992 research outputs found

    Unconventional TV Detection using Mobile Devices

    Full text link
    Recent studies show that the TV viewing experience is changing giving the rise of trends like "multi-screen viewing" and "connected viewers". These trends describe TV viewers that use mobile devices (e.g. tablets and smart phones) while watching TV. In this paper, we exploit the context information available from the ubiquitous mobile devices to detect the presence of TVs and track the media being viewed. Our approach leverages the array of sensors available in modern mobile devices, e.g. cameras and microphones, to detect the location of TV sets, their state (ON or OFF), and the channels they are currently tuned to. We present the feasibility of the proposed sensing technique using our implementation on Android phones with different realistic scenarios. Our results show that in a controlled environment a detection accuracy of 0.978 F-measure could be achieved.Comment: 4 pages, 14 figure

    An Interactive Augmented Reality Alphabet 3-Dimensional Pop-up Book For learning and Recognizing the English Alphabet

    Get PDF
    This document describes the process developing an Augmented Reality (AR) alphabet book mobile application. Using only an android phone camera, the child could view the superimposed virtual alphabet 3 dimensional objects in a fun and interactive manner using the marker-less physical alphabet book as the interaction tool. The reason behind choosing alphabet teaching as the topic of the book is that the Alphabet knowledge is the core knowledge of any language. It is a jump-start for children to start reading and recognizing words and sentences, thus learning the alphabet is extremely important, for many researchers, emphasizing on how early, child’s education shapes the child’s successful future. Though there are, a great deal of technology based alphabet books; parents still prefer buying the old style physical books or some might use a virtual technology based book application. The problem is that though the physical book possesses many benefits, that our generation and the generations long before us, have experienced, yet from the current generation children’s point of view, they may in fact find it dull and boring. For, it is commonly recognized, that the current generation children are surrounded all around by technology and gadgets, that can make them board, easily distracted, and may refuse to willingly use a plain non-technology book to learn, and if using a virtual application, they will lose the benefits offered by a physical book. Knowing this, the use of Augmented Reality should solve such a problem. For Augmented Reality (AR) is considered the best of both worlds, where, real and virtual objects are combined in the real environment, that will allow the use of both technology based application and a traditional physical book, combining the benefits of both and meeting the child and the parent midway. Although AR technology is not new, its possible potential in education is just beginning to be investigated. The main aim of this research is to develop an interactive 3-Dimentional alphabet pop-up book, and using digital storytelling, to help teach children to learn and recognize the alphabets. The objectives of the study are to enhance the interactions of the alphabet book, by creating an android application that contains animated interactive 3-Dimentional models, interactive sounds, songs and music. Furthermore, to investigate the use of digital storytelling (music, sounds), interactions and animation effect in learning engagement, through using the augmented reality technology. The scope of this project and research is very wide, it includes the 3D modeling, texturing, rigging & animation, book design and content decision research, furthermore, Augmented Reality and Android applicatio

    Performance et facteur d'efficacité de la bielle de poutres profondes en béton armé avec des barres de PRFV

    Get PDF
    Abstract : Deep reinforced concrete beams are commonly used as transfer girders or bridge bents, at which its safety is often crucial for the stability of the whole structure. Such elements are exposed to the aggressive environment in northern climates causing steel-corrosion problems due to the excessive use of de-icing salts. Fiber-reinforced polymers (FRP) emerged as non-corroded reinforcing materials to overcome such problems in RC elements. The present study aims to address the applicability of concrete deep beams totally reinforced with FRP bars. Ten full-scale deep beams with dimensions of 1200 × 300 × 5000 mm were constructed and tested to failure under two-point loading. Test variables were shear-span depth ratio (equal to 1.47, 1.13, and 0.83) and different configurations of web reinforcement (including vertical and/or horizontal web reinforcement). Failure of all specimens was preceded by crushing in the concrete diagonal strut, which is the typical failure of deep beams. The test results indicated that, all web reinforcement configurations employed in the tested specimens yielded insignificant effects on the ultimate strength. However, strength of specimens containing horizontal-only web reinforcement were unexpectedly lower than that of specimens without web reinforcement. The web reinforcement’s main contribution was significant crack-width control. The tested specimens exhibited reasonable deflection levels compared to the available steel-reinforced deep beams in the literature. The development of arch action was confirmed through the nearly uniform strain distribution along the length of the longitudinal reinforcement in all specimens. Additionally, the basic assumption of the strut-and-tie model (STM) was adequately used to predict the strain distribution along the longitudinal reinforcement, confirming the applicability of the STM for FRP-reinforced deep beams. Hence, a STM based model was proposed to predict the strength of FRP-reinforced deep beams using the experimental data, in addition to the available experimentally tested FRP-reinforced deep beams in the literature. Assessment of the available STMs in code provisions was conducted identifying the important parameters affecting the strut efficiency factor. The tendency of each parameter (concrete compressive strength, shear span-depth ratio, and strain in longitudinal reinforcement) was individually evaluated against the efficiency factor. Strain energy based calculations were performed to identify the appropriate truss model for detailing FRP-reinforced deep beams, hence, only four specimens with vertical web reinforcement exhibited the formation of two-panel truss model. The proposed model was capable to predict the ultimate capacity of the tested deep beams. The model was also verified against a compilation of a data-base of 172 steel-reinforced deep beams resulting in acceptable level of adequacy. The ultimate capacity and performance of the tested deep beams were also adequately predicted employing a 2D finite element program (VecTor2), which provide a powerful tool to predict the behavior of FRP-reinforced deep beams. The nonlinear finite element analysis was used to confirm some hypotheses associated with the experimental investigations.RĂ©sumĂ© : Les poutres profondes en bĂ©ton armĂ© (BA) sont couramment utilisĂ©es comme poutre de transfert ou coude de pont, comme quoi sa sĂ©curitĂ© est souvent cruciale pour la sĂ©curitĂ© de l’ensemble de la structure. Ces Ă©lĂ©ments sont exposĂ©s Ă  un environnement agressif dans les climats nordiques causant des problĂšmes de corrosion de l’acier en raison de l’utilisation excessive de sels de dĂ©glaçage. Les polymĂšres renforcĂ©s de fibres (PRF) sont apparus comme des matĂ©riaux de renforcement non corrodant pour surmonter ces problĂšmes dans les BA. La prĂ©sente Ă©tude vise Ă  examiner la question de l'applicabilitĂ© des poutres profondes en bĂ©ton complĂštement renforcĂ©es de barres en PRF. Dix poutres profondes Ă  grande Ă©chelle avec des dimensions de 1200 × 300 × 5000 mm ont Ă©tĂ© construites et testĂ©es jusqu’à la rupture sous chargement en deux points. Les variables testĂ©es comprenaient diffĂ©rents ratios de cisaillement portĂ©/profondeur (Ă©gal Ă  1.47, 1.13 et 0.83) ainsi que diffĂ©rentes configurations d’armature dans l’ñme (incluant un renforcement vertical avec ou sans renforcement horizontal). La rupture de tous les spĂ©cimens a Ă©tĂ© prĂ©cĂ©dĂ©e par l’écrasement du bĂ©ton dans le mĂąt diagonal, ce qui est la rupture typique pour les poutres profondes en BA. Les rĂ©sultats ont rĂ©vĂ©lĂ© que toutes les configurations de renforcement de l’ñme employĂ©es dans les spĂ©cimens d'essais avaient un effet nĂ©gligeable sur la rĂ©sistance ultime. Toutefois, la rĂ©sistance des spĂ©cimens contenant uniquement un renforcement horizontal Ă©tait Ă©tonnamment infĂ©rieure Ă  celle des spĂ©cimens sans renforcement. La contribution principale du renforcement de l’ñme Ă©tait dans le contrĂŽle de la largeur de fissuration. Les spĂ©cimens examinĂ©s prĂ©sentaient une dĂ©flexion raisonnable par rapport Ă  ce qui est disponible pour les poutres profondes renforcĂ©es en acier dans la littĂ©rature. Le dĂ©veloppement de l'effet d'arche a Ă©tĂ© confirmĂ© par la distribution quasi uniforme des dĂ©formations le long du renforcement longitudinal dans tous les spĂ©cimens. En outre, l'hypothĂšse de base du modĂšle des bielles et tirants (MBT) a Ă©tĂ© utilisĂ©e adĂ©quatement pour prĂ©dire la distribution de dĂ©formation le long du renforcement longitudinal, confirmant l'applicabilitĂ© du MBT pour les poutres profondes armĂ©es de PRF. Par consĂ©quent, un modĂšle basĂ© sur un MBT a Ă©tĂ© proposĂ© afin de prĂ©dire la rĂ©sistance des poutres profondes renforcĂ©es de PRF en utilisant les donnĂ©es expĂ©rimentales en plus de la mise Ă  l'Ă©preuve expĂ©rimentalement des poutres profondes renforcĂ©es de PRF trouvĂ©es dans la littĂ©rature. Une Ă©valuation des MTB disponibles dans les dispositions des codes a Ă©tĂ© menĂ©e afin de dĂ©terminer les paramĂštres importants affectant le facteur d'efficacitĂ© de la bielle. La tendance de chaque paramĂštre (la rĂ©sistance Ă  la compression du bĂ©ton, le ratio de cisaillement portĂ©/profondeur, et la dĂ©formation dans le renforcement longitudinal) a Ă©tĂ© Ă©valuĂ©e individuellement contre le facteur d'efficacitĂ©. Des calculs basĂ©s sur l’énergie des dĂ©formations ont Ă©tĂ© effectuĂ©s pour identifier le modĂšle de treillis appropriĂ© afin de dĂ©tailler les poutres profondes renforcĂ©es de PRF. Par consĂ©quent, seulement quatre spĂ©cimens avec un renforcement vertical dans l’ñme prĂ©sentaient la formation de modĂšles avec deux panneaux de treillis. Le modĂšle proposĂ© a Ă©tĂ© capable de prĂ©dire la capacitĂ© ultime des poutres profondes testĂ©es. Le modĂšle a Ă©galement Ă©tĂ© vĂ©rifiĂ© contre une base de donnĂ©es de 172 poutres profondes renforcĂ©es en acier aboutissant en un niveau acceptable de pertinence. La capacitĂ© ultime et la performance des poutres profondes testĂ©es ont Ă©tĂ© Ă©galement adĂ©quatement prĂ©dites employant un programme d'Ă©lĂ©ments finis en 2D (VecTor2), ce qui fournira un puissant outil pour prĂ©dire le comportement des poutres profondes renforcĂ©es de PRF. L'analyse non linĂ©aire par Ă©lĂ©ments finis a Ă©tĂ© utilisĂ©e afin de confirmer certaines hypothĂšses associĂ©es Ă  l'Ă©tude expĂ©rimentale

    STR-864: PROPOSED STRUT-AND-TIE MODEL FOR CONCRETE DEEP BEAMS REINFORCED WITH FRP BARS

    Get PDF
    A compiled database of 53 tests of FRP-reinforced concrete deep beams with shear span–depth ratios of less than two was used to evaluate the strut-and-tie models (STM) provided in ACI 318 (2014), CSA S806 (2012), CEB-fib (1999), and JSCE (2007). All provisions were found to be inadequate in calculating the capacity of FRP-reinforced deep beams due to inherent shortcomings in each provision. Hence, a new STM-based procedure for FRP-reinforced deep beams was proposed. The new model incorporates the effect of shear span–depth ratio (a/d), concrete compressive strength (fc’), and tensile strain in the adjoining tie (Δ1). The contribution of the web reinforcement on the strut efficiency factor was found to be insignificant. The new model was capable of predicting the ultimate capacity of the compiled FRP-reinforced concrete deep beams with satisfactory conservatism

    Improvement Optical and Electrical Characteristics of Thin Film Solar Cells Using Nanotechnology Techniques

    Get PDF
    This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer.  Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.

    Fatigue cycles and performance evaluation of accelerating aging heat treated aluminum semi solid materials designed for automotive dynamic components

    Get PDF
    The A357-type (Al-Si-Mg) aluminum semi solid casting materials are known for their excellent strength and good ductility, which make them materials of choice, preferable in the manufacturing of automotive dynamic mechanical components. Semi-solid casting is considered as an effective technique for the manufacturing of automotive mechanical dynamic components of superior quality performance and efficiency. The lower control arm in an automotive suspension system is the significant mechanical dynamic component responsible for linking the wheels of the vehicle to the chassis. A new trend is to manufacture this part from A357 aluminum alloy due to its lightweight, high specific strength, and better corrosion resistance than steel. This study proposes different designs of a suspension control arm developed, concerning its strength to weight ratio. Furthermore, this study aims to investigate the effect of accelerating thermal aging treatments on the fatigue life of bending fatigue specimens manufactured from alloy A357 using the Rheocasting semi-solid technology. The results revealed that the multiple aging cycles, of WC3, indicated superior fatigue life compared to standard thermal aging cycles. On the other hand, the proposed designs of automotive suspension control components showed higher strength-to-weight ratios, better stress distribution, and lower Von-Mises stresses compared to conventional designs
    • 

    corecore