Browsing by Author "Mvuma, Aloys"

Now showing 1 - 3 of 3
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    Complex adaptive notch filters for frequency estimation of three-phase power systems
    (Institute of Electictrical and Electronics Engineers, 2013) Nishimura, Shotaro; Mvuma, Aloys; Hinamoto, Takao
    This paper presents a new technique for adaptive estimation of the frequency of unbalanced three-phase power systems using complex coefficient first-order notch filters. The input complex sinusoid is given by a sum of sequences with positive and negative frequencies. The analytical expression of a estimation error oscillation introduced by the sequence with negative frequency has been derived. Closed form expression for frequency tracking error has been also derived for a complex linear chirp signal. Computer simulation results are presented to validate the analysis.
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    Design of land administration and title registration model based on blockchain technology
    (Materials and Energy Research Center, 2017) Kombe, Cleverence; Manyilizu, Majuto; Mvuma, Aloys
    Land administration and title registration system is the system for storing land title information and managing transactions involving land titles. Due to the sensitivity of land issues, land administration and title registration system should be strong to avoid any document forgery, available all the time, and take a short time to complete tasks. Thus, this study aims at designing a model for such system based on blockchain technology. The proposed model is designed using UML diagrams and then tested for verification using statistical usage models (Markov chains). The proposed model integrates the Integrated Land Management Information System (ILMIS) with factom and bitcoin blockchains which enables encryption of information from ILMIS to get the fingerprint information of each land title and store it to the blockchains. The model further encrypts the land information from ILMIS when needed and then compare it with fingerprints from blockchains for verification. Such implementation of the proposed model will help ILMIS to have the capability of providing tamper proof for stored data, providing the self-notarization mechanism, and availability of evidence for the land title from distributed databases. Furthermore, the society is expected to benefit from this study as the time and cost for registering land title will decrease and the possibilities of a piece of land having more than one owner will not be there.
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    Tracking properties of complex adaptive notch filter for detection of multiple real sinusoids
    (Institute of Electictrical and Electronics Engineers, 2013) Nishimura, Shotaro; Mvuma, Aloys; Hinamoto, Takao
    This paper presents a new realization of adaptive notch filter based on a cascade of adaptive IIR notch filters using complex coefficient first-order notch filters. The input is multiple real linear chirp signals embedded in a white Gaussian noise. Closed-form expression for frequency tracking mean square error (MSE) is given. Optimum step size parameter and notch bandwidth coefficient that minimize the tracking MSE are also derived. Computer simulation results are presented to validate the analysis.