We report simultaneous meteor echo observations using the Arecibo 430MHz and 46.8-MHz radars. Using identical data-taking and meteor selection criteria, 1868 and 367 meteors were found in the 430-MHz and 46.8-MHz beams, respectively, while 145 were found in both beams during the 7 hours of observation. Of the 367 VHF echoes, there were only 10 trail echoes, while the rest were head echoes, whic...

BACKGROUND Cerebral cavernous malformations (CCMs) are congenital vascular anomalies that can cause seizures, intracranial hemorrhages, focal neurological deficits, and migrainelike headaches. Magnetic resonance (MR) imaging has substantially facilitated diagnosis of CCM. It is now widely accepted that familial clustering with an autosomal dominant inheritance pattern should be suspected in cas...

In this paper, echo cancellation is done using genetic algorithm (GA). The genetic algorithm is implemented by two kinds of crossovers; heuristic and microbial. A new procedure is proposed to estimate the coefficients of adaptive filters used in echo cancellation with combination of the GA with Least-Mean-Square (LMS) method. The results are compared for various values of LMS step size and diff...

Ten patients (six women and four men) with endomyocardial disease, four with and six without hypereosinophilia, were studied by two-dimensional echocardiography (2-D echo). Eight had biventricular congestive heart failure and two had atypical chest pain with ischemic electrocardiographic changes. The patients were 15-50 years old (mean 40 years) and duration of illness was 2-9 years (mean 4.4 y...

This paper proposes an efficient array beam-forming method using spatial matched filtering (SMF) for ultrasonic imaging. In the proposed method, ultrasonic waves are transmitted from an array subaperture with fixed transmit focus as in conventional array imaging. At receive, radio frequency echo signals from each receive channel are passed through a spatial matched filter that is constructed ba...

This study reports an adaptation of a parametric echosounder system using 15 kHz as secondary frequency to investigate the angular response of sub-bottom backscatter strength of layered mud, providing a new method for enhanced acoustic detection of buried targets. Adaptions to achieve both vertical (0°) and non-vertical inclination (1– 15°, 30°, 45° and 60°) comprise mechanical tilting of the a...

The objectives of this study were to investigate patients treated for scrotal trauma at our institute for the last three decades to describe our experience with an emphasis on the etiologies and ultrasonographic findings in these patients. We reviewed medical records of patients who underwent scrotal ultrasonography for evaluation of testicular trauma at our institutes from 1986 to 2015. Trends...