• Communications of the Korean Institute of Information Scientists and Engineers
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• v.28 no.8
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• pp.38-45
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• 2010

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.237-244
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• 2011

Vehicular communications extend their application areas by combining communication technologies with roads/vehicles, and one of major applications is Smart Highway project. Smart Highway is a new advanced highway system which enhances the current highway system in Korea by improving reliability, safety and convenience. In this paper, we introduce wireless access technologies for vehicular communications especially focusing on Smart Highway. We first introduce the overall communication system architecture and the basic service and communication requirements for Smart Highway. Then, we discuss wireless access technologies including L2-level hand-over scheme. In addition, the results of experimental measurements of Wireless Access in Vehicular Environments (WAVE) system are introduced.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.177-183
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• 2012

Cell-phones functions have advanced so rapidly and they are now called 'smart-phones.' Typical approach to optimization the performance of a smartphone is the increasing the speed of device and acquiring more free memory. In this paper, we propose relatively simple techniques that average users can apply to their devices to optimize the performance. For performance upgrade, we proposed an over-clocking technique usually used by computer manufacturers. For memory optimization, we proposed deleting unnecessary apps and replacing with better-functioning apps. We also performed experimentation by applying these techniques to a popular Android phone model and presented the results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.51-56
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• 2008

In this paper, we propose a printed planar antenna suitable for mobile wireless communications. Since the printed antenna is easy to fabricate due to simplicity, low cost, and light weight, it is widely used in communications systems. The conventional patch antenna takes too much surface area to be applied to a mobile receiver. Although the size is reduced using the printed antenna, still reasonably wide bandwidth should be considered. To overcome the disadvantage of narrow bandwidth, the substrate should be physically thick and the dielectric constant should be small. In this work, we suggest a simple form of printed planar antenna and show the optimal input impedance depending on the antenna size and operating frequency. The performance evaluation is achieved analytically for a prototype antenna model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1076-1086
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• 2006

In providing video-on-demand (VoD) services to a number of clients through networks, the bandwidth requirements of video transmission restrict VoD services. For this reason, many significant broadcasting-based VoD schemes have been proposed to efficiently support services. However, the broadcasting-based VoD schemes approach needs frequency channel hopping, using many channels at the same time and managing many segments of a video. These make it difficult to implement. In this paper, we propose a Harmonic Staggered broadcasting scheme which has a simple structure and substantially improved VoD efficiency. The numerical results demonstrate that the viewer's waiting time of the Harmonic Staggered broadcasting scheme is close to the harmonic broadcasting scheme and the maximum buffer requirements of this can be adapted for demanding rate by adjusting the short front part of a video sizes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.75-81
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• 2012

RFID is new recognition technology which can trace IC chip(built in information) with wireless frequency. The present RFID is used in parcel service, missing child potection system, bus card, and extensive areas. This paper proposes and designs a belongings position tracking system using RFID with GPS. The main features of the proposed system are as follows. First, the system can in real time track the lost belongings. Second, the system can provide lost belonging location information to the users. The performance evaluation of the proposed system is performed by using AVD(Android Virture Device).

• Asia Marketing Journal
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• v.14 no.3
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• pp.103-118
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• 2012

Although music is one of the most important attributes of broadcasting communications, few studies have examined the relationship between background music and the behavior of audiences, particularly in the context of TV home shopping programs, where purchase decisions are made while watching the show. The objective of this study is to examine whether certain characteristics of music in broadcasting communications can affect the audiences' purchase intentions or behaviors. Unlike previous studies on this issue, this study considers the impulse-inducing capability (IIC) of music as an important variable affecting consumers' purchase intension. A 2×3 (high/low involvement and high/low/no IIC music) between subjects design was used for the experiments in the study. The TV home shopping programs in the high or low involvement condition were identical except for the type of background music: high IIC music, low IIC music, and no music. A total of 188 undergraduate students at a college in Seoul, South Korea participated in the study. Their ages range from 20 to 25 (median age = 22), and nearly 60% were male. Our analysis showed that in the low involvement condition, high IIC music was more likely to have a positive effect on purchase intentions than low IIC (common) music or no music did. Meanwhile, there was not any significant relationship between music and purchase intentions in the high involvement condition. Given that previous studies have provided no clear evidence of the effects of music on consumers' purchase intentions or behaviors, this study makes an important contribution to the literature in this field. The result of this study provides implications to the practitioners in the market, too. Marketers need to reevaluate the value of music used in broadcasting communications and pay more attention to find the right music for their campaigns. Limitations of this study as well as directions for future studies are also discussed.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.12-18
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• 1998

In non-geostationary orbit(NGSO) satellite communication links, satellite's elevation angle at terminal is changed continuously because of the satellite movement relative to earth surface. Therefore the characteristics of the fade-effected signal received by a terminal from a NGSO satellite is also varied continuously even if the terminal is operated at fixed location. In this paper, we determine a general statistic model for the fading characteristics over NGSO satellite communication links and set up the parameters of the fading model in terms of the elevation angle according to various propagation environment and find the parameter values using the data of fading margin for commercial NGSO mobile satellite communication systems. And the fading charateristics for each environment are analyzed using this model. These results can be applied to develop the compensation algorithm and to analyze the performance of the transmission schemes for NGSO mobile satellite communication systems.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.38-53
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• 2007

Nowadays, as it goes on digitalization of the broadcasting and the convergence of the broadcasting and communications , it has been developed into the ubiquitous individual media consuming pattern which can easily and comfortably consume the favorite contents through any devices at anytime and/or anywhere. For this, in this paper, we propose personalized broadcasting service that can provide a convenient access of the contents that users want to watch at anytime by considering the user preference and consumption characteristics as well as an efficient browsing and watching of the particular program segments more advanced than the data broadcasting services. Moreover, it is implemented the TV-Anytime standard based on personalized broadcasting terminal platform by us. The developed services and terminal will used on broadcasting environment in which many services and the contents. The result of that is the broadcasters/service providers and content providers can provide differential broadcasting services which is suitable to each user such as personalized broadcasting service in near future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.96-102
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• 2003

The thermal design of MGSE(Mechanical Ground Support Equipment) panel is performed for thermal vacum thest of Ka-band EQM(Engineering Qualification Model) payload of communications and broadcasting satellite. The thermal environments are predicted to evaluate the performance of transponder equipments in the thermal vacum chamber. SINDA is used to verify the thermal design of the heat pipe layout. Embedded 16 heat pipes in the EQM payload developed for Ka-band trasponder equipments are designded properly. The heat fluz loaded on the external facesheet is 265W/㎡ for the hot platear function test of the traspinder equipments, and the zero heat flux for the cold plateau case. The maxium predicted heat transport capability is 2723 W-cm.