• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.17-20
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• 2008

A clustering scheme for ad hoc networks is aimed at managing a number of mobile devices by utilizing hierarchical structure of the networks. In order to construct and maintain an effective hierarchical structure in ad hoc networks where mobile devices may move at high mobility, the following requirements must be satisfied. The role of each mobile device for the hierarchical structure is adaptive to dynamic change of the topology of the ad hoc networks. The role of each mobile device should thus change autonomously based on the local information. The overhead for management of the hierarchical structure is small. The number of mobile devices in each cluster should thus be almost equivalent. This paper proposes an adaptive multihop clustering scheme for highly mobile ad hoc networks. The results obtained by extensive simulation experiments show that the proposed scheme does not depend on mobility and node degree of mobile devices in the ad hoc network, which satisfy the above requirements.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.136-141
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• 2022

In this paper, we designed, implemented, and verified the SLAM system that can be used on mobile devices. Mobile SLAM is composed of a stand-alone type that directly performs SLAM operation on a mobile device, and a mapping server type that additionally configures a mapping server based on FastAPI to perform SLAM operation on the server and transmits data for map visualization to a mobile device. The mobile SLAM system proposed in this paper is to mix the two types in order to make SLAM operation and map generation more efficient. The stand-alone type SLAM system was configured as an Android app by porting the OpenVSLAM library to the Unity engine, and the map generation and performance were evaluated on desktop PCs and mobile devices. The mobile SLAM system in this paper is an open source project, so it is expected to help develop AR contents based on SLAM in a mobile environment.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.5
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• pp.434-441
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• 2004

In this paper, an exoskeleton-type motion capturing system is designed and implemented. The device is designed to have 12 degree-of-freedom entirely to represent human arm motions. Forward and inverse kinematics of the device are analyzed to make sure of its singular positions. With the designed model parameters, simulation studies are conducted to verify that the designed motion capturing system is effective to represent human motions within the workspace. As a counterpart of the exoskeleton system, a mobile robot is built to follow human motion restrictively. Experimental studies of teleoperation from the exoskeleton device to control the mobile robot are carried out to show feasible application of wireless man-machine interface.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.5-8
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• 2010

Opened a court in February 10, 2006, a rule of safety management of the diagnosis radiation system was promulgated for safety of the radiation worker, patients and patients' family members. The purpose of this rule is to minimize the risk of being exposed to radiation during the process of handling X-ray. For this reason, we manufactured shielding device of mobile X-ray unit collimator for diminution of skin dose. Shielding device is made to a thickness of Pb 0.375mm. For portable chest radiography, we measured skin dose 50cm from center ray to 200cm at intervals of 20cm by Unfors Xi detector. As a result, a rule of safety management of the diagnosis radiation system has been strengthened. But there are exceptions, such as ER, OR, ICU to this rule. So shielding device could contribute to protect unnecessary radiation exposure and improve nation's health.

• Korean Management Science Review
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• v.28 no.1
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• pp.25-42
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• 2011

The mobile industry is the key foundation of digital convergence, and its constant growth is expected. Among mobile industries, new products leading the development of devices are the Emerging Device. This study is conducted to find out factors making differentiated by comparing the structural equation model(SEM) of the Tablet PC and the e-Book Reader. The main findings are as follows. First, the application of TAM to the Emerging Device shows that fitness of the model is generally high but the effect of Perceived Ease of Use has not been verified or found insignificant. Second, the acceptance model of the Tablet PC and the e-Book Reader has found that playfulness stimulates acceptance intentions. Third, the cost level of the Emerging Device acceptance model is not a factor stimulating consumers' acceptance intentions. Fourth, product attributes of the Tablet PC and the e-Book Reader to differentiate themselves from the other device are Functionality and Playfulness respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.320-323
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• 2008

Due to the improvement of mobile device capabilities, a demand for various contents service is increasing. But the differences from heterogeneous mobile devices force to develop contents which is dependent on a mobile. To solve this problem, adaptation course that reorganize contents by the device capability is needed. In this course, device description is described using device description language but there are some problems that is absence of device description repository and the way to get device description data. In this paper, I suggest device description acquisition module and define the interfaces to access device description repository that I designed and implemented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.2091-2096
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• 2008

Due to the improvement of mobile device capabilities, a demand for various contents service is increasing. But the differences from heterogeneous mobile devices force to develop contents which is dependent on a mobile. To solve this problem, adaptation course that reorganize contents by the device capability is hooded. In this course, device description is described using device description language but there are some problems that is absence of device description repository and the way to get device description data. In this paper, I suggest device description acquisition module and define the interfaces to access device description repository that I designed and implemented.

• The Journal of Engineering Research
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• v.8 no.1
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• pp.97-106
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• 2006

Chord system, structured P2P system based on distributed hashed table, didn't consider the mobility of mobile device. Mobility of mobile node may cause performance falloff of both mobile node and P2P network. Not only Chord system but also the greater part of P2P system didn't consider the mobility of mobile node. Recently it is researched on mobility in P2P system. In this paper, it proposed the method of the supporting mobility in chord system. Mobile node joins to the P2P network through the stationary node meaning the parents node. Mobile node require or offer the service for the parents node.

• Journal of Information Technology Services
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• v.17 no.2
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• pp.17-33
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• 2018

The purpose of this study is to verify the moderating effect of mobile divide on the relationship between individual characteristics and the use outcomes of smart device. Data was collected through a survey for periods from May 12, 2017, to May 17, 2017. As a result of multiple regression analysis based on collected data, self-efficacy, information seeking desire and culture capital have a positive effect on the use outcomes of smart device. To examine the moderating effect of mobile divide, we conducted a hierarchical regression analysis by calculating the interaction variables of the independent variable and the mobile literacy. As a result of the analysis, it was found that mobile literacy has negative moderating effect between self-efficacy and the use outcomes of smart device. The results of this study can be interpreted as the higher the self-efficacy and information desire for ICT technology users are. In addition, it can be interpreted that the smart device is convenient in the cultural activities of individuals, and therefore, it is highly utilized. Next, among those who have excellent mobile use ability, those who have high confidence in ICT technology can be interpreted as having low utilization because they recognize that the benefits provided by smart devices are familiar and natural. The results of this study confirm that the digital divide problem in the smart environment is influenced by individual characteristics as well as demographic variables. Therefore, we expect the government to set appropriate policies considering the characteristics of individuals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.986-992
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• 2012

As the utilization of smart mobile devices such as smartphones increases, the desire to utilize such devices to control and monitor combat situations also arises. As smart mobile devices with various ICT get integrated with various weaponry system, a new phase of future warfare can be introduced. Moreover, smartphone-based real-time information technology for joint battle command system will be converged with surveillance control to become a leading example of convergence of cyber defense and information technology. Furthermore, mobile device security technology ideal for mobile wireless network environments can be applied to military robots. The following paper will give an overview of smart mobile device usage used for military purposes in battle command system, various security threats and the mobile device security technology to correspond to such security threats.