1,084 research outputs found

    Semilogarithmic Nonuniform Vector Quantization of Two-Dimensional Laplacean Source for Small Variance Dynamics

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    In this paper high dynamic range nonuniform two-dimensional vector quantization model for Laplacean source was provided. Semilogarithmic A-law compression characteristic was used as radial scalar compression characteristic of two-dimensional vector quantization. Optimal number value of concentric quantization domains (amplitude levels) is expressed in the function of parameter A. Exact distortion analysis with obtained closed form expressions is provided. It has been shown that proposed model provides high SQNR values in wide range of variances, and overachieves quality obtained by scalar A-law quantization at same bit rate, so it can be used in various switching and adaptation implementations for realization of high quality signal compression

    Asymptotic Analysis of Optimal Piecewise Uniform Polar Quantization

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    In this paper, a simple and complete asymptotical analysis is given for a mean square error (MSE) piecewise uniform polar quantizer (PUPQ). We show that PUPQ has the same performance as the asymptotic nonuniform polar quantizer (NPQ) and has implementation complexity between complexities of NPQ and uniform polar quantization. The goal of this paper is solving the quantization problem in case of PUPQ and finding the corresponding support region

    Design and standalone characterisation of a capacitively coupled HV-CMOS sensor chip for the CLIC vertex detector

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    The concept of capacitive coupling between sensors and readout chips is under study for the vertex detector at the proposed high-energy CLIC electron positron collider. The CLICpix Capacitively Coupled Pixel Detector (C3PD) is an active High-Voltage CMOS sensor, designed to be capacitively coupled to the CLICpix2 readout chip. The chip is implemented in a commercial 180180 nm HV-CMOS process and contains a matrix of 128×128128\times128 square pixels with 2525 μ\mum pitch. First prototypes have been produced with a standard resistivity of 20\sim20 Ω\Omegacm for the substrate and tested in standalone mode. The results show a rise time of 20\sim20 ns, charge gain of 190190 mV/ke^{-} and 40\sim40 e^{-} RMS noise for a power consumption of 4.84.8 μ\muW/pixel. The main design aspects, as well as standalone measurement results, are presented.Comment: 13 pages, 13 figures, 2 tables. Work carried out in the framework of the CLICdp collaboratio

    Effects of Alfaxalone or Propofol on Giant-Breed Dog Neonates Viability During Elective Caesarean Sections

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    Nowadays, thanks to the increased awareness of owners and breeders and to the most recent techniques available to veterinarians, the management of parturition, especially of C-sections, has become a topic of greater importance. Anesthesia is crucial and must be targeted to both the mother and neonates. The present study aimed to evaluate the effect of the induction agent alfaxalone on the vitality of puppies born from elective C-section, in comparison to propofol. After inducing general anesthesia for elective C-section, puppies from the mothers induced with alfaxalone had higher 5-min Apgar scores than those induced with propofol. The concentration of cortisol in fetal fluids collected at birth is neither influenced by the anesthetic protocol used, nor does it differ between amniotic and allantoic fluids. Nevertheless, the cortisol concentration in fetal fluids affects the relationship between anesthesia and the Apgar score: the present study highlights a significant relationship between the anesthetic protocol used and Apgar score in puppies, and fetal fluids cortisol concentration acts as a covariate of this relationship. Alfaxalone is a safe and effective drug for the induction of anesthesia in dogs, and it can be successfully employed for elective C-section, with neonatal wellbeing improvements

    Effects of Phytogenic Feed Additive and Enzyme on Growth Performance of Broilers Fed Diets with Reduced Energy Concentrations

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    The effects of dietary supplementation with phytogenic feed additives (PFA) and enzyme (E) on performance parameters were investigated using Ross 308 as hatched broilers fed standard diets or diets with reduced energy concentrations. Birds were assigned to 5 treatments with 5 replications each and fed either a standard basal diet or a re-formulated basal diet with reduced energy concentrations. Reduction was made according to enzyme matrix (Ronozyme WX, DSM). Treatments were: (1) Standard diet; (2) Negative control (NC) – 4% reduction in ME (3) NC + E; (4) NC + PFA (5) NC + E + PFA. Body weight and feed consumption were recorded weekly. Mortality was recorded on daily basis. Foot pad lesions were scored at day 35 using scale from 0 (no lesion) to 2 (lesion extending through skin). The results showed that birds fed Negative control diets had a significantly lower body weights (P0.05). Mortality and FCR did not differ significantly between treatments. Average foot pad lesion score was the highest in Negative control (1.05) and the lowest in NC+E (0.55). In conclusion, re-formulation of diets for 4% energy reduction decreased broiler growth rate. Supplementation of diets with PFA improved live weight especially in combination with enzyme, hence confirming a growth-promoting effect of both phytogenics and enzymes in broilers

    Effect of Litter Treatment on the Occurrence of Foot Pad Lesions

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    Pododermatitis (foot pad lesions) is one of the main welfare problems in modern broiler production in countries with developed poultry farming. Factors contributing to the occurrence of these lesions are nutrition, stocking density and material used for litter. There are a number of different procedures that can be applied in order to prevent and reduce the number of lesions with the most pronounced defects. The experiment was conducted on broiler chickens grown in 10 buildings of 240 m2 each. The stocking density was 35 kg/m2. The experiment was set up in five treatments with two replicates. Treatment one (T1) - control with a straw litter, treatment two (T2) - litter treated with microbial preparation Micropan®, treatment three (T3) – litter with addition of lignin, treatment four (T4) – litter with addition of lignin and Micropan® and treatment five (T5) - chopped straw without supplements. At the end of the experiment, on day 42 the intensity of the lesions was scored on the slaughter line. The presence of lesions was scored using scale from 0 (no lesions) to 3 (plantar pads with more than 50% damage). Based on the results of the trial it can be concluded that litter has a significant impact on the presence and the degree of foot pad lesions. The lowest score of foot pad lesions was observed in the treatment T5 (chopped straw). Different treatments of litters may also contribute to the solution of the problem of pododermatitis since the results in all treated groups (T2, T3, T4 and T5) were better when compared to the control

    Design and characterization of the monolithic matrices of the H35DEMO chip

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    HIGH PERFORMANCE DIGITAL CURRENT CONTROL IN THREE PHASE ELECTRICAL DRIVES

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    Majority of contemporary static power converters makes use of three-phase, PWM controlled IGBT inverters. Typical applications include the electrical drives and grid connected converters. In both cases, it is of uttermost importance to obtain a high bandwidth control of the output current. The bandwidth is constrained by the problems of the feedback acquisition. The current ripple at the PWM frequency requires anti-aliasing measures that introduce delays, reduce the stability margin and restrain the bandwidth. We propose the feedback acquisition method which is robust against the ripple and noise, and minimizes delays. We also devise the current controller with control actions which suppress the effects of the delays. Proposed parameter setting procedures meet both the bandwidth requirements and the robustness against the noise and the parameter changes. Experimental verification proves that the proposed current controller achieves the response speed and the robustness against the noise which outperforms the competitive solutions.
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