Browsing by Author "Chanhemo, Wilson"

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    Design of encoding calculator software for huffman and shannon-Fano algorithms
    (World Academy of Science, Engineering and Technology, 2011) Chanhemo, Wilson; Mgombelo, Henry. R.; Hamad, Omar F; Marwala, T.
    This paper presents a design of source encoding calculator software which applies the two famous algorithms in the field of information theory-the Shannon-Fano and the Huffman schemes. This design helps to easily realize the algorithms without going into a cumbersome, tedious and prone to error manual mechanism of encoding the signals during the transmission. The work describes the design of the software, how it works, comparison with related works, its efficiency, its usefulness in the field of information technology studies and the future prospects of the software to engineers, students, technicians and alike. The designed “Encodia” software has been developed, tested and found to meet the intended requirements. It is expected that this application will help students and teaching staff in their daily doing of information theory related tasks. The process is ongoing to modify this tool so that it can also be more intensely useful in research activities on source coding.
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    Performance evaluation of coap and http on tsch minimal schedule
    (The University of Dodoma, 2016) Chanhemo, Wilson
    Wireless Sensor Networks (WSNs) usually consist of sensor nodes and gateways with limited resources such as memory, power and size. As a result, WSNs require bandwidth-efficient, memory-efficient and energy-efficient application protocols for data transmission. If data transmission at the application layer is not efficient, more re-transmissions will occur across the network which consumes limited resources of the WSN. Therefore a careful and extensive performance evaluation is needed for the application protocols in use by any WSN. Two existing application protocolsin WSN were evaluated namely Hypertext Transfer Protocol (HTTP) and Constrained Application Protocol (CoAP).The performance evaluation was done using Cooja that emulate Contiki operating system and Z1 motes. Performance evaluation was done based on two metrics namely Resource Retrieval Time (RRT) and bytes per transaction. Based on the analysis of the simulation data under different scenarios, the performance of HTTP and CoAP were evaluated and the results showed that CoAP performs better than HTTP. Simulation results revealed that CoAP messages have lower RRT than HTTP. Moreover, CoAP messages generated lower overhead resulting to lower bytes per transaction as compared to HTTP. Results advocate CoAP as a better protocol for WSN. CoAP ensures short sessions with lower overhead which enables lower memory and bandwidth requirements. In addition to that, CoAP conserves energy of motes by having lower transmission overhead.