• Title/Summary/Keyword: MOBILE

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TCP Performance Enhancement Using Mobile Agents In Mobile IP Evironment (Mobile IP 환경에서 Mobile Agents를 이용한 TCP 성능 개선)

  • 우시남;송상철;김연중;이지영;안순신
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.10c
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    • pp.411-413
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    • 2000
  • Internet망에서 mobile comupting에 대한 관심은 커져하고 있다. Mobile IP는 노드의 이동성을 지원하는 방법 중의 하나이다. 그렇지만 handoff 하는 과정에서 발생하는 패킷 손실 때문에 신뢰성의 문제가 발생한다. 게다가 mobile node(MN)와 foreign agent(FA)사이가 무선 링크인 경우 패킷 손실은 더욱 심각하다. TCP/IP는 고정된 네트워크에서 고안되어진 것이기 때문에 기존의 TCP/Mobile IP가 무선에는 부적합하다. 그러므로 본 논문에서 TCP/Mobile IP와 application사이에 midddleware로써 mobile agen(MA)를 사용하는 것을 제안했다. TCP mobile agent(TCP MA)을 여러 application에서 TCP 성능의 향상을 위해 제안했다. TCP MA는 FA와 MN를 위해 행동하고, 그리고 MN의 현재 위치에 상관없이 MN에 결과를 보낸다. 이러한 TCP MA는 handoff 동안에 발생하는 패킷 손실을 감소시킨다.

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Asymmetric Regulation of Mobile Access Charges and Consumer Welfare with Price Regulation

  • Lee, Jong-Yong;Lee, Duk-Hee;Jung, Choong-Young
    • ETRI Journal
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    • v.32 no.3
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    • pp.447-456
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    • 2010
  • Asymmetric regulation as applied to mobile termination rates refers to regulatory arrangements in which different mobile operators charge different termination rates, even though the services provided are essentially identical. The asymmetric regulation has been frequently used as a regulatory tool to support new entrants to a mobile market. This paper examines the economic effects of asymmetric regulation of mobile termination rates using a theoretical model and its simulation. The result shows that when there is no noticeable difference in brand loyalty between mobile operators with the high degree of substitutability between services provided by mobile operators, and the costs of new entrants are low, a reduction in the asymmetry of mobile access prices results in an enhancement of consumer welfare. These findings provide positive evidence for the argument that in certain situations asymmetric pricing of mobile access services may be counterproductive for consumer welfare.

Applying the Cloud Computing Technology for Mobile BIM based Project Management Information System (모바일 BIM 공사관리시스템을 위한 클라우드 컴퓨팅 기술 활용 방안)

  • Lee, Jong-Ho;Eom, Shin-Jo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05a
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    • pp.145-148
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    • 2011
  • As a futuristic construction model, building information model(BIM) based project management system(PMIS) and mobile PMIS have been showing visible sign. However, researches on the 3D BIM based PMIS using mobile device are hard to find, result from limitation of mobile device application(slow speed at huge BIM file, display size, and etc.) and undefined standard of business processes. Therefore, this research aims at studying feasibility of mobile BIM PMIS based on cloud computing as a business model. In case of applying mobile BIM PMIS, 3D drawings and integrated building informations are possible on mobile devices in real time. it would support increasing the productivity of project participants as designer, engineer, supervisor, and etc. Globally, BIM based PMIS and Mobile BIM system, cloud computing based mobile BIM simulator are in the concept or experimental phase, therefore it is possible to secure global leading technology of IT and construction merger in the mobile BIM.

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Implementation of Mobile Cliented-Server System for Real-Time Processing (실시간 처리 기반의 모바일 클라이언트-서버 시스템 구현)

  • Joo, Hae-Jong;Hong, Bong-Wha
    • The Journal of Information Technology
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    • v.9 no.4
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    • pp.35-47
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    • 2006
  • Many researches are going on with regard to issues and problems related to mobile database systems, which are caused by the weak connectivity of wireless networks, the mobility and the portability of mobile clients. Mobile computing satisfies user's demands for convenience and performance to use information at any time and in any place, but it has many problems to be solved in the aspect of data management. The purpose of our study is to Implement Real-Time Mobile Query Processing System(MQPS) to solve problems related to database hoarding, the maintenance of shared dataconsistency and the optimization of logging, which are caused by the weak connectivity and disconnection of wireless networks inherent in mobile database systems under mobile client server environments. In addition, we proved the superiority of the proposed MQPS by comparing its performance to the C I S(Client-Intercept-Srever) model.

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Portability Evaluation Technique of Application for Heterogeneous Mobile Platform (이기종 모바일 플랫폼에 애플리케이션 이식성 평가 기법)

  • Park, Hae-Yoon;Yoo, Hae-Young
    • The KIPS Transactions:PartD
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    • v.18D no.2
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    • pp.123-132
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    • 2011
  • However a mobile application has limited compatibility to other platforms and device. So a mobile application should be rebuilt as particular restrictions of platforms or mobile phones when the mobile application is reused for other platforms. However a mobile application has limited compatibility to other platforms and device. So a mobile application should be rebuilt as particular restrictions of platforms or mobile phones when the mobile application is reused for other platforms. This paper ascertains problems when a mobile application is transplanted for reusing into other platforms, and suggests to evaluation systems of portability's quality that we can check the portability convenience of the existing mobile application. As we confirm its grade that shows convenience of suggested portability, we are able to check problems issued when a mobile application implants to other platforms. Then it is expected that we can check capability of rebuilding and endeavor rate. Also if the method will be considered at the first step of designing a mobile application, it will be the best way to develop the better mobile application that we can easily implant many other mobile platforms.

Localization of a High-speed Mobile Robot Using Ultrasonic/RF Sensor and Global Features (RF/초음파센서와 이동특성에 기반한 고속 이동로봇의 위치추정기법)

  • Lee, Soo-Sung;Choi, Mun-Gyu;Park, Jae-Hyun;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.7
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    • pp.734-741
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    • 2009
  • A new localization algorithm is proposed for a fast moving mobile robot, which utilizes only one beacon and the global features of the differential-driving mobile robot. It takes a relatively long time to localize a mobile robot with active beacon sensors since the distance to the beacon is measured by the traveling time of the ultrasonic signal. When the mobile robot is moving slowly the measurement time does not yield a high error. At a higher mobile robot speed, however, the localization error becomes too large to locate the mobile robot. Therefore, in high-speed mobile robot operations, instead of using two or more active beacons for localization, only one active beacon and the global features of the mobile robot are used to localize the mobile robot in this research. The two global features are the radius and center of the rotational motion for the differential-driving mobile robot which generally describe motion of the mobile robot and are used for the trace prediction of the mobile robot. In high speed operations the localizer finds an intersection point of this predicted trace and a circle which is centered at the beacon and has the radius of the distance between the mobile robot and the beacon. This new approach resolves the large localization error caused by the high speed of the mobile robot. The performance of the new localization algorithm has been verified through the experiments with a high-speed mobile robot.

A Scalable and Practical Authentication Protocol in Mobile IP (Mobile IP에서 확장성과 실용성 있는 인증 프로토콜 제안 및 분석)

  • Lee, Yong;Lee, Goo-Yeon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.11
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    • pp.35-44
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    • 2005
  • In Mobile IP protocol, because a mobile node still uses its home IP address even though it moves to foreign network from home network, authentication among mobile node, foreign network and home network is critical issue. Many researches about this issue have been based on shared secret, for example mobile node and home agent authenticate each other with pre-shared symmetry key. And they missed several security issues such as replay attack. Although public key scheme could be applied to this issue easily, since the public key cryptography is computationally complicated, it still has the problem that it is not practical to realistic environment. In this paper, we describe several security issues in Mobile IP protocol. And we propose new Mobile IP authentication protocol that is applicable to realistic environment using public key algorithm based on certificate. It has scalability for mobile nodes and is applicable to the original Mobile IP protocol without any change. Finally we prove security of the proposed protocol and that it might not affect performance of the original Mobile IP protocol.

Design and Implementation of a Mobile Middleware System for Mobile Business (모바일 비즈니스를 위한 모바일 미들웨어 시스템 설계 및 구현)

  • Lee, Il-Joo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.2
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    • pp.102-113
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    • 2014
  • Present communication and network environment have been moving rapidly toward wireless and mobile base from existing wired internet base. This change of trend influences greatly on business methods accordingly. Therefore many enterprises are trying hard to adopt mobile business in order to gain competitive edge of their products and they are in need of more effective and stable mobile solutions. However, the method of establishing optimal mobile computing environment and how to handle existing business process and use vast amount of database are still needed. Therefore this paper tries to realize a mobile middleware system as a mobile business establishment supporting tool that could link various computational resource on wired internet with wireless LAN, mobile phone network, and mobile devices. To accomplish that specific goal, this paper provides a powerful tool of mobile and wireless application data access that could expand the line of business already set up in general enterprises easily and rapidly into mobile environment. When this suggested solution is applied in the field of industry, it can economically change legacy business process into mobile environment without having to change existing logic and resources at all.

An Analysis and Web Accessibility Assessment of Mobile Service of University Libraries (대학도서관의 모바일 서비스 사례 분석 및 웹 접근성 평가에 관한 연구)

  • Gu, Jung-Eok
    • Journal of the Korean Society for Library and Information Science
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    • v.45 no.1
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    • pp.75-101
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    • 2011
  • With the popularization of smartphones, the mobile demand for information from libraries is increasing and mobile library service will soon be quired. This study analyzed the mobile library services for the mobile webs established by 4 university libraries in Korea and 56 belonging to ARL in the United States. It examined 42 mobile applications developed by universities and university libraries in Korea, and 18 mobile applications developed by the universities and university libraries belonging to ARL in the United States. Mobile accessibility was assessed by conducting mobileOK test for the mobile websites of the same libraries. The study shows that university libraries in Korea should establish mobile websites focusing on key contents which reflect the demand for mobile information of users, and secure mobile web accessibility which the users could conveniently use.

The Design of the Selection and Alignment Queries Using Mobile Program (J2ME) for Database Query Optimization

  • Min, Cheon-Hong;Kumar, Prasanna
    • 한국경영정보학회:학술대회논문집
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    • 2008.06a
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    • pp.620-627
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    • 2008
  • In this paper, recognizing the importance of the database query optimization design methods, we implemented mobile database with mobile program (J2ME) which is a useful database procedures. In doing so, we emphasize the logical query optimization which brings mobile database to performance improvement. The research implies that the suggested mobile program (J2ME) would contribute to the realization of the efficient mobile database as the related technology develops in the future.

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