448 research outputs found

    A Motion Estimation Algorithm Using DTCWT and ARPS

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    In this paper, a hybrid motion estimation algorithm utilizing the Dual Tree Complex Wavelet Transform (DTCWT) and the Adaptive Rood Pattern Search (ARPS) block is presented. The proposed algorithm first transforms each video sequence with DTCWT. The frame n of the video sequence is used as a reference input and the frame n+2 is used to find the motion vector. Next, the ARPS block search algorithm is carried out and followed by an inverse DTCWT. The motion compensation is then carried out on each inversed frame n and motion vector. The results show that PSNR can be improved for mobile device without depriving its quality. The proposed algorithm also takes less memory usage compared to the DCT-based algorithm. The main contribution of this work is a hybrid wavelet-based motion estimation algorithm for mobile devices. Other contribution is the visual quality scoring system as used in section 6

    The role of Hong Kong in Sino-US economic relations

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    This paper represents a first attempt to isolate the relative contributions of Hong Kong manufactures and exporters to the export earnings from their joint ventures based in China

    General Strategies in Developing Alloy Steel Fuzzy Model for Machinability Data Selection of Turning Process

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    In this paper, several fuzzy models have been proposed for machinability data selection of turning process of alloy steel. The selection of the machinability data is a crucial task, and normally done by the skilled machinists. Thus, fuzzy models-have been suggested for predicting the optimum machinability data, which are cutting speed and feed rate. These fuzzy models are developed based on the relationship of two-input (material hardness and depth of cut) and two-utput (cutting speed and feed rate). A few general strategies in developing fuzzy models are presented and discussed in this paper. Generally, there are three different strategies that are suggested in this paper. The objective of implementing these strategies is to simplify the process of fuzzy model development. The predicted cutting speed and feed rate are compared with the data obtained from the Machining Data Handbook (Metcut Research Associate 1980) and a good correlation has been shown throughout the comparison

    Effects of Different Inoculation Regimes of Torulaspora delbrueckii and Oenococcus oeni on Fermentation Kinetics and Chemical Constituents of Durian Wine

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    This work evaluated the effects of inoculation time of Oenococcus oeni on the kinetics of fermentation and chemical constituents of durian wine produced using a non-Saccharomyces yeast, Torulaspora delbrueckii.  The growth of T. delbrueckii in mixed-culture fermentations was significantly adversely affected by the presence of O. oeni, and the growth of malolactic bacteria was also affected by the metabolism of yeast during fermentation. The level of ethanol produced in simultaneous alcoholic and malolactic fermentation (SIM, 6.93%, v/v) was comparable to that in the Saccharomyces cerevisiae EC-1118 control (6.75%, v/v); both levels were relatively higher than that in the T. delbrueckii Biodiva control (6.39%, v/v) and the other two sequential fermentations (oenococci inoculated after four and seven days of alcoholic fermentation, SEQ 4th, 6.34% and SEQ 7th, 6.33% v/v respectively). The final concentrations of organic acids and esters in the mixed-culture wines were correlated with the inoculation time of O. oeni. SIM produced relatively higher levels of ethyl esters (ethyl esters of hexanoate, octanoate, decanoate and lactate) and acetate esters (ethyl acetate and isoamyl acetate) than those in SEQ 4th, SEQ 7th and the Biodiva control. This suggests that SIM would contribute fruity aroma properties to and modulate the mouthfeel of durian wine. The production of 3-(ethylthio)-1-propanol could compensate for the weak onion-like odour caused by the decrease in initial volatile sulphur compounds. Overall, this research suggests that SIM treatment is an effective way to produce durian wine with higher ester production

    Impulsivity in disorders of food and drug misuse.

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    BACKGROUND: Evidence suggests some overlap between the pathological use of food and drugs, yet how impulsivity compares across these different clinical disorders remains unclear. Substance use disorders are commonly characterized by elevated impulsivity, and impulsivity subtypes may show commonalities and differences in various conditions. We hypothesized that obese subjects with binge-eating disorder (BED) and abstinent alcohol-dependent cohorts would have relatively more impulsive profiles compared to obese subjects without BED. We also predicted decision impulsivity impairment in obesity with and without BED. METHOD: Thirty obese subjects with BED, 30 without BED and 30 abstinent alcohol-dependent subjects and age- and gender-matched controls were tested on delay discounting (preference for a smaller immediate reward over a larger delayed reward), reflection impulsivity (rapid decision making prior to evidence accumulation) and motor response inhibition (action cancellation of a prepotent response). RESULTS: All three groups had greater delay discounting relative to healthy volunteers. Both obese subjects without BED and alcohol-dependent subjects had impaired motor response inhibition. Only obese subjects without BED had impaired integration of available information to optimize outcomes over later trials with a cost condition. CONCLUSIONS: Delay discounting appears to be a common core impairment across disorders of food and drug intake. Unexpectedly, obese subjects without BED showed greater impulsivity than obese subjects with BED. We highlight the dissociability and heterogeneity of impulsivity subtypes and add to the understanding of neurocognitive profiles across disorders involving food and drugs. Our results have therapeutic implications suggesting that disorder-specific patterns of impulsivity could be targeted.V.V. is a Wellcome Trust Intermediate Fellow in Clinical Neurosciences (Wellcome Trust grant no. WT093705MA). Y.W. is supported by the Fyssen Fondation. N.A.H. is a Wellcome Trust Intermediate Fellow in Clinical Neurosciences. The BCNI is supported by both the Wellcome Trust and Medical Research Council.This is the accepted manuscript. The final version is available from CUP at http://dx.doi.org/10.1017/S003329171400183

    Magnetotunnelling in resonant tunnelling structures with spin-orbit interaction

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    Magnetotunnelling spectroscopy of resonant tunnelling structures provides information on the nature of the two-dimensional electron gas in the well. We describe a model based on nonequilibrium Green's functions that allows for a comprehensive study of the density of states, tunnelling currents and current spin polarization. The investigated effects include the electron-phonon interaction, interface roughness scattering, Zeeman effect and the Rashba spin-orbit interaction. A qualitative agreement with experimental data is found regarding the satellite peaks. The spin polarization is predicted to be larger than ten percent for magnetic fields above 2 Tesla and having a structure even at the satellite peaks. The Rashba effect is confirmed to be observable as a beating pattern in the density of states but found to be too small to affect the tunnelling current.Comment: 31 pages, 11 figure

    A Metamaterial-Inspired Model for Electron Waves in Bulk Semiconductors

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    Based on an analogy with electromagnetic metamaterials, we develop an effective medium description for the propagation of electron matter waves in bulk semiconductors with a zincblende structure. It is formally demonstrated that even though departing from a different starting point, our theory gives results for the energy stationary states consistent with Bastard's envelope function approximation in the long-wavelength limit. Using the proposed approach, we discuss the time evolution of a wave packet in a bulk semiconductor with a zero-gap and linear energy-momentum dispersion.Comment: 43 pages, 4 figure

    The relative balance of goal-directed and habitual behaviours in obsessive-compulsive disorder

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    Our decisions are based on parallel and competing systems of goal-directed and habitual learning, systems which can be impaired in pathological behaviours. Here we focus on the influence of motivation and compare reward and loss outcomes in subjects with obsessive-compulsive disorder (OCD) on model-based goal-directed and model-free habitual behaviours using the two-step task. We further investigate the relationship with acquisition learning using a one-step probabilistic learning task. Forty-eight OCD subjects and 96 healthy volunteers were tested on a reward and 30 OCD subjects and 53 healthy volunteers on the loss version of the two-step task. Thirty-six OCD subjects and 72 healthy volunteers were also tested on a one-step reversal task. OCD subjects compared with healthy volunteers were less goal oriented (model-based) and more habitual (model-free) to reward outcomes with a shift towards greater model-based and lower habitual choices to loss outcomes. OCD subjects also had enhanced acquisition learning to loss outcomes on the one-step task, which correlated with goal-directed learning in the two-step task. OCD subjects had greater stay behaviours or perseveration in the one-step task irrespective of outcome. Compulsion severity was correlated with habitual learning in the reward condition. Obsession severity was correlated with greater switching after loss outcomes. In healthy volunteers, we further show that greater reward magnitudes are associated with a shift towards greater goal-directed learning further emphasizing the role of outcome salience. Our results highlight an important influence of motivation on learning processes in OCD and suggest that distinct clinical strategies based on valence may be warranted.The study was funded through a Wellcome Trust Intermediate Clinical Fellowship for VV (093705/Z/10/Z).This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/tp.2015.16
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