Mahmoud E. Allam

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Direction-of-arrival (DOA) estimation of signals is an important area of research in sonar and radar signal processing. Over the last few decades, numerous techniques have been developed for high resolution DOA estimation. In this paper, we show that velocity measurement using pulsed-wave Doppler ultrasound and DOA estimation are isomorphic problems. We(More)
In part I of this work, we presented the basic principles for applying high resolution wideband Direction-of-Arrival estimation techniques to pulsed-wave Doppler ultrasound. Such techniques provide high resolution velocity profiles and enable the identification of multiple velocity components inside a sample volume. Another important application is the(More)
BACKGROUND High plasma total homocysteine has emerged as a new risk for cognitive decline with age. OBJECTIVES The aim of the present study was to examine the association of plasma homocysteine with cognitive performance in normal aged Egyptians. SUBJECT AND METHODS Forty five aged Egyptians subjects were included in the study. Their cognitive(More)
This study investigates the long-term neuropsychiatric manifestations of single or combined chemicals: manganese; zinc phosphide; lead, mercury, and TNT; and pesticides among exposed industrial workers. We found that 75% of the exposed subjects as a whole and 50% of those exposed to each of Zinc phosphide and pesticides presented with more than one(More)
Objective: The aim of this study is to assess brain perfusion SPECT as a diagnostic tool in detection of subclinical cognitive deficits in non-demented elderly people. METHODS: The tracer distribution was measured with Tc99m-HMPAO and SPECT in 37 elderly subjects; age range 60-84 yrs. Results: Patients were divided according to Mini-Mental State Examination(More)
This paper proposes an algorithm to reconstruct a High Resolution (HR) image from a set of blurred, warped, undersampled, and noisy measured images. The proposed algorithm uses the affine block-based algorithm in the maximum likelihood (ML) estimator. It is tested using synthetic images, where the reconstructed image can be compared with its original. A(More)
Phase aberration due to tissues with inhomogeneous acoustic speeds is a major source for image degradation in medical ultrasound. In most phased array pulse-echo ultrasound systems, the delay used to steer and focus the beams are calculated assuming constant speed. In practice, however, the acoustic speed varies for different types of tissue. In this paper,(More)
Face verification has been widely studied during the past two decades. One of the challenges is the rising concern about the security and privacy of the template database. In this paper, we propose a secure face verification system which employs a user dependent one way transformation based on a two stage hashing algorithm. We first hash the face image(More)