The local polynomial Fourier transform (LPFT) based algorithm for autofocusing SAR images has recently been proposed by the authors. It produces a well focused image of moving targets, without defocusing stationary targets or inducing undesired cross-terms. The drawback of this algorithm is its high computational burden caused by the large number of elements in the set of used chirp-rates. We p...

In this paper we extend Wilcox’s classical results to the case of subregions of R2. This generalization enables us to construct many promising new waveforms with desired ambiguity profiles in the regions being considered. Key-Words: Radar waveform design, Ambiguity function, Non-linear optimization, Hermite waveform.

In previous work, the spread has been presented as a means to quantify nonstationarity. This is done by estimating the support of the joint time-frequency correlation function known as the expected ambiguity function. Two fundamental issues concerning the spread are addressed here. The first is that the spread is not invariant under basis transformation. We address this problem by introducing t...

CAZAC (Constant Amplitude Zero Auto-Correlation) sequences are important in waveform design because of their optimal transmission efficiency and tight time localization properties. Certain classes of CAZAC sequences have been used in radar processing for many years, while recently discovered sequences invite further study. This paper compares different classes of CAZAC sequences with respect to...

We propose equilibrium notions for incomplete information games involving players who perceive ambiguity about the types of others. Players have smooth ambiguity preferences (Klibanoff, Marinacci and Mukerji, 2005) and may be ambiguity averse. In the smooth ambiguity model it is possible to hold the agents’information fixed while varying the agent’s ambiguity attitude from aversion to neutralit...

In this paper, a new method of pulse compression polyphase code synthesis based on the aperiodic autocorrelation function properties and the assumption of coherent processing in the radar receiver is presented. Properties of the proposed code, including spectrum, ambiguity function, precompression bandlimiting effects, and the noise/clutter influence are analyzed. The main features of the synth...

BACKGROUND Several studies have examined the link between atrial fibrillation (AF) and various echocardiographic measures of cardiac structure and function in whites and other racial groups but not in blacks. Exploring AF risk factors in blacks is important given that the lower incidence of AF in this racial group despite higher risk factors, is not completely explained. METHODS We examined t...

BACKGROUND We hypothesized that chronic atrial fibrillation (AF) originated from the pulmonary veins, and was maintained by irregular activations of the posterior left atrium. We had performed the box pulmonary vein isolation procedure for the elimination of chronic AF associated with solitary mitral valve disease from 1999 to 2004. This paper evaluated the long-term results of this procedure o...

AIMS Beneficial effects of atrial fibrillation (AF) ablation have been demonstrated in patients with congestive heart failure (CHF) and significantly impaired left ventricular ejection fraction (LVEF). However, the impact of pulmonary vein isolation (PVI) on cardiac function in patients with paroxysmal AF and impaired LVEF remains under discussion. This study aimed to evaluate the impact of PVI...

AIMS Atrial fibrillation (AF) is the most common sustained arrhythmia in the elderly, and shares several risk factors with diastolic dysfunction, including hypertension and advanced age. The purpose of this study is to examine diastolic dysfunction as a risk for incident AF. METHODS AND RESULTS We examined the association of echocardiographic parameters of diastolic function with the incidenc...