46 research outputs found

    Coupling of capillary RBC flow failure with neuronal depolarization

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    RBC (oxygen-carrier) behaviour in the cerebrocortical microvasculature during K^+^-induced cortical spreading depression (CSD) was examined in urethane-anesthetized male Wistar rats (n=10). The movements of FITC-labeled RBCs in single capillaries in the cortical region were traced with a high-speed camera laser scanning confocal fluorescence microscope and analyzed with Matlab domain software, KEIO-IS2, to obtain the velocities of all labeled RBCs appearing in local capillaries during CSD wave propagation. We found that CSD induced periodic decreases in both RBC number and velocity until RBCs halted or disappeared for 3.3 +/- 2.3 s, and then RBC flow was restored. The RBC flow stall was statistically significant (P < 0.05). During capillary flow failure in association with CSD spread, systemic arterial blood pressure remained unchanged. We conclude that RBCs are transiently sieved and stalled in capillaries during neuronal depolarization, and we suggest that this neuro-capillary coupling involves a hemorheological (viscosity-related) mechanism

    Gestalt vision experiments from an image processing perspective

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    Abstract In the late 19th century, the Gestalt Psychology rebelled against the popular new science of Psychophysics. The Gestalt revolution used many fascinating visual examples to illustrate that the whole is greater than the sum of all the parts. The physical interpretation of sensations and their quantification by JND's and Weber fractions were met with innumerable examples in which two identical physical stimuli did not look the same. The debate continues today with proponents of both physical, pixel-based thinking and perceptual, image based thinking. Image processing concepts can provide a new way of analyzing famous Gestalt displays. By this way of thinking, simple multi-resolution spatial processes can account for the various appearances of identical stimuli by analyzing the spatial properties of the entire image. Benary's Cross, Adelson's diamonds and Logvinenko's gradients can all be modeled by the low-, middle-and high-spatial-frequency components of the image. Pixel based analogs of physics and object cognition can be replace by familiar image processing concepts, such as multiresolution spatial comparisons

    Experimental Measurements of Far Field Cough Airflows Produced by Healthy and Influenza- Infected Human Subjects

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    The present work details an experimental study of the cough airflow fields produced by subjects infected with influenza and when they are convalescent, together with data from healthy cohorts. The PIV and HWA measurements were taken far downstream at 1 m from the source within a cough chamber, along with droplet sampling at two different locations and nasal swabs from the sick subjects. The measured data over different seasons were used to evaluate and compare the results from sick, convalescent and healthy subjects. Although a total of 8 sick participants from winter 2014 and 2017 yielded positive nasal swab analysis, the total number of subjects involved in this work were 49 in number. The results from HWA show modest differences between sick and convalescent states of a participant, but the normalized cough velocity time histories from both the techniques follow similar trends. It is anticipated that a larger samples size will provide a clear conclusive difference among coughs from the three categories

    Analysis of Quasi-Optical Components for Far-Infrared Astronomy

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    This thesis is concerned with the development and analysis of quasi-optical components used in experiments to measure of the CMB in the terahertz and submillimetre wavebands. I have concentrated on corrugated horn structures in the Planck and QUBIC experiments. A precise analysis of the electromagnetic and optical performance of such instruments is required if they are to reach the sensitivity goals required. The analysis of these components was done through computer simulations and experimentation. There were a number of techniques used to model the horns. These techniques were implemented in NUI Maynooth's in-house simulation code 'Scatter' and a commercial software package known as CST. They were used to predict the beam pattern of corrugated horns including the effects of likely manufacturing errors. NUI Maynooth's Vector Network Analyser was used to confirm the results obtained by the simulations. The results in this thesis show that variations in corrugated horn made with the efectroforming technique could result in significant degraded performance but that small gaps between the metal sheets in platelet arrays are acceptable

    High definition systems in Japan

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    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems

    Low complexity hardware oriented H.264/AVC motion estimation algorithm and related low power and low cost architecture design

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    制度:新 ; 報告番号:甲2999号 ; 学位の種類:博士(工学) ; 授与年月日:2010/3/15 ; 早大学位記番号:新525

    Perception-Oriented Single Image Super-Resolution using Optimal Objective Estimation

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    Single-image super-resolution (SISR) networks trained with perceptual and adversarial losses provide high-contrast outputs compared to those of networks trained with distortion-oriented losses, such as L1 or L2. However, it has been shown that using a single perceptual loss is insufficient for accurately restoring locally varying diverse shapes in images, often generating undesirable artifacts or unnatural details. For this reason, combinations of various losses, such as perceptual, adversarial, and distortion losses, have been attempted, yet it remains challenging to find optimal combinations. Hence, in this paper, we propose a new SISR framework that applies optimal objectives for each region to generate plausible results in overall areas of high-resolution outputs. Specifically, the framework comprises two models: a predictive model that infers an optimal objective map for a given low-resolution (LR) input and a generative model that applies a target objective map to produce the corresponding SR output. The generative model is trained over our proposed objective trajectory representing a set of essential objectives, which enables the single network to learn various SR results corresponding to combined losses on the trajectory. The predictive model is trained using pairs of LR images and corresponding optimal objective maps searched from the objective trajectory. Experimental results on five benchmarks show that the proposed method outperforms state-of-the-art perception-driven SR methods in LPIPS, DISTS, PSNR, and SSIM metrics. The visual results also demonstrate the superiority of our method in perception-oriented reconstruction. The code and models are available at https://github.com/seungho-snu/SROOE.Comment: Code and trained models will be available at https://github.com/seungho-snu/SROO
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