Sergio Carrato

University of Trieste | UNITS · Department of Engineering and Architecture

III-V-compound semiconductors offer many advantages over silicon-based technologies traditionally used in solid-state photodetectors, especially in hard X-ray applications that require high detection efficiency and short response times. Amongst them, gallium arsenide (GaAs) has very promising characteristics in terms of X-ray absorption and high ca...

At Elettra, the Italian synchrotron light source, an internal project has been started to develop an electron beam position monitor capable of achieving sub-micron resolution with a self-compensation feature. In order to fulfil these requirements, a novel RF front end has been designed. A high isolation coupler combines the input signals with a kno...

The last decades have witnessed substantial efforts in the development of several detector technologies for X-ray fluorescence (XRF) applications. In spite of the increasing trend towards performing, cost-effective and reliable XRF systems, detectors for soft X-ray spectroscopy still remain a challenge, requiring further study, engineering and cust...

ULTRASPIN is an apparatus devoted to the measurement of the spin polarization (SP) of electrons ejected from solid surfaces in a UHV environment. It is designed to exploit ultrafast light sources (free electron laser or laser high harmonic generation) and to perform (photo)electron spin analysis by an arrangement of Mott scatteringpolarimeters that...

The XAFS beamline at Elettra Synchrotron in Trieste combines X-ray absorption spectroscopy and X-ray diffraction to provide chemically specific structural information of materials. It operates in the energy range 2.4-27 keV by using a silicon double reflection Bragg monochromator. The fluorescence measurement is performed in place of the absorption...

Micro and nanomechanical resonators represent a promising platform for proteins label-free detection because of their extreme sensitivity, fast response and low cost. Micro-pillars are columnar resonators that can be easily arranged in dense arrays of several thousand sensors in a squared mm. To exploit such a large density, however, a method for t...

Timepix3 chip is a new ASIC specifically designed to readout hybrid pixel detectors. The main purpose of Timepix3 is to measure the time of arrival of events. This characteristic can be exploited very effectively to develop detectors for time resolved experiments at synchrotron radiation facilities. In order to investigate how the ASIC can be appli...

The TwinMic spectromicroscope at Elettra is a multipurpose experimental station for full-field and scanning imaging modes and simultaneous acquisition of X-ray fluorescence. The actual LEXRF detection setup consists of eight single-cell Silicon Drift Detectors (SDD) in an annular configuration. Although they provide good performances in terms of bo...

This work investigates the long term stability of suspensions of surfactant-free gold nanostars with mean diameter of 78 ± 13 nm (measured from tip to tip across the nanostar).We monitored the optical and morphological properties of the nanostars over the course of several days after synthesis by observing the changes in the UV-visible absorption s...

The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite eleme...

Simultaneous photon-beam position and intensity monitoring is becoming of increasing importance for new-generation synchrotron radiation sources and free-electron lasers (FEL). Thus, novel concepts of beam diagnostics are required in order to keep such beams under control. From this perspective diamond is a promising material for the production of...

Pillars resonators arrays are emerging as powerful sensors for their peculiar characteristics, namely high mass sensitivity, high active areas density and operation in liquid. On the other hand, their characteristic vertical geometry and fabrication strategy hinders a direct integration within integrated circuits. So far, the examples reported in l...

The industrial spray-painting process is currently split into two main branches: the uniform covering of surfaces (e.g. automotive), and decorative painting (e.g. furniture, porcelain). While the former makes extensive use of robotics, the latter does not, relying instead on the manual skills of expert painters. In this paper we propose an innovat...

Diamond is one of the most promising materials for developing innovative electronic devices. Chemical vapour deposition (CVD) homoepitaxial growth allows the synthesis of high quality single crystal diamond plates. However, the use of these crystals for electronic applications is hampered by their small area (typically of the order of 10 mm2). Larg...

Diamond is a promising material for the production of semitransparent in situ photon beam monitors which can withstand the high dose rates occurring in new generation synchrotron radiation storage rings and in free electron lasers. We report on the development of a 500 μm thick freestanding, single crystal chemical vapor deposited diamond detector...

New generation Synchrotron Radiation (SR) sources and Free Electron Lasers (FEL) require novel concepts of beam diagnostics to keep photon beams under surveillance, asking for simultaneous position and intensity monitoring. To deal with high power load and short time pulses provided by these sources, novel materials and methods are needed for the n...

Diamond is an outstanding material for the production of semitransparent in situ photon beam monitors which can withstand the high dose rates occurring in new generation synchrotron radiation storage rings and in free electron lasers. Here we report on the development of a 500 µm thick freestanding, single-crystal chemical vapor deposited diamond d...

AtmoCube belongs to the class of CubeSat nano-satellites. It represents an innovative and low-cost measurement system to study the near-Earth space environment. This project is carried out by a cooperation between the Departments of Physics and Industrial Engineering and Information Technology of the University of Trieste with the involvement of th...

Fingerprints are one the oldest biometrics used in investigations. The fingerprint morphology is considered unique and immutable and it is routinely used to identify an individual from the mark found at the crime scene. The comparison is based solely on the ridges flow and on their discontinuities (i.e. the minutiae), without considering other info...

Regular moderate-intensity exercise is strongly recommended for its beneficial effects in all people. In patients with type 1 diabetes, however, the exercise-associated glycemic imbalances remain an unresolved clinical challenge. Current guidelines require an in-depth understanding of the glycemic responses to exercise and each patient has to disco...

Forensic science is already taking benefits from synchrotron radiation (SR) sources in trace evidence analysis. In this contribution we show a multi-technique approach to study fingerprints from the morphological and chemical point of view using SR based techniques such as Fourier transform infrared microspectroscopy (FTIRMS), X-ray fluorescence (X...

Higher order spectra analysis can be employed to reconstruct a corrupted signal via the third-order spectrum, i.e. the bispectrum. However, this technique is plagued by an unknown misplacement of the origin of the restored signal, this being true both for ID signals such as audio and 2D signals such as images. In this contribution we tackle and sol...

AtmoCube is a low-cost one-unit CubeSat that has been designed and developed at the University of Trieste. Aimed at probing the near-Earth space environment via a set of scientific payloads like a GPS, a magnetometer and a radiation detector, AtmoCube is one of the nine CubeSat projects selected by the ESA Education Office to be launched cost-free by...

AtmoCube belongs to the class of CubeSat nanosatellites. It appears as a one unit cubesat with a total mass around 1 kg, and an aluminium structure. It represents an innovative and low cost measurement system for the study of the near Earth space environment above 350 km of altitude. This project is being carried on by a cooperation among the Depar...

This paper focuses on the minimum hardware implementation of a digital compensator for digitally controlled dc-dc converters. A novel serial PID architecture is presented that, together with the adopted representation of controller parameters, minimizes the area requirements while allowing the representation of a wide range of parameter values. Lar...

Shoeprints found on the crime scene are useful to understand the crime dynamics; currently some systems have been proposed to automatically identify the make and model of the shoe that left the mark on the crime scene. However these systems have been tested on shoe marks synthesized artificially with different noise adding techniques. Here we prese...

Shoe marks found on the crime scene are invaluable for the identification of the culprit when no other piece of evidence is available. Thus semi-automatic and automatic systems have been recently proposed to find the make and model of the footwear that left the shoe marks. The systems proposed up to now have two main drawbacks, as they (i) are gene...

Shoe prints found on the crime scene are useful to understand the crime dynamics. Several semi-automatic and automatic systems have already been proposed to identify the make and model of the shoe that left the mark on the crime scene, however these systems have been tested on simulated shoe marks, i.e. not coming from real crime scene but artifici...

Shoe marks found on crime scenes can lead to the identification of the culprit, thus it is important to find the make and model of the footwear that left the marks. Some semi-automatic and automatic systems have been proposed in literature for the purpose, but they have been all tested on synthetic shoe marks, i.e. sole prints with added synthetic...

Shoeprints found on the crime scene are useful to understand the crime dynamics. Several semi-automatic and automatic systems have already been proposed to identify the make and model of the shoe that left the mark on the crime scene, however these systems have been tested on simulated shoe marks, i.e. not coming from real crimes scene but artifici...

Shoeprints found on the crime scene contain useful information for the investigator: being able to identify the make and model of the shoe that left the mark on the crime scene is important for the culprit identification. Semi-automatic and automatic systems have already been proposed in the literature to face the problem, however all previous work...

In this paper a new large-signal discrete time model for dc-dc converters is derived. The model is meant to overcome the lack of large-signal dc-dc converter models which, firstly, are able to accurately predict converter behavior in different operating modes and, secondly, can be implemented both in Matlab/SIMULINK and HDL language. The model is w...

Mechanical oscillators became a main focus of research in recent years for potential applications in biomolecule detectors. We recently demonstrated the feasibility of a scheme based on twin cantilevers with a sensitivity down to the single molecule. This approach is extremely promising under the condition that the two terminals of the device can b...

We present a new bidimensional detector setup, based on cross delay line technology, specifically developed for time resolved experiments and particularly suited to work in conjunction with pump-and-probe systems. Thanks to the particular architecture of the acquisition electronics, the detector is able to correlate each event with the time it occu...

As a step towards the realization of a γ-ray 8x8 modular imaging probe, the single pixel element has been extensively tested. It consists of a 6.1 mm2 x 3.7 mm CsI(Tl) scintillation crystal optically coupled to the backside of a 3.6 mm2 PiN diode on a 300 um fully depleted silicon wafer. The γ-ray detection system has been irradiated with the radio...

Portable image acquisition devices often operate in challenging outdoor environments. The quality of the acquired scenes is often low due to the low dynamics of current sensors. Moreover, these sensors are typically equipped with low-cost hardware. Hence, the image-enhancement algorithms are bounded to work in real time using limited resources and...

CMOS video cameras with high dynamic range (HDR) output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorit...

We present an image processing software suite, based on the Matlab environment, specifically designed to be used as a forensic tool by law enforcement laboratories in the analysis of crime scene videos and images. Our aim is to overcome some drawbacks which normally appear when using standard image processing tools for this application, i.e. mainly...

Recently, there has been growing interest in sensors based on frequency shift detection of mechanical resonators, that has led to extremely sensitive diagnostic methods for medicine and biology. Here the authors propose and demonstrate a strategy capable of detecting the presence of a few macromolecules, which uses an asymmetrical cantilever struct...

The dynamic range of an image is defined as the ratio between the maximum and minimum luminance value it contains. This value in real images can be several thousands or even millions, whereas the dynamic range of consumer imaging devices rarely exceeds 100; therefore some processing is needed in order to display a high dynamic range image correctly...

A novel prototype detector for scintimammography is presented. The detector is built according to a modular strategy. Each module is composed of an array of p–i–n diodes, coupled to a CsI(Tl) scintillator and to mixed-mode ASICs with self-triggering, sparsifying, A/D conversion and bidirectional serial data I/O transfer capabilities. The front-end...

Structural properties of cheese highly influence its chemical, mechanical and nutritive properties. The analysis and quantification of relevant fea- tures in cheese imagery is the basis of modern food microscopy. Processing Scanning Electron Microscopy (SEM) images is a powerful tool to estimate microstructural cheese features. In this paper, we pr...

In this paper, we report the development of a prototype for a new kind of detector intended for scintimammography imaging. Traditional photon counting information is available; moreover, digital words representing the amplitude of each event and suitable image elaboration methods significantly enhance the detector capabilities.The prototype detecto...

In this paper we report the development of a prototype for a new kind of detector intended for scintimammography imaging. Traditional photon counting information is available; moreover digital words representing the amplitude of each event and suitable image elaboration methods significantly enhance detector capabilities. The prototype detector is...

In the paper we present our project concerning a modular image processing environment to be used as a forensic tool by law enforcement laboratories in the analysis of crime scene videos and images. It is designed to overcome one of the main drawbacks of standard image processing tools, mainly the lack of full control and documentation on the operat...

An X-ray detector will be presented that is the combination of a segmented ionization chamber featuring one-dimensional spatial resolution integrated with an intelligent ADC front-end, multi DSP processing and embedded PC platform. This detector is optimized to fan beam geometry with an active area of 192 mm (horizontal) and a vertical acceptance o...

AtmoCube represents an innovative measurement system for the study of the near Earth space environment starting from about 400 km altitude. It appears as a cubic nano-satellite, 13 cm side, with a total mass of 1.3 kg (aluminum structure). The scientific instrument is a spectral dosimeter monitoring the radiation environment. The payload also inclu...

Digital cameras, new generation phones and in general modern image acquisition devices, requires algorithms for image enhancement suitable to work in real time and possibly with a limited power consumption. Unfortunately most of the systems present in the literature either require a very high computational effort or do not provide good performances...

A novel noise reduction system for video sequences is presented. It is based on a simple and accurate estimation algorithm, which is used to enable a filter in a suitable set of rational and median operators. The system, which has been implemented in real time for common intermediate format images on a commercial multimedia digital signal processor...

Video segmentation into shots is the first step in content-based analysis of digital video. This chapter provides a comprehensive taxonomy and critical survey of the existing techniques for video segmentation operating on MPEG video stream. Their performance, relative merits and limitations are discussed and contrasted. The gradual development of t...

We present a new approach for MPEG-2 video summarization and browsing based on the Growing Cell Struc- tures (GCS) neural algorithms. Our system VideoGCS first applies GCS to select keyframes for each shot using the color histograms of the dc-images of I frames. These keyframes are then clustered by TreeGCS to form a hier- archical view of the vide...

AtmoCube represents an innovative measurement system for the study of the Earth atmosphere starting from altitude of the order of 600 km. It appears as a cubic nano-satellite that has dimensions of 10×10×10 cm³ with a total weight of 1 kg (aluminium structure). The main scientific instrument is a spectral dosimeter-radiometer allowing co...

In this paper we present a digital image enhancement technique which relies on the application of a nonlinear operator within the Retinex approach. The basic idea of this approach is to separate the illumination and reflectance components of the image, so that by reducing the contribution of the former it is possible to effectively control the dyna...

Some modifications to the filterbank algorithm for fingerprint recognition are proposed. Particular attention is paid to core localization and full database coverage. The present implementation improves recognition results while keeping almost the same computational load.

Modern integrated circuits require insulating materials with a dielectric constant as low as possible in order to obtain device speed improvements through lower RC delay. We have investigated the electrical and structural properties of PTFE thin films obtained from Algoflon s -PTFE nanoemulsions, via spin coating deposition, followed by sintering....

AtmoCube represents an innovative measurement system for the study of the Earth atmosphere starting from altitude of the order of 600 km. It appears as a cubic nano-satellite that has dimensions of 10x10x10 cm^3 with a total weight of 1 kg (aluminium structure). The main scientific instrument is a spectral dosimeter-radiometer allowing continuous m...

An approach for video segmentation into shots and sub-shots that works directly in the MPEG compressed domain is presented. It is based only on the information about macroblock coding mode and motion vectors in P and B frames. The system follows a two-pass scheme and has a hybrid rule-based/neural structure. A rough scan over the P frames locates t...

Frame misalignment is a serious problem that affects most old films: it reduces their visual quality and hampers their restoration. We propose a simple and very effective frame stabilization algorithm that is able to efficaciously eliminate this artifact. Camera-panning effects, which may be present in the scene in the form of global motion, are no...

In this paper two algorithms for the compression of the data generated by the Time Projection Chamber (TPC) detector of the ALICE experiment at CERN are described. The first algorithm is based on a lossless source code modelling technique, i.e. the original TPC signal information can be reconstructed without errors at the decompression stage. The s...

We present in this paper a novel and effective system for removing blotches in old film sequences. In particular we propose a new very efficacious detection method: it is able to yield a high correct detection rate while minimizing, at the same time, the false alarm rate. Moreover, it is very efficient also in presence of slow motion, since it expl...

We present in this paper a novel and effective system for removing blotches in old film sequences. In particular we propose a new very efficacious detection method: it is able to yield a high correct detection rate while minimizing, at the same time, the false alarm rate. Moreover, it is very efficient also in presence of slow motion, since it expl...

A novel irregular and nonuniform sampling scheme for image data is presented in this paper. Its main characteristics are the particular distribution of the samples along image edges and in textured areas, which is obtained following a multiresolution approach, and the low computational complexity.As an example of application, an image coding system...

We present an automatic technique employing the H.263 standard to compress video sequences which have been generated by consumer equipment. The purpose is to optimise H.263 parameters on sequences having a wide range of characteristics in terms of detail content and motion, to obtain a low cost and low bit-rate video coder with acceptable performan...

In this paper we describe the realization of an ASIC which may significantly simplify the instrumental apparatus for measures in UHV (ultra-high vacuum, p 10 Gamma9 mbar) while permitting very fast acquisitions. The chip will first be used in ESCA experiments; however, its parallel architecture and the fast serial protocol for data transmission may...

. Temporal video segmentation is the first step towards automatic annotation of digital video for browsing and retrieval. This article gives an overview of existing techniques for video segmentation that operate on both uncompressed and compressed video stream. The performance, relative merits and limitations of each of the approaches are comprehen...

In this paper we present an innovativeinterpolator which performs high quality N Theta interpolation on both synthetic and real world images. Its structure, which is based on a rational operator, provides edge sensitive data interpolation, so that sharp and artifact free images are obtained. 1 INTRODUCTION Generally, linear interpolation methods su...

In this paper we present an innovative interpolator which performs high quality 2Theta interpolation on both synthetic and real world images. Its structure, which is based on a rational operator, provides edge sensitive data interpolation, so that sharp and artifacts free images are obtained, notwithstanding a resonable computational cost. Keywords...

A complete system for old picture restoration is described: in particular, a frame alignment method, a simple deblotching algorithm and a nonlinear approach for contrast enhancement are proposed. The frame alignment uses a global motion compensation, with a logarithmic search for the correction vector. The blotch removal step consists of two stages...

In this paper, we present an innovative interpolator that performs high quality 2/spl times/interpolation on both synthetic and real world images. Its structure, which is based on a rational operator, provides edge-sensitive data interpolation so that sharp- and artifacts-free images are obtained at a reasonable computational cost.

We present a novel approach for the reconstruction of coded images and video, which permits fast recovery of the data with good quality in case of limited channel bandwidth. It is based on the use of a neural network which is able to interpolate the DC components of the coded data with higher accuracy and lower artifacts with respect to standard in...

We present a pulse counting multichannel data acquisition system, characterized by the high number of high speed acquisition channels, and by the modular, embedded system architecture. The former leads to very fast acquisitions and allows to obtain sequences of snapshots, for the study of time dependent phenomena. The latter, thanks to the integrat...

this paper, we propose a new fast algorithm to estimate motion vectors (MVs) in video coding applications; it is based on the correlation which is present in the MV fields. To evaluate the MV of each block of a coded frame, information on MVs of adjacent blocks is used to give a first MV estimate, which is then refined by performing block matching...

In this paper we describe the realization of an ASIC which significantly simplifies the instrumental apparatus for measurements in UHV (ultrahigh vacuum, p⩽10^-9 mbar) while permitting very fast acquisitions. The chip will first be used in ESCA experiments; however its parallel architecture and the fast serial protocol for data transm...

This paper presents a robust and flexible method for the extraction of mouth corners from videophone sequences. Robustness is referred to illumination conditions, speaker variability, pose and image quality, while flexibility is given by the fuzzy environment which allows to efficiently perform the fusion of several sources of information

An adaptive nonuniform sampling technique for alias-free image representation is presented. It is both fast, thanks to the use of pseudo-Poisson disks (PPDs), and effective, because a higher sample density is used in areas which are rich in details; these zones of the image are located using a skewness-based operator, which is both simple and accur...

: In this paper, we present a fuzzy system that estimates the relationship between continuous acoustic and visual speech, inspired by the humanway of perceiving this relationship as an association between recognized phonetic and visual units. The system, however, does not perform accurate speech recognition but it relies on the clustering tendency...

An approach for parsing MPEG compressed video into shots and sub-shots based only on the macroblock (MB) and motion vector (MV) information is presented. The system follows a two-pass scheme and has a hybrid rule-based/neural structure. A rough scan over the P frames locates the potential shot boundaries and the solution is then refined by a precis...

A nonlinear spatio-temporal filter capable of significantly attenuating noise in image sequences without corrupting image details is presented. The characteristics of the filter are described, and the results of several simulations on real-world sequences are shown. A real-time implementation of the algorithm on a last generation DSP is also descri...

In this paper, the problem of the interpolation of the DC components of JPEG or MPEG-coded images is addressed, and the use of nonlinear interpolators is proposed which are able to accurately reconstruct the images yielding both sharp details and low blocking artifacts. 1. INTRODUCTION In the recent years there has been an increased interest in ima...

A nonlinear spatio-temporal filter capable of significantly attenuating noise in image sequences without corrupting image details is presented. A real-time implementation of the algorithm for CIF images at 10 frames/s on the TMS320C80 DSP is also described. Introduction There is presently an increasing interest in nonlinear digital techniques for n...

A novel scheme for edge-preserving image interpolation is introduced, which is based on the use of a simple nonlinear filter which accurately reconstructs sharp edges. Simulation results show the superior performances of the proposed approach with respect to other interpolation techniques

Vector quantization (VQ) applies effectively to very low bit-rate image transmission. The high compression ratios are often balanced by limited reconstruction quality due to blockiness effects due to coarse quantization. Interpolating different codevectors can overcome such drawback by enhancing the generalization ability and the adaptiveness of th...

A novel edge-preserving image interpolation algorithm is introduced. It is based on the use of a simple nonlinear filter which reconstructs sharp edges accurately and without the ringing effects which are present in other interpolation techniques. Some simulation results on one- and two-dimensional data are presented, and a possible VLSI implementa...

single network infrastructure. In order to achieve the above mentioned goal, embedded and variable bit-rate (VBR) multimode encoding should be combined to fully exploit the capacity of the system: more precisely, such coding schemes solve the difficult problem of having the output bit-rate vary in an optimal sense, in response to source entropy as...

A novel image interpolation scheme is presented, in which a neural network is used to segment the image according to the presence of oriented edges; a set of different directional adaptive filters then interpolate the image, the filter outputs being weighted according to the neural network output. The filters are designed in order to accurately rep...

A hierarchical video source coding algorithm based on MPEG-2 is presented. The proposed coding scheme is characterized by (i) non-interlaced pictures for each layer; (ii) hierarchical motion estimation able to provide physical motion vectors for both “B” and “P” pictures; (iii) hierarchical spatial scalability-which is the main feature of a system...

A nonlinear filtering technique for the preprocessing of very low contrast images has been applied to optical profilometry, as an attempt to improve the accuracy of the measurement of objects in harsh conditions. The technique is based on the application of a nonlinear architecture composed of linear Laplacian filters followed by quadratic filters...

We consider the application of self-organizing feature maps (SOFMs) to the problem of image vector quantization. We show that, using a SOFM- based codebook, vector quantizers which are better than conventionally designed ones can be obtained if their property of ordering is suitably exploited. In fact, there are at least three possible applications...

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The partial discharge (PD) height distributions are processed by using digital signal processing techniques. When several PD phenomena are simultaneously active, they can combine their own pattern and produce plurimodal distribution. In order to locate the peaks in the mixture (where they start, end and attain their maxima), an automatic peak-detec...