Comparison of traditional and reductive winemaking: influence on some fixed components and sensorial characteristics

An explorative study to verify the applicability of reductive winemaking (RW) on two cultivars was carried out. To this purpose, traditional winemaking (TW) and RW were carried out on a semi-aromatic white grape (Sauvignon blanc) and a white neutral one (Trebbiano romagnolo). All phenolic parameters were higher in RW wines, while other substances such as alcohol, reducing sugars, acids, and volatile acidity acids were less affected by the different winemaking technique. A deeper yellow color (OD 420) was a direct consequence of the higher phenolic content of RW wines, while OD 320 was strictly related to caftaric acid integrity. Analyses showed a modification of the RW wines, also in the case of a neutral cultivar. Principal component analysis (PCA) was applied to the data set, and the first two PCs explained almost 85% of the total variability and divided TW and RW wines in two groups to demonstrate that the effect of winemaking overwhelmed maturation differences. Panelists preferred RW wines, which were characterized by a richer and more delicate aroma. The study demonstrated that a careful exclusion of air combined with an effective oxidation prevention yields to more characterized and pleasant wines.     

Super-resolution reconstruction in a computational compound-eye imaging system

From consumer electronics to biomedical applications, device miniaturization has shown to be highly desirable. This often includes reducing the size of some optical systems. However, diffraction effects impose a constraint on image quality when we simply scale down the imaging parameters. Over the past few years, compound-eye imaging system has emerged as a promising architecture in the development of compact visual systems. Because multiple low-resolution (LR) sub-images are captured, post-processing algorithms for the reconstruction of a high-resolution (HR) final image from the LR images play a critical role in affecting the image quality. In this paper, we describe and investigate the performance of a compound-eye system recently reported in the literature. We discuss both the physical construction and the mathematical model of the imaging components, followed by an application of our super-resolution algorithm in reconstructing the image. We then explore several variations of the imaging system, such as the incorporation of a phase mask in extending the depth of field, which are not possible with a traditional camera. Simulations with a versatile virtual camera system that we have built verify the feasibility of these additions, and we also report the tolerance of the compound-eye system to variations in physical parameters, such as optical aberrations, that are inevitable in actual systems.     

A New Cost Function for Air Quality Modeling

In this paper a new Back-Propagation (BP) algorithm cost function is appropriately studied for the modeling of air pollution time series. The underlying idea is that of modifying the error definition in order to improve the capabilities of this kind of models to forecast episodes of poor air quality. The proposed error definition can be regarded as a generalization of the traditional squared error cost function thanks to the presence of a parameter α which allows to obtain the ordinary BP as a special case when α = 1. A criterion for choosing this parameter is stated based on setting a-priori a maximum level of allowable false alarms. The goodness of the proposed approach is assessed by means of case studies both on synthetic and measured air quality data.

Automated defect detection in uniform and structured fabrics using Gabor filters and PCA

This paper describes an algorithm for texture defect detection in uniform and structured fabrics, which has been tested on the TILDA image database. The proposed approach is structured in a feature extraction phase, which relies on a complex symmetric Gabor filter bank and Principal Component Analysis (PCA), and on a defect identification phase, which is based on the Euclidean norm of features and on the comparison with fabric type specific parameters. Our analysis is performed on a patch basis, instead of considering single pixels. The performance has been evaluated with uniformly textured fabrics and fabrics with visible texture and grid-like structures, using as reference defect locations identified by human observers. The results show that our algorithm outperforms previous approaches in most cases, achieving a detection rate of 98.8% and a false alarm rate as low as 0.20–0.37%, whereas for heavily structured yarns misdetection rate can be as low as 5%.     

A SiGe BiCMOS 24-GHz receiver front-end for automotive short-range radar

This paper presents a fully integrated SiGe BiCMOS 24-GHz receiver front-end implemented for a ultra-wideband automotive short-range radar sensor. The circuit consists of a homodyne I/Q down-converter and a 24-GHz synthesizer. The receiver front-end is able to achieve a power conversion gain as high as 30 dB and a 6-dB noise figure, while preserving high linearity performance thanks to a 1-bit gain control. The frequency synthesizer, which also includes an on-chip loop filter, guarantees a phase noise of −104 dBc/Hz at 1-MHz offset from the 24.125-GHz carrier and a 4.7-GHz tuning range from 20.4 to 25.1 GHz.     

Discussion on the objective evaluation of virgin olive oil bitterness

The study aims at investigating the suitability of absorbance at 225 nm as an objective means to evaluate virgin olive oil (VOO) bitterness. Calculation of oleuropein score (OLS) using a standard curve instead of the so far employed K₂₂₅ value is proposed and a “taste index” based on the total phenol content determined by fluorimetry is examined as a complementary tool. Data from sensory evaluation of a series of VOO samples and RP-HPLC determination of phenolic compounds using diode array, fluorimetric or MS detection supported the applicability and merits of the introduced criteria. Phenol profiling using fluorescence detection (280 nm_excitation/320 nm_emission) became useful regarding oil bitterness. The presence of the non-fluorescent elenolic acid at 225 nm, indicated that the K₂₂₅ value is influenced by the presence of this non-bitter compound found at significant levels even in fresh oils. Our finding offers further ground to our proposal for the calculation of the “taste index”.