• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.24-35
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• 2008

We propose a tree-based integrated network of infrastructure network and mobile ad hoc network to effectively support Mobile IP for mobile ad hoc networks and also proposed a network management protocol for formation and management of the integrated network and a tree-based routing protocol suitable for the integrated network. The integrated network has fixed gateways(IGs) that connect two hybrid networks and the mobile nodes in the network form a small sized trees based on the mobile nodes that are in the communication distance with a IG. A new node joins an arbitrary tree and is registered with its HA and FA along tree path. In addition, the proposed protocol establishes a route efficiently by using the tree information managed in every node. We examined the effectiveness of the tree-based integrated network for some possible network deployment scenarios and compared our routing protocol against the Mobile IP supported AODV protocol.

• Fashion & Textile Research Journal
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• v.15 no.3
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• pp.393-405
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• 2013

This study considers the effect of smartphone involvement for purchase intentions in fashion shopping malls based on mobile web apps and on PC web apps; in addition, it investigates the correlation between purchase intention in fashion shopping malls (based on activated PC web apps) and those of fashion shopping malls (based on newly created mobile web apps). The results of this study are: First, the analysis of smartphones factors showed that smartphones consist of 6 kinds of dimensions of 'appearance involvement', 'time and information search involvement', 'application involvement', 'entertainment involvement', 'communication involvement', and 'transaction involvement'. Second, the higher the entertainment and transaction involvement among descriptive variables for smartphone involvement were due to the positive responses displayed towards fashion shopping mall purchases based on mobile web apps. Third, a higher application and entertainment involvement in the descriptive variables for smartphones resulted in a positive response displayed for purchases in fashion shopping malls based on PC web apps shown in a regression analysis that verified the smartphone and purchase intention relationship in fashion shopping malls based on PC web apps. Fourth, consumers with high purchase intention in the existing PC web app based fashion shopping malls were shown to have a high purchase intention in mobile web app based fashion shopping malls due to the results of a correlation analysis that analyzed the relationship between purchase intention in PC web app based fashion shopping malls and mobile web app based fashion shopping malls.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.114-116
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• 2012

According to common use of smart mobile devices, various services based on the location become to appear. Futhermore, as the number of social media users using the mobile devices grows rapidly, the needs for Social Media services based on location also increase. With proposing the method to access and analysis the location-based social media database by standard SNS API, this thesis introduces technical methods to generate and the information which users want to get and to service them by mobile in real time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.3254-3272
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• 2017

With the development of wireless access technologies and the popularity of mobile intelligent terminals, cloud computing is expected to expand to mobile environments. Attribute-based encryption, widely applied in cloud computing, incurs massive computational cost during the encryption and decryption phases. The computational cost grows with the complexity of the access policy. This disadvantage becomes more serious for mobile devices because they have limited resources. To address this problem, we present an efficient verifiable outsourced scheme based on the bilinear group of prime order. The scheme is called the verifiable outsourced computation ciphertext-policy attribute-based encryption scheme (VOC-CP-ABE), and it provides a way to outsource intensive computing tasks during encryption and decryption phases to CSP without revealing the private information and leaves only marginal computation to the user. At the same time, the outsourced computation can be verified by two hash functions. Then, the formal security proofs of its (selective) CPA security and verifiability are provided. Finally, we discuss the performance of the proposed scheme with comparisons to several related works.

• International Journal of Contents
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• v.9 no.1
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• pp.18-25
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• 2013

Recently, augmented reality has been proved immensely useful on a day to day basis when tied with location-based technology. In this paper, we present a new method for displaying augmented reality contents on mobile devices. We add 3D models on the view of the camera and use location-based services, motion sensors to calculate the transformation of models. Instead of remaining at a fixed position on camera view while moving around a 3D model, the model rotates on display in the opposite direction that the user is walking. We also design client as a ubiquitous client to reduce constraints on disk space and memory capacity on mobile devices. Implementation results show effective use in creating GPS-based 3D view augmented reality contents for Smart Mobile Devices.

• Journal of Information Technology Services
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• v.10 no.2
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• pp.189-202
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• 2011

It is important issue how to evaluate the economic feasibility of computing factors in the real world when we build ubiquitous spaces. In this paper, we propose a simple model that can evaluate the economic feasibility of mobile RFID-based ubiquitous computing system which enables seamless communication between offline and online via embedded computing factors in the real world. To achieve this, we explore the meaning of mobile RFID system, the difference between our research and extant researches concerning the evaluation of economic feasibility in RFID system, and propose the so-called 'Tag-based Evaluation Model' (TEM) which is an evaluation model to access the economic feasibility of mobile RFID systems. We also analyze the TEM via simulation cases based on proposed model and discuss the future of TEM.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.203-211
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• 2013

Due to the rapid growth of mobile devices and applications, mobile cloud computing is becoming an important platform in the development of cloud services. However, the mobile cloud computing is facing many challenges in terms of the computing resources and communications. One of them is the performance issue between mobile devices and cloud server. In the paper, we implemented a hadoop-based android mobile application, called mobile TPC-C, and used it for evaluating the performance aspect between mobile devices and cloud server. The mobile TPC-C was implemented based on the existing TPC-C, to make it possible to execute on top of android mobile devices. The performance measurement using mobile TPC-C was executed on various transactions while changing the number of mobile clients. By comparing it to the evaluation on the personal PC, we tried to point out the important aspects affecting the performance improvement between mobile clients and cloud server.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.133-138
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• 1993

This paper presents neural network based position estimation method in slippery environment as an approach to solve one of problems which are engaged in dead reckoning method. Position estimator is composed of slip detector and linear velocity estimator. Both of them are based on the fact that dynamic characteristic of mobile robot in slippery environment is different from the case without slip. To find out the dynamic relation among driving torque, angular acceleration of driving wheel and linear acceleration of mobile robot, accelerometer is used for measuring acceleration of mobile robot and neural network is used for dynamic system identifier in slippery environment.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.1
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• pp.49-53
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• 2011

Path following of the mobile robot is one research hot for the mobile robot navigation. For the control system of the wheeled mobile robot(WMR) being in nonhonolomic system and the complex relations among the control parameters, it is difficult to solve the problem based on traditional mathematics model. In this paper, we presents a simple and effective way of implementing an adaptive following controller based on the PID for mobile robot path following. The method uses a non-linear model of mobile robot kinematics and thus allows an accurate prediction of the future trajectories. The proposed controller has a parallel structure that consists of PID controller with a fixed gain. The control law is constructed on the basis of Lyapunov stability theory. Computer simulation for a differentially driven nonholonomic mobile robot is carried out in the velocity and orientation tracking control of the nonholonomic WMR. The simulation results of wheel type mobile robot platform are given to show the effectiveness of the proposed algorithm.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.567-570
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• 2005

Recently, as mobile paradigms such as telematics or LBS (Location Based Service) have been being more diverse and mobile devices such as PDA (Personal Digital Assistance) or several telematics terminals have been being used more widely, mobile services, for example, mobile geographic information service have been being put more importance by people. In this paper, we propose to adopt S/W and data streaming mechanism as a method to improve performance of mobile geographic information service which is a representative of mobile services based on client-server architecture. The show the effectiveness of proposed methods, we design and implement S/W streaming prototype system and sample mobile geographic information service to be executed on the S/W streaming system.