6,313 research outputs found

    Support for participation in electronic paper prototyping

    Get PDF
    In this paper, we examine a range of tools for early prototyping of interactive systems that might be described as enabling 'electronic paper prototyping'. We then introduce Gabbeh, a prototype that we are developing to re-enable participatory design when using such tools. Paper-prototyping is an established approach to the creation of early prototypes in the participatory design of computer systems. Recent years have seen the rapid development of new interaction devices in which a display screen is combined with pen-based input to allow users to create sketches or hand-written notes in an interaction that is similar to writing with a pen on paper. Research with such devices has shown how this capability can be used to rapidly create simple prototypes of interactive systems such as websites. However, previous systems have not considered how end-users and other stakeholders could contribute to design dialogues around such prototypes.</p

    Anesthetic Neurotoxicity in Pediatric Patients

    Get PDF
    In recent years, an increasing number of publications have shown the negative effects of anesthetics on the developing brain and have made inquiries about anesthesia for pediatric patients in practice. Anesthesia is applied to millions of children for surgery, imaging, and other invasive procedures; the issue is very serious and concerns. In this chapter, experimental and clinical studies about the issue have been summarized. As a result, anesthetic drugs except alpha-2 adrenergic agonist anesthetic (NMDA antagonist or a GABA agonist) used in pediatric patients (especially if there is no painful situation) have potential neurotoxicity. Particularly, if anesthesia exposure was applied in the fragile period (the first 4 years) and if used at higher concentrations or repeated anesthesia application, adverse effects of anesthesia exposure on the developing brain have been claimed. But, the issue is not fully clarified yet

    Numerical Investigation of Turbulent Hydrogen-Methane-Nitrogen Non-Premixed Jet Flame

    Get PDF
    In this work, the numerical investigation of the two-dimensional axisymmetric turbulent diffusion flame of a composite fuel was performed by using a computational fluid dynamics code to predict flame structure. The composite fuel was an H2/CH4/N2 gas mixture. The amount of H2 and N2 in the fuel mixture varies under constant volumetric fuel flow rate. Fluent, which solves the governing and reaction equations using the finite volume method, was used as the computational fluid dynamics program. The non-premixed model was used for computation of the combustion. The standard k-Δ model was used for modeling the turbulent flow. The interaction of the chemistry and turbulence was accounted for by the program with the probability density function model. This model was validated against the experimental data taken from literature. In general, the numerical results of the temperature, velocity, and CO2 concentration distributions were in satisfactory agreement with the experimental results. The numerical results showed that adding H2 to the fuel mixture decreases the flame length and generally increases the maximum temperature of the flame. On the other hand, adding N2 to the mixture decreases both the flame length and maximum flame temperature. The flame length corresponds to the axial position of the peak flame temperature. Keywords: Combustion Modeling; Composite Fuels; Diffusion Flame; H2/CH4/N2 Flame; Flame Length; Emission

    Numerical Investigation of the Effect of Different Conical Turbulators on the Performance of a Liquid Fuelled Boiler

    Get PDF
    The increment in the combustion of fossil fuels for heating and power generation in recent years has led researchers to design more efficient energy conversion systems by increasing the efficiency of the existing systems and by minimizing energy losses. In this study, increasing the efficiency of the liquid fuelled smoke tube boilers used for domestic heating was researched. In this context, turbulators with full conical and frusto-conical geometries placed to smoke tubes of boiler and their effects on flame structure, heat transfer and boiler efficiency were investigated numerically. Calculations were carried out at two dimensional axisymmetric conditions and Fluent was used as the computational fluid dynamics software. In all cases, the standard k-Δ model was used for modelling the turbulent flow and the species transport model was used for modelling the combustion. The results obtained by using these turbulators were evaluated for each placement condition of the turbulators. Besides, the temperature and the stream function distribution and the pressure drop in the boiler were investigated according to the type of turbulators. Finally, it was discussed which type of turbulator would be most appropriate at boilers. Keywords: Spray Combustion; Combustion Modelling; Boilers; Conical Turbulator

    Second chance: A hybrid approach for dynamic result caching and prefetching in search engines

    Get PDF
    Cataloged from PDF version of article.Web search engines are known to cache the results of previously issued queries. The stored results typically contain the document summaries and some data that is used to construct the final search result page returned to the user. An alternative strategy is to store in the cache only the result document IDs, which take much less space, allowing results of more queries to be cached. These two strategies lead to an interesting trade-off between the hit rate and the average query response latency. In this work, in order to exploit this trade-off, we propose a hybrid result caching strategy where a dynamic result cache is split into two sections: an HTML cache and a docID cache. Moreover, using a realistic cost model, we evaluate the performance of different result prefetching strategies for the proposed hybrid cache and the baseline HTML-only cache. Finally, we propose a machine learning approach to predict singleton queries, which occur only once in the query stream. We show that when the proposed hybrid result caching strategy is coupled with the singleton query predictor, the hit rate is further improved. © 2013 ACM

    Metal–semiconductor–metal photodetector on as-deposited TiO2 thin films on sapphire substrate

    Get PDF
    Cataloged from PDF version of article.TiO2 thin films are prepared on c-plane sapphire substrates by the RF magnetron sputtering method. The performance of the Pt contact metal–semiconductor–metal (MSM) photodetector fabricated on as-deposited films is studied. The dark current density and the responsivity obtained were 1.57 × 10−9 A/cm2 at 5 V bias and 1.73 A/W at 50 V bias, respectively. Breakdown is not observed up to 50 V bias. Rise and fall times for the photocurrent were 7 and 3 s, respectively. Our results show that high quality MSM photodetectors can be fabricated without high temperature and complicated fabrication steps

    Cache-based query processing for search engines

    Get PDF
    Cataloged from PDF version of article.In practice, a search engine may fail to serve a query due to various reasons such as hardware/network failures, excessive query load, lack of matching documents, or service contract limitations (e.g., the query rate limits for third-party users of a search service). In this kind of scenarios, where the backend search system is unable to generate answers to queries, approximate answers can be generated by exploiting the previously computed query results available in the result cache of the search engine.In this work, we propose two alternative strategies to implement this cache-based query processing idea. The first strategy aggregates the results of similar queries that are previously cached in order to create synthetic results for new queries. The second strategy forms an inverted index over the textual information (i.e., query terms and result snippets) present in the result cache and uses this index to answer new queries. Both approaches achieve reasonable result qualities compared to processing queries with an inverted index built on the collection. © 2012 ACM

    Possible Single Resonant Production of the Fourth Generation Charged Leptons at Îłe\gamma e Colliders

    Full text link
    Single resonant productions of the fourth standard model generation charged lepton via anomalous interactions at gamma e colliders based on future linear e^+ e^- colliders with 500 GeV and 1 TeV center of mass energies are studied. Signatures of γe→ℓ4→eγ\gamma e\to \ell_4\to e\gamma and γe→ℓ4→eZ\gamma e\to \ell_4\to eZ anomalous processes followed by the hadronic and leptonic decay of the Z boson and corresponding standard model backgrounds are discussed in details. The lowest necessary luminosities to observe these processes and the achievable values of the anomalous coupling strengths are determined.Comment: 9 pages, 6 figures, 4 table
    • 

    corecore