Virtual Blocks: a serious game for spatial ability improvement on mobile devices

This paper presents a novel spatial instruction system for improving spatial abilities of engineering students. A 3D mobile game application called Virtual Blocks has been designed to provide a 3D virtual environment to build models with cubes that help students to perform visualization tasks to promote the development of their spatial ability during a short remedial course. A validation study with 26 freshman engineering students at La Laguna University (Spain) has concluded that the training had a measurable and positive impact on students’ spatial ability. In addition, the results obtained using a satisfaction questionnaire show that Virtual Blocks is considered an easy to use and stimulating application.     

Sex Attractant Pheromone from the Neotropical Red-Shouldered Stink Bug, <Emphasis Type="Italic">Thyanta perditor</Emphasis> (F.)

Olfactometer bioassays showed that odors from mature Thyanta perditor males attracted females but not males. Furthermore, odors from females did not attract either sex, indicating that like other phytophagous pentatomid bugs, the males produce a sex pheromone. Attraction appeared to peak in late afternoon to evening. The headspace volatiles collected from male and female T. perditor were analyzed by GC-MS and HPLC. A male-specific compound, methyl (2E,4Z,6Z)-decatrienoate (2E,4Z,6Z-10:COOMe), was identified along with a number of other compounds found in extracts from both sexes. Bioassays carried out with 2E,4Z,6Z-10:COOMe showed it was as attractive to females as the crude extract of male volatiles, suggesting that the male-produced sex pheromone consists of 2E,4Z,6Z-10:COOMe as a single component. Consecutive volatiles collections from males showed that 2E,4Z,6Z-10:COOMe began appearing in extracts from males about 9 d after the final molt, as the males became sexually mature.     

Attractant pheromone for nearctic stink bug,Euschistus obscurus (Heteroptera: Pentatomidae): Insight into a neotropical relative

Volatiles fromEuschistus obscurus males were found to be attractive to conspecific females in bioassays. A new type of olfactometer assembled from commercially available glassware was used to bioassay aeration extracts of the Nearctic stink bug,E. obscurus. Fractionated extracts suggest that pheromonal activity is associated with late-eluting, male-specific compounds. Research onE. obscurus offered a means to indirectly study the pheromone of the Neotropical pest species,E. heros, without importing this soybean pest into the United States.Research performed as a Visiting Scientist at: USDA-ARS, Insect Chemical Ecology Laboratory, Beltsville, Maryland 20705. Mention of commercial products does not constitute an endorsement by the U.S. Department of Agriculture.Supported by a grant from CNPq.     

Monocular Visual-Inertial SLAM-Based Collision Avoidance Strategy for Fail-Safe UAV Using Fuzzy Logic Controllers

In this paper, we developed a novel Cross-Entropy Optimization (CEO)-based Fuzzy Logic Controller (FLC) for Fail-Safe UAV to expand its collision avoidance capabilities in the GPS-denied environments using Monocular Visual-Inertial SLAM-based strategy. The function of this FLC aims to control the heading of Fail-Safe UAV to avoid the obstacle, e.g. wall, bridge, tree line et al, using its real-time and accurate localization information. In the Matlab Simulink-based training framework, the Scaling Factor (SF) is adjusted according to the collision avoidance task firstly, and then the Membership Function (MF) is tuned based on the optimized Scaling Factor to further improve the control performances. After obtained the optimal SF and MF, 64 % of rules has been reduced (from 125 rules to 45 rules), and a large number of real see-and-avoid tests with a quadcopter have done. The simulation and experiment results show that this new proposed FLC can precisely navigates the Fail-Safe UAV to avoid the obstacle, obtaining better performances compared to only SF optimization-based FLC. To our best knowledge, this is the first work to present the optimized FLC using Cross-Entropy method in both SF and MF optimization, and apply it in the UAV.     

In situ TPR/TPO-Raman studies of dispersed and nano-scaled mixed V-Nb oxides on alumina

Various catalysts containing niobium and vanadium oxides supported on alumina were prepared by wet impregnation via aqueous solution using several precursors. The total loading of V and Nb oxides were below their dispersion limit on alumina. Vanadyl sulfate, ammonium metavanadate and ammonium niobate(V) oxalate were the precursors for supported vanadia and niobia. The reduction/oxidation properties were studied by conventional TPR/TPO and TPR/TPO-Raman. Surface vanadium oxide species tend to increase their polymerization degree upon TPR/TPO cycles. A broad weak feature near 900 cm⁻¹ appears associated to V³⁺–O–Al³⁺ bond vibration in the reduced vanadia-alumina catalysts. Niobia appears to retard vanadia reduction. Regarding supported niobia, a fraction of surface niobia is significantly more reducible than surface vanadia and another fraction is significantly less reducible. The more reducible niobia appears associated to an incipient Nb–Al–O phase that may account for a fluorescence background observed in the Raman spectra. The less reducible niobia phases appears associated to dispersed niobium oxide species on alumina. Niobium has an effect on vanadia reduction profiles in VNb/Al₂O₃ system.     

Functionalization of polyester PET fibers

In order to promote chemical linkage between polyester PET fibers and thermoplastic or elastomer matrices, a diazide derivative has been synthetized and reacted with the free hydroxyl groups of the fibers. The completion of the reaction was controlled by means of IR spectroscopy and chemical analysis, and fiber characterization was carried out by thermogravimetric and DSC techniques. The obtained results permit the determination of the suitability of the synthetized diazide to functionalize PET fibers that could be used as reinforcing fibers for polymer matrices composites. © 1993 John Wiley & Sons, Inc.     

A practical approach for active camera coordination based on a fusion-driven multi-agent system

In this paper, we propose a multi-agent system architecture to manage spatially distributed active (or pan-tilt-zoom) cameras. Traditional video surveillance algorithms are of no use for active cameras, and we have to look at different approaches. Such multi-sensor surveillance systems have to be designed to solve two related problems: data fusion and coordinated sensor-task management. Generally, architectures proposed for the coordinated operation of multiple cameras are based on the centralisation of management decisions at the fusion centre. However, the existence of intelligent sensors capable of decision making brings with it the possibility of conceiving alternative decentralised architectures. This problem is approached by means of a MAS, integrating data fusion as an integral part of the architecture for distributed coordination purposes. This paper presents the MAS architecture and system agents.     

Analysis of operating system diversity for intrusion tolerance

One of the key benefits of using intrusion‐tolerant systems is the possibility of ensuring correct behavior in the presence of attacks and intrusions. These security gains are directly dependent on the components exhibiting failure diversity. To what extent failure diversity is observed in practical deployment depends on how diverse are the components that constitute the system. In this paper, we present a study with operating system's (OS's) vulnerability data from the NIST National Vulnerability Database (NVD). We have analyzed the vulnerabilities of 11 different OSs over a period of 18 years, to check how many of these vulnerabilities occur in more than one OS. We found this number to be low for several combinations of OSs. Hence, although there are a few caveats on the use of NVD data to support definitive conclusions, our analysis shows that by selecting appropriate OSs, one can preclude (or reduce substantially) common vulnerabilities from occurring in the replicas of the intrusion‐tolerant system. Copyright © 2013 John Wiley & Sons, Ltd.     

Nanostructured CuO thin film electrodes prepared by spray pyrolysis: a simple method for enhancing the electrochemical performance of CuO in lithium cells

Nanostructured CuO thin films were prepared by using a spray pyrolysis method, copper acetate as precursor and stainless steel as substrate. The textural and structural properties of the films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed thorough coating of the substrate and thickness of 450-1250 nm; the average particle size as determined from the AFM images ranged from 30 to 160 nm. The XRD patterns revealed the formation of CuO alone and the XPS spectra confirmed the presence of Cu²⁺ as the main oxidation state on the surface. The films were tested as electrodes in lithium cells and their electrochemical properties evaluated from galvanostatic and step potential electrochemical spectroscopy (SPES) measurements. The discharge STEP curves exhibited various peaks consistent with the processes CuO ⇔ Cu₂O ⇔ Cu and with decomposition of the electrolyte, a reversible process in the light of the AFM images. The best electrode exhibited capacity values of 625 Ah kg⁻¹ over more than 100 cycles. This value, which involves a CuO ⇔ Cu reversible global reaction, is ca. 50% higher than that reported for bulk CuO. The nanosize of the particles and the good adherence of the active material to the substrate are thought to be the key factors accounting for the enhanced electrochemical activity found.