2,326 research outputs found
SUBSTITUTABILITY AMONG SPECIES IN THE JAPANESE TUNA MARKET: A COINTEGRATION ANALYSIS
This paper examines two sets of hypotheses concerning the existence and the cause of the long-run, inter-species price relationships in the Japanese tuna market. A shock variable is introduced into the system to determine the degree of influence on the price relationships as well as the magnitude of the power in explaining the variation in prices of tuna species. Although in most cases the coefficient estimates of the shock variable are statistically significant, overall, the variable does not have significant explanatory power in both bivariate and multivariate regressions. We also find that the degree of substitutability between bigeye and albacore is substantially lower than the degree of substitutability between bigeye and yellowfin and, yellowfin and albacore.Industrial Organization, Resource /Energy Economics and Policy,
Text Localization in Video Using Multiscale Weber's Local Descriptor
In this paper, we propose a novel approach for detecting the text present in
videos and scene images based on the Multiscale Weber's Local Descriptor
(MWLD). Given an input video, the shots are identified and the key frames are
extracted based on their spatio-temporal relationship. From each key frame, we
detect the local region information using WLD with different radius and
neighborhood relationship of pixel values and hence obtained intensity enhanced
key frames at multiple scales. These multiscale WLD key frames are merged
together and then the horizontal gradients are computed using morphological
operations. The obtained results are then binarized and the false positives are
eliminated based on geometrical properties. Finally, we employ connected
component analysis and morphological dilation operation to determine the text
regions that aids in text localization. The experimental results obtained on
publicly available standard Hua, Horizontal-1 and Horizontal-2 video dataset
illustrate that the proposed method can accurately detect and localize texts of
various sizes, fonts and colors in videos.Comment: IEEE SPICES, 201
Circuit complexity in interacting QFTs and RG flows
We consider circuit complexity in certain interacting scalar quantum field
theories, mainly focusing on the theory. We work out the circuit
complexity for evolving from a nearly Gaussian unentangled reference state to
the entangled ground state of the theory. Our approach uses Nielsen's geometric
method, which translates into working out the geodesic equation arising from a
certain cost functional. We present a general method, making use of integral
transforms, to do the required lattice sums analytically and give explicit
expressions for the cases. Our method enables a study of circuit
complexity in the epsilon expansion for the Wilson-Fisher fixed point. We find
that with increasing dimensionality the circuit depth increases in the presence
of the interaction eventually causing the perturbative calculation to
breakdown. We discuss how circuit complexity relates with the renormalization
group.Comment: 50 pages, 2 figures; references updated; version to appear in JHE
\u3cem\u3eEx Vivo\u3c/em\u3e Diffusion Tensor Imaging of Spinal Cord Injury in Rats of Varying Degrees of Severity
The aim of this study was to characterize magnetic resonance diffusion tensor imaging (DTI) in proximal regions of the spinal cord following a thoracic spinal cord injury (SCI). Sprague–Dawley rats (n = 40) were administered a control, mild, moderate, or severe contusion injury at the T8 vertebral level. Six direction diffusion weighted images (DWIs) were collected ex vivo along the length of the spinal cord, with an echo/repetition time of 31.6 ms/14 sec and b = 500 sec/mm2. Diffusion metrics were correlated to hindlimb motor function. Significant differences were found for whole cord region of interest (ROI) drawings for fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusion coefficient (LD), and radial diffusion coefficient (RD) at each of the cervical levels ( p \u3c 0.01). Motor function correlated with MD in the cervical segments of the spinal cord (r2 = 0.80). The diffusivity of water significantly decreased throughout ‘‘uninjured’’ portions of the spinal cord following a contusion injury ( p \u3c 0.05). Diffusivity metrics were found to be altered following SCI in both white and gray matter regions. Injury severity was associated with diffusion changes over the entire length of the cord. This study demonstrates that DTI is sensitive to SCI in regions remote from injury, suggesting that the diffusion metrics may be used as a biomarker for severity of injury
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