6 research outputs found

    Study of K-Nearest Neighbour classification performance on fatigue and non-fatigue EMG signal features

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    © 2020, Science and Information Organization. For our body to move, the muscle must activate by relaxing and contracting. Muscle activation produces bio-electric signals that can be detected using Electromyography or EMG. The signal produced by the muscle is affected by the type of contraction done by the muscle. The eccentric contraction generating different EMG signals from concentric contraction. EMG signal contains multiple features. These features can be extracted using MATLAB software. This paper focuses on the bicep brachii and brachioradialis in the upper arm and forearm, respectively. The EMG signals are extracted using surface EMG whereby electrical pads are placed onto the surface of the muscle. Features can then be extracted from the EMG signal. This paper will focus on the MAV, VAR, and RMS features of the EMG signal. The features are then classified into eccentric, concentric or isometric contraction. The performance of the K-Nearest Neighbour (KNN) classifier is inconsistent due to the EMG data variabilities. The accuracy varies from one data set to another. However, it is concluded that non-fatigue signal classification accuracy is higher than fatigue signal classification accuracy

    Fuzzy sliding control with non-linear observer for magnetic levitation systems

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    © 2016 IEEE. Magnetic levitation (Maglev) systems make significant contribution to industrial applications due their reduced power consumption, increased power efficiency and reduced cost of maintenance. Common applications include Maglev power generation (e.g. wind turbine), Maglev trains and medical devices (e.g. magnetically suspended artificial heart pump). This paper proposes fuzzy sliding-mode controller 'FSMC' with a nonlinear observer been used to estimate the unmeasured states. Simulations are performed with nonlinear mathematical model of the Maglev system, and the results show that the proposed observer and control strategy perform well

    Hybrid spiral-dynamic bacteria-chemotaxis algorithm with application to control two-wheeled machines

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    This paper presents the implementation of the hybrid spiral-dynamic bacteria-chemotaxis (HSDBC) approach to control two different configurations of a two-wheeled vehicle. The HSDBC is a combination of bacterial chemotaxis used in bacterial forging algorithm (BFA) and the spiral-dynamic algorithm (SDA). BFA provides a good exploration strategy due to the chemotaxis approach. However, it endures an oscillation problem near the end of the search process when using a large step size. Conversely; for a small step size, it affords better exploitation and accuracy with slower convergence. SDA provides better stability when approaching an optimum point and has faster convergence speed. This may cause the search agents to get trapped into local optima which results in low accurate solution. HSDBC exploits the chemotactic strategy of BFA and fitness accuracy and convergence speed of SDA so as to overcome the problems associated with both the SDA and BFA algorithms alone. The HSDBC thus developed is evaluated in optimizing the performance and energy consumption of two highly nonlinear platforms, namely single and double inverted pendulum-like vehicles with an extended rod. Comparative results with BFA and SDA show that the proposed algorithm is able to result in better performance of the highly nonlinear systems

    Type II Heat-Labile Enterotoxins from 50 Diverse Escherichia coli Isolates Belong Almost Exclusively to the LT-IIc Family and May Be Prophage Encoded

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    Some enterotoxigenic Escherichia coli (ETEC) produce a type II heat-labile enterotoxin (LT-II) that activates adenylate cyclase in susceptible cells but is not neutralized by antisera against cholera toxin or type I heat-labile enterotoxin (LT-I). LT-I variants encoded by plasmids in ETEC from humans and pigs have amino acid sequences that are ≥95% identical. In contrast, LT-II toxins are chromosomally encoded and are much more diverse. Early studies characterized LT-IIa and LT-IIb variants, but a novel LT-IIc was reported recently. Here we characterized the LT-II encoding loci from 48 additional ETEC isolates. Two encoded LT-IIa, none encoded LT-IIb, and 46 encoded highly related variants of LT-IIc. Phylogenetic analysis indicated that the predicted LT-IIc toxins encoded by these loci could be assigned to 6 subgroups. The loci corresponding to individual toxins within each subgroup had DNA sequences that were more than 99% identical. The LT-IIc subgroups appear to have arisen by multiple recombinational events between progenitor loci encoding LT-IIc1- and LT-IIc3-like variants. All loci from representative isolates encoding the LT-IIa, LT-IIb, and each subgroup of LT-IIc enterotoxins are preceded by highly-related genes that are between 80 and 93% identical to predicted phage lysozyme genes. DNA sequences immediately following the B genes differ considerably between toxin subgroups, but all are most closely related to genomic sequences found in predicted prophages. Together these data suggest that the LT-II loci are inserted into lambdoid type prophages that may or may not be infectious. These findings raise the possibility that production of LT-II enterotoxins by ETEC may be determined by phage conversion and may be activated by induction of prophage, in a manner similar to control of production of Shiga-like toxins by converting phages in isolates of enterohemmorhagic E. coli

    A longitudinal study of vero cytotoxin producing Escherichia coli in cattle calves in Sri Lanka

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    Two cohorts of 10 and 16 calves were followed at weekly or fortnightly intervals from 4-28 and 1-9 weeks respectively to determine whether natural infection by Vero cytotoxin (VT) producing Escherichia coli (VTEC) occurred. Ninety-one of 171 (53%) faecal specimens were VTEC positive and 20-80% of animals at any given time excreted VTEC. Of 104 VTEC strains studies further, 6 different serogroups (O 22.H16; O 25.H5; O 49.H-; O 86.H26; O 88.H25; O 153.H12) and an untypable strain (O @?.H21) were identified. All strains belonging to the same serotype had identical profiles of reactivity with DNA probes to toxins VT1 or 2. LTI or II and a probe (CVD419) derived from a plasmid carried by entero-haemorrhagic Escherichia coli O 157.H7. Four of these serotypes were found in the faecal flora of the calves, taken as a group, throughout the 4-month study period. Sixty percent of the strains hybridized with the probe for VT1, 4% with the probe for VT2, and 36% with both probes. Faecal VTEC were significantly associated with overt diarrhoeal illness in animals < 10 weeks of age, but no characterisitic profile of markers (serotype or hybridization pattern) in E. coli isolates was associated with diarrhoea. A serological response to VT1 was detected in some animals, but faecal VT1 VTEC excretion persisted in spite of seroconversion. VT1 seroconversion was not associated with diarrhoea. A serological response to VT2 was not detected even in those animals excreting VT2 VTEC in the faeces.link_to_subscribed_fulltex
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