| 1. |
- Anatory, Justinian, et al.
(författare)
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A broadband power-line communication system design scheme for typical Tanzanian low-voltage network
- 2009
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Ingår i: IEEE Transactions on Power Delivery. - USA : IEEE. - 0885-8977 .- 1937-4208. ; 24:3, s. 1218-1224
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Tidskriftsartikel (refereegranskat)abstract
- Information and communications technologies (ICTs) are gaining importance in developing countries. Power-line network is a potential infrastructure for ICT services provision. Power-lines are highly interconnected network with stochastic variation in number of branches. Under such distributed network conditions the design of a broadband power-line communication (BPLC) system is a challenge. In this paper a case study of an actual power-line network, representative of a low-voltage BPLC channel in Dar es Salaam, Tanzania is considered. We shall investigate the performance of such a low-voltage channel that uses orthogonal frequency division multiplexing (OFDM) technique with binary phase shift keying (BPSK) modulation scheme for communication. For sensitivity analysis, three different transmitter locations were chosen and receiver points were varied to identify the possible degraded performance scenarios. Analysis show that in the frequency bands of 100 MHz, the channel delay spread for such networks is about 4 s, giving a maximum number of subchannels 4096 with 512 cyclic prefix. To improve the degraded performance scenarios, the concatenated Reed Solomon outer code with punctured convolution inner code was applied to the network. It was found that when the branches were terminated by its corresponding characteristic impedances the performance is improved by 10-20 dB compared to a corresponding uncoded system. On the contrary for a coded system when the branches were terminated either in low or higher impedances compared to branch characteristic impedances the improvement was greater than 2-15 dB. This study demonstrates that the specification proposed by IEEE-802.16 broadband wireless access working groups can be used for performance improvement of distributed low-voltage systems.
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| 2. |
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| 3. |
- Anatory, Justinian, et al.
(författare)
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The Effects of Multipath on OFDM Systems for Broadband Power-Line Communications a Case of Medium Voltage Channel
- 2009
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Ingår i: World Academy of Science, Engineering and Technology. - 2070-3724. ; 54, s. 205-208
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Tidskriftsartikel (refereegranskat)abstract
- Power-line networks are widely used today for broadband data transmission. However, due to multipaths within the broadband power line communication (BPLC) systems owing to stochastic changes in the network load impedances, branches, etc., network or channel capacity performances are affected. This paper attempts to investigate the performance of typical medium voltage channels that uses Orthogonal Frequency Division Multiplexing (OFDM) techniques with Quadrature Amplitude Modulation (QAM) sub carriers. It has been observed that when the load impedances are different from line characteristic impedance channel performance decreases. Also as the number of branches in the link between the transmitter and receiver increases a loss of 4dB/branch is found in the signal to noise ratio (SNR). The information presented in the paper
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| 4. |
- Anatory, Justinian, et al.
(författare)
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The influence of load impedance, line length, and branches on underground cable power-line communications (PLC) systems
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:1, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- An underground cable power transmission system is widely used in urban low-voltage power distribution systems. In order to assess the performance of such distribution systems as a low-voltage broadband power-line communication (BPLC) channel, this paper investigates the effects of load impedance, tine length, and branches on such systems, with special emphasis on power-line networks found in Tanzania. From the frequency response of the transfer function (ratio of the received and transmitted signals), it is seen that the position of notches and peaks in the magnitude are largely affected (observed in time-domain responses too) by the aforementioned network configuration and parameters. Additionally, channel capacity for such PLC channels for various conditions is investigated. The observations presented in this paper could be helpful as a suitable design of the PLC systems for better data transfer and system performance.
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| 5. |
- Ben Dhaou, I., et al.
(författare)
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Communication and security technologies for smart grid
- 2018
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Ingår i: Fog Computing: Breakthroughs in Research and Practice. - : IGI Global. - 9781522556503 - 1522556494 - 9781522556497 ; , s. 305-331
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The smart grid is a new paradigm that aims to modernize the legacy power grid. It is based on the integration of ICT technologies, embedded system, sensors, renewable energy and advanced algorithms for management and optimization. The smart grid is a system of systems in which communication technology plays a vital role. Safe operations of the smart grid need a careful design of the communication protocols, cryptographic schemes, and computing technology. In this article, the authors describe current communication technologies, recently proposed algorithms, protocols, and architectures for securing smart grid communication network. They analyzed in a unifying approach the three principles pillars of smart-gird: Sensors, communication technologies, and security. Finally, the authors elaborate open issues in the smart-grid communication network.
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| 6. |
- Dhaou, I. B., et al.
(författare)
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Communication and security technologies for smart grid
- 2017
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Ingår i: International Journal of Embedded and Real-Time Communication Systems. - : IGI Global. - 1947-3176 .- 1947-3184. ; 8:2, s. 40-65
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Tidskriftsartikel (refereegranskat)abstract
- The smart grid is a new paradigm that aims to modernize the legacy power grid. It is based on the integration of ICT technologies, embedded system, sensors, renewable energy and advanced algorithms for management and optimization. The smart grid is a system of systems in which communication technology plays a vital role. Safe operations of the smart grid need a careful design of the communication protocols, cryptographic schemes, and computing technology. In this article, the authors describe current communication technologies, recently proposed algorithms, protocols, and architectures for securing smart grid communication network. They analyzed in a unifying approach the three principles pillars of smart-gird: Sensors, communication technologies, and security. Finally, the authors elaborate open issues in the smart-grid communication network.
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| 7. |
- Ibwe, K. S., et al.
(författare)
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The impact of industry participation on challenge based learning
- 2018
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Ingår i: International Journal of Engineering Education. - : Tempus Publications. - 0949-149X. ; 34:1, s. 187-200
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Tidskriftsartikel (refereegranskat)abstract
- The future of learning is being revolutionized by challenge based learning (CBL), where academia offers solutions to real life challenges. Unfortunately, in developing countries academia overlook the importance of involving stakeholders who are the prospective owners of the solutions developed. This is because of the weak link between academic institutions and industry in research and development activities. However, to solve real life challenges faced by the society the researchers need to work closely and continuously with the targeted community for them to get the sense of ownership and for the solutions to take into account all relevant factors. This paper presents the impacts realized when eight stakeholders were fully involved from identification to developing solutions of the challenges facing the electrical power sector in Tanzania which is wholly managed by a public utility company TANESCO from generation to distribution. Challenge based courses introduced in taught PhD and MSc programs were used to create the necessary skills but also to evaluate the effectiveness of the approach in realizing the intended objectives. Nine PhD and six MSc students were involved. The stakeholders' involvement helped the research students to align the identification of the challenges to be in line with societal perception rather being purely scientific and/or technical like excessive reactive power or skin effect and to work in multidisciplinary teams. This paper presents the process adopted in real life challenges identification, the proposed solutions to the identified challenges and how academia can link with industry in solving real-life problems facing the society, in particular the higher learning institutions in developing countries.
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| 8. |
- Kalinga, E. A., et al.
(författare)
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Active learning through smart grid model site in challenge based learning course
- 2018
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Ingår i: IMSCI 2018 - 12th International Multi-Conference on Society, Cybernetics and Informatics, Proceedings. - : International Institute of Informatics and Systemics, IIIS. - 9781941763926 ; , s. 120-126
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Konferensbidrag (refereegranskat)abstract
- Smart Grid is a new and growing technology to developing countries. Its implementation and sustainability rely on well trained experts. Sustainability of the smart grid need local experts, hence a project named iGRID: Smart Grid Capacity Development and Enhancement in Tanzania was started. The project is running at the College of Information and Communication Technologies, University of Dar es Salaam. It intends to generate the necessary technical and scientific skills to ensure sustainable implementation of smart grid. iGRID project introduced taught PhD and Masters programs focusing on society, innovation and entrepreneurship in iGRID aspects, as well as to facilitate implementation of automation of monitoring, evaluation, analysis, control and management of electrical power system (smart grid) in order to improve delivery efficiency and to optimize operational costs in the electrical power system in Tanzania. The project made use of Challenge-Based Learning (CBL) methodology to engage students to work together with stakeholders in identifying challenges facing electrical power system in Tanzania. This paper presents the experience of using CBL methodology to achieve active learning to engineering students. The dynamicity of the teaching model, allowed students to acquire skills necessary to solve medium to high tech complex problems. The results build a continuous learning platform for students researching in electrical field.
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| 9. |
- Lujara, Suzan, et al.
(författare)
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Introduction of Open-Source e-Learning Environment and Resources : A Novel Approach for Secondary Schools in Tanzania
- 2007
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Ingår i: International Journal of Social Sciences. - 1306-973X. ; 1:4, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- The concept of e-Learning is now emerging in Sub Saharan African countries like Tanzania. Due to economic constraints and other social and cultural factors faced by these countries, the use of Information and Communication Technology (ICT) is increasing at a very low pace. The digital divide threat has propelled the Government of Tanzania to put in place the ICT Policy in 2003 which is defines the direction of all ICT activities nationally. Among the main focused areas is the use of ICT in education, since for the development of any country, there is a need of creating knowledge based society. This paper discusses the initiatives made so far to introduce the use of ICT tools to some secondary schools using open source software in e-content development to facilitate a self-learning environment
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| 10. |
- Rwegasira, Diana, et al.
(författare)
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A Demand-Response Scheme Using Multi-Agent System for Smart DC Microgrid
- 2022
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Ingår i: Research Anthology on Smart Grid and Microgrid Development. - : IGI Global. ; , s. 700-720
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This article describes a framework for load shedding techniques using dynamic pricing and multi-agent system. The islanded microgrid uses solar panels and battery energy management system as a source of energy to serve remote communities who have no access to the grid with a randomized type of power in terms of individual load. The generated framework includes modeling of solar panels, battery storage and loads to optimize the energy usage and reduce the electricity bills. In this work, the loads are classified as critical and non-critical. The agents are designed in a decentralized manner, which includes solar agent, storage agent and load agent. The load shedding experiment of the framework is mapped with the manual operation done at Kisiju village, Pwani, Tanzania. Experiment results show that the use of pricing factor as a demand response makes the microgrid sustainable as it manages to control and monitor its supply and demand, hence, the load being capable of shedding its own appliances when the power supplied is not enough.
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