• Title/Summary/Keyword: Realtime

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Realtime/Non-realtime Multimedia Traffic Transmission in cdma 2000 (cdma2000에서 실시간/비실시간 멀티미디어 트래픽 전송)

  • 이종찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1340-1347
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    • 2000
  • The international mobile telecommunication-2000(IMT-2000) system can support not only the non-realtime multimedia traffic such as data such as data image but also the realtime multimedia traffic such as voice, video. In the paper we propose multicode allocation and handoff schemes for efficient transmission of realtime and non-realtime data in cdma2000. In those schemes the bandwidth of target cell is reserved based on moving direction of mobiles to support QoS of realtime multimedia data and the reserved bandwidths is used by the non-realtime mobiles of the target cell until the mobiles want to perform hadoff. Our framework is able to guarantee QoS continuity of realtime multimedia data and carries the maximum number of subscriber. System performance is evaluated and compared with conventional scheme considering transmission delay channel utilization and blocking probability by computer simulation.

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A Dynamic Channel Allocation Algorithm Based on Time Constraints in Cellular Mobile Networks

  • Lee Seong-Hoon
    • International Journal of Contents
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    • v.1 no.2
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    • pp.31-34
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    • 2005
  • The new realtime applications like multimedia and realtime services in a wireless network will be dramatically increased. However, many realtime services of mobile hosts in a cell cannot be continued because of insufficiency of useful channels. Conventional channel assignment approaches didn't properly consider the problem to serve realtime applications in a cell. This paper proposes a new realtime channel assignment algorithm based on time constraint analysis of channel requests. The proposed algorithm dynamically borrows available channels from neighboring cells. It also supports a smooth handoff which continuously serves realtime applications of the mobile hosts.

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Swarm Intelligence Based Data Dependant Routing Algorithm for Ad hoc Network (군집단 지능 알고리즘 기반의 정보 속성을 고려한 애드 혹 네트워크 라우팅)

  • Heo, Seon-Hoe;Chang, Hyeong-Soo
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.5
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    • pp.462-466
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    • 2008
  • In this paper, we propose a Data Dependant Swarm Intelligence Routing Algorithm(DSRA) based on "ant colony optimization" to improve routing performance in Mobile Ad hoc Network(MANET). DSRA generates a different routing path depending on data's characteristics: Realtime and Non-Realtime. DSRA achieves a reduced delay for Realtime data and an enhanced network lifetime from a decentralized path selection for Non-Realtime data. We demonstrate these results by an experimental study comparing with AODV, DSR and AntHocNet.

A Dynamic Channel Allocation Algorithm Based on Time Constraints in Cellular Mobile Networks

  • Lee, Seong-Hoon;Lee, Sang-Gu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.18-22
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    • 2003
  • The new realtime applications like multimedia and realtime services in a wireless network will be dramatically increased. However, many realtime services of mobile hosts in a cell cannot be continued because of insufficiency of useful channels. Conventional channel assignment approaches didn't properly consider the problem to serve realtime applications in a cell. This paper proposes a new realtime channel assignment algorithm based on time constraint analysis of channel requests. The proposed algorithm dynamically borrows available channels from neighboring cells. It also supports a smooth handoff which continuously serves realtime applications of the mobile hosts.

Residential Gateway Design under Realtime Linux Environment (실시간 Linux 환경에서 상주형 게이트웨이의 설계)

  • Shim, Jang-Sup;Kim, Jong-Kyum;Jung, Soon-Key
    • The KIPS Transactions:PartA
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    • v.11A no.1
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    • pp.21-28
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    • 2004
  • In this paper, we describe the study of residential gateway design and the implementation of its core functional features under the realtime linux environment. This Paper has also suggested the developing example of device driver that can execute the realtime linux with stability based on the recent research findings of which is related to the functions of existing realtime operating system for residential gateway, and explained methods that can further improve performance by analyzing the performance characteristics of the system. And as a result, it was able to suggest the possibility of effective implementation of residential gateway under the realtime linux environment in this paper.

Design of a robot controller using realtime-multiasking OS (실시간 다중처리 운영체제를 이용한 로보트 제어기의 설계)

  • 최성락;정광조
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.654-659
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    • 1993
  • In this paper, a robot controller that has a real time-multitasking OS (Operating System) is developed. It can do given jobs in realtime, so its effectiveness is increased. The controller has several CPU boards, and it is needed to communicate among these boards. For that reason, it is adopted VME bus system and VMEexec OS that can process multiprocess in realtime. Multiprocess includes robot language edit process, vision process, low level motion control process, and teach process in higher layer. And dynamics, kinematics, and inverse kinematics that require realtime calculation are included in lower layer.

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BLOCK LOSS DISTRIBUTION IN AN M/M/1 QUEUE WITH A CELL DISCARDING SCHEME

  • Lee, Gye-Min;Kwag, Min-Kon;Jeon, Jong-Woo;Kim, Chong-Kwon
    • Communications of the Korean Mathematical Society
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    • v.13 no.3
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    • pp.635-642
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    • 1998
  • When an integrated communication system is congested, we may reserve some spaces for non-realtime traffic by discarding a part of realtime traffic. That is sensible because realtime traffic is insensitive to a few losses. Several discarding schemes have been developed including Separate Queue (SQ). Under such schemes, the block loss distribution, i.e., the distribution of the number of losses within a given block which consists of successive data of a type, is important. We derive the block loss distribution of the SQ scheme and modifies the SQ scheme with a threshold.

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Robust Lane Detection Algorithm for Realtime Control of an Autonomous Car (실시간 무인 자동차 제어를 위한 강인한 차선 검출 알고리즘)

  • Han, Myoung-Hee;Lee, Keon-Hong;Jo, Sung-Ho
    • The Journal of Korea Robotics Society
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    • v.6 no.2
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    • pp.165-172
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    • 2011
  • This paper presents a robust lane detection algorithm based on RGB color and shape information during autonomous car control in realtime. For realtime control, our algorithm increases its processing speed by employing minimal elements. Our algorithm extracts yellow and white pixels by computing the average and standard deviation values calculated from specific regions, and constructs elements based on the extracted pixels. By clustering elements, our algorithm finds the yellow center and white stop lanes on the road. Our algorithm is insensitive to the environment change and its processing speed is realtime-executable. Experimental results demonstrate the feasibility of our algorithm.

Application of Realtime Monitoring of Oceanic Conditions in the Coastal Water for Environmental Management

  • Choi, Yang-Ho;Ro, Young-Jae
    • Journal of the korean society of oceanography
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    • v.39 no.2
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    • pp.148-154
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    • 2004
  • This study describes the realtime monitoring system for water quality conditions in coastal waters. Some issues on the data qualify control and quality analysis are examined along with examples of erroneous data. Three different cases of database produced by the realtime monitoring system are presented and analyzed, namely 1) hypoxic condition, 2) over-saturated D.O. and 3) short-term variability of temperature and D.O. In utilizing the realtime database, D.O. prediction and warning models are developed based on autoregressive stochastic process. The model is very simple, yet, users in various levels from powerful and useful with its ability to send warning messages to users in varous levels from governmental administrative staff to local fisherman, and give them some allowances to cope with the situation.

Design of the Realtime GNSS Surveying Software for Advancement of Geospatial Information Construction Technology

  • Park, Joon Kyu;Jung, Kap Yong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.4
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    • pp.425-430
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    • 2016
  • Currently, start of the operation US GPS, the Russian Glonass, European Galileo, the Chinese Compass satellites for positioning are celebrating a true GNSS (Global Navigation Satellite System) generation. Korea is building advanced infrastructure such as a national network consisting of CORS (Continuously Operating Reference Station), VRS service for real-time precise positioning and perform continuous upgrading. However, the acquisition of geospatial information using the national infrastructure requires many steps and high dependence on foreign software part in this process. This study contributes to advanced construction technology of geospatial information by design of realtime GNSS surveying system. As a results, it has designed the surveying software that can effectively positioning realtime. Designed realtime surveying software can utilized in various fields.