• Title/Summary/Keyword: Seamless transfer

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The two-tired Proxy system for seamless multimedia service in mobile computing environment (이동 컴퓨팅환경에서 원활한 멀티미디어 서비스를 위한 2-계 층 프록시 시스템)

  • 김정락;서대화
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04d
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    • pp.181-183
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    • 2003
  • 이동 컴퓨팅 환경에서 미디어 서비스를 할 경우 일반 웹 서비스와는 달리 설러 가지 문제들이 발생한다 예를 들면 무선망의 특성상 네트워크 대역폭이 낮고, 네트워크 단절이 발생한다. 본 논문에서는 무선망의 이런 특성에도 불구하고 이동 컴퓨팅 환경에서 실시간 멀티미디어 서비스를 무선 단말에 원활하게 제공하는 방법으로 two-tiered proxy system을 제안한다. 그리고, 효율적인 캐시 관리 메커니즘과 효과적인 handoff를 지원하기 위한 proxy transfer protocol를 또한 제안한다.

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A Study on the Characteristics of Evaporative Heat Transfer for Carbon Dioxide in a Horizontal Tube (수평원관 내 이산화탄소의 증발열전달 특성 연구)

  • Cho, E.S.;Yoon, S.H.;Kim, M.S.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.104-107
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    • 2000
  • Evaporative heat transfer characteristics of carbon dioxide has been investigated. Experiment has been carried out for seamless stainless steel tube with outer diameter of 9.55 mm and inner diameter of 7.75 mm. Direct heating method is used for supplying heat to the refrigerant was uniformly heated by electric current which was applied to the tube wall. The saturation temperature of refrigerant is calculated from the measured saturation pressure by using an equation of state. Inner wall temperature was calculated from measured outer wall temperature, accounting for heat generation in the tube and heat conduction through the tube wall. Mass Quality of refrigerant was calculated by considering energy balance in the preheater and the test section. Heat fluxes were set at 12, 16, 20, 23, and $27kW/m^2$, mass fluxes were controlled at 212, 318, 424, and $530 kg/m^2s$, and saturation temperature of refrigerant were adjusted at 0, 3.4, 6.7 and $10.5^{\circ}C$. From this study, heat transfer coefficients of carbon dioxide have been provided with respect to quality for several mass fluxes, heat fluxes. Finally, the experimental results in this study are compared with the correaltion by Gungor and Winterton(1987).

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연결완전성 제고와 프라이버시 보호를 위한 유비쿼터스 지불 프로세스의 설계

  • Lee, Gyeong-Jeon;Jeong, Mu-Jeong
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2005.11a
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    • pp.226-233
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    • 2005
  • Ubiquitous computing is a study area explained in a myriad of contexts and technological terms. So when you try to define it with simple words, it gets even more confusing. Payment. however, refers in nature to an act of money transfer from one entity to another, and it is obvious that a payment method will be valued as long as the transaction can be completed with safety no matter what technology was used. In the end, the key to U-payment is convenience and security in the transfer of financial information. The purpose of this paper is to find a desirable U-payment scheme by looking at the characteristics of seamlessness under the ubiquitous environments, Strong Personal Device, and peer-based if information transactions. We also propose U-SDT Protocol integrating critical technologies such as Radio Frequency Identification (RFID), Bluetooth, Personal Payment Device, Account Managing Application and Transaction ID as a way to make transactions between users seamless and secure better privacy protection.

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Current and Voltage Control Mode Transfer Method for PCS (PCS의 전류제어모드와 전압제어모드의 전환기법)

  • Jung, J.H.;Park, H.Y.;Nho, E.C.;Kim, I.D.;Kim, H.G.;Chun, T.W.
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.265-266
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    • 2010
  • This paper describes a new method for the seamless operation mode transfer of a PCS. The proposed method provides reduced STS turn off time and smooth mode change between current and voltage control of the PCS in case of line fault. The usefulness of the method is verified through simulations.

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Global Mobility Management Scheme for Seamless Mobile Multicasting Service Support in PMIPv6 Networks

  • Song, Myungseok;Cho, Jun-Dong;Jeong, Jong-Pil
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.2
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    • pp.637-658
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    • 2015
  • The development of multimedia applications has followed the development of high-speed networks. By improving the performance of mobile devices, it is possible to provide high-transfer-speed broadband and seamless mobile multicasting services between indoor and outdoor environments. Multicasting services support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handoff latency. In order to solve these problems, many protocols and handoff methods have been studied. In this paper, we propose inter local mobility anchor (inter-LMA) optimized handoff model for mobile multicasting services in proxy mobility IPv6 based (PMIPv6-based) networks. The proposed model removes the tunnel convergence issue and reduces the router processing costs. Further, it the proposed model allows for the execution of fast handoff operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handoff latency in comparison with existing schemes and ensures fast handoff when moving the inter-LMA domain.

Mobility Support Architecture in Locator-ID Separation based Future Internet using Proxy Mobile IPv6

  • Seok, Seung-Joon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.2
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    • pp.209-217
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    • 2014
  • Of several approaches for future Internet, separating two properties of IP address into locator and identifier, is being considered as a highly likely solution. IETF's LISP (Locator ID Separation Protocol) is proposed for this architecture. In particular, the LISP model easily allows for device mobility through simple update of information at MS (Mapping Server) without a separate protocol. In recent years, some of the models supporting device mobility using such LISP attributes have emerged; however, most of them have the limitation for seamless mobility support due to the frequent MS information updates and the time required for the updates. In this paper, PMIPv6 (Proxy Mobile IPv6) model is applied for mobility support in LISP model. PMIPv6 is a method that can support mobility based on network without the help of device; thus, this we define anew the behavior of functional modules (LMA, MAG and MS) to fit this model to the LISP environment and present specifically procedures of device registration, data transfer, route optimization and handover. In addition, our approach improves the communication performance using three tunnels identified with locators between mobile node and corresponding node and using a route optimized tunnel between MN's MAG and CN's MAG. Finally, it allows for seamless mobility by designing a sophisticated handover procedure.

Design of Short Messaging Service based Public Address System for Industrial Architectures over Wireless Networks

  • Caytiles, Ronnie D.;Park, Byungjoo
    • Journal of Advanced Information Technology and Convergence
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    • v.9 no.2
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    • pp.15-27
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    • 2019
  • This paper deals with a web-based public address system for conveying information for different institutions. An architecture for a Short Messaging Service (SMS) based public address (PA) system that can be programmed by an authorized mobile phone or device is proposed. This PA system will facilitate information transfer from heads of offices, managers, directors, and deans of the institutions to its constituents or unit area as well as enable postings of information with proper authentication and validation remotely. The system supports high priority messaging, allowing the conveyance of critical and time sensitive information. The mobility management support for the PA system will be based on the Hierarchical Mobile Internet Protocol version 6 (HMIPv6), hence, allowing for a seamless connectivity to the system. The major advantage of this proposed PA system as compared with the traditional electronic displays and bulletin boards is seamless mobility wherein the display devices can be programmed remotely by heads of the institutions and business organization. It also allows faster communication and immediate actions concerning the different institutions, organizations, and businesses, thus, ensuring high productivity.

A Seamless Adaptive Streaming Scheme for Interactive Multimedia Service in HTTP Adaptive Streaming (HTTP 적응적 스트리밍에서 끊김 없는 대화형 멀티미디어 스트리밍을 위한 전송 기법)

  • Kim, Heekwang;Chung, Kwangsue
    • Journal of KIISE
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    • v.44 no.5
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    • pp.545-552
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    • 2017
  • Because of the explosive growth of mobile devices and development of network technologies, HTTP (Hypertext Transfer Protocol) adaptive streaming has become a new trend in video delivery to provide efficient multimedia streaming services. As interest in personalized broadcasting grows, the study of interactive multimedia has been actively pursued. The interactive multimedia service is a method of playing media according to a scenario selected by the user. Providing the interactive multimedia service with the existing HTTP adaptive streaming causes switching delay and buffer underflow according to the point in time when the user selects the scenario while the client streams the interactive multimedia and therefore decreases the user QoE (Quality of Experience). In this paper, we propose an adaptive streaming scheme for interactive multimedia service in HTTP adaptive streaming to provide seamless playback. We design the architecture and prefetching scheme for interactive multimedia streaming.

Realtime Media Streaming Technique Based on Adaptive Weight in Hybrid CDN/P2P Architecture

  • Lee, Jun Pyo
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.3
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    • pp.1-7
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    • 2021
  • In this paper, optimized media data retrieval and transmission based on the Hybrid CDN/P2P architecture and selective storage through user's prediction of requestability enable seamless data transfer to users and reduction of unnecessary traffic. We also propose a new media management method to minimize the possibility of transmission delay and packet loss so that media can be utilized in real time. To this end, we construct each media into logical segments, continuously compute weights for each segment, and determine whether to store segment data based on the calculated weights. We also designate scattered computing nodes on the network as local groups by distance and ensure that storage space is efficiently shared and utilized within those groups. Experiments conducted to verify the efficiency of the proposed technique have shown that the proposed method yields a relatively good performance evaluation compared to the existing methods, which can enable both initial latency reduction and seamless transmission.

Control of Grid Connected Type PCS to Minimize Voltage Disturbance at Line Fault (계통 사고 발생시 전압 변동을 최소화 하기위한 계통연계형 PCS의 제어 기법)

  • Jung, Jae-Hun;Kwon, Chang-Keun;Nho, Eui-Cheol;Kim, In-Dong;Kim, Heung-Geun;Chun, Tae-Won
    • Proceedings of the KIPE Conference
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    • 2011.11a
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    • pp.257-258
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    • 2011
  • This paper describes a new method for the seamless operation mode transfer of a PCS with minimized voltage disturbance. The proposed method provides reduced STS turn off time after line fault and smooth mode change between current and voltage control of the PCS. The usefulness of the method is verified through simulations with the consideration of the time delay in detecting a line fault and SCR turn-off time.

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