• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.703-705
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• 2004

휴대 인터넷 서비스는 휴대용 무선 단말기를 사용하며 언제 어디서나 정지 및 중 저속 이동 상태에서 고속의 전송속도로 인터넷에 접속 기능을 제공하는 서비스를 말한다. 휴대 인터넷상에서 다양한 멀티미디어 서비스를 제공하기 위해서는 유선과 마찬가지로 멀티캐스트 기법과 노드가 이동 중에도 지속적으로 연결을 제공하는 기능이 요구된다. 본 논문에서는 휴대 인터넷 망에서 효율적인 멀티캐스트 서비스를 제공하기 위해 노드의 이동성을 지원하는 핸드오프 기법을 제안한다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.448-448
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• 2004

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.495-499
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• 2005

Recently, with the rise of wireless Internet, it is becoming popular to use PDA. Also, the more wireless Internet Infra increases, the more services and a variety of contents are needed. Actually, a number of services is being used for PDA. Accordingly, this paper designs and implements naming service based on wireless Internet which is portable and easy for information. We develope the algorithm, design and implement the service for naming service.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.84-89
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• 2015

About 30% of Mongolian population is populated in the capital of the nation. Too many hospitals are concentrated in size as compared to the capital. This creates a difficult environment to provide equal distribution of medical benefit. In order to resolve this issue of medical benefit inequality, a portable/travelling medical treatment system using 'M-LIMS' is proposed for real-life application. The system with M-LIMS to be designed will include functions such as composing, sharing charts among doctors, standardizing charts. M-LIMS will be designed considering Mongol's regional characteristics, and application plans will be proposed accordingly.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.169-173
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• 2009

We analyzed in this study on aesthetic areas of Mobile Edu-games Contents developers and users respectively in Mobile Platform. As a result, it indicates that through the aesthetics of Edu-games and the effectiveness of animation layout, women developers and users take more interest in storytelling and animation layout than men developers and users. We can estimate that Edu-games Contents in portable mobile platform is popular as it often contains easy learning materials and fun activities can enhance effective learning.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.6
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• pp.1147-1165
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• 2011

We present a simple and cost effective rate control scheme for streaming video over a wireless channel by using the information of mobile devices' buffer level. To prevent buffer fullness and emptiness at receivers, the server should be able to adjust sending rate according to receivers' buffer status. We propose methods to adjust sending rate based on the buffer level and discrete derivative of the buffer occupancy. To be compatible with existing network protocols, we provide methods to adjust sending rate by changing the inter-packet delay (IPD) at the server side. At every round-trip time, adjustments of sending rate are made in order to achieve responsiveness to sudden changes of buffer availabilities. A series of simulations and the prototype system showed that the proposed methods did not cause buffer overflows and it can maintain smoother rate control and react to bandwidth changes promptly.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.107-112
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• 2011

In this paper, we introduce the implementation of the security system using iris recognition. This system acquires images with infrared camera and extracts the 2D code from a infrared image which uses scale-space filtering and concavity. We examine the system by (i) extract 2D code and (ii) compare the code that stored on the server (iii) measure FAR and FRR using pattern matching. Experiment results show that the proposed method is very suitable.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.1
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• pp.41-46
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• 2008

With widespread use of the Internet and improvements in streaming media and compression technology, digital music, video, and image can be distributed instantaneously across the Internet to end-users. However, most conventional Digital Right Management are often not secure and fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. In this paper, we propose the copyright protection using encryption of DCT coefficients and motion vector in MPEG-4 video codec of mobile device. This paper presents a new Digital Rights Management that modifies the Motion Vector of Macroblock for mobile device. Experimental results indicate that the proposed DRM can not only achieve very low cost of the encryption but also enable separable authentication to individual mobile devices such as Portable Multimedia Player and Personal Digital Assistants. The performance of the proposed methods have low complexity and low increase of bit rate in overhead.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2453-2467
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• 2017

Wireless communication is a telecommunication technology, which enables wireless transmission between the portable devices to provide wireless access in all types of environments. In this research, the measurements and various empirical models are analysed and compared in order to find out a suitable propagation model to provide guidelines for cell planning of wireless communication systems. The measured data was taken in urban region with low vegetation and some trees at 900 MHz frequency band. Path loss models are useful planning tools, which permit the designers of cellular communication to obtain optimal levels for the base station deployment and meeting the expected service level requirements. Outcomes show that these empirical models tend to overestimate the propagation loss. As one of the key outputs, it was observed that the calculations of Weissberger model fit with the measured data in urban environment.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.189-191
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• 2014

This paper provides an overview of the E-learning service education on the last decade, In the early 2000's the emphasis of educational technology was on interactive multimedia- stand alone packages on computer hard disks or portable memory, which integrated a range of media forms in the lately. Customers handle finding the best sources of content.The system then uses social signals such as those coming from Facebook, Twitter, LinkedIn, delicious as well as clicks and views. The SNS and network infrastructure is sufficiently mature that the focus should shift to how to use the technology most appropriately to facilitate learning. As we study environmental conditions of the traditional internet and the mobile internet users in some ways. In this paper, analyze the nature of learning, role of educational and suggest alternative policy, innovation of e-learning service and effective e-learning environment in developing technology.