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61.
62.
The present study examined the ability of newborns and 2-month-olds to detect phonetic differences between syllables. By relying on the modified high-amplitude sucking procedure, which did not permit the infants to use a simple same–different response, the present experiments tapped the perceptual representations of the speech sounds. Infants as young as a few days old displayed some capacity to represent differences in a set of syllables varying in their phonetic composition, although there was no convincing evidence that their representations were structured in terms of phonetic segments. Finally, evidence of developmental changes in speech processing were noted for the first time with infants in this age range. The change noted was a tendency from global toward more specific representations on the part of the older infants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
63.
The autocorrelation is often used in signal processing as a tool for finding repeating patterns in a signal. In image processing, there are various image analysis techniques that use the autocorrelation of an image in a broad range of applications from texture analysis to grain density estimation. This paper provides an extensive review of two recently introduced and related frameworks for image representation based on autocorrelation, namely Patch Autocorrelation Features (PAF) and Translation and Rotation Invariant Patch Autocorrelation Features (TRIPAF). The PAF approach stores a set of features obtained by comparing pairs of patches from an image. More precisely, each feature is the euclidean distance between a particular pair of patches. The proposed approach is successfully evaluated in a series of handwritten digit recognition experiments on the popular MNIST data set. However, the PAF approach has limited applications, because it is not invariant to affine transformations. More recently, the PAF approach was extended to become invariant to image transformations, including (but not limited to) translation and rotation changes. In the TRIPAF framework, several features are extracted from each image patch. Based on these features, a vector of similarity values is computed between each pair of patches. Then, the similarity vectors are clustered together such that the spatial offset between the patches of each pair is roughly the same. Finally, the mean and the standard deviation of each similarity value are computed for each group of similarity vectors. These statistics are concatenated to obtain the TRIPAF feature vector. The TRIPAF vector essentially records information about the repeating patterns within an image at various spatial offsets. After presenting the two approaches, several optical character recognition and texture classification experiments are conducted to evaluate the two approaches. Results are reported on the MNIST (98.93%), the Brodatz (96.51%), and the UIUCTex (98.31%) data sets. Both PAF and TRIPAF are fast to compute and produce compact representations in practice, while reaching accuracy levels similar to other state-of-the-art methods.  相似文献   
64.
A Gibbs Point Process for Road Extraction from Remotely Sensed Images   总被引:3,自引:2,他引:3  
In this paper we propose a new method for the extraction of roads from remotely sensed images. Under the assumption that roads form a thin network in the image, we approximate such a network by connected line segments.To perform this task, we construct a point process able to simulate and detect thin networks. The segments have to be connected, in order to form a line-network. Aligned segments are favored whereas superposition is penalized. These constraints are enforced by the interaction model (called the Candy model). The specific properties of the road network in the image are described by the data term. This term is based on statistical hypothesis tests.The proposed probabilistic model can be written within a Gibbs point process framework. The estimate for the network is found by minimizing an energy function. In order to avoid local minima, we use a simulated annealing algorithm, based on a Monte Carlo dynamics (RJMCMC) for finite point processes. Results are shown on SPOT, ERS and aerial images.  相似文献   
65.
The use of active personal dosemeters (APD) in interventional radiology was evaluated by Working Group 9 (Radiation protection dosimetry of medical staff) of the CONRAD project, which is a Coordination Action supported by the European Commission within its sixth Framework Programme. Interventional radiology procedures can be very complex and they can lead to relatively high doses to personnel who stand close to the primary radiation field and are mostly exposed to radiation scattered by the patient. For the adequate dosimetry of the scattered photons, APDs must be able to respond to low-energy [10-100 keV] and pulsed radiation with relatively high instantaneous dose rates. An intercomparison of five APD models deemed suitable for application in interventional radiology was organised in March 2007. The intercomparison used pulsed and continuous radiation beams, at CEA-LIST (Saclay, France) and IRSN (Fontenay-aux-Roses, France), respectively. A specific configuration, close to the clinical practice, was considered. The reference dose, in terms of H(p)(10), was derived from air kerma measurements and from the measured and calculated energy distributions of the scattered radiation field. Additional Monte Carlo calculations were performed to investigate the energy spectra for different experimental conditions of the intercomparison. The results of this intercomparison are presented in this work and indicate which APDs are able to provide a correct response when used in the specific low-energy spectra and dose rates of pulsed X-rays encountered in interventional radiology.  相似文献   
66.
This work aims to relate near-infrared (NIR) vibration bands to physicochemical (PC) parameters in order to discriminate honey samples. To the study, 14 Jatai weyrauchi honey samples from Roraima State (northern Brazil) and 15 Jatai angustula honey samples from Paraná State (southern Brazil) were evaluated by analyzing physicochemical parameters (moisture, pH, acidity, formaldehyde index, ashes, electric conductivity, color, hydroxymethylfurfural, protein, reducing sugars, total reducing sugars and sucrose, viscosity, and water activity), besides being submitted to spectral measurements in the near-infrared range from 900 to 1700 nm. By applying ComDim multiblock analysis, it was possible to simultaneously evaluate the results from NIR spectroscopy and the evaluated PC parameters. This tool allowed to highlight the relation between NIR spectra and PC parameters by producing informative graphs showing the relationship among the samples through the scores, the saliences of the blocks, and the loadings of the variables responsible for the similarities observed in the samples scores. Based on the principal component analysis, it was possible to conclude that the PC parameters can be replaced by NIR spectroscopy in the discrimination of honey samples, improving its evaluation regarding on the speed and decreasing the amount of reagents used for this purpose.  相似文献   
67.
68.
Summary Bilayer films composed of a wheat gluten layer and a functionalized polyolefin film were performed by hot press process with the aim to improve the moisture barrier property of hydrophilic gluten films. An ethylene/acrylic ester/maleic anhydride terpolymer (Lotader 3410) and an ethylene/glycidyl methacrylate copolymer (Lotader GMA) were used. The use of both Lotader products had no incidence on film opacity, and was effective to reduce dispersion in water and water vapor permeability. In the presence of the terpolymer, the mechanical properties were enhanced and the wide range selectivity of gluten films was preserved. Received: 23 June 1999/Revised version: 30 September 1999/Accepted: 30 September 1999  相似文献   
69.
Manganese (Mn) is widely distributed in the biosphere but occurs in only trace amounts in animal tissues. Although Mn deficiency and toxicity both have pathological consequences, the underlying biochemical lesions have not been well defined. In vitro studies suggest that transport proteins are affected by Mn, lead (Pb), and selenium (Se). Among these transport proteins, the calmodulin-regulated calcium pump (Ca(2+)Mg(2+)ATPase) could be inhibited by Mn. In order to understand Mn biochemical pathways, we examined the relationships between Mn blood levels and red blood cell Ca-pump activity among 248 mothers and newborns, environmentally exposed to Mn, Pb, and Se. POPULATION AND METHODS: 248 mother-newborn pairs were recruited at Robert Debré University Hospital (Paris). Blood Mn and Pb concentrations were measured by absorption spectrophotometry. Se was measured by fluorometric method. Red blood cell membrane suspensions were obtained for Ca-pump activity measurements. Linear and quadratic regression models and Pearson correlation were performed. RESULTS: A non-linear parabolic relationship between maternal Mn blood levels and newborn Ca-pump activity was discovered from the analysis of the observed data. The peak level of maternal Mn that corresponded to a maximal activity of the newborn Ca-pump was estimated at 23.9 microg/l with a 95% confidence interval of 17.6 to 32.4 microg/l. An inhibition of this enzyme was observed at low and high levels of maternal Mn. The relationships between the newborn Ca-pump activity and maternal Se and Pb levels became non-significant after adjustment on all the co-factors included in the final model. CONCLUSION: Maternal environmental exposure to Mn, as reflected by maternal blood levels of this metal, is associated with a reduced activity of newborn erythrocyte Ca-pump in a non-linear pattern. Mn levels between 17.6 and 32.4 microg/l in maternal blood probably correspond to the optimal physiological concentration for the metabolism of this enzyme in newborns.  相似文献   
70.
Propolis is a resinous substance composed of a mixture of different plant parts and molecules secreted by bees. Chemically, it is defined as a complex matrix containing biologically active molecules with antibacterial, antifungal, antiviral, antiparasitic, hepatoprotective, and immunomodulatory activities. It is widely employed in cosmetic formulations and pharmaceutical products and is one of the most widely used natural products. However, the effects and strength of these biological activities depend on the chemical profile and composition of each propolis type. This composition is associated with the diversity of local flora, the place and period of collection, and the genetics of the bees. In this context, the objective of this review was to investigate the biological, chemical, and microbiological properties of propolis. A technological prospection was also performed on patents for products designed to be used in animal health. Our investigation shows that the literature contains diverse studies dedicated to comparing and describing the composition and therapeutic properties of propolis. These studies demonstrate the potential biological use of propolis in veterinary medicine, showing the applications of propolis extracts in different formulations. However, there are a low number of propolis-based veterinary products with a registered patent. Thus, the development of products based on propolis is a promising market to be exploited. © 2019 Society of Chemical Industry  相似文献   
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