Simulated annealing is applied to the synthesis of arrays in order reduce peaks side lobes by acting on elements' positions and weight coefficients. In case considered, number array elements spatial aperture an unequally spaced are a priori fixed. Thanks high flexibility simulated annealing, results obtained for 25-element over 50/spl lambda/ improve those reported literature.

Two-dimensional arrays offer the potential for producing three-dimensional acoustic imaging. The major problem is complexity arising from large number of elements in such arrays. In this paper, a synthesis method proposed that aimed at designing an aperiodic sparse two-dimensional array to be used with conventional beam-former. stochastic algorithm simulated annealing has been utilized minimize necessary produce spatial response meets given requirements. highly innovative, as it can design...

Underwater exploration is becoming more and important for many applications involving physical, biological, geological, archaeological, industrial issues. This paper aims at surveying the up-to-date advances in acoustic acquisition systems data processing techniques, especially focusing on three-dimensional (3-D) short-range imaging scene reconstruction understanding. In fact, advent of smarter efficient has allowed generation good quality high-resolution images related design proper...

ABSTRACT In this study, we optimized procedures to enumerate viruses from marine sediments by epifluorescence microscopy using SYBR Green I as a stain. The highest virus yields the bulk of were obtained utilizing pyrophosphate and 3 min sonication. efficiency extraction benthic pyrophosphate-ultrasound treatment was about 60% extractable particles. Samples treated with nucleases had increased counts, suggesting masking effect extracellular DNA. No significant differences observed between...

In conventional beamforming systems, the use of aperiodic arrays is a powerful way to obtain high resolution employing few elements and avoiding presence grating lobes. The optimized design such required task in order control side-lobe level distribution. this paper, an optimization method aimed at designing linear sparse with great flexibility proposed. Simulated annealing, which stochastic methodology, has been utilized synthesize positions weight coefficients array minimize peak sidelobes...

Frequency-invariant beam patterns are often required by systems using an array of sensors to process broadband signals. If the spatial aperture is shorter than involved wavelengths, a superdirective beamforming essential get efficient system. In this context, robustness imperfections crucial feature. literature, only few approaches have been proposed design robust, superdirective, frequency-invariant beamformer based on filter-and-sum architecture; all them achieve frequency-invariance...

In this paper, the preliminary design and assessment of a high-resolution 3-D acoustic imaging system based on sparse planar array sensors, which is particularly intended for underwater applications, are presented. Critical issues in development sonar systems 1) cost hardware, associated with huge number sensors that compose array, 2) computational burden processing signals were gathered. Here, such problems overcome by optimized synthesis an aperiodic allows device to operate at different...

A planar array of sensors is required to collect the signals coming from a 3-D scene generate volumetric underwater acoustic images. The method most frequently used process acquired digital beamforming algorithm. In general, owing high number and beam signals, computational load prohibitive for real-time image generation. literature, frequency-domain technique based on chirp zeta transform (CZT), which efficient computationally advantageous, has been introduced linear arrays working in far...

This paper addresses the spatial processing of signals collected by a linear array sensors that feeds filter-and-sum, data-independent beamformer. When frequency band spanned to be processed is extremely wide, given can shorter than wavelength (at lowest frequencies) and, at same time, too scarcely populated for correct sampling wavefield highest frequencies). Superdirectivity and aperiodic sparse layouts are possible solutions these two problems. However, have never been considered jointly...

Solid oxide fuel cells (SOFCs) are a promising option for power generation plants, but the design of fault diagnosis methods remains key challenge. We propose use quantitative model such plant (validated by real experiments) with support vector machine (SVM) to detect and classify possible faults. The adoption classification approach as an identification strategy in model-based process represents major innovation field SOFC plants. Constant-voltage constant-current control strategies...

Audio imaging can play a fundamental role in computer vision, particular automated surveillance, boosting the accuracy of current systems based on standard optical cameras. We present here new hybrid device for acoustic-optic imaging, whose characteristics are tailored to surveillance. In particular, allows realtime, high frame rate generation an acoustic map, overlaid over image using geometric calibration audio and video streams. demonstrate potentialities target tracking three challenging...

Abstract A numerical procedure based on a genetic algorithm is proposed in order to synthesize linear, sparse, and aperiodic array be used beamforming processor. The method aimed minimize the sidelobe peak of beam pattern acting elements' positions weights. Obtained results also confirm effectiveness approach comparison with other techniques related literature. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 194–196, 2002.

Frequency-invariant beam patterns (FIBPs) are often required by systems using an array of sensors to process broadband signals. Although several methods have been proposed design a beamformer (typically characterized finite impulse response (FIR) filter for each sensor) with FIBP, until now, the case in which spatial aperture is shorter than involved wavelengths has very rarely considered. In such case, use superdirective pattern essential attaining efficient system. this context, robustness...

To generate volumetric underwater acoustic images, a planar array of sensors is required to collect the signals coming from 3-D scene. The method most frequently used process acquired beamforming algorithm. In general, owing high number and beam signals, computational load prohibitive for real-time image generation. An efficient frequency implementation based on use chirp zeta transform (CZT) has been proposed in literature case involving linear arrays. this paper, we propose an algorithm...

Planar arrays are used jointly with filter-and-sum beamforming to achieve 3-D spatial discrimination in processing broadband signals. In these systems, the beams steered various directions investigate a given portion of space. The band can be so wide as require both superdirective performance (to increase directivity at low frequencies) and sparse aperiodic layouts avoid grating lobes high frequencies). We propose an original method simultaneously optimize transducer positions coefficients...

A synthesis method is proposed that aimed at designing a planar, sparse, and aperiodic array to be used in beamforming processor. This minimises the number of elements able generate beam pattern fulfils various priori fixed constraints. The obtained results are better than those related literature.

Noise in the ocean is result of many contributions. Sources emitting sound open sea as well a coastal area can be placed both surface and underwater. Excluding self-noise, noise impinging sonar system called ambient usually split two groups: anthropic natural. In this paper we focus modeling produced by ship transit, which falls category, due to agitation, that classified natural source. particular aspire simulate acoustic radiated machinery vessel once rotational speed propeller induces...

Dual-mode contrast agents (CAs) have great potential for improving diagnostics. However, the effectiveness of CAs is strictly related to both solution adopted merge two into a single probe unit, and ratio between agents. In this study, dual-mode simultaneous magnetic resonance imaging (MRI) ultrasound (UI) were assessed. For purpose, different densities superparamagnetic iron oxide nanoparticles (SPIONs) anchored external surface polymer-shelled microbubbles (MBs) or physically entrapped...

The success of distributed power generation by plants based on solid oxide fuel cells (SOFCs) is hindered reliability problems that can be mitigated through an effective fault detection and isolation (FDI) system. However, the numerous operating conditions under which such operate random size possible faults make identifying damaged plant components starting from physical variables measured in very difficult. In this context, we assess two classical FDI strategies (model-based with signature...