Moving object detection using adaptive subband decomposition and fractional lower order statistics in video sequences

Cataloged from PDF version of article.In this paper, a moving object detection method in video sequences is described. In the 3rst step, the camera motion is eliminated using motion compensation. An adaptive subband decomposition structure is then used to analyze the motion compensated image. In the “low–high” and “high–low” subimages moving objects appear as outliers and they are detected using a statistical detection test based on fractional lower-order statistics. It turns out that the distribution of the subimage pixels is almost Gaussian in general. On the other hand, at the object boundaries the distribution of the pixels in the subimages deviates from Gaussianity due to the existence of outliers. By detecting the regions containing outliers the boundaries of the moving objects are estimated. Simulation examples are presented. (C) 2002 Elsevier Science B.V. All rights reserved

Adaptive methods for dithering color images

Cataloged from PDF version of article.Most color image printing and display devices do not have the capability of reproducing true color images. A common remedy is the use of dithering techniques that take advantage of the lower sensitivity of the eye to spatial resolution and exchange higher color resolution with lower spatial resolution. In this paper, an adaptive error diffusion method for color images is presented. The error diffusion filter coefficients are updated by a normalized least mean square-type (LMS-type) algorithm to prevent textural contours, color impulses, and color shifts, which are among the most common side effects of the standard dithering algorithms. Another novelty of the new method is its vector character: Previous applications of error diffusion have treated the individual color components of an image separately. Here, we develop a general vector approach and demonstrate through simulation studies that superior results are achieved. © 1997 IEEE

Robust direction of arrival estimation in non-Gaussian noise

Cataloged from PDF version of article.In this correspondence, a nonlinearly weighted least-squares method is developed for robust modeling of sensor array data. Weighting functions for various observation noise scenarios are determined using maximum likelihood estimation theory. Computational complexity of the new method is comparable with the standard least-squares estimation procedures. Simulation examples of direction-of-arrival estimation are presented

Effect of short-term pre-hatch heat shock of incubating eggs on subsequent

The aim of this study was to investigate the effect of thermal conditioning of broiler chickens during embryonic development on subsequent performance under standard rearing conditions. During incubation eggs from 32-, 45- and 56-week old Ross 308 broiler parent stock were subjected to a 2 h heat shock of 39 °C on days 14 and 15 of incubation. Eggs in the control were incubated throughout incubation at 37 °C. Chicks were feather sexed and equal numbers of each sex were placed in each pen per treatment, and reared for 42 days. Live weight, mortality and feed conversion ratio (FCR) were used as measures of performance. The final (six-week) live weights of broilers from young, mid and older parents for the treatment and control groups were 2113 ± 13.8 vs. 2159 ± 20.0, 2084 ± 29.2 vs. 2139 ± 20.0 and 2096 ± 17.6 vs. 2131 ± 24.3 g, respectively. The six-week live weight of the heat-treated group (2098 ± 12.0 g) was significantly lower than that of the control (2143 ± 12.2 g). The 1-6 week mortality figure was significantly lower in the heat-treated group of chickens from the young (83) and mid parent (77) groups compared to their controls (130 and 119), respectively. However, in the treatment group the incidence of mortality in broilers from the older parent group was significantly higher (105) than that of the control (79). The overall mortality without considering the parent age group was significantly lower in the treatment group (265) than in the control group (328). Mean FCR (g feed/g gain) of the chickens of the three parent groups was 1.79 ± 0.02 vs. 1.75 ± 0.03, 1.85 ± 0.03 vs. 1.77 ± 0.02 and 1.80 ± 0.03 vs. 1.77 ± 0.03 for the treatment vs. control groups, respectively, but the difference was significant only in the mid age parent group. These results suggest that prenatal thermal conditioning is not detrimental to broiler growth under standard rearing conditions in the absence of thermal stress. However, survival rate was improved but live weight and FCR were in some cases significantly poorer. Keywords: Heat stress, incubation, parent age, live weight, mortalitySouth African Journal of Animal Science Vol. 38 (1) 2008: pp. 58-6

Detection of microcalcifications in mammograms using higher order statistics

Cataloged from PDF version of article.A new method for detecting microcalcifications in mammograms is described. In this method, the mammogram image is first processed by a subband decomposition filterbank. The bandpass subimage is divided into overlapping square regions in which skewness and kurtosis as measures of the asymmetry and impulsiveness of the distribution are estimated. The detection method utilizes these two parameters. A region with high positive skewness and kurtosis is marked as a region of interest. Simulation results show that this method is successful in detecting regions with microcalcifications

Short Communication Effects of short chain fatty acid (SCFA) supplementation on performance and egg characteristics of old breeder hens

A study was conducted to determine the effect of supplementing the diet of breeder hens with a short-chain fatty acid (SCFA) premix, containing 509 g fatty acid salts/kg of which 285 g were calcium butyrate, on their eggshell characteristics and the hatching percentage of the eggs. One thousand six hundred 66-week old White Bovans laying breeder hens were used in this experiment. They were housed in eight identical pens, each containing 200 birds, and four pens were used per treatment. The SCFA premix was included at 1000 mg/kg in the treatment diet, and fed for a period of nine weeks. Responses were compared with an unsupplemented treatment. Supplementation started when the hens were 66 weeks old. From day 75 eggs were collected for the next seven weeks and the occurrence of cracked, dirty and misshapen eggs was recorded, and the hatching percentage of the eggs was determined. Eggshell strength was lower in eggs from the control (1.76 ± 0.05) than from the treatment group (2.07 ± 0.03). The percentage of eggs produced by the control group (68.6 ± 0.08) was significantly lower than that by the supplemented group (71.5 ± 0.15). Percentage of dirty, cracked and misshapen eggs, and the hatchability percentage of the control group (1.15 ± 0.03, 3.44 ± 0.05, 6.27 ± 0.03 and 88.93 ± 0.06, respectively) were also significantly lower than in the group receiving SCFA (0.47 ± 0.03, 2.21 ± 0.03, 3.81 ± 0.03 and 93.36 ± 0.05, respectively). It was concluded that dietary supplementation of SCFA to layer breeder hens from 66 weeks of age onwards improved eggshell strength, reduced the percentage of dirty, cracked and misshapen eggs and increased the hatching percentage of the eggs. The positive responses were suggested to be largely due to the butyrate in the SCFA. Keywords: Butyrate; SCFA; eggshell quality; hatching characteristics South African Journal of Animal Science Vol. 37 (3) 2007: pp.158-16

Structure of nanoparticles embedded in micellar polycrystals

We investigate by scattering techniques the structure of water-based soft composite materials comprising a crystal made of Pluronic block-copolymer micelles arranged in a face-centered cubic lattice and a small amount (at most 2% by volume) of silica nanoparticles, of size comparable to that of the micelles. The copolymer is thermosensitive: it is hydrophilic and fully dissolved in water at low temperature (T ~ 0{\deg}C), and self-assembles into micelles at room temperature, where the block-copolymer is amphiphilic. We use contrast matching small-angle neuron scattering experiments to probe independently the structure of the nanoparticles and that of the polymer. We find that the nanoparticles do not perturb the crystalline order. In addition, a structure peak is measured for the silica nanoparticles dispersed in the polycrystalline samples. This implies that the samples are spatially heterogeneous and comprise, without macroscopic phase separation, silica-poor and silica-rich regions. We show that the nanoparticle concentration in the silica-rich regions is about tenfold the average concentration. These regions are grain boundaries between crystallites, where nanoparticles concentrate, as shown by static light scattering and by light microscopy imaging of the samples. We show that the temperature rate at which the sample is prepared strongly influence the segregation of the nanoparticles in the grain-boundaries.Comment: accepted for publication in Langmui

Frustrated 3-Dimensional Quantum Spin Liquid in CuHpCl

Inelastic neutron scattering measurements are reported for the quantum antiferromagnetic material Cu_2(C_5H_12N_2)_2Cl_4 (CuHpCl). The magnetic excitation spectrum forms a band extending from 0.9 meV to 1.4 meV. The spectrum contains two modes that disperse throughout the a-c plane of the monoclinic unit cell with less dispersion along the unique b-axis. Simple arguments based on the measured dispersion relations and the crystal structure show that a spin ladder model is inappropriate for describing CuHpCl. Instead, it is proposed that hydrogen bond mediated exchange interactions between the bi-nuclear molecular units yield a three-dimensional interacting spin system with a recurrent triangular motif similar to the Shastry-Sutherland Model (SSM). Model independent analysis based on the first moment sum rule shows that at least four distinct spin pairs are strongly correlated and that two of these, including the dimer bond of the corresponding SSM, are magnetically frustrated. These results show that CuHpCl should be classified as a frustration induced three dimensional quantum spin liquid.Comment: 13 pages, 17 figures (Color) ReSubmitted to Phys. Rev. B 9/21/2001 resubmission has new content email comments to [email protected] or [email protected]

Prime movers : mechanochemistry of mitotic kinesins

Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation