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AFRICON 2009最新文献

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Towards a converged network: Video streaming over WiMAX vs. HSDPA in the rural environment 迈向融合网络:WiMAX视频流与农村环境中的HSDPA视频流
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308196
M. Odhiambo, P. O. Amimo-Rayolla, A. Kurien
{"title":"Towards a converged network: Video streaming over WiMAX vs. HSDPA in the rural environment","authors":"M. Odhiambo, P. O. Amimo-Rayolla, A. Kurien","doi":"10.1109/AFRCON.2009.5308196","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308196","url":null,"abstract":"as the telecommunications industry evolves towards a converged IP-Core network the role of cellular/wireless broadband technologies in achieving Long Term Evolution (LTE) must be greatly evaluated. This would in effect provide lessons for improvement and blueprints for final adoption in NGN (Next Generation Networks). The emergence of BWA (broadband wireless access) as a reliable player, in some cases a substitute for fibre/ADSL, maybe attributed to poor or non-existent copper/fibre, largely inefficient telecommunications management and/or ineffective telecommunications policies in mostly underserviced areas. In this paper, video streaming over existing 3G high-speed packet networks is evaluated against WiMAX as alternatives to fibre/ADSL. Simulation results show WiMAX was found to be a viable and better alternative barring capital expenditure (CAPEX) and operational expenditure (OPEX) considerations. HSDPA was found to achieve rates per user equipment (UE) that meet QoS needs for codec streaming Q-levels of 16 and 64kbps. The 16kbps codec rarely requires extensive preroll buffer requirements. However, WiMAX was found to perform better by at least three times for throughput and capacity.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"201 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128611250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
A critical review of Stevens' and Sinclair's equation 对史蒂文斯和辛克莱公式的批判性回顾
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308115
Emeka D. Okaekwu, N. Ade
{"title":"A critical review of Stevens' and Sinclair's equation","authors":"Emeka D. Okaekwu, N. Ade","doi":"10.1109/AFRCON.2009.5308115","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308115","url":null,"abstract":"A finite-source queuing model is very useful in determining performance equations, probability of delay of users who queue for a free server when all servers are busy. The aim of this paper is to critically examine and analyze Stevens' and Sinclair's equation to show that it is a performance equation for the probability of delay in private mobile radio (PMR) systems. We analyze such an equation mathematically and present a computational program using MATLAB. The system is an M/M/r/K/K queuing model with finite sources of traffic. Some of the basic traffic characteristics and assumptions are also reviewed.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129955341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A review of next generation satellite networks: Trends and technical issues 下一代卫星网络综述:趋势和技术问题
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308072
A. A. Ajibesin, Felix Bankole, A. Odinma
{"title":"A review of next generation satellite networks: Trends and technical issues","authors":"A. A. Ajibesin, Felix Bankole, A. Odinma","doi":"10.1109/AFRCON.2009.5308072","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308072","url":null,"abstract":"The next generation satellite networks will provide broadband communications at low cost. The recent developments in satellites technology, transmission techniques, antennas, and launch capabilities have enabled a new generation of services to be made available to users especially when communications satellites have been widely considered to complement the terrestrial systems. In this paper, a survey of next generation satellite networks through the satellite background are discussed. The satellite network requirements for the future mobile system are presented. The proposed satellite-UMTS which have been accepted for the third generation wireless network is showned to be internetworked with the proposed all IP network. This consideration is inevitable because of high-speed transmission requirements and roaming capability that the next generation network system demand.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130776520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
Mass-losses relationship in an optimized 8-pole radial AMB for Long Term Flywheel Energy Storage 优化的8极径向AMB长期飞轮储能的质量损耗关系
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308164
L. Bakay, M. Dubois, P. Viarouge, J. Ruel
{"title":"Mass-losses relationship in an optimized 8-pole radial AMB for Long Term Flywheel Energy Storage","authors":"L. Bakay, M. Dubois, P. Viarouge, J. Ruel","doi":"10.1109/AFRCON.2009.5308164","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308164","url":null,"abstract":"This paper presents the effect of losses on a radial Active magnetic bearings (AMB), used in the Long Term Flywheel Energy Storage (LTFES). The study does not take into account the losses due to power electronics and windage losses (due to the friction between external rotor surface and the air). Therefore, we restricted the loss computation to those of radial AMB only. To simplify this work, we focused on the effect of external disturbance on unbalance force induced by rotor eccentricity for instance. The unbalance force has fixed the maximum radial load capacity of the rotor in order to design the radial AMB. 2-D Finite Element Method (FEM) has been used to validate the theoretical model. We have optimized AMB system in order to search the best design which minimises overall losses (Copper and iron Losses) for different magnitudes of external force. Then, mass versus losses curve of AMB has been shown for the same angular velocity speed of rotor namely 9000 rpm.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130801345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Laser sources at 760 nm wavelength for metrology of length 波长为760nm的激光光源用于长度计量
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308091
B. Mikel, Z. Buchta, J. Lazar, O. Cíp
{"title":"Laser sources at 760 nm wavelength for metrology of length","authors":"B. Mikel, Z. Buchta, J. Lazar, O. Cíp","doi":"10.1109/AFRCON.2009.5308091","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308091","url":null,"abstract":"First set-up of the laser source based on the DFB (Distributed FeedBack) laser diode is presented. We used the DFB laser diode at 760 nm wavelength with mode-hop free tuning range above 1 nm and fiber output up to 10 mW. We present our first characteristics without external stabilization of the output wavelength. We compared our new DFB laser source with our previously developed laser source with VCSEL (Vertical Cavity Surface Emitting Laser) diode. Results are presented. Both laser sources were developed for laser interferometry, laser metrology of length. We present set-up of the laser interferometer proposed with respect to using of our laser sources. The design of optical set-up of the experimental interferometer is realized using fiber optics to reduce the influence of the index of refraction of air. The laser interferometer in the first set-up was used for absolute measurement of length. We used the method of the frequency stabilization on optical resonator to stabilize of frequency of laser diode and measurement of the tuneability of the wavelength.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129000871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Experiments on PAVIN platform for cooperative inter-vehicle communication protocol (CIVIC) 基于PAVIN平台的协同车际通信协议(CIVIC)实验
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308145
Xunxing Diao, M. Kara, Jianjin Li, K. Hou, Haiying Zhou, Aurélien Jacquot, Abdelaziz Amamra
{"title":"Experiments on PAVIN platform for cooperative inter-vehicle communication protocol (CIVIC)","authors":"Xunxing Diao, M. Kara, Jianjin Li, K. Hou, Haiying Zhou, Aurélien Jacquot, Abdelaziz Amamra","doi":"10.1109/AFRCON.2009.5308145","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308145","url":null,"abstract":"This paper describes a cooperative MANET protocol dedicated to intelligent transportation systems and its new experiment results in mobile scenarios. The protocol is named CIVIC (Communication Inter Véhicule Intelligente et Coopérative). It is an auto-configuration inter-vehicle communication protocol, which supports ad-hoc and infrastructure networks, contains reactive and proactive routing components, and adapts different wireless standards. It is also a location-based and context-aware protocol reacting to vehicle status, road traffic, and geographic environment. The CIVIC protocol has been implemented on the LiveNode sensor developed by our laboratory. The new experiments of CIVIC protocol are carried out on PAVIN platform (Plate-forme d'Auvergne pour Véhicules Intelligents) supported by the TIMS (Technologies de l'Information de la Mobilité et de la Sûreté) research federation. These experiments demonstrate the feasibility and reliability of CIVIC in mobility scenarios. In addition, an application project named MobiPlus will be introduced.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126225627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Statistical modeling of video object's behavior for improved object tracking in visual surveillance 视频对象行为的统计建模，以改进视觉监控中的目标跟踪
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308178
G. Yin, D. Bruckner, G. Zucker
{"title":"Statistical modeling of video object's behavior for improved object tracking in visual surveillance","authors":"G. Yin, D. Bruckner, G. Zucker","doi":"10.1109/AFRCON.2009.5308178","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308178","url":null,"abstract":"This paper describes a post processing method for detected video objects to enhance the quality of detection. Starting with a basic set of video parameters (such as video frame and time, label of objects, the objects position in pixel, the width and height of object's bounding box) statistical parameters (such as arithmetic mean and standard deviation) about features are computed and with these parameters different statistical models are built. These models can be used to estimate the “normality” of an object's behavior.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126044106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Critical design parameters for a low altitude long endurance solar powered UAV 低空长航时太阳能无人机的关键设计参数
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308105
Grant Wilkins, D. Fourie, J. Meyer
{"title":"Critical design parameters for a low altitude long endurance solar powered UAV","authors":"Grant Wilkins, D. Fourie, J. Meyer","doi":"10.1109/AFRCON.2009.5308105","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308105","url":null,"abstract":"The paper presented provides theoretical findings of the critical solar UAV parameters required for prolonged flight. The parameters being, battery energy density, wing surface area, total UAV weight and solar surface area. The findings are based on two individual models, a solar and an aerodynamic model, which are combined to form a solar powered UAV model.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123813266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 16
Electric load management and information technology 电力负荷管理与信息技术
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308094
P. Palensky
{"title":"Electric load management and information technology","authors":"P. Palensky","doi":"10.1109/AFRCON.2009.5308094","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308094","url":null,"abstract":"Load management can be an important contribution to the electricity grid. Its main usage is improving grid stability (physical optimization) and optimize consumption patterns (financial optimization). In recent years, load management developed towards a more “global” scale. Wide area load management tries to translate the experiences of local load management to entire regions. It is Information Technology that enables this. This paper describes the various flavors of load management and names the open points before this idea can be deployed in a larger scale.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133105677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Earned Value as a performance measurement tool for small and large construction projects in a South African environment 挣值作为南非环境中小型和大型建筑项目的绩效衡量工具
AFRICON 2009 Pub Date : 2009-11-03 DOI: 10.1109/AFRCON.2009.5308080
M. Vertenten, L. Pretorius, J. Pretorius
{"title":"Earned Value as a performance measurement tool for small and large construction projects in a South African environment","authors":"M. Vertenten, L. Pretorius, J. Pretorius","doi":"10.1109/AFRCON.2009.5308080","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308080","url":null,"abstract":"The foundation of Earned Value Performance Management was the Cost/Schedule Control Systems Criteria originally defined in the USA in 1967. Earned Value Performance Management has traditionally been used in Defense projects with budgets in excess of $100M. Private industry is now implementing Earned Value Performance Management (EVPM) for major projects, which are large, complex or geographically dispersed. It is the purpose of this paper to determine whether the Earned Value concept as developed over the years to the form it is in today is being used in the South African construction industry. The aim of this paper is to explore the concept of Earned Value and how it is related to Project Control and Project Management focused more on the South African environment.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114285614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
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