AFRICON 2009最新文献

{"title":"Smart demand-side energy management based on cellular technology - a way towards Smart Grid technologies in africa and low budget economies","authors":"M. Abdullah, B. Dwolatzky","doi":"10.1109/AFRCON.2009.5308142","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308142","url":null,"abstract":"The century-old power grids were not designed to meet modern requirements. The current need to use electricity more efficiently and to introduce “green” sources of energy is not well supported by existing grid technology. A particular problem is that detailed information about consumption of electricity is not provided to users and network operators. This is one of the prime reasons for electricity wastage. The “Smart Grid” concept is a solution to this problem. Smart Grid solutions at this moment in time are expensive to deploy. For developing countries it is particularly difficult to benefit from Smart Grid solutions. This paper proposes a system that can be used in developing economies as a way of reducing the consumption and wastage of electricity. The solution uses cell phones as an instrument to both display information and allow consumers to control appliances in their homes. This will be integrated into a larger Smart Grid application. The paper presents a concept that is still to be implemented and tested.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"11 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":"127755068","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}

{"title":"Iterative OFDM receiver with Decision Directed Channel Estimation","authors":"O. Oyerinde, S. Mneney","doi":"10.1109/AFRCON.2009.5308381","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308381","url":null,"abstract":"Iterative technique at any communication receiver has been confirmed to exhibit some gains over its non-iterative counterpart. In this paper, we consider a turbo-coded OFDM system employing Iterative receiver that comprises of Turbo decoder and the Iterative Decision Directed Channel Estimation (DDCE) scheme that are working together in an iterative mode. The iterative DDCE scheme is based on the Fast Data Projection Method (FDPM)-based Channel Impulse Response (CIR) Estimator and the Normalized Least Mean Square (NLMS)-based adaptive predictor. The performance of the Iterative DDCE is compared, through computer simulation, with the non-Iterative DDCE operating on a non-iterative receiver. It was found that the former outperformed the latter. The Iterative DDCE employing FDPM based-CIR Estimator is also compared with another one employing a popular subspace tracking algorithm, the Projection Approximation Subspace Tracking with deflation (PASTd) algorithm. It was also found that the proposed Iterative DDCE employing FDPM-based CIR Estimator exhibited performance gain over the Iterative DDCE employing PASTd based-CIR Estimator.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"136 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":"131642038","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}

{"title":"White-light interference fringe detection using color CCD camera","authors":"Z. Buchta, P. Jedlicka, M. Matějka, V. Kolarik, B. Mikel, J. Lazar, O. Cíp","doi":"10.1109/AFRCON.2009.5308093","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308093","url":null,"abstract":"We describe in this paper a pilot experiment of a white-light fringe analysis with a low-cost color CCD camera. The used detection technique employs the phase-crossing algorithm which identifies the zero optical path difference as the point where the phase difference between the red, green and blue part of the white-light interference fringe becomes equal to zero. An experimental arrangement is based on superluminescent LED diode. The experimental setup is designed to be a crucial part of the complex system for automatic contactless diagnostic and calibration of gauge blocks.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"265 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":"133287120","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}

{"title":"Multiconverter controller design for an infrared heater grid","authors":"M. Adonis, Kahn Mte","doi":"10.1109/AFRCON.2009.5308139","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308139","url":null,"abstract":"Power control methods are introduced for the regulation of a multiple-input-multiple-output (MIMO) dc-dc converter. The sliding-mode control and the synergetic mode control techniques are contrasted. These two methods are studied for the stability that each portrays to a disturbance. The advantages and disadvantages of each scheme is studied. Simulation results are used in order to predict the most stable control scheme. The simulation and experimental results reinforced the argument for the efficacy of the desired control implementation.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"41 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":"129005320","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}

{"title":"Economic and operational effects of introducing Independent Power Producers into the Kenyan power system","authors":"A. Akumu, A. Oduor, L. Ngoo","doi":"10.1109/AFRCON.2009.5308227","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308227","url":null,"abstract":"Some significant occurrences like increase in the electricity demand, degrading catchment areas and unpredictable climatic patterns have a direct impact on the energy sector. To address this scenario, a number of changes have been made in the energy sector by the Kenyan Government. These include the unbundling of the power generation from Transmission and Distribution functions and contracting the Independent Power Producers (IPPs), and Cogeneration (collectively referred to as Non Utility Generation - NUG) to supplement the power generation from the state controlled entity - The Kenya Electricity Generating Company (KenGen) so as to meet the national electrical demand. This research study aimed at analyzing the effects of these IPPs on the cost of electrical energy in Kenya and also on the operational flexibility of the Kenyan Power System. These studies have been done using the Supervisory Control and Data Acquisition (SCADA) system from the Kenya Power and Lighting Company (KPLC). The economic aspect of this study has been done by taking a sample of four large power consumers (Kenya Pipeline Company - KPC, Sameer Africa, British American Tobacco — BAT and East African Portland Cement — E.A Portland) and analyzing their electricity bills while focusing on the Fuel Cost Adjustment (FCA) levy from the year 2003 to 2007, since majority of the IPPs run on a variety of fuels that are quite expensive and these costs are passed on to the customers at a rate proportional to the energy they consume. More so, the cost of the fuels used for power generation is dependent on the fluctuating international prices. This study has shown that the IPPs have improved the operational flexibility of the power system in terms of management of system outages and the loading of various power system equipment, but have also made the cost of electricity to increase exorbitantly to the customers. This study may further assist all the stakeholders in the energy sector to plan, design and control power system operations, while at the same time putting more emphasis on industrial cogeneration.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":" 66","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113947877","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}

{"title":"Analysis of bus voltage regulation and OLTC performance on mismatched parallel-connected transformers","authors":"Ls Madzonga, J. Munda, A. Jimoh","doi":"10.1109/AFRCON.2009.5308082","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308082","url":null,"abstract":"This paper analyzes the regulation of bus voltage when master-follower or master-slave tap change control method is used when two mismatched-transformers are operated in parallel. Bus voltage regulation at a distribution substation relies on the use of the AVR relay that controls the OLTC. The circulating current method yields expected performance regarding bus voltage regulation when mismatched transformers are operated in parallel. When the master-follower/slave method is used, the standard voltage set-point of 103% results in low voltages being experienced by the customer at the end of the feeder. The simulations done on the network suggests that the voltage set point of each AVR relay be determined with the consideration of the upstream and downstream AVR relay settings.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"27 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":"122940548","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}

{"title":"A residential energy and power conservation System Utilizing an Optimization Model","authors":"H. Zhang, X. Xia, J. Zhang","doi":"10.1109/AFRCON.2009.5308303","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308303","url":null,"abstract":"This paper presents a residential energy and power conservation system that utilizes an optimization model and user side controller. The aim of this paper is to enforce a reduction in the users' current level of consumption and yet minimize any discomfort as the result. An energy usage optimization model is the foundation of this work. It computes a set of directives for a specific user based on the historical electrical devices usage data and the conservation requirement. A user side controller utilizes this directive and actively allows or denies user's access to certain appliance. This system has the following advantages: it ensures the conservation requirement is met by all of the end users; it has relatively low cost; it is highly efficient.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"74 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":"124097347","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}

{"title":"User defined controllers in power system stability analysis using PacDyn 8.1 simulation tool","authors":"Dovhani Selby Mudau, Folly Ka, K. Awodele","doi":"10.1109/AFRCON.2009.5308138","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308138","url":null,"abstract":"This paper presents the small-signal stability analysis of a power system using PacDyn 8.1 simulation tool. PacDyn is a comprehensive small-signal stability analysis package which was developed by CEPEL. This software package supports built-in as well as user defined models. The user defined models are investigated and results compared to those obtained using traditional built-in models for excitation systems. A single machine equipped with an Automatic Voltage Regulator (AVR) and a power system stabilizer (PSS) and connected to an infinite bus power system model is used as a test system. Eigensolution (Modal analysis) results, time domain as well as frequency domain simulations are compared to validate the findings of the investigations. The results showed that built-in models are computationally efficient, well-defined with fixed structures while user defined models offer unlimited model structures with additional dynamic variables that can be monitored during simulations. Results for both modal, time domain and frequency simulations showed slight variations in results when using built-in and user defined models.","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":"129072615","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}

{"title":"Analysis of a low noise amplifier with LC-ladder matching and capacitive shunt-shunt feedback","authors":"M. Weststrate, S. Sinha","doi":"10.1109/AFRCON.2009.5308169","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308169","url":null,"abstract":"In this paper a new low noise amplifier configuration is proposed to achieve wideband operation. This configuration consists of an LC-ladder filter and a common-emitter stage employing shunt-shunt capacitive feedback to realize wideband matching. Design equations for this configuration are derived, as well as equations for the important performance measures namely noise figure, gain and IIP3. The results of a design for achieving typical low noise amplifier specifications in the ultra-wideband are calculated from these equations and plotted. Without any optimization S11 of less than −10 dB over the entire frequency band and a minimum noise figure of 2.87 dB are predicted when achieving S21 of 20 dB. These results indicate that very good performance can be attained through the use of this technique.","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"20 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":"117163822","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}

{"title":"About software engineering frameworks and methodologies","authors":"Ernest Mnkandla","doi":"10.1109/AFRCON.2009.5308117","DOIUrl":"https://doi.org/10.1109/AFRCON.2009.5308117","url":null,"abstract":"Defining software engineering can be a rather challenging task depending on the purpose of the definition and the intended beneficiaries. Talking about frameworks and methodologies in software engineering can be even more complex under whatever circumstances due to the many different ways in which the issues concerning frameworks, processes, approaches and methodologies have been handled. This paper explores software engineering frameworks and methodologies and related topics. The purpose of this study is to add further understanding in the area of software engineering frameworks and methodologies. Data from published literature is analysed to establish a position on the status of software engineering frameworks and methodologies. The fundamental questions to consider here are; what kind of benefits can be derived from a better understanding of these issues? Would a better understanding of frameworks and methodologies improve the way we design, develop, implement, maintain and use Information Systems?","PeriodicalId":122830,"journal":{"name":"AFRICON 2009","volume":"51 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":"116644927","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}