• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.43-48
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• 2012

In As the proliferation of wireless LAN and smart devices like smart phone, the importance of the wireless Internet local broadcasting service is increasing. In order to provide broadcasting data for the multiple devices, one-way roadcasting technology which could not support re-transmission, should be used and the receiving frame error is major problem. Furthermore unlicense devices cause interference to the receiver, burst frame error tends to be happened. In this paper, new method to overcome the burst and random frame error is proposed and the effect is analyzed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.99-104
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• 2014

In this paper, the authors propose a multi-transmission mechanism of heterogeneous network environment which is applicable to the SMART screen services over wire and wireless convergence network. This paper presents study results including a SMART screen handover algorithm among multiple collaborative devices under wire and wireless convergence and heterogeneous network environment, and a service operation and management system and a NAS system providing SMART services of AV streaming and contents files. These validate implementation feasibility of a call processing engine for seamless SMART screen collaborative services, AV streaming services and SMART screen collaborative services supporting mobility management and multiple users/multiple streams.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.159-167
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• 2005

Through the increment of group oriented application services, the multicast communication in wire/wireless network has become a widely discussed researching topic. However solution for security, efnciency and scaleability of a multicast communications are not enough to be satisfactory. Tn this paper, we Propose a new secure, efficient and scalable multicasting protocols to provide a integrated multicast service. Our protocol is an authenticated key establishment protocol which has been designed specifically for use with low powered computationally weak equipment such as Cellular phone and PDA(Personal Digital Assistant).

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1121-1128
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• 2008

Ad-Hoc network is consisted with the device of wireless communication. Therefore, the organization of network is dynamic and the changing communication channel is essential. According this, the study of secure routing route and certification technique has to be needed. In we research, we suggest not only the secure routing scheme in Ad-Hoc circumstance but also the method that user can be serviced the type of network which is connected Ad-Hoc network and wireless lam. In case of the routing form of Ad-Hoc Network, although in preexist study, when the device of organization withdraws, routing is needed, in we research, we suggest the detour route that is used hop frequency. We can offer the service of ubiquitous that the certification of secure user and the creation of routing route in Ad-Hoc network.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.325-333
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• 2004

Since 1995, One of the NGIS(National Geographic Information System) projects, the underground utilities project has been finished in 2003. The 19 cities in korea for this project will use underground utilities management system using underground utilities database focusing on water and sewage system. However, special expert, technical and experience problem in computer environment has not been had in working department for water and sewage management and maintenance for each local government. The management and maintenance of underground utilities database by manual method is getting lowered a data quality of underground utilities database because of the data omitting, error in writing and securing of the lasted database. Therefore, in this study, Application test for field workers using a mobile tool and environment analysis of wireless communication in Korea and application test of GPS receiver for mobile tools had been processed and made a mobile working environment. The efficient management and maintenance method for underground utilities database has been developed an off- line method for modification and update of database about general work which has a high working frequency because of the limitation of wireless communication environment Also, the emergency working has been applied for on-line method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2107-2113
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• 2015

This paper proposed a Prior Forecast System of Crossroad Traffic Information that allows vulnerable road users to perceive traffic signal changes beforehand and respond in concentrated traffic areas such as crossroads. Also, it mapped out information linking procedures of the proposed system and it designed a PHY based wireless communication simulator to verify the operational feasibility of wireless communications. Conclusively, by conducting performance analysis according to crossroad channel environments using the simulator designed in this paper, it verified that a Prior Forecast System of Crossroads Traffic Information service for vehicle IT based decision-making support for vulnerable road users is a possibility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1961-1965
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• 2008

During communication between wireless users, disconnection may occur during the handover process. The high handover latency during the process of handover degrades the service quality of the wireless communications. This problem becomes more crucial if the operation network is transmitting real-time multimedia applications. This paper studies the hanover procedure of mobile IPv6 and investigates various factors affecting the handover latency through mobile IPv6 testbed and evaluates the various parameters for reducing the handover latency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2062-2068
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• 2008

In a u-City project in Busan, public transportation which is one of ITS has been considered. RFID system embedded with PXA255 chip and middleware capable of communicating a server side was developed. To perform data communication link with traffic card, developed system consists of wireless modules that are wireless LAN (IEEE802.11a/b and IEEE802.16. Using developed RFID system and middleware, it is expected that this system becomes a basic infrastructure to support a service of u-Traffic for u-City construction.

• Journal of the Korea Convergence Society
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• v.5 no.3
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• pp.1-5
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• 2014

The development of communication method for a variety of intelligent automobiles are delivering comfortable and safe information. However the development of such communication method must also think about security. Even the update of navigation to be used for intelligent automobiles uses the wireless updating methods but the updating methods currently being used has no reliable security measures. The navigation communications used in the intelligent automobiles are being provided with TTI(Traffic and Travel Information) service using a variety of methods by the countries. In the case of Korea, most are based on T-DMB using the TPEG method for transmitting the information. By identifying the characteristics on the navigation wireless update, a security solution is proposed for delivering the reliable update information after creating the attack scenario.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.25-30
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• 2024

Smart City, a key application area of the AIoT (Artificial Intelligence of Things), provides various services in safety, security, and healthcare sectors through location tracking and location-based services. an IPS (Indoor Positioning System) is required to implement location-based services, and wireless communication technologies such as WiFi, UWB (Ultra-wideband), and BLE (Bluetooth Low Energy) are being applied. BLE, which enables data transmission and reception with low power consumption, can be applied to various IoT devices such as sensors and beacons at a low cost, making it one of the most suitable wireless communication technologies for indoor positioning. BLE utilizes the RSSI (Received Signal Strength Indicator) to estimate the distance, but due to the influence of multipath fading, which causes variations in signal strength, it results in an error of several meters. In this paper, we conducted research on a path loss model that can be applied to BLE IPS for proximity services, and confirmed that optimizing the free space propagation loss coefficient can reduce the distance error between the Tx and Rx devices.