1,108 research outputs found

    Chaotic behaviors of stable second-order digital filters with two’s complement arithmetic

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    In this paper, the behaviors of stable second-order digital filters with two’s complement arithmetic are investigated. It is found that even though the poles are inside the unit circle and the trajectory converges to a fixed point on the phase plane, that fixed point is not necessarily the origin. That fixed point is found and the set of initial conditions corresponding to such trajectories is determined. This set of initial conditions is a set of polygons inside the unit square, whereas it is an ellipse for the marginally stable case. Also, it is found that the occurrence of limit cycles and chaotic fractal pattern on the phase plane can be characterized by the periodic and aperiodic behaviors of the symbolic sequences, respectively. The fractal pattern is polygonal, whereas it is elliptical for the marginally stable case

    Intelligent imaging system for optimal night time driving

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    In the recent era, vehicles become a need of public. According to Statistic Portal, in year 2018 alone, more than 81 million vehicles were sold. This results in a large number of vehicles commuting on roads, thus increases the risks of road users. Road safety is the paramount and joint responsibility of all road users, which include pedestrians and travellers using different means of transport. Safety is always a main concern for drivers. It is a complex and difficult task even for an experienced senior driver. Road accident is the most unwanted thing to happen to a road user; it was reported that most of the road users are familiar with the general rules and safety measures when using roads, nonetheless their carelessness are causing the accidents and crashes. Zhang et.al [1] proposed an intelligent driver assist system for urban driving. This system provided smart navigation for its users with intelligent parking assistance to improve driving comfort while ensure the safety of the driver. The investigations of the system performance showed high precisions in the determination of the traffic flow and parking availabilit

    Construction of RFLP and AFLP Genetic Linkage Maps For Oil Palm (Elaeis Guineensis Jacq.) Using a Deli Dura X Yangambi Pisifera Cross

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    Conventional oil palm improvement using traditional breeding is a slow and expensive process. If markers linked to a useful trait, such as yield, shell thickness and embryogenesis rate, can be identified, marker-assisted selection (MAS) can be carried out, which can reduce the time taken for conventional breeding. Generating a linkage map is the first step towards marker-assisted selection. In this study, two oil palm maps were generated based on 87 F1 progeny of a controlled cross (Deli dura x Yangambi pisifera). A total of 106 RFLP markers and 171 AFLP markers were identified and scored. Of the 277 markers scored, 28 markers (10.1%) were deviated from expected Mendelian ratio (p<0.05). Pseudo-testcross strategy was used to generate two parental maps. The dura map consisted of 18 linkage groups and covered a total map distance of 584.1cM. The pisifera map resolved into 19 linkage groups and covered a total map distance of 1099.3cM. Of all the markers analyzed, 16.9% of the dura markers and 25.1% of the pisifera markers remained unlinked. RFLP marker although difficult to develop, proved very useful because only a small fraction is deviated from the expected Mendelian ratio. Furthermore, about 80% of the RFLP markers can be mapped on both parental maps. More markers will be needed to reduce the number of linkage groups of both parental maps to the haploid chromosome number of oil palm (n=16). Five homologous regions between the dura and the pisifera maps were identified by comparing the co-dominant RFLP markers. The orders of the homologous markers were conserved and the overall distances were nearly the same in both varieties, although a small difference was observed in one homologous region on linkage group D3 and P5. This difference might be due to unequal recombinations that occurred at that particular region

    The Effect of Bleaching Clay on the Quality of Refined and Bleached Palm Oil

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    The aim of this study was to characterize the physicochemical properties of the bleaching clays used in the refining of palm oil. Acid-activated, neutral and natural clays as well as synthetic adsorbent were analysed by various techniques: scanning electron microscopy, thermal analysis (Differential Thermal Analysis and Thermogravimetric Analysis), X-ray diffraction (XRD), determination of surface area, pore-size and particle-size distribution. The effects of these physical and chemical properties of bleaching clays on the quality of refined palm oil were subsequently investigated. The XRD patterns showed that silica (quartz) was present in all of the analyzed commercial clays. The acid activated clays - Tonsil and WAC Omega consisted mainly of montmorillonite. The TGA, DTA and XRD results showed that the commercial clay - Pure Flo was essentially attapulgite type of clay. WAC Supreme, the acid activated clay, displayed a complicated XRD pattern indicating that besides tron magnesium aluminium silicate (montmorillonite), attapulgite and other impurities were present. The study on the effect of degumming acid on the quality of RBO oil indicated that increased concentration of phosphoric acid facilitated the removal of iron in the RBO oil. On the other hand, the copper content in the oil was likely to be influenced by the type of clay used in the bleaching process. Langmuir isotherm was more applicable than Freundlich isotherm in the adsorption of trace metals, copper and iron, from degummed palm oil on Pure Flo. The adsorption of phosphorus by Pure Flo, Attapulgite and WAC Supreme conformed to both Langmuir and Freundlich isotherms. On the other hand, adsorption of pigments, chlorophyll and carotene on the clay adsorbents fitted the Freundlich model better than the Langmuir model. The data showed that the acid activated clay of WAC Supreme with high surface area and large pore volume did not necessary possess better bleaching efficiency than Pure Flo and Attapulgite. Pure Flo is the best clay adsorbent compared to WAC Supreme and Attapulgite (Hudson Resource). The degummed-bleached palm oil after bleaching with Pure Flo showed the lowest concentration of phosphorus, copper, chlorophyll and carotene pigments. Conversely, WAC Supreme is a poor adsorbent of phosphorus, iron and secondary oxidation products. High concentrations of copper and carotene were retained in the degummed-bleached palm oil after bleaching with Attapulgite (Hudson Resource)

    Research Paper For A Master\u27s Recital Of Piano: Beethoven\u27s Piano Sonata, Op. 109, Debussy\u27s L\u27Isle Joyeuse, L. 106, Rachmaninoff\u27s Etude-Tableaux, Op. 39, No. 5, And Chopin\u27s Second Piano Sonata, Op. 35

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    The objective of this paper is to provide a comprehensive study of the four works presented in the author’s Masters recital: Beethoven’s Piano Sonata in E major, Op. 109, Debussy’s L’Isle Joyeuse, L. 106, Rachmaninoff’s Etude-Tableaux in E-flat minor, Op. 39, No. 5, and Chopin’s Piano Sonata No. 2 in B-flat minor, Op. 35. Aspects of harmony, structure, character, etc., of all four works are discussed, one work in each chapter. The links in each movement are also discussed in multi-movement works

    How do individuals with anorexia nervosa (AN) experience the voice dialogue method in the context of experiencing an internal eating disorder voice? A Thematic Analysis

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    Objective: The internal eating disorder voice (EDV) has been implicated in the development and maintenance of anorexia nervosa (AN). However, limited research has examined interventions for this phenomenon. This study expanded the literature by exploring the acceptability of using such interventions by exploring how women with a diagnosis of AN experienced the voice dialogue method as a way of understanding and managing their EDV. Method: Nine women participated in the study. Data was collected through semi-structured interviews upon the completion of a single voice dialogue intervention. Thematic Analysis (TA) was used to understand how participants experienced the voice dialogue method and its relevance for treating AN. Results: Three main themes were identified: “externalizing and separating from the EDV”, “better understanding of the EDV” and “recovery: hopeful, motivated and afraid”. Conclusions: Participants found voice dialogue to be an acceptable approach for working with their EDV. Preliminary results suggest that voice dialogue might hold promise in the treatment of AN. However, more research is needed to verify these findings and determine the effectiveness of voice dialogue in treating AN. Implications for addressing the EDV using voice focused interventions are explored

    Photoacoustic Technology for Biological Tissues Characterization

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    The existing PA imaging systems showed mixed performance in terms of imaging characteristic and signal-to-noise ratio (SNR). The aim of this work is to present the use of an in-house assembled photoacoustic (PA) system using a modulating laser beam of wavelength 633 nm for two-dimensional (2D) characterization of biological tissues. The differentiation of the tissues in this work is based on differences in their light absorption, wherein the produced photoacoustic signal detected by a transducer was translated into phase value (Ф) that corresponds to the peak amplitude of tissue optical absorption. This research investigated variation in PA response between the considered different parts of chicken carcasses: fat, liver and muscle. This work found fat tissue to produce the strongest PA signals with mean ± standard deviation (SD) Ф = 2.09 ± 0.31 while muscle produced the least signal strength with Ф = 1.03 ± 0.17. This work attributes these observations and the presence of stripes pattern in 2D Ф images of fat and muscle to the differences in the optical and structural properties of these samples. In addition, a comparison has been made in an attempt to better assess the performance of the developed system with the related ones.This work concluded that the developed system may be useful as an alternative means in the noninvasive and label-free visualization and characterization of intact biological tissues in terms of their structural and physiological context in the future

    Piezoelectric Photoacoustic System for Fluid Flow Monitoring

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    The aim of this study is to investigate the feasibility of using a laboratory assembled piezoelectric based photoacoustic (PA) system for noncontact monitoring fluid flow. This is to overcome the drawbacks of some existing fluid flow detection systems, which include expensive equipment and their maintenance cost, limited sensitivity and specificity in detecting signals from restricted regions or at low flow velocity. The produced PA signal waves detected by a piezoelectric transducer used in this study was processed to determine the required phase value (Ф), which value was found to correlate linearly with fluid flow status. The fluid pressure difference of 1.16 pascals (Pa) and 11.90 Pa applied to the developed mock circulatory system was observed to produce changes in phase value with mean ± standard deviation (SD) ΔФ of 0.79 ± 0.07 rad and 2.17 ± 0.07 rad, respectively, suggesting a linear response of the developed system with changes in circulation system. This trend was supported with the relatively low absolute difference of 0.07 ± 0.01 rad in the predicted values as compared to that of the ground truth. This work concluded that the capabilities and simplicity of the proposed PA system renders it feasible for cost effective, non-destructive assessment of fluid flow in future studies

    MAP1B rescues LRRK2 mutant-mediated cytotoxicity

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    Leucine-rich repeat kinase 2 (LRRK2) mutations are the most common cause of dominant and sporadic Parkinson’s disease (PD), a common neurodegenerative disorder. Yeast-two-hybrid screening using human LRRK2 kinase domain as bait identified microtubule associated protein 1B (MAP1B) as a LRRK2 interactor. The interacting domains were LRRK2 kinase and the light chain portion of MAP1B (LC1). LRRK2 + LC1 interaction resulted in LRRK2 kinase inhibition. LRRK2 mutants (R1441C, G2019S and I2020T) exhibited decreased endogenous LC1 expression and its co-expression with LC1 rescued LRRK2 mutant-mediated toxicity. This study presented the first data on the effects of LRRK2 + LC1 interaction and also suggested that LCI possibly rescued LRRK2 mutant-induced cytotoxicity by inhibiting LRRK2 kinase activity. Compounds that upregulate LC1 expression may therefore hold therapeutic potential for LRRK2-linked diseases

    Photoacoustic imaging system for fluid flow visualization and biological tissues characterization

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    Photoacoustic (PA) imaging is a biomedical imaging modality, which work is based on the photoacoustic effect, to provide illumination of biological tissues with strong optical absorption contrast and high spatial resolution at a short scanning time. The drawbacks of some existing PA fluid imaging systems, which include expensive equipment and their maintenance cost, limited sensitivity in detecting signals from restricted regions. This research describes an in-house developed two-axis PA imaging system for investigation of fluid flow and photoacoustic signatures of biological tissues using a continuous laser beam of output wavelength 633 nm to deliver light to the targeted tissue samples and fluid. The resulting acoustic signal detected by a transducer was used to determine the amplitude of tissues optical absorption via the measured phase value (Ф). This research began with the validation of the functionality of the developed system using biological system comprised of a mock circulatory system overlaid by different parts of poultry namely fat, liver and muscle of different sizes. The validated system was then deployed for use on human subjects, and the considered experiment settings included at rest, under warm water and arterial blood flow occlusion conditions. This work reported a consistent increase in the PA signals of all tissues with both sample size and the fluid flow rate. In addition, fat tissues were found to produce the largest PA signals with mean ±standard deviation (SD) Ф = 1.12 ± 0.11, while muscle produced the least signals with Ф = 0.828 ±0.20, which trend agreed well with the previous literature. It was found from the experiments on human subjects that phase difference (ΔФ) was proportional to the change in the velocity of blood flow within microcirculation of an investigated site. The mean and SD of percent relative phase difference for these volunteers were calculated as 51.68 % ± 24.27 % and -68.57 % ± 14.78 % for warm water and blood flow occlusion condition, respectively. The overall sensitivity of the system is 77. 3%. This work concluded the feasibility of this system for non-invasive assessment and visualization of blood perfusion and biological tissues, which deemed it suitable for implementation in healthcare applications
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