• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.15-26
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• 2011

As quick and secure mobility service is becoming a critical issue in the ubiquitous environment. Internet Engineering Task Force (IETF) has done a lot of meaningful work in order to cope with the critical issues, which is a key technology of guaranteeing the legally and safely using of network resources, they has proposed Hierarchical Mobile IPv6 (HMIPv6) to complement for such problems as handover latency and signaling overhead in existing MIPv6. Most of the current research about HMIPv6 focuses on how to optimize the interactive processes between the HMIPv6 and AAA (Authentication, Authorization, Accounting) protocol. This paper describes a cost-effective hierarchical authentication scheme, which makes its focus on minimizing the authentication latency in AAA processing. In this scheme, a hierarchical AAA architecture is proposed, in which the AAA servers are deployed on the Mobility Anchor Point (MAP), the Root AAA server manages several Leaf AAA servers and the Brokers on behalf of the AAA server in home domain. The simulation results shows that the proposed scheme reduces the handoff and authentication latency evidently compared to the previous traditional authentication combination modeling.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.58-64
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• 2012

In this paper, we proposed a distributed gateway for ubiquitous healthcare system. We also designed and implemented protocol conversion and processing algorithms to exchange a seamless information, the bio signals between the databases and the receiving devices from ZigBee to gateway and from the gateway to database and network. The distributed gateway system consists of the bio signal acquisition, ZigBee modules, distributed databases, and gateways. The bio signals detected by the ZigBee module are sent to the gateway. The distributed gateway analyzes the data being transferred, sends those to the receiving devices, and lets the authorized personnel access. The proposed system can be utilized in various fields including activity analysis for the elderly, security systems, home network service, and so on.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.115-129
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• 2007

The ubiquitous and autonomic computing environments is open and dynamic providing the universal wireless access through seamless integration of software and system architectures. The ubiquitous computing have to offer the user-centric pervasive services according to the wireless access. Therefore the roaming services with the predefined security associations among all of the mobile devices in various networks is especially complex and difficult. Furthermore, there has been little study of security coordination for realistic autonomic system capable of authenticating users with different kinds of user interfaces, efficient context modeling with user profiles on Smart Cards, and providing pervasive access service by setting roaming agreements with a variety of wireless network operators. This paper proposes a Roaming Coordinator-based security management framework that supports the capability of interoperator roaming with the pervasive security services among the push service based network domains. Compared to traditional mobile systems in which a Universal Subscriber Identity Module(USIM) is dedicated to one service domain only, our proposed system with Roaming Coordinator is more open, secure, and easy to update for security services throughout the different network domains such as public wireless local area networks(PWLANs), 3G cellular networks and wireless metropolitan area networks(WMANs).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1087-1095
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• 2014

A recent major development in computer technology is the advent of the wearable computer system that is based on human-centric interface technology trends and ubiquitous computing environments. Wearable computer systems can use the wireless universal serial bus (WUSB) that refers to USB technology that is merged with WiMedia PHY/MAC technical specifications. In this paper, we focus on an integrated system of the wireless USB over the IEEE 802.15.6 wireless body area networks (WBAN) for wireless wearable computer systems supporting U-health services. And a communication structure that can differentiate QoS of U-health WBAN and WUSB traffic with different priorities is proposed for WUSB over IEEE 802.15.6 hierarchical protocol. In our proposal and performance evaluation, throughputs of U-health WBAN and WUSB traffic are analyzed under single and multiple QoS classes to evaluate the effectiveness of proposed QoS differentiating structure in WUSB over IEEE 802.15.6.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1509-1520
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• 2009

Contrary to ubiquitous environments, indoor computing environments like home network doesn't support user mobility. This paper suggests UPnP A/V multimedia system using prediction of mobility for adaption of seamless multimedia service. The multimedia system enables indoor mobile users to play multimedia contents by transferring the current session to an adjacent device automatically. The system represents users' contextual information by Five Ws and One H model, and predicts user's movements by using contextual information and transitions of locations. The prediction basically includes multiple locations so that it improves accuracy of prediction. We evaluated the suggested system using in accuracy of prediction, time for prediction, handover time for service, and the system showed that adapt ion of seamless multimedia service was enabled by using prediction of mobility on mobile user.

• Convergence Security Journal
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• v.14 no.2
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• pp.35-41
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• 2014

With ubiquitous computing and network, the concern of government, business and academy for IT or ICT convergence has been increased. In this paper, through the analysis of keyword trend for ICT convergence services from 2000's mid, the efficient policy is proposed by estimating the understanding and concern of common people. In addition to, the concept and development step of convergence are analyzed, and the keyword analysis for the ICT convergence services defined in TTA is performed. The services are classified into smart home work transportation, Health ICT, RFID USN, M2M IoT, e-Navigation, intelligent robot, and the keywords for each service are analyzed. The analytic results indicate that the keyword trend varies in the time, and highly indexing keywords and new trend are defined. To provide the efficient ICT services, the new ICT convergence services needed for customer will be proposed with new IT technology development, IT standard, law management, and policy provisioining.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.839-847
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• 2014

A recent major development in computer technology is the advent of the wearable computer system that is based on human-centric interface technology trends and ubiquitous computing environments. Wearable computer systems can use the wireless universal serial bus (WUSB) that refers to USB technology that is merged with WiMedia PHY/MAC technical specifications. In this paper, we focus on an integrated system of the wireless USB over the wireless body area networks (WBAN) for wireless wearable computer systems supporting U-health services. To construct the WUSB over WBAN communication systems, we propose a WBAN beaconing structure to assign WUSB communication periods. In the proposed structure, WUSB uses private periods of WBAN. In our performance evaluations, we compare theoretical results and simulation results about throughputs of WUSB under various WBAN channel occupations to evaluate the effectiveness of proposed structure in WUSB over WBAN communications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.105-108
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• 2007

In this paper, we have developed a UPnP-OSGi Bundle for digital convergence based on UPnP middleware. UPnP-OSGi bundle is demanded sustaining realtime monitering system based on UPnP middleware that is possible multimedia ability of a piece with a multiplicity of service and joint user data , service lifecycle , management division service for home network system offered convergence service. This bundle is possible a multiplicity of control and monitering service segmentation so develop a multiplicity of service is easy. and provide zero-configuration system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.11-19
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• 2007

A ubiquitous network environment is a system where the user can avail of the network's services anytime, anywhere. To establish such an environment, studies continue being conducted on wireless communication technology and mobile terminals. The company that provides such services should have an established system for authentication, authorization and charging for users. This service is referred to as Authentication, Authorization, Accounting(AAA), and its aspects have been consistently studied. On the other hand, existing studies have been promoted with regard to the authentication and efficiency of the mobile terminal. One of the method is that the mobile terminal contacts to the home authentication server through the external authentication server every time it is required and; another one is to use a medium server to provide authentication in the middle between them. Thus, this study aims to determine the best method to use ticketing, where tickets are provided through a mobile terminal, complete with authentication and authorization features. Also, as it uses ticket, it can efficiently provide mobile verification processing.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.456-459
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• 2008

We are now in the era of digital convergence with CE products and PC at the center, but product diversification occurs in the same breath. Each device may perform its own functions itself independently, but proportion of the inter-device usage is increasing gradually by concept of a home network and ubiquitous widely prevailed. The consumer's need of inter-device connection will take the dominative position of the market. Therefore, we can easily forecast that diversification of the products may inevitably lead connectivity patterns complicated considering recent market situation and trends. In this paper, we propose the methodology for designing inter-device connectivity which covers issues such like segmenting numerous number of connectivity pattern, and establishing their structure of control. Our methodology also supports the inter-device connection with extensive latitudes and a multi-device simultaneous control. In order to present inter-device connectivity guideline, we define four stages of a user experience - Connection, Configuration, Use, Disconnection. Based on the 4 user experience stages, we suggest a specific connectivity designing guideline for each step.