• ETRI Journal
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• v.33 no.3
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• pp.443-453
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• 2011

This paper evaluates the efficiency of mobile content firms through a hybrid approach combining data envelopment analysis (DEA) to analyze the relative efficiency and performance of firms and principal component analysis (PCA) to analyze data structures. We performed a DEA using the total amount of assets, operating costs, employees, and years in business as inputs, and revenue as output. We calculated fifteen combinations of DEA efficiency in the mobile content firms. We performed a PCA on the results of the fifteen DEA models, dividing the mobile content firms into those having either 'asset-oriented' or 'manpower and experience-oriented' efficiency. Discriminant analysis was used to validate the relationship between the efficiency models and mobile content types. This paper contributes toward the construction of a framework that combines the DEA and PCA approaches in mobile content firms for use in comprehensive measurements. Such a framework has the potential to present major factors of efficiency for sustainable management in mobile content firms and to aid in planning mobile content industry policies.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.705-706
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• 2006

A novel plug and play system for a mobile device has been proposed and demonstrated to provide an easy inter-operation between the mobile device and external modules. It supports an automatic installation and execution of the device drivers stored in the external modules into the mobile devices when the external module is connected to the mobile device. It also enables an automatic removal of the derivers when the external module is disconnected from the mobile device, which makes the user use the resource of the mobile devices more efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.129-132
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• 2001

The ad hoc network was composed of Mobile hosts. Due to the limited transmission range of each mobile node hosts, in such an environment, it is essential for other hosts to coorperate to transfer packet to destination. Moreover, the existing routing protocol algorithms are not efficient on the ad hoc network because a mobile host operates router without fixed router. In this paper, we will compare and analysis for the performance of existing ad hoc network routing protocols through simulation.

• The Journal of Information Technology
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• v.10 no.4
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• pp.85-93
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• 2007

RFID applied in many area. I think that RFID enlarge for our life more and more. The application technology of RFID change the Mobile RFID using mobile phone and PDF etc. I think, Mobile RFID enlarge application technology gradually. In this paper, we propose the quality measurement metrics for mobile RFID middleware. I propose the quality testing model for interoperability and security of mobile RFID middleware. We examine the international standard for mobile RFID and software testing. In this paper, I proposed the evaluation model of mobile RFID middleware on the basis of international standard ISO/IEC 9126-2 and ISO/IEC 25000 series.

• Journal of the Korea Society of Computer and Information
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• v.23 no.2
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• pp.35-43
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• 2018

In this paper, we propose a grid-based efficient routing protocol for a mobile sink in wireless sensor networks. In the proposed protocol, the network is partitioned into grids and each grid has a grid head. For the efficient routing to a mobile sink, the proposed protocol uses a mobile sink representative node to send the data to a mobile sink and grid heads are used as a mobile sink representative node. Furthermore, the proposed protocol uses nodes in the boundary of the center grid as position storage nodes. The position storage nodes store the position of a mobile sink representative node and provide source nodes with it for data delivery. With these features, the proposed protocol can reduce a lot of overhead to update the position information and improve the delay of data delivery to a mobile sink. The proposed protocol performs better than other protocols in terms of the delay and the energy consumption per node in the performance evaluation.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.86-96
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• 2015

In mobile communication, mobile services [MSs] (e.g., phone calls, short/multimedia messages, and Internet data) incur a cost to both mobile users (MUs) and mobile service providers (MSPs). The proposed model MobPrice consists of dynamic data pricing schemes for mobile communication in order to achieve optimal usage of MSs at minimal prices. MobPrice inspires MUs to subscribe MSs with flexibility of data sharing and intra-peer exchanges, thereby reducing overall cost. The main contributions of MobPrice are three-fold. First, it proposes a novel k-level data-pricing (kDP) scheme for MSs. Second, it extends the kDP scheme with the notion of service-sharing-based pricing schemes to a collaborative peer-to-peer data-pricing (pDP) scheme and a cluster-based data-pricing (cDP) scheme to incorporate the notion of 'cluster' (made up of two or more MUs) in mobile communication. Third, our performance study shows that the proposed schemes are indeed effective in maximizing MS subscriptions and minimizing MS's price/user.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.277-284
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• 2014

Recently the use of smart phones and mobile devices is increasing rapidly, data search and retrieval in the mobile environments are generalized. There are only few mobile applications available in the area of agriculture while huge amount of new applications are developed and uploaded. The purpose of this study was to develop the android based mobile application for providing agricultural infrastructure and disaster information. The mobile application was designed through the database establishment and management system, server management system, and mobile application development. The database is composed of weather data, agricultural infrastructure data, and agricultural disaster data. By developing the mobile application which provides agricultural infrastructure information, it is expected to improve the accessibility to agricultural information and mitigate the agricultural disaster damages.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.158-167
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• 1997

For the use of a mobile robot in dynamic environment, a collision-avoidance algorithm with moving obsta- cle is necessary. In this paper, a collsion-avoidance algorithm of a mobile robot is presented, when a mobile robot detects the collision with moving obstacle on the navigational path. Using reported positions of moving obstacle with sensors, the mobile robot predicts the next position of moving obstacle with possibility of collision. The velocity of moving obstacle is modeled as random walk process with Gaussian distribution. The optimal collision-avoidance path in which turning motion of the mobile robot is considered is generated with relative velocity between the mobile robot and moving obstacle. For the safety of collision-avoidance path, attractive potential with the safety factor is suggested. The simulation results using this algorithm show the mobile robot avoids collision with moving obstacle in many cases.

• Journal of the Korea Computer Industry Society
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• v.6 no.2
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• pp.345-354
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• 2005

Mobile grid can provide the grid service to grid users regardless of space and time. There are many restrictions to use grid service in mobile environment such as battery power of mobile device, movement pattern of mobile device etc. So it is difficult to apply the grid technologies of wired network to wireless network environments. Therefore, to provide the mobile grid service, we suggested the mobile grid architecture using ad-hoc network. Also we showed that hybrid routing protocol is efficient for mobile grid service by considering the battery power of mobile device and simulations of evaluating the delay time of three routing protocols using NS-2. We will study the methods of resource allocations and network reliability to provide the mobile grid service.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.543-548
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• 2001

In the case of mobile internet service using WAP it was connected to http protocol using WAP Gateway, So users take increased cost of mobile internet service. And it was generated inner security problem because it watched user information in the WAP Gateway. To solve this problem we use java language Which is independant of platform and low cost and intensely security an downloadable application. Additional , Using socket connection. Wire.Wireless Messaging system(WWMS) will connect real time between PC-Client and Mobile-Client, Mobile-Client and Mobile-Client, and so on. In this paper, as design and implementation of multi-platform wire.wireless messaging use J2Me. It will be foundation do develop various mobile application in the future.