• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.325-330
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• 2014

The era of convergence is being applied to all areas of Information and Communication Technology (ICT). The convergence of broadcasting service and communication service almost occurs on smart devices including smartphone. The smart hybrid Digital Multimedia Broadcasting (DMB) is a typical example of the convergence of broadcasting and wireless communication service. The hybrid mobile broadcasting service can support seamless video, 3D, high quality, and additional data services based on network connection between the broadcasting and wireless network. The gateway and terminal (including apps on the smartphone) take the role of the main components on the hybrid service. This paper presents the service concept, main components structure, the implementation of gateway and terminals, and field test to the urban areas for the mobile hybrid system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.1998-2014
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• 2016

In recent years, cloud computing services based on smart phones and other mobile terminals have been a rapid development. Cloud computing has the advantages of mass storage capacity and high-speed computing power, and it can meet the needs of different types of users, and under the background, mobile cloud computing (MCC) is now booming. In this paper, we have put forward a new classification-based virtual machine placement (CBVMP) algorithm for MCC, and it aims at improving the efficiency of virtual machine (VM) allocation and the disequilibrium utilization of underlying physical resources in large cloud data center. By simulation experiments based on CloudSim cloud platform, the experimental results show that the new algorithm can improve the efficiency of the VM placement and the utilization rate of underlying physical resources.

• Journal of the Korea Society for Simulation
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• v.7 no.2
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• pp.153-165
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• 1998

In the Is-95 soft handoff scheme of CDMA, there occurs a tradeoff between improving quality due to the space diversity and additional resource management like updates of the active set during soft handoffs. In addition, if a mobile terminal is alternating two adjacent cells, a well-known phenomenon called ping-ping causes the resource management to be seriously degraded. By noting that in general the probability that a user initiates additional handoffs is exponentially decreased as the user has already handed over one or more times, we present a soft handoff algorithm making use of handoff profiles of mobile terminals to improve resource utilization. In the proposed algorithm the number of handoffs made so far during the call is recorded in the mobile profile and the profile data is used for adjusting handoff parameters such as the value of add or drop threshold (T_ADD or T_DROP). Through simulations, the result of the proposed algorithm is shown to improve the handoff performance by lowering the number of handoffs while simultaneously reducing resource waste.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.147-161
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• 2012

In recent years, machine-to-machine (M2M) communications are under rapid development to meet the fast-increasing requirements of multi-type wireless services and applications. In order to satisfy M2M communications requirements, heterogeneous networks convergence appears in many areas, i.e., mobile cellular networks (MCNs) and wireless sensor networks (WSNs) are evolving from heterogeneous to converged. In this paper, we introduce the system architecture and application requirement for converged MCN and WSN, where mobile terminals in MCN are acting as both sensor nodes and gateways for WSN. And then, we discuss the joint optimization of converged networks for M2M communications. Finally, we discuss the technical challenges in the converged process of MCN and WSN.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.11-21
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• 2014

In this paper, concerning the various advertising and policy advertising of the election with respect to whether to deliver a message to a large number of people, we design and implement an automative system what enables sending the text messages directly from the server to the client and also fast feedback is enabled by utilizing a number of operational programs to connect to the server. Therefore, we design and implement the automative communication system which enables delivering message to each user mobile terminal from a plurality of relay mobile terminals by utilizing the mobile instant messenger, not to deliver a message from the server to the mobile instant messenger user directly. In result of comparative analysis on the number of times of data transmission, this automative communication system utilizing mobile instant messenger shows the result that it enables transmitting five times per minute as it can copy and paste in the automation system regardless of the size of the data loading, otherwise in case of transmitting manually it show the result that the number of times of data transmission is reduced if the size of the data is larger.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1075-1076
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• 2009

The mobile application Open Market of the Apple company's App-store is serviced by the domestic communication company. The domestic developer concentrates on the development and trading ont the market of the application. But App-store's I-pod is different from the Korean mobile. The developer can't use the mobile test because there are a lot of mobile in korea. To solve this, we propose that developers can more easily use the mobile test with mobile simulators on the web. This system does the least amount of tests with many mobile terminals and is the verified trading application.

• Journal of Digital Convergence
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• v.10 no.2
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• pp.171-182
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• 2012

The many companies and developers develop new mobile applications for serving to users. But, most of it is disappeared in a brief. Because Many applications weren't satisfy the needs of user. In this paper, it analysis to reason short life of mobile application in the smart terminals and mobile applications. Therefore, we develop dynamic user usability analysis system of applications to solve the problem. User usability analysis method is surveyed users and masters at present and then occurs high cost. In this paper, we develop dynamic user usability analysis system for real users. If usage of mobile applications upgrading, benefit of developers increased and serviced target contents to users.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.169-175
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• 2011

This paper addresses mobile IP router which communicate between nodes in Ad Hoc network as well as supply attachment to outer Internet. Ad Hoc network is one which exchanges information through cooperations among nodes without wire infrastructure, mobile IP router considers the network as one mobile unit, and supports Internet connection in mobile as well as fixed spaces. Therefore, this router can accommodate the routing of Ad Hoc network, and provide nodes in Ad Hoc network with Internet connection. So mobile IP router can provide Ad-Hoc terminals with the diverse wireless services, such as Internet connection service, routing, mobility, and so on.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.559-566
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• 2003

As cell phone and PDA have been in common use recently, there is a growing tendency to utilize the mobile terminals for M-Commerce. The information security and the receipt of e-trade are very important to support reliable digital transactions in wireless environment as in wired environment. Even though some work such as WML digital signature and WPKI has been studied for M-Commerce, there are several problems on the aspects of the functional limitation of the mobile terminals and the unsecure data transformation of WAP gateway. In this study we have designed and implemented a prototype system of issuing and verifying the electronic receipt that guarantees authentication, data integrity and non-repudiation for secure mobile e-commerce. Moreover, we have enhanced the system performance by letting the trusted independent server verify and manage the electronic receipt.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.113-118
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• 2016

This study found that there are problems in sending mails at the postal service reception desks and proposes a system which transmits address information to POSNET(the terminals at post office reception) without the use of an additional security system based on address information which is stored in the terminals of mobile phones. The system proposed transforms the information of users into two-dimensional barcode(QR code) of the POSNET and a number of address information is texturized and transmitted to the POSNET with the use of how to read QR code and LAN such as bluetooth. When the system proposed is connected to the postal reception system, it can create and output mail addresses for mobile computers automatically and contribute to better performance for the post office reception clerks and better economic results.