• Journal of Digital Convergence
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• v.15 no.11
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• pp.77-83
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• 2017

The Korea Expressway Corporation announced that road casualties on expressways in 2016 were 262 deaths, a 24% decrease compared to 343 deaths in 2015, thanks to the expansion of rest areas for sleepy drivers. And the installation of large-sized banners containing strong messages such as "dozing while driving means your death" helped to reduce the casualty caused by driving while drowsy by 35% compared to that in 2015. Accordingly, this study tried to analyze the impact of public advertisements designed to prohibit dozing while driving on expressways upon drivers, and to present a direction for improvement of such public advertisements in the future. Based on case studies and library researches, the study contemplated the effects of public advertisements on expressways at home and abroad. It was confirmed that the accident rate has been higher on straight roads than on curved roads and that the framing of negative messages using provocative images or slogans on traffic accidents has been considerably effective. In conclusion, if the installation of outdoor billboards for public advertisements at rest areas for sleepy drivers is institutionalized and the systematic provision of information by road section inside and outside of vehicles via Variable Message Sign (VMS) services on expressways, outdoor billboards, or navigation services (including smartphones) is available, it would be possible to maximize the effect of the public advertisements.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.163-170
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• 2017

As the usage of smart phones continues to increase, the control UI, which users have to continue to use, sometimes finds a heavy burden on users. Therefore, in this study, we have studied the control user interface structure along with the theoretical background of the control user interface, and we have studied the role and usage of the control component based on it. Typical commonly used controls are button controls for transmission, selection controls for various selections, link controls for navigation, text controls for inputting characters, indicator controls for feedback on progress, A message control that displays information about warnings and errors, and a window control such as a dialog box. The structure of the control should be designed according to the use of the separated control to help the user efficiently use the control user interface. Based on the analysis of the theoretical usage of representative components belonging to the separated controls, we presented a new and correct way to use the control to improve the user experience. The use of improved control components will help to design the control structure efficiently and to improve the user experience.

• Journal of Information Technology Services
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• v.7 no.3
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• pp.1-30
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• 2008

This paper proposes an integrated model of customer loyalty in the context of Internet shopping based on a review of two competing perspectives - transactional and relational views. The research model suggests that the usability and trust associated with an Internet shopping site are key determinants of customer loyalty. In this paper, factors such as promotion, ease of use/navigation, and purchase facilitation are posited as major determinants of usability. Trust, on the other hand, is assumed to be influenced by the quality of communication, social shopping service, and safety level associated with an Internet shopping site. This paper also asserts that the lack of consideration for individual differences is one of the key reasons for the inconsistent and mixed research findings in user acceptance literature. In this regard, the elaboration likelihood model (ELM) is considered to be appropriate referent theory as it may theoretically explain why a particular information technology (IT) related message has varying influences on different adopters. The research model comprising 11 hypotheses was derived from and validated through a survey involving 271 university students. The partial least square(PLS) method was used to test the suitability of the research model and its hypotheses. Overall, the results suggest that the usability and trust associated with an Internet shopping site play an important role in acquiring loyal customers. In particular, the user's Internet shopping involvement is found to moderate the relationship between trust and customer loyalty.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.37-44
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• 2003

The aim of this research was performance of Web-based real time DGPS using MS visual basic 6.0 Active X control. This system supported the navigation of rover by transmitting the DGPS correction information of base station via internet and monitored the moving of rover by displaying the corrected results received from rover as well as permitting Web users monitoring for rover. The Web-based DGPS server and the client system using MS visual basic 6.0 Active X control for DGPS displayed on Web-browser with the pre analysis was constructed and the system loading test via Web-browser was performed after debugging this system through the static GPS test and publishing it on Web. Also, the wireless internet DGPS test on Web by changing the distance between a base station and a rover was carried out. As the result of the test, the real time DGPS could be performed by transmitting the correction message which calculated from the server system to the client system continually. The rover could be managed by displaying the location information which received from the client system. Other users also could monitor the rover by connecting with this system via internet in real time.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.3
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• pp.230-237
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• 2008

Recently, lots of interest and competition in developments related to the autonomous-vehicle robot are being further increased. However, the absence of the standard architectures for effectively controlling the autonomous-vehicle robot led to many difficulties such as the long duration of development and the uncompatibility with other autonomous-vehicle robots. Accordingly, we implemented a mobile autonomous-vehicle robot system based on JAUS standard architecture. The mobile robot communicates with the remote-control system by using wireless LAN UDP/IP JAUS command massages. Its effectiveness is showed through the experimental results related to the navigation of implemented robot.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.425-432
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• 2016

When user estimates user's position, GPS positions can be obtained from the navigation message transmitted from the GPS. However, the broadcast ephemeris cannot be used in the applications required high-level accuracies because it can cause errors of several meters. To correct satellite positions and clocks, user can use RTS corrections provided by IGS. In this paper, the accuracy of broadcast and RTS corrections are analyzed by comparing with the IGS final for 3-months. The RTS errors are analyzed for each user's locations and satellite blocks. The correlations between errors and shadow condition, and solar and geomagnetic activities are analyzed. The latency is applied to the RTS corrections, and these are extrapolated by polynomial. Then, the extrapolated RTS are compared with true RTS. The single-day performances of the PPP by broadcast ephemeris and RTS corrected ephemeris are analyzed. As a result, RTS 3D orbit and clock errors are 1/20 and 1/3 less than broadcast ephemeris errors. 3D positioning error of the RTS is 1/5 less than that of broadcast ephemeris.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1015-1024
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• 2011

Mobile P2P protocols in ad-hoc networks have gained large attention recently. Although there has been much research on P2P algorithms for wired networks, existing P2P protocols are not suitable for mobile ad-hoc networks because they do not consider mobility of peers. This study proposes a new cluster-based P2P protocol for ad hoc networks which utilizes peer mobility. In typical cluster-based P2P algorithms, each cluster has a super peer and other peers of the cluster register their file list to the super peer. High mobility peers would cause a lot of file list registration traffic because they hand-off between clusters frequently. In the proposed scheme, while peers with low mobility behave in the same way as the peers of the typical cluster-based P2P schemes, peers with high mobility behave differently. They inform their entrance to the cluster region to the super peer but they do not register their file list to the super peer. When a peer wishes to find a file, it first searches the registered file list of the super peer and if fails, query message is broadcasted. We perform mathematical modeling, analysis and optimization of the proposed scheme regarding P2P traffic and associated routing traffic. Numerical results show that the proposed scheme performs much better than or similar to the typical cluster-based P2P scheme and flooding based Gnutella.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.48-52
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• 2007

Recently, the research of GPS receiver which uses the Software-Defined Radio(SDR) technique is being actively proceeded instead of traditional hardware-based receiver. The software-based GPS receiver indicates that the signal acquisition and tracking treated by the hardware-based platform are processed as the software technique through a microprocessor. In this paper, GPS software receiver is designed by using SDR technique and then the signal acquisition, tracking, and the navigation message decoding parts are verified through the PC-based simulation. Moreover, the efficient algorithms are developed about the signal acquisition and tracking parts in order to obtain the accurate pseudorange. Finally, the pseudorange is calculated through the relative channel delay received through the different satellite of L1 frequency band. GPS software receiver proposed in this paper will be included in the element of GPS/Galileo complex system of development target and will provide not only the method that verifies the performance for Galileo Sensor Station standard but also usability by providing various debugging environments.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.684-690
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• 2010

Recently, the NG(Next Generation) system is studied for supporting convergence of various services and multi mode of single terminal. And a demand of user for taking the various services is getting increased, for supporting these services, many systems being able to transmit a large message have been appeared. In the NG system, it has to be supporting the CDMA and WCDMA besides the tele communication systems using OFDM method with single terminal An intergrated system can be improved with adopting of SoC technique. For adopting SoC technique on the intergrated terminal, we have to solve the non linear problem of HPA(High Power Amplifier). Nonlinear characteristic of HPA distorts both amplitude and phase of transmit signal, this distortion cause deep adjacent channel interference. We adopt a polynomial pre-distortion technique for this problem. In this paper, a noble modem design for NG mobile communication service and a method using polynomial pre-distorter with PAPR technique for counterbalancing nonlinear characteristic of the HPA are proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.685-688
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• 2016

SBAS(Satellite Based Augmentation System) broadcasts the correction message based on satellite communication to improve the positioning accuracy of GNSS user. For this reason, SBAS is actively being utilized on navigation part. To apply SBAS to navigation part, it should satisfy not only accuracy but also integrity, continuity, availability, coverage requirements and so on. Since SBAS reference station is the base infrastructure of SBAS, it is the main factor to determine the environment, position, and geometry of reference stations to achieve SBAS service performance. Therefore, a site environmental analysis should be performed prior to the selection of SBAS reference station. In this paper, it performs the environmental analysis of NDGPS(Nationwide Differential GPS) reference station sites on the premise that SBAS reference station will be co-operated in the same site of NDGPS operated by MOF(Ministry of Oceans and Fisheries). The environmental analysis is conducted as carrying out the visibility analysis of GPS satellite and interference analysis. This paper also presents the brief procedures and requirements for site survey of SBAS reference station.