1,631 research outputs found

    Advances in Pattern Recognition Algorithms, Architectures, and Devices

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    Over the last decade, tremendous advances have been made in the general area of pattern recognition techniques, devices, and algorithms. We have had the distinct pleasure of witnessing this remarkable growth as evidenced through their dissemination in the previous Optical Engineering special sections we have jointly edited— January 1998, March 1998, May 2000, and January 2002. Twenty-six papers were finally accepted for this latest special section, encompassing the recent trends and advancements made in many different areas of pattern recognition techniques utilizing algorithms, architectures, implementations, and devices. These techniques include matched spatial filter based recognition, hit-miss transforms, invariant pattern recognition, joint transform correlator JTC based recognition, morphological processing based recognition, neural network based recognition, wavelet based recognition, fingerprint and face recognition, data fusion based recognition, and target tracking, as well as other techniques. These papers summarize the work of 70 researchers from eight countries

    A Cloud Platform-as-a-Service for Multimedia Conferencing Service Provisioning

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    Multimedia conferencing is the real-time exchange of multimedia content between multiple parties. It is the basis of a wide range of applications (e.g., multimedia multiplayer game). Cloud-based provisioning of the conferencing services on which these applications rely will bring benefits, such as easy service provisioning and elastic scalability. However, it remains a big challenge. This paper proposes a PaaS for conferencing service provisioning. The proposed PaaS is based on a business model from the state of the art. It relies on conferencing IaaSs that, instead of VMs, offer conferencing substrates (e.g., dial-in signaling, video mixer and audio mixer). The PaaS enables composition of new conferences from substrates on the fly. This has been prototyped in this paper and, in order to evaluate it, a conferencing IaaS is also implemented. Performance measurements are also made.Comment: 6 pages, 6 figures, IEEE ISCC 201

    Tin Sulfide (SnS) Films Deposited by an Electric Field-Assisted Continuous Spray Pyrolysis Technique with Application as Counter Electrodes in Dye-Sensitized Solar Cells

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    The deposition of tin sulfide (SnS) nanostructured films using a continuous spray pyrolysis technique is reported with an electric field present at the nozzle for influencing the atomization and the subsequent film deposition. In the absence of the electric field, the X-ray diffraction pattern shows the orthorhombic phase of SnS with a crystallographic preferred orientation along the (040) plane. The application of the electric field results in significant improvement in the morphology and a reduction in surface roughness (28 nm from 37 nm). The direct optical band gap of the films deposited with and without the electric field is estimated to be 1.5 and 1.7 eV, respectively. The photothermal deflection spectroscopy studies show a lower energetic disorder (no Urbach tail), which indicates an annealing effect in the SnS films deposited under the electric field. The improvement in the film properties is reflected in the expected improvement in the power conversion efficiency (PCE) of dye-sensitized solar cells fabricated using the SnS film as a counter electrode. An enhancement of PCE from 2.07% for the film deposited without the electric field to 2.89% for the film deposited with the electric field shows the role of the electric field in the fabrication of improved SnS film

    Joint Wavelet Transform Correlation with Separated Target and Reference Planes

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    In recent years, we realize the usefulness of feature extraction for optical correlator and hereby, we investigate the capability of Laplace operator in feature extraction of multiple targets. The first-order terms and the false alarm terms in the correlation output would be removed using electronic power spectrum subtraction technique. Most importantly, the entire magneto-optic SLM is completely utilized for displaying only targets in the input scene. A new cost efficient hardware implementation is proposed and aforementioned result of the proposed system is evaluated through computer simulation

    Antioxidant, antimicrobial and cytotoxic activities of Corypha taliera Roxb

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    The methanol extract of Corypha taliera fruits as well as its n-hexane, carbon tetrachloride, dichloromethane and aqueous soluble fractions were subjected to screening for antioxidant, antimicrobial and cytotoxic activities. The methanolic crude extract exhibited the highest antioxidant activity (IC50 19.33 μg/ml as compared to 9.5 μg/ml for the standard agent, BHT). The crude methanol extract and its carbon tetrachloride, dichloromethane and aqueous soluble fractions showed mild to moderate inhibition of microbial growth against some of the tested organisms. All the extractives exhibited strong cytotoxic properties, among which the methanol extract revealed the strongest cytotixicity (LC50 = 0.43 μg/ml).Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Antioxidant, antimicrobial and cytotoxic activities of Corypha taliera Roxb

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    The methanol extract of Corypha taliera fruits as well as its n-hexane, carbon tetrachloride, dichloromethane and aqueous soluble fractions were subjected to screening for antioxidant, antimicrobial and cytotoxic activities. The methanolic crude extract exhibited the highest antioxidant activity (IC50 19.33 μg/ml as compared to 9.5 μg/ml for the standard agent, BHT). The crude methanol extract and its carbon tetrachloride, dichloromethane and aqueous soluble fractions showed mild to moderate inhibition of microbial growth against some of the tested organisms. All the extractives exhibited strong cytotoxic properties, among which the methanol extract revealed the strongest cytotixicity (LC50 = 0.43 μg/ml).Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Ferroelectricity and Large Piezoelectric Response of AlN/ScN Superlattice

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    Based on density functional theory, we investigate the ferroelectric and piezoelectric properties of the AlN/ScN superlattice, consisting of ScN and AlN buckled monolayers alternating along the crystallographic <i>c</i>-direction. We find that the polar wurtzite (w-ScAlN) structure is mechanically and dynamically stable and is more stable than the nonpolar hexagonal flat configuration. We show that ferroelectric polarization switching can be possible for an epitaxially tensile-strained superlattice. Because of the elastic constant <i>C</i><sub>33</sub> softening, together with an increase in <i>e</i><sub>33</sub>, the piezoelectric coefficient <i>d</i><sub>33</sub> of the superlattice is doubled compared to that of pure w-AlN. The combined enhancement of Born effective charges (<i>Z</i><sub>33</sub>) and sensitivity of the atomic coordinates to the external strain (∂u3∂η3) is the origin of the large piezoelectric constant <i>e</i><sub>33</sub>. Moreover, we show that the epitaxial biaxial tensile strain significantly enhances the piezo-response, so that <i>d</i><sub>33</sub> becomes 7 times larger than that of w-AlN at 4% strain. The tensile strain results in a huge enhancement in <i>e</i><sub>33</sub> by increasing <i>Z</i><sub>33</sub> and ∂u3∂η3, which boost the piezoelectric

    Design and concept of renewable energy driven auto-detectable railway level crossing systems in Bangladesh

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    Bangladesh’s railway system mostly uses typical manual railway crossing techniques or boom gates through its 2955.53 km rail route all over the country. Accidents frequently happen at railway crossings due to the lack of quickly operating gate systems, and to fewer safety measures at the railway crossing as well. Currently, there are very few automatic railway crossing systems available (without obstacle detectors). Additionally, all of them are dependent on the national power grid, without a backup plan for any emergency cases. Bangladesh is still running a bit behind in generating enough power for its consumption; hence, it is not possible to have a continuous power supply at all times all over the countryside. We aim to design and develop a smart railway crossing system with an obstacle detector to prevent common types of accidents at railway crossing points. We use two infrared (IR) sensors to operate the railway crossing systems, which are controlled by an Arduino Uno. This newly designed level crossing system is run with the help of sustainable renewable energy, which is cost-effective and eco-friendly, and applied under the national green energy policy towards achieving sustainable development in Bangladesh as a part of the global sustainable goal to face climate change challenges. We have summarized the simulated the results of several renewable energy sources, including a hybrid system, and optimized the Levelized Cost of Energy (LCOE) and the payback periods

    Education for Human Resources Development in Bangladesh: Policies,Plans, and Issues

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    Human resources development (HRD) through education is a long term endeavor in Bangladesh, and this article brings out the need to invest more heavily in this area. If the target level of 7.3 percent GDP growth in the Fifth Five Year Plan is to be achieved, hard issues of priorities will need to be faced in deciding on inter-and intrasectoral allocation of public funds. The purpose of this article is to give a broad outlook of what is currently happening at various levels and structures of HRD in this country as well as of developments over the past 30 years or so. The authors describe the whole process with three objectives in mind: To examine the current situation of HRD; to examine policies and plans so far made for HRD; and to critically pinpoint obstacles to HRD and bring forth some issues and policy recommendations for discussion and implementation. The discussion emphasizes the point that a better education system bridges HRD and economic development

    Microbial imbalance in inflammatory bowel disease patients at different taxonomic levels

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    Background Inflammatory bowel disease (IBD), is a debilitating group of chronic diseases including Crohn’s Disease (CD) and ulcerative colitis (UC), which causes inflammation of the gut and affects millions of people worldwide. At different taxonomic levels, the structure of the gut microbiota is significantly altered in IBD patients compared to that of healthy individuals. However, it is unclear how these IBD-affected bacterial groups are related to other common bacteria in the gut, and how they are connected across different disease conditions at the global scale. Results In this study, using faecal samples from patients with IBD, we show through diversity analysis of the microbial community structure based on the 16S rRNA gene that the gut microbiome of IBD patients is less diverse compared to healthy individuals. Furthermore, we have identified which bacterial groups change in abundance in both CD and UC compared to healthy controls. A substantial imbalance was observed across four major bacterial phyla including Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria, which together constitute >98% of the gut microbiota. Next, we reconstructed a bacterial family co-abundance network based on the correlation of abundance profiles obtained from the public gut microbiome data of >22000 samples of faecal and gut biopsies taken from both diseased and healthy individuals. The data was compiled using the EBI metagenomics database [1]. By mapping IBD-altered bacterial families to the network, we show that the bacterial families which exhibit an increased abundance in IBD conditions are not well connected to other groups, implying that these families generally do not coexist together with common gut organisms. Whereas, the bacterial families whose abundance is reduced or did not change in IBD conditions compared to healthy conditions are very well connected to other bacterial groups, suggesting they are highly important groups of bacteria in the gut that can coexist with other bacteria across a range of conditions. Conclusions IBD patients exhibited a less diverse gut microbiome compared to healthy individuals. Bacterial groups which changed in IBD patients were found to be groups which do not co-exist well with common commensal gut bacteria, whereas bacterial groups which did not change in patients with IBD were found to commonly co-exist with commensal gut microbiota. This gives a potential insight into the dynamics of the gut microbiota in patients with IBD
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