Automation trust increases under high-workload multitasking scenarios involving risk

Cognition, Technology & Work - Trust is a critical construct that influences human–automation interaction in multitasking workspaces involving imperfect automation. Karpinsky et al. (Appl...     

Visual search asymmetries within color-coded and intensity-coded displays.

Color and intensity coding provide perceptual cues to segregate categories of objects within a visual display, allowing operators to search more efficiently for needed information. Even within a perceptually distinct subset of display elements, however, it may often be useful to prioritize items representing urgent or task-critical information. The design of symbology to produce search asymmetries (Treisman & Souther, 1985) offers a potential technique for doing this, but it is not obvious from existing models of search that an asymmetry observed in the absence of extraneous visual stimuli will persist within a complex color- or intensity-coded display. To address this issue, in the current study we measured the strength of a visual search asymmetry within displays containing color- or intensity-coded extraneous items. The asymmetry persisted strongly in the presence of extraneous items that were drawn in a different color (Experiment 1) or a lower contrast (Experiment 2) than the search-relevant items, with the targets favored by the search asymmetry producing highly efficient search. The asymmetry was attenuated but not eliminated when extraneous items were drawn in a higher contrast than search-relevant items (Experiment 3). Results imply that the coding of symbology to exploit visual search asymmetries can facilitate visual search for high-priority items even within color- or intensity-coded displays. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of highly active nanocrystalline WO3 and its application in laser-induced photocatalytic removal of a dye from water

Tungsten oxide nanoparticles were synthesized using the sol–gel process and applied for heterogeneous photocatalytic removal of a dye using a 355 nm laser radiation generated from Nd:YAG for the first time. Effect of various parameters, such as calcination temperature, calcination time, catalyst concentration and laser energy on the photocatalytic removal of dye has been investigated. The study showed that almost complete degradation of dye can be achieved within very short time of reaction (within few minutes) in presence of nanocrystalline WO₃ under laser irradiation. The removal process obeys first-order kinetics with an appreciable rate constant 0.146 min⁻¹. The main reason of high efficiency is the nanostructure nature of WO₃ and the laser as an excitation source as compared with the conventional setups using lamps and conventional microstructure catalysts.     

Three-dimensional imaging using a new synthetic aperture focusingtechnique

The drawbacks of the multifrequency automatic focusing technique (MF-AFT) have been eased considerably when the scanned-frequency signals are transmitted simultaneously in a pulse. While the focusing capabilities of the MF-AFT are maintained, substantial reduction in data processing is obtained when the new procedure is used. In addition, the derived pulse can be tailored to further enhance the quality of the image produced by this new procedure. Simulation results are included to demonstrate the focusing capabilities of the procedure for both two- and three-dimensional objects     

Synthesizing and Physical Properties of GdPr-123 High-Tc Superconductor

Ceramic Gd_1-xPr_xBa₂Cu₃O_7-y (GdPr-123) high-T_c superconductors have been synthesized by the standard solid state reaction method and characterized by XRD, SEM, TGA, and DT techniques in the range of x, 0.0 ≤ x ≤ 1.0 Samples have orthorhombic structure with Pmmm symmetry and there is a small percentage (less than 1%) of the Ba sites occupied by Pr ions in some Pr-rich samples. In these samples a small trace of BaCuO₂ and Pr BaO₃ secondary phases persist with the main peaks at 2θ = 29.3° and 28.9° respectively. Microstructure analysis indicates a uniform grain size distribution with a mean size of 5 μm. No significant change of grain size is shown throughout the range of x studied. The valence of Pr and Cu were determined by magnetization measurements in the temperature range 100 to 250°K. These data reveal a valence of 3.86+ for Pr in all samples independant of x. The similarity of the superconducting and insulating properties in this system to those of the oxygen deficient RBa₂Cu₃O₇ (R-123) (R: Y or rare earth) system implies that the mechanism of superconductivity in high-T_c. superconductors cannot be two-dimensional, even though the superconductive current occurs in two dimensions.     

On-line monitoring of remediation process of chromium polluted soil using LIBS

Due to large growth in leather and textile industries to cater for the needs of a growing world population, contamination of soil and water resources by chromium has become a great threat for humans and animals. In this work, Laser Induced Breakdown Spectroscopy (LIBS) was applied to monitor the remediation process of soil contaminated with Chromium metal. This study was conducted at a laboratory scale by setting up an experiment in a container holding soil contaminated with chromium. This setup represents actual field conditions where remediation process could be applied and monitored for the removal of toxic metals like Cr. For generation of LIBS spectrum, the plasma was produced by focusing a pulsed Nd: YAG laser at 1064 nm on the soil contaminated with chromium under remediation process. The evaluation of the potential and capabilities of LIBS as a rapid tool for remediation process of contaminated sites is discussed in detail. Optimal experimental conditions were evaluated for improving the sensitivity of our LIBS system for monitoring of remediation process through parametric dependence study. The minimum detection limit of our spectrometer for chromium in soil matrix was 2 mg Kg(-1).     

Role of defects and dopants in zinc oxide nanotubes for gas sensing and energy storage applications

Spin-polarized density functional theory (DFT) is employed to study the adsorption of H₂ gas molecules on zinc oxide nanotubes (ZnO-NTs) with intrinsic defects (oxygen and zinc vacancies) and dopants (Pd and Pt). Results indicate that defects lead to a strong chemisorption process, associated with strong splitting of the H₂ molecule, rendering an irreversible process; that is, desorption is not possible. Such strong chemisorption process results in large adsorption energy and charge transfer between the defective-ZnO-NTs and H₂ molecules. On the other hand, a weaker chemisorption process, associated with weak splitting of H₂ molecule, takes place in the case of Pd or Pt dopants. The chemisorption of H₂ on defective sites and dopants changes the energy gap to a large extent, resulting in major changes in the electrical conductivity of the ZnO-NTs and consequently revealing their relevance for gas sensing applications with an enhancement of sensor response. From a different perspective, Pd ought to be a good dopant for ZnO-NT based hydrogen storage material as it weakens the adsorption strength between H₂ and ZnO-NT.     

A scene image classification technique for a ubiquitous visual surveillance system

Multimedia Tools and Applications - The concept of smart cities has quickly evolved to improve the quality of life and provide public safety. Smart cities mitigate harmful environmental impacts and...     

A comparison study on node clustering techniques used in target tracking WSNs for efficient data aggregation

Wireless sensor applications are susceptible to energy constraints. Most of the energy is consumed in communication between wireless nodes. Clustering and data aggregation are the two widely used strategies for reducing energy usage and increasing the lifetime of wireless sensor networks. In target tracking applications, large amount of redundant data is produced regularly. Hence, deployment of effective data aggregation schemes is vital to eliminate data redundancy. This work aims to conduct a comparative study of various research approaches that employ clustering techniques for efficiently aggregating data in target tracking applications as selection of an appropriate clustering algorithm may reflect positive results in the data aggregation process. In this paper, we have highlighted the gains of the existing schemes for node clustering‐based data aggregation along with a detailed discussion on their advantages and issues that may degrade the performance. Also, the boundary issues in each type of clustering technique have been analyzed. Simulation results reveal that the efficacy and validity of these clustering‐based data aggregation algorithms are limited to specific sensing situations only, while failing to exhibit adaptive behavior in various other environmental conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

Facile synthesis of titanium dioxide‐cadmium sulfide nanocomposite using pulsed laser ablation in liquid and its performance in photovoltaic and photocatalytic applications

Narrow band gap semiconductors like cadmium sulfide (CdS) are being applied as an agent to reduce the band gap of metal oxide semiconductors like titanium dioxide (TiO₂). In order to obtain a TiO₂/CdS nanocomposite with reduced electron‐hole recombination and improved stability, we coupled 10%, 20%, and 40% by weight of CdS with TiO₂ in this work using pulsed laser ablation in liquid technique. Here, 532 nm wavelength generated from neodymium‐doped yttrium aluminum garnet laser was directed into the TiO₂/CdS mixture prepared in a colloid form to produce the TiO₂/CdS nanocomposites. The effect of the CdS concentration on the performance of the obtained nanocomposite in a dye‐sensitized solar cell and photocatalytic degradation of methyl orange in water was studied in detail. However, the nanocomposite with 10% percentage weight of CdS in anatase TiO₂ showed the best performance as compared with pure TiO₂, and the photoconversion efficiency of the dye‐sensitized solar cell was improved from 0.6% to 4.3%, while the percentage of methyl orange degraded was enhanced from 58% to 82% after 36 min irradiation using ultraviolet–visible light. This improvement in photovoltaic and photodegradation properties is due to limited electron hole recombination rate, higher conduction of charge carriers, their longer lifetime during the photocatalytic process, improved ultraviolet–visible light activity, reduced photocorrosion, and improved pore size. Copyright © 2017 John Wiley & Sons, Ltd.