In this paper, we propose an efficient acquisition scheme for GPS receivers. It is shown that GPS signals can be effectively sampled and detected using a bank of randomized correlators with much fewer chip-matched filters than those used in existing GPS signal acquisition algorithms. The latter use correlations with all possible shifted replicas of the satellite-specific C/A code and an exhaust...

BACKGROUND We hypothesized that abnormalities in regional systolic strain (epsilon) might be present among hypertensive subjects with normal ejection fraction, and, if present, could be used to identify patients at high risk for heart failure. The aim of the current case-control study was to use speckle tracking imaging to identify subclinical global and regional systolic function abnormalities...

A 12-year-old-boy was admitted to our Medical Imaging Department for scrotal/perineal heamatoma and a painless partial erection after bicycle trauma. He had no other medical history. Doppler US and angiography of penile region were performed. A gray-scale US (axial view, Fig. A)) shows an irregular hypoechoic region within the echogenic cavernous tissue and cavernosal lacuna (arrows). The color...

There is a basic constraint imposed on radar measurements when the transmitted signal is a simple, CW pulse. As a result, the radardesigner may wish to use a more complex signal and thereby extract more information from an echoing object. Unfortunately, the processed returns of the sophisticated waveforms usually consist of a peak response and small adjacent responses (called "time sidelobes") ...

An attempt was made to derive a useful noninvasive index to evalute a change in myocardial contractile state using transcutaneous Doppler flow-velocity curve from the carotid artery. In 5 mongrel dogs and in 43 patients with various heart disease, Doppler flow velocity curves were obtained from the ascending aorta intravascularly using a Doppler catheter and/or from carotid artery transcutaneou...

background and aims. although salivary gland tumors are not very common, early diagnosis and treatment is crucial because of their proximity to vital organs, and therefore, determining the efficacy of new imaging procedures becomes important. this study aimed to evaluate the efficacy of magnetic resonance imaging (mri) and color doppler ultrasonography parameters in the diagnosis and differenti...

Objective- The aim of this study was to test the repeatability, the variability, and to establish the reference values of PW measurements in healthy Markhoz goats.Design- Retrospective study.Animals- 20 female Markhoz goats.Procedure- Using a standardized PW Doppler echocardiographic protocol, 20healthy adult unsedated female Markhoz goats were investigated three times at one-...

Objective- The purpose of this study was to investigate the feasibility of performing echocardiography in apparently healthy pigeons, and measurement of the quantitative cardiac indices using B-mode and Doppler techniques. Design- Experimental study Animals- Ten apparently healthy pigeons Procedures- Echocardi...

Abstract Doppler and recoil effects are an integral part of the photoemission process at high kinetic energies reached in hard x-ray photo-electron spectroscopy (HAXPES) have a major effect on observed lineshape, resulting broadening, energy losses discrete excitations. These can be modeled with degree detail for small systems like diatomic molecules, larger such treatment is often superfluous ...

The tube in flow rigs used for testing Doppler ultrasound instruments can attenuate and distort the beam and sample volume by refraction, reflection, absorption and mode conversion. The attenuation and degree of distortion has been measured by using a moving string test object and candidate tubes have been compared. Tubes of rubber, TFE-Teflon, Perspex, heatshrink and C-Flex have been tested le...