• ETRI Journal
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• v.32 no.5
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• pp.823-826
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• 2010

This letter proposes a handover ranging power adjustment scheme to improve handover performance. Incorrect ranging power can degrade handover performance due to the increased handover latency; therefore, the proposed scheme exploits the uplink channel information to adjust the uplink handover ranging power. Simulation results demonstrate that the proposed scheme reduces call outage probability by 33% compared to that of the conventional scheme. It also improves the number of users who satisfy the system requirements for handover interruption time.

• Educational Technology International
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• v.11 no.2
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• pp.25-41
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• 2010

Challenges brought by applications of advanced technologies in education call for new approaches that can best ensure the provision of quality e-learning experiences. This paper presents an ecological approach as one of such approaches to quality assurance in e-learning that can monitor, assess and improve the effectiveness and the links between the various elements of e-learning. The ecological model for QA in e-learning emphasizes interrelation transactions between elements (e.g. providers, learners, cultures and policies) and systemic integration of those elements, and stresses that all these elements within a QA system play an equal role in maintaining balance of the whole. The model focuses attention both on individual and societal/cultural environmental factors as cornerstones for QA efforts in e-learning. It addresses the importance of QA efforts directed at changing QA transactions from provider-centered to 'all stakeholder-oriented', from one-size-fits-all model to 'globally oriented, locally adaptive model' and from control framework to 'culture creation framework'.

• Journal of information and communication convergence engineering
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• v.9 no.1
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• pp.1-5
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• 2011

Everyday, technology is evolved in many different disciplines. Computer and smart devices revolution take part of the evolved technology that continuously promising new features. Moreover, social networks services recently become widely popular, which most people in the world become a social-network-fond. In addition to the revolution of the evolved technology and social networks services, ubiquitousness is taking significant part in our daily lives. Although, there are many e-learning systems already existed, which use Internet technology along with a Web technology to provide education in various ways, in despite of that, there is no such existing system exploits the usefulness of smart devices along with the legacy of the online social networks besides the power of the ubiquitous computing technology. Therefore, we propose a smart device application, which fills the gap that has been missing in the recent contemporary era. It is an application that runs on smart devices particularly Smartphone devices; we call our system “Smart Device based Social E-learning System(SDES)”. We have preliminary implemented our system on Android OS. In this paper, we intentionally propose the system in order to ease the way people learn, to provide interactive accessibility in our system, and to utilize the advanced technology more wisely.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.257-260
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• 1998

In this paper, we describe an IMT-2000 system architecture, a protocol stack, and basic MAP scenarios(e.g., registration, call delivery) based on the IS-41 and IS-41 and IS-751. This paper focuses on the MAP scenarios to support the IMSI which is defined for the global roaming between GSM and IS-41 Networks through the Family of System approach. This paper also deals with the design of the MAP protocol stack transported over the ATM networks and introduces the software structure of MAP in IMT-2000 MSC.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.2
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• pp.135-144
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• 2003

Traffic performance in a microcellular system is much more affected by cell dwell time and channel holding time in each cell. Cell dwell time of a call is characterized by its mobility pattern, i.e., stochastic changes of moving speed and direction. Cell dwell time provides important information for other analyses on traffic performance such as channel holding time, handover rate, and the average number of handovers per call. In the next generation mobile communication system, the cell size is expected to be much smaller than that of current one to accommodate the increase of user demand and to achieve high bandwidth utilization. As the cell size gets small, traffic performance is much more affected by variable mobility of users, especially by that of pedestrians. In previous work, analytical models are based on simple probability models. They provide sufficient accuracy in a simple second-generation cellular system. However, the role of them is becoming invalid in a picocellular environment where there are rapid change of network traffic conditions and highly random mobility of pedestrians. Unlike in previous work, we propose an improved probability model evolved from so-called Random walk model in order to mathematically formulate variable mobility of pedestrians and analyze the traffic performance. With our model, we can figure out variable characteristics of pedestrian mobility with stochastic correlation. The above-mentioned traffic performance measures are analyzed using our model.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1664-1675
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• 2001

In this paper, the development of a new group controller for high-speed elevators is described utilizing the approach of adaptive dual fuzzy logic. Some goals of the control are to minimize the waiting time, mean-waiting time and long-waiting time in a building. When a new hall call is generated, all adaptive dual fuzzy controller evaluates the traffic patterns and changes the membership function of a fuzzy rule base appropriately. A control algorithm is essential to control the cooperation of multiple elevators in a group and the most critical control function in the group controller is an effective and proper hall call assignment of the elevators. The group elevator system utilizing adaptive dual fuzzy control clearly performs more effectively than previous group controllers.

• Electronics and Telecommunications Trends
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• v.38 no.3
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• pp.57-65
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• 2023

Emergency numbers, such as 112 and 119, are used in many countries to connect people in need with emergency services such as police, fire, and medical assistance. We describe development directions of intelligent response technology for emergency calls. The development of this technology refers to enhancing the efficiency and effectiveness of response systems by using advanced methods such as artificial intelligence, machine learning, and big data analytics. We focus on a system that assists the receptionist of an emergency call. In the future, the recognition rate and decision-making accuracy of intelligent response technologies should be improved considering characteristics of public safety and emergency domain data. Although the current technology remains at the level of assisting a receptionist, a fully autonomous response technology is expected to emerge in the future.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.939-945
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• 2011

We show a new scheme and implementation of maritime data communication systems for GMDSS ship which performs e-Navigation and removes the functional limitation of those systems through comparing to service fee, call processing reliability, and bit rates of all of those systems within communication range at sea. We confirmed available each frequency band communication and application services at sea by experimental result with proposed new system, MF/HF band being useful to a short text message service, VHF band to 9600bps email service, Fleet Broadband Maritime Satellite system to one or more Mbps multimedia service each.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.209-215
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• 2005

The first wave of e-government projects dating from the early 1990s primarily focused on setting up national and global information infrastructure, internal organizational reform, digital procurement, and the digital delivery of government services to citizens. Most of these e-Government projects have concentrated on the development of systems focusing on strengthening the formal agencies and institutions of government. To date, despite many theoretical and empirical studies on citizen involvement in terms of governance, relatively little attention has been paid to developing e-government systems with a focus on improving citizen involvement, which we call e-governance systems. This paper discusses the characteristics of the e-governance systems, identifies core requirements for its development, and suggests an e-governance system architecture that can satisfy the core requirements.

• The Journal of Korea Robotics Society
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• v.5 no.2
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• pp.93-101
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• 2010

This paper presents the system design and implementation of 'Mon-e', the KT's edutainment robot for young children. We paid our special attention to the computer- illiterate young children, and the provision of the physical and friendly human interface of robots. Specifically, the paper focuses on the video telephony and home monitoring service using the Mon-e robot. RFID cards -based calling makes it possible for the computer-illiterate children to make a phone call to their parents. The SIP and DTMF based remote control of the robot enables the search and track of the children. This experimental development shows the potentialities and values of the convergence service of telecommunication and robotics.