60 research outputs found

    Map++: A Crowd-sensing System for Automatic Map Semantics Identification

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    Digital maps have become a part of our daily life with a number of commercial and free map services. These services have still a huge potential for enhancement with rich semantic information to support a large class of mapping applications. In this paper, we present Map++, a system that leverages standard cell-phone sensors in a crowdsensing approach to automatically enrich digital maps with different road semantics like tunnels, bumps, bridges, footbridges, crosswalks, road capacity, among others. Our analysis shows that cell-phones sensors with humans in vehicles or walking get affected by the different road features, which can be mined to extend the features of both free and commercial mapping services. We present the design and implementation of Map++ and evaluate it in a large city. Our evaluation shows that we can detect the different semantics accurately with at most 3% false positive rate and 6% false negative rate for both vehicle and pedestrian-based features. Moreover, we show that Map++ has a small energy footprint on the cell-phones, highlighting its promise as a ubiquitous digital maps enriching service.Comment: Published in the Eleventh Annual IEEE International Conference on Sensing, Communication, and Networking (IEEE SECON 2014

    It's the Human that Matters: Accurate User Orientation Estimation for Mobile Computing Applications

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    Ubiquity of Internet-connected and sensor-equipped portable devices sparked a new set of mobile computing applications that leverage the proliferating sensing capabilities of smart-phones. For many of these applications, accurate estimation of the user heading, as compared to the phone heading, is of paramount importance. This is of special importance for many crowd-sensing applications, where the phone can be carried in arbitrary positions and orientations relative to the user body. Current state-of-the-art focus mainly on estimating the phone orientation, require the phone to be placed in a particular position, require user intervention, and/or do not work accurately indoors; which limits their ubiquitous usability in different applications. In this paper we present Humaine, a novel system to reliably and accurately estimate the user orientation relative to the Earth coordinate system. Humaine requires no prior-configuration nor user intervention and works accurately indoors and outdoors for arbitrary cell phone positions and orientations relative to the user body. The system applies statistical analysis techniques to the inertial sensors widely available on today's cell phones to estimate both the phone and user orientation. Implementation of the system on different Android devices with 170 experiments performed at different indoor and outdoor testbeds shows that Humaine significantly outperforms the state-of-the-art in diverse scenarios, achieving a median accuracy of 1515^\circ averaged over a wide variety of phone positions. This is 558%558\% better than the-state-of-the-art. The accuracy is bounded by the error in the inertial sensors readings and can be enhanced with more accurate sensors and sensor fusion.Comment: Accepted for publication in the 11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (Mobiquitous 2014

    The Impact of Gender Differences and Geographic Locations on Social Media Literacy Among Public Universities Students

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    The objective of this study was to investigate the effect of both gender difference and geographic location on social media literacy levels among undergraduate students in public universities in Egypt. Four aspects related to social media literacy were considered in the Likert-scale survey, including basic technical skills, digital interactions, information evaluation, and privacy and security practices. A total of 520 students participated in this exploratory research, of which 265 males and 255 females enrolled at four public universities in different geographic locations. Cairo University and Ain Shams University represent the urban areas. The other two universities are located in center-periphery areas with Mansoura University representing the Nile Delta and Minia University representing Upper Egypt. Cross tabulation was used to analyze the subjects’ responses using the MS Excel and SPSS softwares. The findings showed that male students are more proficient in basic technical skills on social networking sites than their female counterparts. Moreover, it has been found that there is a slight higher awareness in favor of male students with regards to digital interactions and privacy practices. Concerning digital information evaluation, it appeared that male and female students share the same level of competence in verifying online content and being receptive to disparate opinions. The second part of the study analysis strongly indicated that urban students are more conversant with the four measured competences related to social media literacy than their center-periphery peers

    Use of SiO2 - TiO2 Nanocomposite as Photocatalyst for the Removal of Trichlorophenol: A Kinetic Study and Numerical Evaluation

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    A series of silica-titania nanocomposite materials with different silica–titania ratios was prepared in presence of a novel ethoxylated sulphanilamide of molecular weight 1053 by the sol-gel method. Several characterisation techniques were adopted such as thermal analysis (differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA)), N2-adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR), and transmission electron microscopy (TEM) connected with energy dispersive spectroscopy (EDS). The surface acidity was investigated by pyridine adsorption using FTIR spectroscopy. The photocatalytic activity and the adsorptive ability of the composites were evaluated based on the photodegradation of 2, 4, 6- trichlorophenol (TCP) under UV irradiation with a wavelength of 254 nm. The maximum TCP adsorption onto the composites was measured in darkness. The results showed that there was no adsorption of TCP on pure SiO2. The 10% TiO2-SiO2 catalyst showed the highest rate of TCP removal among the synthesised composites. The removal % reached to 87 % after 90 min irradiation time. This activity was caused by the large surface area and pore volume as well as the formation of a mesoporous structure, as evidenced from the pore size distribution curve. Finally, the numerical evaluation of the photodegradation of TCP was conducted. Keywords: Nanocomposite, Ethoxylated sulphanilamide, Photocatalytic degradation, UV irradiation, 2,4,6-TCP, Numerical evaluation

    In vitro assessment of the antifungal effects of neem powder added to polymethyl methacrylate denture base material

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    Denture with antimicrobial activities is desirable to prevent Candida albican adhesion subsequently decreasing the susceptibility of denture stomatitis incidence. Azadirachta Indica, commonly known as Neem powder has antimicrobial effect but the effect of its addition to acrylic denture base on C. albicans adhesion has not been investigated. The aim of this study was determine whether adding neem powder to acrylic denture base materials could reduce Candida albicansadhesion. One hundred and twenty acrylic resin denture specimens were fabricated and divided into heat-polymerized (n=60) and auto-polymerized (n=60) groups. Each group was further divided into 6 groups (n=10) based on the neem concentration: 0, 0.5, 1, 1.5, 2 and 2.5 wt% of the polymer. After polymerization, the specimens were polished, stored in distilled water, sonicated, sterilized, submerged in artificial saliva containing C. albicans, and finally, placed in an incubator at 37°C. Slide counting and direct culture methods were used to assess the antifungal effects of the neem addition. An analysis of variance and post hoc Tukey?s test were performed for the data analysis (p?0.05 was statistically significant). Based on the results, the neem addition significantly decreased the C. albicans count when compared to the control group (p?0.05). Moreover, the count decreased as the neem concentration increased (lowest count with 2.5 wt%). The results suggest that adding neem powder to acrylic resin denture base materials reduces the adhesion of C. albicans; therefore, the incorporation of neem could be a possible denture stomatitis prevention method

    Assessment of patient safety culture perception among healthcare workers in intensive care units of Alexandria Main University Hospital, Egypt

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    Background: Patient safety culture (PSC) is a vital feature to assess the ability of any healthcare setting in addressing and reducing patients harm. This study attempted to assess the PSC in Intensive Care Units (ICUs) at Alexandria Main University Hospital (AMUH) from the point of view of physicians and nurses. Methods: A cross-sectional study was implemented in two ICUs at AMUH over period of six months. Seventy-two participants were interviewed using the Hospital Patient Safety Scale, customized by the Agency for Healthcare Research and Quality (AHRQ). Results: The average positive response to individual items in the patient safety scale ranged from 2.7% to 79.2%. The “Teamwork within Units” dimension had the utmost average percentage positive score (63.5%) amongst all participants, on the other hand, the “Non-Punitive Response to Errors” dimension had the lowest one (12.0%). Less than half (45.8%) of the interviewed participants rated patient’s safety at the hospital as accepted. Conclusions: PSC is friable in targeted ICUs, much of work is needed to raise the responsiveness of health care givers regarding this issue. Executives and supervisors need to encourage the practices of PS through a blame free culture
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