نتایج جستجو برای: echo pattern
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هدف این مطالعه صحت‌سنجی مقادیر دما و بارش مدل‌های گردش عمومی و سناریوهای انتشار در ایستگاه‌های کرمانشاه، روانسر و اسلام‌آباد غرب برای دورۀ آماری 2008-1989 است. ابتدا مقادیر دما و بارش مشاهداتی از سازمان هواشناسی و مقادیر دما و بارش مدل‌ها و سناریوها از پایگاه دادۀ کانادا تهیه شد. سپس از آزمون نیکویی برازش، برای بررسی معنا‌داری مدل‌ها و از معیارهای ارزیابی ضریب تبیین (R2)، میانگین خطای مطلق(MAE)...
Stereophonic acoustic echo cancellation is one of the expanding areas in the field of the speech/multimedia communication systems. In a conventional stereophonic acoustic echo canceller, working in a stereo communication system, the existence of the strong cross-correlation between the input signals to the two channels has the problem of the low convergence speed of the weights of the adaptive ...
BACKGROUND Ischemic mitral regurgitation (iMR) predisposes to right ventricular (RV) pressure and volume overload, providing a nidus for RV dysfunction (RVDYS) and non-ischemic fibrosis (NIF). Echocardiography (echo) is widely used to assess iMR, but performance of different indices as markers of RVDYS and NIF is unknown. METHODS iMR patients prospectively underwent echo and cardiac magnetic ...
BACKGROUND In this study, we used functional MRI (fMRI) to investigate the pattern of cortical activations after a simple motor task in patients with migraine and white matter (WM) abnormalities on conventional MRI scans of the brain. We also investigated whether the extent of brain activations was correlated with WM structural pathology measured using diffusion tensor (DT) MRI. METHODS From ...
Introduction We present a multi-echo fMRI study at 7 T with 0.75 mm isotropic voxels and TEs ranging from 4.8 to 56 ms. This makes it possible to determine T2 at an unprecedented spatial scale making it possible to assess the local influence of myelinisation and vascularisation. As expected [1], the signal superficial to the cortex decays non-mono-exponentially because of a mixed compartment of...
Many morphological and dynamic properties of the common carotid artery (CCA), e.g. lumen diameter, distension and wall thickness, can be measured non-invasively with ultrasound (US) techniques. As common to other medical image segmentation processes, this requires as a preliminary step the manual recognition of the artery of interest within the ultrasound image. In real-time US imaging, such ma...
OBJECTIVE To assess whether three-dimensional imaging of the Achilles tendon by ultrasonographic tissue characterisation (UTC) can differentiate between symptomatic and asymptomatic tendons. DESIGN Case-control study. SETTING Sports Medical Department of the Hague Medical Centre. PATIENTS Twenty-six tendons from patients with chronic midportion Achilles tendinopathy were included. The "ma...
We performed functional magnetic resonance imaging (MRI) in professional piano players and control subjects during an overtrained complex ®nger movement task using a blood oxygenation level dependent echo-planar gradient echo sequence. Activation clusters were seen in primary motor cortex, supplementary motor area, premotor cortex and superior parietal lobule. We found signi®cant differences in...
The aim of this study in vitro of human fresh specimens was to quantitatively evaluate the contribution of the aqueous phase-intima interface (the first 400 msec of the reflected signal) in normal and atherosclerotic arterial walls. Seventy-five samples were studied, 15 normal, 15 fatty, 15 fibrofatty, 15 fibrous, and 15 calcific. A broadband transducer (4 to 14 MHz) was used. The aqueous phase...
in solvo-hydrothermal method, xrd pattern was indicated presence of intermediate of ammonium octatmolybdate and ammonium tetramolybdate, which were changed to stble phase of ?-moo3 annealing. sem images were indicated nanoparticle with semispheical morphology and tem image was demonstrated nanoparticles with a diameter size of 25nm. also in impregnate method. the xrd pattern was shown high crys...
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