3,199 research outputs found

    Volatile Production and Lipid Oxidation of Irradiated Cooked Sausage with Different Packaging

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    Irradiation dose had a significant effect on the production of volatiles in both vacuum- and aerobic-packaged cooked pork sausage, but its effect on the thiobarbituric acid reactive substances (TBARS) values was minor. Storage increased the production of volatiles and changed the composition of volatiles only in aerobic-packaged sausage. Among the volatile components, 1-heptene and 1-nonene were influenced most by irradiation dose, and aldehydes by packaging type. The TBARS values and volatiles of vacuum-packaged irradiated cooked sausage had very low correlation.The TBARS, however, had very high correlation with the amount of aldehydes and total volatiles, and ketones and alcohols with long retention times in aerobic-packaged pork sausage. Heptene and 1-nonene could be used as indicators for irradiation, and propanal, pentanal, and hexanal for the oxygen-dependent changes of cooked meat. The results indicated that irradiation had some effect on lipid oxidation of cooked pork sausages, especially with aerobic packaging, but oxygen availability (packaging) to meat during storage had much stronger impact. The low correlations of irradiation-dependent volatiles (e.g., 1-heptene and 1-nonene) with TBARS values regardless of packaging and storage conditions indicated that volatile compounds responsible for irradiation odor were different from those of lipid oxidation odor in cooked pork sausages

    Quantitative Screening of Cervical Cancers for Low-Resource Settings: Pilot Study of Smartphone-Based Endoscopic Visual Inspection After Acetic Acid Using Machine Learning Techniques

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    Background: Approximately 90% of global cervical cancer (CC) is mostly found in low- and middle-income countries. In most cases, CC can be detected early through routine screening programs, including a cytology-based test. However, it is logistically difficult to offer this program in low-resource settings due to limited resources and infrastructure, and few trained experts. A visual inspection following the application of acetic acid (VIA) has been widely promoted and is routinely recommended as a viable form of CC screening in resource-constrained countries. Digital images of the cervix have been acquired during VIA procedure with better quality assurance and visualization, leading to higher diagnostic accuracy and reduction of the variability of detection rate. However, a colposcope is bulky, expensive, electricity-dependent, and needs routine maintenance, and to confirm the grade of abnormality through its images, a specialist must be present. Recently, smartphone-based imaging systems have made a significant impact on the practice of medicine by offering a cost-effective, rapid, and noninvasive method of evaluation. Furthermore, computer-aided analyses, including image processing-based methods and machine learning techniques, have also shown great potential for a high impact on medicinal evaluations

    Advertising spending, firm performance, and the moderating impact of CSR

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    This article investigates the potential of corporate social responsibility (CSR) to influence the link between advertising spending and firm performance. Drawing upon the literature of CSR, we hypothesize that CSR positively moderates the relationship between advertising spending and firm performance. We focus on two types of firm performance: sales and firm value. Using two samples from both the hotel and restaurant industries, we found that firms with higher levels of CSR enjoy higher returns on advertising spending than firms with lower levels of CSR. We discuss the theoretical and managerial implications of these findings and provide direction for future research

    POEM: Pricing Longer for Edge Computing in the Device Cloud

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    Multiple access mobile edge computing has been proposed as a promising technology to bring computation services close to end users, by making good use of edge cloud servers. In mobile device clouds (MDC), idle end devices may act as edge servers to offer computation services for busy end devices. Most existing auction based incentive mechanisms in MDC focus on only one round auction without considering the time correlation. Moreover, although existing single round auctions can also be used for multiple times, users should trade with higher bids to get more resources in the cascading rounds of auctions, then their budgets will run out too early to participate in the next auction, leading to auction failures and the whole benefit may suffer. In this paper, we formulate the computation offloading problem as a social welfare optimization problem with given budgets of mobile devices, and consider pricing longer of mobile devices. This problem is a multiple-choice multi-dimensional 0-1 knapsack problem, which is a NP-hard problem. We propose an auction framework named MAFL for long-term benefits that runs a single round resource auction in each round. Extensive simulation results show that the proposed auction mechanism outperforms the single round by about 55.6% on the revenue on average and MAFL outperforms existing double auction by about 68.6% in terms of the revenue.Comment: 8 pages, 1 figure, Accepted by the 18th International Conference on Algorithms and Architectures for Parallel Processing (ICA3PP

    Spin Hall torque magnetometry of Dzyaloshinskii domain walls

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    Current-induced domain wall motion in the presence of the Dzyaloshinskii-Moriya interaction (DMI) is experimentally and theoretically investigated in heavy-metal/ferromagnet bilayers. The angular dependence of the current-induced torque and the magnetization structure of Dzyaloshinskii domain walls are described and quantified simultaneously in the presence of in-plane fields. We show that the DMI strength depends strongly on the heavy metal, varying by a factor of 20 between Ta and Pa, and that strong DMI leads to wall distortions not seen in conventional materials. These findings provide essential insights for understanding and exploiting chiral magnetism for emerging spintronics applications

    An Investigation of Stochastic Variance Reduction Algorithms for Relative Difference Penalized 3D PET Image Reconstruction

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    Penalised PET image reconstruction algorithms are often accelerated during early iterations with the use of subsets. However, these methods may exhibit limit cycle behaviour at later iterations due to variations between subsets. Desirable converged images can be achieved for a subclass of these algorithms via the implementation of a relaxed step size sequence, but the heuristic selection of parameters will impact the quality of the image sequence and algorithm convergence rates. In this work, we demonstrate the adaption and application of a class of stochastic variance reduction gradient algorithms for PET image reconstruction using the relative difference penalty and numerically compare convergence performance to BSREM. The two investigated algorithms are: SAGA and SVRG. These algorithms require the retention in memory of recently computed subset gradients, which are utilised in subsequent updates. We present several numerical studies based on Monte Carlo simulated data and a patient data set for fully 3D PET acquisitions. The impact of the number of subsets, different preconditioners and step size methods on the convergence of regions of interest values within the reconstructed images is explored. We observe that when using constant preconditioning, SAGA and SVRG demonstrate reduced variations in voxel values between subsequent updates and are less reliant on step size hyper-parameter selection than BSREM reconstructions. Furthermore, SAGA and SVRG can converge significantly faster to the penalised maximum likelihood solution than BSREM, particularly in low count data

    Ground state properties of ferromagnetic metal/conjugated polymer interfaces

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    We theoretically investigate the ground state properties of ferromagnetic metal/conjugated polymer interfaces. The work is partially motivated by recent experiments in which injection of spin polarized electrons from ferromagnetic contacts into thin films of conjugated polymers was reported. We use a one-dimensional nondegenerate Su-Schrieffer-Heeger (SSH) Hamiltonian to describe the conjugated polymer and one-dimensional tight-binding models to describe the ferromagnetic metal. We consider both a model for a conventional ferromagnetic metal, in which there are no explicit structural degrees of freedom, and a model for a half-metallic ferromagnetic colossal magnetoresistance (CMR) oxide which has explicit structural degrees of freedom. The Fermi energy of the magnetic metallic contact is adjusted to control the degree of electron transfer into the polymer. We investigate electron charge and spin transfer from the ferromagnetic metal to the organic polymer, and structural relaxation near the interface. Bipolarons are the lowest energy charge state in the bulk polymer for the nondegenerate SSH model Hamiltonian. As a result electrons (or holes) transferred into the bulk of the polymer form spinless bipolarons. However, there can be spin density in the polymer localized near the interface.Comment: 7 figure

    Reversible Random Sequential Adsorption of Dimers on a Triangular Lattice

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    We report on simulations of reversible random sequential adsorption of dimers on three different lattices: a one-dimensional lattice, a two-dimensional triangular lattice, and a two-dimensional triangular lattice with the nearest neighbors excluded. In addition to the adsorption of particles at a rate K+, we allow particles to leave the surface at a rate K-. The results from the one-dimensional lattice model agree with previous results for the continuous parking lot model. In particular, the long-time behavior is dominated by collective events involving two particles. We were able to directly confirm the importance of two-particle events in the simple two-dimensional triangular lattice. For the two-dimensional triangular lattice with the nearest neighbors excluded, the observed dynamics are consistent with this picture. The two-dimensional simulations were motivated by measurements of Ca++ binding to Langmuir monolayers. The two cases were chosen to model the effects of changing pH in the experimental system.Comment: 9 pages, 10 figure

    Structural and superconducting properties of MgB2x_{2-x}Bex_x

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    We prepared MgB2x_{2-x}Bex_{x} (x=0x=0, 0.2, 0.3, 0.4, and 0.6) samples where B is substituted with Be. MgB2_{2} structure is maintained up to x=0.6x=0.6. In-plane and inter-plane lattice constants were found to decrease and increase, respectively. Superconducting transition temperature TcT_{c} decreases with xx. We found that the TcT_{c} decrease is correlated with in-plane contraction but is insensitive to carrier doping, which is consistent with other substitution studies such as Mg1x_{1-x}Alx_{x}B2_{2} and MgB2x_{2-x}Cx_{x}. Implication of this work is discussed in terms of the 2D nature of σ\sigma -band.Comment: 3 pages,4 figures, to be published in Phys. Rev.

    An Extension for Direct Gauge Mediation of Metastable Supersymmetry Breaking

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    We study the direct mediation of metastable supersymmetry breaking by a \Phi^2-deformation to the ISS model and extend it by splitting both Tr\Phi and Tr\Phi^2 terms in the superpotential and gauging the flavor symmetry. We find that with such an extension the enough long-lived metastable vacua can be obtained and the proper gaugino masses can be generated. Also, this allows for constructing a kind of models which can avoid the Landau pole problem. Especially, in our metastable vacua there exist a large region for the parameter m_3 which can satisfy the phenomenology requirements and allow for a low SUSY breaking scale (\sim 100 TeV).Comment: version in Europhys. Let
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