Background subtraction model based on color and depth cues

Background subtraction consists of segmenting objects in movement in a video captured by a static camera. This is typically performed using color information, but it leads to wrong estimations due to perspective and illumination issues. We show that multimodal approaches based on the integrated use of color and depth cues produce more accurate and robust results than using either data source independently. Depth is less affected by issues such as shadows or foreground objects similar to background. However, objects close to the background may not be detected when using only range information, being color information complementary in those cases. We propose an extension of a well-known background subtraction technique which fuses range and color information, as well as a post-processing mask fusion stage to get the best of each feature. We have evaluated the method proposed using a well-defined dataset and different disparity estimation algorithms, showing the benefits of our method for fusion color and depth cues.     

Betweenness estimation in OLSR-based multi-hop networks for distributed filtering

In traditional networks special efforts are put to secure the perimeter with firewalls: particular routers that analyze and filter the traffic to separate zones with different levels of trust. In wireless multi-hop networks the perimeter is a concept extremely hard to identify, thus, it is much more effective to enforce control on the nodes that will route more traffic. But traffic filtering and traffic analysis are costly activities for the limited resources of mesh nodes, so a trade-off must be reached limiting the number of nodes that enforce them. This work shows how, using the OLSR protocol, the centrality of groups of nodes with reference to traffic can be estimated with high accuracy independently of the network topology or size. We also show how this approach greatly limits the impact of an attack to the network using a number of firewalls that is only a fraction of the available nodes.     

Heat Induced Structure Modifications in Polymer‐Layered Silicate Nanocomposites

Summary: The success of the use of layered silicates in polymer nanocomposites, to improve physical and chemical properties is strictly related to a deeper knowledge of the mechanistic aspects on which the final features are grounded. This work shows the temperature induced structural rearrangements of nanocomposites based on poly[ethylene‐co‐(vinyl acetate)] (EVA) intercalated‐organomodified clay (at 3–30 wt.‐% silicate addition) which occur in the range between 75 and 350 °C. In situ high temperature X‐ray diffraction (HT‐XRD) studies have been performed under both nitrogen and air to monitor the modifications of the nanocomposite structure at increasing temperatures under inert/oxidative atmosphere. Heating between 75 and 225 °C, under nitrogen or air, causes the layered silicate to migrate towards the nanocomposite surface and to increase its interlayer distance. The degradation of both the clay organomodifier and the VA units of the EVA polymer seems to play a key role in driving the evolution of the silicate phase in the low temperature range. The structural modifications of the nanocomposites in the high temperature range (250–350 °C), depended on the atmosphere, either inert or oxidizing, in which the samples were heated. Heating under nitrogen led to deintercalation and thus a decrease of the silicate interlayer space, whereas exfoliation was the main process under air leading to an increase of the silicate interlayer space.

Heat induced structural modification of EVA‐clay nanocomposite under nitrogen and air.     

Aromatization of [1-14C]heptane over “nonacidic” platinum-alumina catalyst

[1-¹⁴C]Heptane was aromatized under 5 atm pressure over a “nonacidic” 3% platinum on alumina catalyst maintained at 500 °C. The reactant was pumped in at a HLSV of 0.88, and the hydrogen-to-heptane mole ratio was 5.1. The samples of product were collected (one during the first 90 min and another during the next 90 min), the toluene was separated from the respective samples, and the radioactivity in each position of the toluene was determined by a degradation sequence. The distribution of radioactivity in sample 1 was as follows: in position 1–2.6%, 2–38.6%; 3–14.5%; 4–4.2%, and in the methyl group—40.1%. Approximately similar distribution of radioactivity was found in sample 2. 1,6-Ring closure is the most important pathway leading to the formation of toluene from [1-¹⁴C]heptane; lesser amounts of repetitive, 1,5-ring closure and hydrogenolysis, and bond shift reactions followed by 1,6-ring closure and dehydration can explain the distribution of radioactivity. The participation of 1,7-ring closure in the reaction is also indicated.     

Introduction to the special issue of the 19th International Conference on Runtime Verification

International Journal on Software Tools for Technology Transfer -     

Anti-BlUFf: towards counterfeit mitigation in IC supply chains using blockchain and PUF

International Journal of Information Security - The complexity of today’s integrated circuit (IC) supply chain, organised in several tiers and including many companies located in different...     

Lithium disilicate glass produced at high pressure: Characterization of structural,thermal and mechanical properties

In this work, high-density lithium disilicate (LS₂) vitreous systems were produced by melting and quenching under high pressure (7.7 GPa) following two distinct experimental routes. In the first case, LS₂ glass was remelted at 7.7 GPa and 1600°C and, then, quenched. In the second case, a stoichiometric mixture of precursor oxides (Li₂O and SiO₂) was melted at 1600°C and 7.7 GPa before quenching. A reference LS₂ glass sample was produced at atmospheric pressure using conventional melting and quenching procedure. The samples were characterized by X-ray diffraction, differential thermal analysis, and instrumented ultramicro hardness measurements. X-ray diffraction confirmed that all samples were amorphous and thermal analysis suggests that different glassy structures were produced depending on the route of synthesis. Hardness and elastic modulus of the glasses produced under high pressure were higher than those of the reference glass, reflecting the irreversible densification effect induced by the high-pressure processing.     

Thermal dehydrochlorination of pure PVC polymer: Part I—thermal degradation kinetics by thermogravimetric analysis

Thermal degradation of PVC occurs in two stages, with each stage subdivided into two substages. The first refers to the dehydrochlorination, where hydrochloric acid is formed, and giving polyene structures. Hitherto, the degradation mechanism and action of hydrochloric acid as a catalyst during the dehydrochlorination stage are poorly known. Recently, the importance of the tacticity has gained attention for its influence on the dehydrochlorination mechanism. The present work focused on the dehydrochlorination stage, studying the molecular structure by FTIR analysis and the kinetic parameters by TGA analysis in Nitrogen atmosphere, based on three mathematical methods: Friedman, Kissinger, and Flynn-Wall-Ozawa. The sample was a pure homopolymer obtained by suspension polymerization. The dehydrochlorination kinetics follows a first order reaction model and occurs by nucleation and growth. The dehydrochlorination begins with the loss of very labile chlorine atoms present in defective and isotactic molecular segments. The formed HCl acts as a catalyst in the degradation. Following 40% conversion, a drop in Ea is observed. After that, chlorine atoms present in syndiotactic and atactic sequences, are released and, added to the large number of polyene chain sequences, and an increase in Ea is observed up to 60% conversion, where the dehydrochlorination stage is concluded.     

Analysis of surface integrity for minimum quantity lubricant—MQL in grinding

The quality of machined components is currently of high interest, for the market demands mechanical components of increasingly high performance, not only from the standpoint of functionality but also from that of safety. Components produced through operations involving the removal of material display surface irregularities resulting not only from the action of the tool itself, but also from other factors that contribute to their superficial texture. This texture can exert a decisive influence on the application and performance of the machined component. This article analyzes the behavior of the minimum quantity lubricant (MQL) technique and compares it with the conventional cooling method. To this end, an optimized fluid application method was devised using a specially designed nozzle, by the authors, through which a minimum amount of oil is sprayed in a compressed air flow, thus meeting environmental requirements. This paper, therefore, explores and discusses the concept of the MQL in the grinding process. The performance of the MQL technique in the grinding process was evaluated based on an analysis of the surface integrity (roughness, residual stress, microstructure and microhardness). The results presented here are expected to lead to technological and ecological gains in the grinding process using MQL.