• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.42-46
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• 2012

This paper analyses technical and economical conditions which activate the use of mobile communication spectrum not to limit the growth of mobile broadband service because of mobile big data traffic and proposes the method which activate the use of mobile communication spectrum. To activate new mobile communication spectrum the expenditure and income of investment should be balanced. The activation of new mobile communication spectrum to process mobile big data traffic depends on technical and economical conditions, internal and external factors of service provider. The investment expenditure is relate to CAPEX, OPEX which is internal factors of service provider and to spectrum price which is external factor of service. The investment income is relate to tariff system which is internal factors of service provider and to spectrum neutrality which is external factor of service provider. The activation of new mobile communication spectrum can be implemented when the investment expenditure and investment income meet the balance including the spectrum price in the investment expenditure and the tariff system which is able to extend network and the income based on traffic increase by external contents in the investment income.

• Journal of Information Technology Applications and Management
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• v.24 no.2
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• pp.81-96
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• 2017

Forecasting long-term mobile service demand is inevitable to establish an effective frequency management policy despite the lack of reliability of forecast results. The statistical forecasting method has limitations in analyzing how the forecasting result changes when the scenario for various drivers such as consumer usage pattern or market structure for mobile communication service is changed. In this study, we propose a dynamic model of the mobile communication service market using system dynamics technique and forecast the future demand for long-term mobile communication subscriber based on the dynamic model, and also experiment on the change pattern of subscriber demand under various scenarios.

• Journal of Korea Multimedia Society
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• v.19 no.4
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• pp.780-788
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• 2016

Development of information and communication technologies has given a lot of changes in the business processing methods including the school and class managements. However, many business processing systems are still based on desktop computer. In particular, most of the class management system only supports desktop computers; hence school teachers have difficulty in using their class managements systems on mobile environment. In this paper, we proposed and developed a mobile classroom management system for teachers, which will easily handle information such as personal records of students, student counseling records, student life record and so on. The implementation of the application of mobile-based class management can be managed by many school elements including student register information, student evaluation records and transcripts, counseling report, and so on.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.179-185
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• 2001

Mobile agents have the unique ability to transport themselves from one system in a network to another. The ability to travel allows mobile agents to move to a system that contains services with which they want to interact and then to take advantage of being in the same host or network as the service. But most of conventional mobile agent systems require that the users or the programmer should give the mobile agent its detail behavioral script for accomplishing the given task. And during its runtime, such mobile agents just behave according to the fixed script given by its user. Therefore it is impossible that conventional mobile agents autonomously build their own plants and execute them in considering their ultimate goals and the dynamic world states. One way to overcome such limitations of conventional mobile agent systems is to develop an intelligent mobile agent system embedding a reactive planner. In this paper, we design both a model of agent mobility and a model of inter-agent communication based upon the representative reactive planning agent architecture called JAM. An then we develop an intelligent mobile agent system with reactive planning capability, IMAS, by implementing additional basic actions for agent moves and inter-agent communication within JAM according to the predefined models. Unlike conventional mobile agents. IMAS agents can be able to adapt their behaviors to the dynamic changes of their environments as well as build their own plans autonomously. Thus IMAS agents can show higher flexibility and robustness than the conventional ones.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.3
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• pp.270-274
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• 2002

This paper presents a teleoperation system that combines computer network and an autonomous mobile robot. We control remotely an autonomous mobile robot with vision over the Internet to guide it under unknown environments in the real time. The main feature of this system is that local operators need a web browser and a computer connected to the communication network and so they can command the robot in a remote location through the home page. The hardware architecture of this system consists of an autonomous mobile robot, workstation, and local computers. The software architecture of this system includes the client part for the user interface and robot control as well as the server part for communication between users and robot. The server and client systems are developed using Java language which is suitable to internet application and supports multi-platform. Furthermore. this system offers an image compression method using JPEG concept which reduces large time delay that occurs in network during image transmission.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.4
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• pp.212-220
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• 2014

The current cellular communications are optimized for low mobility users, meaning that their performance is degraded at high speed. Therefore, passengers in a high-speed train experience very poor radio link quality due to the significantly large number of simultaneous handovers. In addition, wireless data traffic is expanding exponentially in trains, subways and buses due to the widespread use of smartphones and mobile devices. To solve the inherent problem of cellular communication networks and meet the growing traffic demand, this paper proposes the mobile hotspot network of a millimeter-wave communication system as a mobile wireless backhaul. This paper describes the physical layer design of uplink and downlink in the proposed system, and the performances of uplink and downlink are evaluated under Rician fading channel conditions. The implemented baseband prototype of the proposed millimeter-wave communication modem is presented. This system can provide a Gbps data rate service in high-speed trains carrying hundreds of wireless Internet users.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.60-67
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• 2002

In this paper, the dual band VCO of mobile communication terminal using oscillation part switching circuit is proposed. In order to model the VCO accurately, the resonator is converted the equivalent circuit which is analyzed to use numerical method and designed optimal the dual band VCO operating GSM and DCS band. In order to demonstrate the objective theory of the proposed VCO, the dual band VCO is designed and experimented. The results of experiment, it is conformed that the VCO can be used mobile communication hand phone and components of three generation mobile communication systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.11
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• pp.1257-1264
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• 2015

With the successful deployment of 4G mobile communications such as Long-Term Evolution(: LTE), global leading countries including Europe, China, and Japan have been made an effort to take the lead in technology, standardization, and market with targeting the commercialization of 5G mobile communication in 2020. In order to judge the future evolution of a 5G mobile communication system, this paper discusses the comprehensive trends and the requirements set by each countries for the 5G mobile communication systems.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2007.02a
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• pp.35-39
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• 2007

We applied digital image processing about BitMap file structure in this research and studied about digital communication system. digital record saving devices can express 'High' and 'Low' as all data. Only, digital technique that two expression methods is used into several expenditures. People and communication that are far away by development of digital technology, became smooth. We wished to make communication system taking advantage of digi-tech. This system was made for communication with disabled and normal person specially. To communication method that we are studied such BitMap file handling image communication system. The goal of this contribution is to present the overview of basic algorithms for image processing using BitMap.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.89-95
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• 2008

The introduction of wireless information technology gives rise to new mobile services in all kinds of areas of out daily life. Mobile healthcare system is a production of composite ICT (Information and Communication Technology) which focused on signal sensing, processing, and communication in wireless environment. The mobile and wireless revolution promises not only expanded access to patient health information, but also improved patient care. In this paper, we describe a surrogate host based mobile healthcare information system which utilized Grid computing for real-time ECG signal processing. The surrogate host provides seamless interface between mobile device and Medical Grid portal. The security extension of GSI (Grid Security Infrastructure) allows mobile users to access Grid portal in a secure and convenient manner. The presented system architecture can be used as a secure enterprise mobile healthcare system for hospital physicians.