Facilitating Collocated Crowdsourcing on Situated Displays

Online crowdsourcing enables the distribution of work to a global labor force as small and often repetitive tasks. Recently, situated crowdsourcing has emerged as a complementary enabler to elicit labor in specific locations and from specific crowds. Teamwork in online crowdsourcing has been recently shown to increase the quality of output, but teamwork in situated crowdsourcing remains unexplored. We set out to fill this gap. We present a generic crowdsourcing platform that supports situated teamwork and provide experiences from a laboratory study that focused on comparing traditional online crowdsourcing to situated team-based crowdsourcing. We built a crowdsourcing desk that hosts three networked terminal displays. The displays run our custom team-driven crowdsourcing platform that was used to investigate collocated crowdsourcing in small teams. In addition to analyzing quantitative data, we provide findings based on questionnaires, interviews, and observations. We highlight 1) emerging differences between traditional and collocated crowdsourcing, 2) the collaboration strategies that teams exhibited in collocated crowdsourcing, and 3) that a priori team familiarity does not significantly affect collocated interaction in crowdsourcing. The approach we introduce is a novel multi-display crowdsourcing setup that supports collocated labor teams and along with the reported study makes specific contributions to situated crowdsourcing research.     

Aqueous degradation of imidacloprid and fenothiocarb using contact glow discharge electrolysis: Degradation behavior and kinetics

Degradation of the pesticides fenothiocarb and imidacloprid in water using contact glow discharge electrolysis (CGDE) achieved rates of 57.8 and 43.2% respectively. Degradation was enhanced using citric or hydrochloric acid to lower the pH to 3.0. Both acids enhanced both the degradation rate and the amount. Fenothiocarb degradation was 77.14% at pH 3 with citric acid, and 100% with HCl. Degradation of imidacloprid at pH 3 was 70.18% with citric acid and 93.02% with HCl. Acidic conditions favor either production of ^·OH radicals or enhancement of the degradation of organic compounds by ^·OH. Both the degradation rates and amounts for fenothiocarb and imidacloprid were reduced in the presence of methanol due to competition between pesticides and MeOH for ^·OH. Degradation of pesticides was not completely inhibited by MeOH. Degradation of both fenothiocarb and imidacloprid using CGDE obeys a first-order rate law with high regression coefficient values (R ²>0.99).     

Cryptanalaysis of an EPCC1G2 Standard Compliant Ownership Transfer Scheme

Recently, Chen and Chien have proposed a novel ownership transfer scheme with low implementation costs and conforming to the EPC Class-1 Generation-2 standard. The authors claimed that the proposed scheme is able to resist all attacks, and hence it has better security and performance than its predecessors. However, in this paper we show that the protocol fails short of its security objectives, and it is even less secure than the previously proposed schemes. In fact, we describe several attacks which allow to recover all the secret information stored in the tag. Obviously, once this information is known, tags can be easily traced and impersonated.     

Modeling of Closed-Vessel Experiments and Ballistic Parameter Estimation

ABSTRACT

Closed vessels have been used for the regression of lumped ballistic parameters for decades. If material and energy balances are coupled with burning rate empirical correlations, uncorrelated parameters can be adjusted, describing accurately the thermochemical behavior of the generated gases, even if the chemical composition of the propellant is unknown (aging of the propellant). This work presents a system of differential Equations integrated to produce pressure profiles within the vessel that are highly dependent on the choice of empirical parameters. Such parameters are manipulated via maximum likelihood statistical procedures, leading to the best set of parameters to describe the propellant.     

Principal Component Analysis as an exploration tool for kinetic modeling of food quality: A case study of a dried apple cluster snack

A Multivariate Accelerated shelf-life Testing (MALST) study of a dried apple cereal-like snack (commercially known as cluster) stored at 18 °C, 25 °C or 35 °C for 17.5 months was conducted. The measured attributes were water activity (Aw), color DE, moisture and sensory properties (aroma, taste, texture and color). The data were deployed to adjust the multivariate kinetics (including the interactions of the attributes) using Principal Component Analysis (PCA), and the results were compared to those obtained using a univariate kinetic model. The predicted shelf-life for the reference storage condition obtained using the multivariate model was 18.3 months, whereas a predicted shelf-life of 15.6 months was obtained using the univariate model. Thus, although the results of both methods are similar, the multivariate kinetic model revealed all of the product shelf-life attributes and their interactions. Finally, the multivariate model reflected the variability of the biochemical phenomena underlying product degradation.     

Brazil’s growing production of scientific articles—how are we doing with review articles and other qualitative indicators?

This article identifies scientific fields in Brazil that have been generating new knowledge, their evolution, tendencies and the relationship between scientific production and the National Postgraduate Program (Programa Nacional de Pós-Graduação—PNPG). It works with review articles and assesses: (a) articles published as reviews by international databases; (b) the growth of Brazilian participation in that context; (c) institutional participation; (d) the predominant fields of knowledge; (e) the most productive authors, and (f) periodicals that published the greatest number of review articles by Brazilian authors. The 5,348 review articles published between 2000 and 2009 were made available in 1,309 scientific publications, and the fields that published the most reviews were Pharmacology, Chemistry, Neurosciences, Biochemistry and Molecular Biology, Psychiatry, Neurology, Endocrinology and Internal Medicine. The reviews were produced by 27,096 authors under the auspices of 20 institutions which, together, answer for 95 % of the Brazilian production, and are public, excepting for the Pontifícia Universidade Católica do Rio Grande do Sul (PUC-RS). In the international scenario, we find that 31 countries are responsible for 90.11 % of the total scientific production and 94.08 % of the review articles. To establish a comparison between Brazil and its closest competitors, these countries can be classified arbitrarily in three groups: (1) countries with a large number of review articles (>3100), an average number of citations above 18, and an h-index greater than 95; (2) countries with a significant production of articles (between 2,000 and 3,000), average number of citations between 12 and 17, and an h-index below 95. Brazil is in the third group, (3) formed by countries with a lower level of production and the two qualitative indicators at opposite poles: the average of citations on a par with the first group (>18) and h-indexes like those of the second group (<95).     

Claim reserving with fuzzy regression and the two ways of ANOVA

The mutant and uncertain behaviour of insurance environments does not make advisable to use a wide data-base when calculating claim reserves and so, quantifying provisions with fuzzy numbers becomes suitable. This paper firstly describes the fuzzy least squares regression that will be used in posterior developments. Subsequently we expose a claim reserving method that combines fuzzy regression with the classical statistical scheme based on two ways of ANOVA. Finally we develop a numerical application where we show in detail how to use our method to fit expected claiming costs and their variability and compare its results with those from conventional ANOVA two ways.     

Nt_STM: A step forward in Scanning Tunneling Microscopy (STM) simulations

We present the Nt_STM software suite designed to help analysis and interpretation of Scanning Tunneling Microscope (STM) images, via the simulation of STM data under different tip and bias conditions and facilitating their comparison against the experimental ones. The Nt_STM package includes two components: (i) an intuitive and directive Graphical User Interface (GUI) designed to build a precise model of the STM set-up and analyze the simulation results and, (ii) a powerful simulation engine (GREEN) allowing an efficient, yet accurate, calculation of the tunneling current necessary to generate current or topographic images, I(V) spectra as well as various properties such as band structures, Local Density Of State (LDOS), etc. The Nt_STM package, at its current version 2.0, gives the opportunity to access parallel computation, a new collection of objects and new Extended Hückel parameters.     

Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix–polyether glycol was studied. AgNps of 4–6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia–polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20–80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO₃ concentration (0.3 wt%).     

Water Resources Assessment and Hydrogeological Modelling as a Tool for the Feasibility Study of a Closure Plan for an Open Pit Mine (La Respina Mine,Spain)

The La Respina mine is an open pit for talc extraction located in a mountainous range of NW Spain. The closure plan foresees the construction of an artificial lake in the void left by the open pit. The open pit is 600 m long by 300 m wide, and has a maximum depth of about 100 m. Karstic springs hydraulically connected to the mine are located down-gradient of the open pit. It is planned that the future lake will be filled using the natural water resources available in the watershed. These water resources have been evaluated by means of a daily-based, lumped hydrologic balance model. The comparison between computed ground water discharges and the flow rates measured at La Respina Springs provide supportive evidence that it is a sound and reliable model. The outputs of the lumped hydrologic balance model have been used as boundary conditions for a finite element hydrogeologic numerical model of the aquifer. By combining the results of both models, a net inflow to the future lake between 2.87 and 3.25 Mm³/year has been predicted. The future lake will induce the water table to rise and therefore, the base flow of the karstic springs is expected to increase.