substrate. Numerical results for a rectangular patch and for a L-shaped patch are given and compared with measured values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.11
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• pp.2604-2612
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• 1997

Media access control(MAC) protocol that is used between aircraft and ground station now is non-persistent CSMA protocol, but this protocol hs defects to apply in the wireless mobile radio communication environment. In this paper, to solve this Problems, the modified ICMA/CD protocol which ban be applied in the wireless environment was proposed and analyzed. In the modified ICMA/CD protocol, instead of usig special control channel, control signal was inserted into the uplink message. After the analysis, simulation was performed to approve the analysis resutls. As a results, modified ICMA/CD protocol can solve the hidden termined effect of CSMA protocol and packet detection delay time problem of ICMA/CD protocol and acquired the same channel throughput as CSMA/CD protocol. This results shows the modified ICMA/CD protocol can be used in the aeronauical telecommunication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1323-1326
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• 2014

In this letter, we compare the performance of two concatenated coding structures in slow FH/SS systems for multimedia/multicast transmission on shipboard. Two outer code symbols are transmitted during a hop. The first structure consists of one inner codeword per one outer code symbol, while the second structure consists of one inner codeword per two outer code symbols. We analyze the overall block error probability in asymptotic region and show that the performance of the second scheme is superior to the first one.

• Journal of Broadcast Engineering
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• v.9 no.2
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• pp.119-130
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• 2004

We have developed a prototype super-high-definition (SHD) digital cinema distribution system that can store, transmit, and display eight-million-pixel motion pictures that have the image quality of a 35-mm film movie. The system contains a movie server, a real-time decoder, and an SHB projector. Using a Gigabit Ethernet link and TCP/IP, the server transmits JPEG2000 compressed motion picture data streams to the decoder at transmission speeds as high as 300 Mbps. The received data streams are decompressed by the decoder, and then projected onto a screen via the projector. By using an enlarged TCP window, multiple TCP streams, and a shaping function to control the data transmission quantity, we achieved real-time streaming of SHD movie data at about 300 Mbps between Chicago and Los Angeles, a distance of more than 3000 km. We also improved the decoder performance to show movies with Image qualities of 450 Mbps or higher. Since UDP is more suitable than TCP for fast long-distance streaming, we have developed an SHD digital cinema UDP relay system, in which UDP is used for transmission over a fast long-distance network. By using four pairs of server-side-proxy and decoder-side-proxy, 450-Mbps movie data streams could be transmitted.

• ETRI Journal
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• v.34 no.1
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• pp.24-34
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• 2012

In this paper, the directional carrier sense multiple access/collision avoidance (CSMA/CA) protocol in the immediate acknowledgement mode for IEEE 802.15.3c is analyzed under saturation environments. For the analysis, a sensing region and an exclusive region with a directional antenna are computed probabilistically and a Markov chain model in which the features of IEEE 802.15.3c and the effects of using directional antennas are incorporated is analyzed. An algorithm to find the maximal number of concurrently transmittable frames is proposed. The system throughput and the average transmission delay are obtained in closed forms. The numerical results show the impact of directional antennas on the CSMA/CA media access control (MAC) protocol. For instance, the throughput with a small beamwidth of antenna is more than ten times larger than that for an omnidirectional antenna. The overall analysis is verified by a simulation. The obtained results will be helpful in developing an MAC protocol for enhancing the performance of mmWave wireless personal area networks.

• Journal of Korean Academy of Nursing Administration
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• v.15 no.4
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• pp.610-616
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• 2009

Purpose: The purpose of this study was to compare and analyze the nurses' image perceived by nursing and health allied college students in Korea. Method: The data was collected from October 15th to November 15th, 2004. Subjects were composed of 679 students in three-year Junior College. The data was analyzed by SPSS 12.0 PC+ Win. The difference of nurse' image among departments and locations of Junior College were analyzed by t-test, ANOVA and Tukey test. Result: The mean score of nurses' image 3.1 point of the total 5 point. Nurses' image is showed significantly difference according to the departments; the department of nursing (3.54), physical therapy (3.01), radiology (2.97), emergency medical technology (2.76) and clinical pathology (2.67). Nurses' image was significantly differed among the 4 domains according to 5 departments; 'the qualification of nurse', 'the role of nurse', 'the interpersonal relationship of nurse', 'the social participation of nurse'. Nurses' image formed through directly contacting with nurses' and seeing nurses' action (69.1%), watching nurse in TV drama (15.9%). Conclusion: It is considered that nursing and health allied college students were affected by inter-communications with nurses' more than by mass media.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.209-215
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• 2017

Character of emoticon is considered suitable for expressivity in the digital era mixing and using contents of conversation with images in the course of having a talk with the other party in the mobile space. For the foregoing, this study carried out multiple regression analysis having factors of character attribute such as awareness, friendliness, self-expressivity and image differentiation as independent variables, and purchase intention of purchasers as a dependent variable. Analysis results show that awareness and image differentiation had a positive influence on the purchase intention, whereas friendliness and self-expressivity exerted no significant influence on the purchase intention.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.815-822
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• 2011

In this paper, a design and implemented of the data communication system on the entails inherent safety with the distress and urgency of maritime data communication services that are required for functional limitations of the existing mounting equipment and services to determine the likelihood MF/HF, VHF, Inmarsat satellite communication has a diversification of the GMDSS ship communication equipment. Proposed role and direction of the GMDSS on the communication media by the communication cost, throughput, communication speed and processing services available, communication range, etc. by conducting a performance analysis and evaluation in the future maritime communications environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.16-22
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• 2006

This papers described with the analysis for electric Field strength on ground level transmitted from DMB transponder in stratosphere HAPS. It is compare with horizontal propagated ground wave. Resultly we confirm the equal strength a electric field on ground level between hish altitude vertical propagated wave and horizontal ground wave, also, is only 1W compare with terrestrial facility as transmitted output power for the DMB transponder in stratosphere HAPS. It is corresponding to 1Kw as same power value in ground propagated wave. Lastly it is new material wave source and also we concluding remarks as ubiquitous communication networking media.