866 research outputs found

    Parametrized post-Newtonian virial theorem

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    Using the parametrized post-Newtonian equations of hydrodynamics, we derive the tensor form of the parametrized post-Newtonian virial theorem.Comment: 10 pages, submitted to CQ

    Localized modes in defective multilayer structures

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    In this paper, the localized surface modes in a defective multilayer structure has been investigated. It is shown that the defective multilayer structures can support two different kind of localized modes depending on the position and the thickness of the defect layer. One of these modes is localized at the interface between the multilayer structure and a homogeneous medium (the so-called surface mode) and the other one is localized at the defect layer (defect localized mode). We reveal that the presence of defect layer pushes the dispersion curve of surface modes to the lower or the upper edge of the photonic bandgap depending on the homogeneous medium is a left-handed or right-handed medium (e.g. vacuum), respectively. So, the existence region of the surface modes restricted. Moreover, the effect of defect on the energy flow velocity of the surface modes is discussed.Comment: 5 pages, 7 figure

    Assessment of a Bio-inspired Artificial Wing for Micro Aerial Vehicle Based on Structural Bio-mimetics

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    This paper presents the structural design assessment of a bio-inspired artificial wing for flapping wing micro air vehicle based on pigeon bird. Bio-inspired ornithopters are unable to implement themselves in surveillance environment due to lack of basic bio-mimetics during conceptual and design phase. The idea of this research is to bridge this gap through assessment of structural parameters including weight, moment of inertia and feather placement leading to development of an artificial wing using actual feathers of pigeon bird and glass fiber-epoxy composite. The camber and wing structure is assessed through the fabrication of mold which is further utilized to define the shape of artificial wing. Future work includes the performance assessment of the developed wing for lift and thrust generation in an actual prototype of flapping type micro air vehicle

    Chi8: a GPU program for detecting significant interacting SNPs with the Chi-square 8-df test

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    BACKGROUND: Determining interacting SNPs in genome-wide association studies is computationally expensive yet of considerable interest in genomics. FINDINGS: We present a program Chi8 that calculates the Chi-square 8 degree of freedom test between all pairs of SNPs in a brute force manner on a Graphics Processing Unit. We analyze each of the seven WTCCC genome-wide association studies that have about 5000 total case and controls and 400,000 SNPs in an average of 9.6 h on a single GPU. We also study the power, false positives, and area under curve of our program on simulated data and provide a comparison to the GBOOST program. Our program source code is freely available from http://www.cs.njit.edu/usman/Chi8

    Renal Hyperfiltration and the Development of Microalbuminuria in Type 1 Diabetes

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    OBJECTIVE: The purpose of this study was to examine prospectively whether renal hyperfiltration is associated with the development of microalbuminuria in patients with type 1 diabetes, after taking into account known risk factors. RESEARCH DESIGN AND METHODS: The study group comprised 426 participants with normoalbuminuria from the First Joslin Kidney Study, followed for 15 years. Glomerular filtration rate was estimated by serum cystatin C, and hyperfiltration was defined as exceeding the 97.5th percentile of the sex-specific distribution of a similarly aged, nondiabetic population (134 and 149 ml/min per 1.73 m2 for men and women, respectively). The outcome was time to microalbuminuria development (multiple albumin excretion rate >30 μg/min). Hazard ratios (HRs) for microalbuminuria were calculated at 5, 10, and 15 years. RESULTS: Renal hyperfiltration was present in 24% of the study group and did not increase the risk of developing microalbuminuria. The unadjusted HR for microalbuminuria comparing those with and without hyperfiltration at baseline was 0.8 (95% CI 0.4–1.7) during the first 5 years, 1.0 (0.6–1.7) during the first 10 years, and 0.8 (0.5–1.4) during 15 years of follow-up. The model adjusted for baseline known risk factors including A1C, age at diagnosis of diabetes, diabetes duration, and cigarette smoking resulted in similar HRs. In addition, incorporating changes in hyperfiltration status during follow-up had minimal impact on the HRs for microalbuminuria. CONCLUSION;S Renal hyperfiltration does not have an impact on the development of microalbuminuria in type 1 diabetes during 5, 10, or 15 years of follow-up.National Institutes of Health Grant (DK 041526

    Interactions between nation branding and corporate branding

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    The aim of this article is studying interactions between nation branding and corporate branding through reviewing the literature. Results show that both branding of a country and its corporates have influence to each other, either positive or negative effect that is called virtuous cycle or a vicious cycle. In fact, these two types of branding, act as a synergistic reinforcement tool to protect, improve or enhance the other one and therefore should be observed and maintained simustainasly.Keywords: National Reputation, CorporateBranding, Brand Positive Cycle, National Identit

    Discovery of Ranking Fraud for Mobile Apps Evidence Aggregation Based Ranking Fraud Detection (EA-RFD)

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    Ranking fraud within the mobile App market refers to dishonest or deceptive activities that have a purpose of bumping up the Apps within the quality list. Indeed, it becomes additional and additional frequent for App developers to use shady suggests that, like inflating their Apps? sales or posting phony App ratings, to commit ranking fraud. Whereas the importance of preventing ranking fraud has been well known, there's restricted understanding and analysis during this space. to the present finish, during this paper, we offer a holistic read of ranking fraud and propose a ranking fraud detection system for mobile Apps. Specifically, we tend to 1st propose to accurately find the ranking fraud by mining the active periods, specifically leading sessions, of mobile Apps. Such leading sessions will be leveraged for detective work the native anomaly rather than world anomaly of App rankings. Moreover, we tend to investigate 3 forms of evidences, i.e., ranking based mostly evidences, rating {based based mostly primarily based mostly} evidences and review based evidences, by modeling Apps? ranking, rating and review behaviors through applied mathematics hypotheses tests. Additionally, we tend to propose AN optimization based mostly aggregation methodology to integrate all the evidences for fraud detection. Finally, we tend to evaluate the projected system with real-world App knowledge collected from the iOS App Store for an extended fundamental measure. Within the experiments, we tend to validate the effectiveness of the projected system, and show the quantifiability of the detection algorithmic program furthermore as some regularity of ranking fraud activities

    Carrier relaxation in GaAs v-groove quantum wires and the effects of localization

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    Carrier relaxation processes have been investigated in GaAs/AlGaAs v-groove quantum wires (QWRs) with a large subband separation (46 meV). Signatures of inhibited carrier relaxation mechanisms are seen in temperature-dependent photoluminescence (PL) and photoluminescence-excitation (PLE) measurements; we observe strong emission from the first excited state of the QWR below ~50 K. This is attributed to reduced inter-subband relaxation via phonon scattering between localized states. Theoretical calculations and experimental results indicate that the pinch-off regions, which provide additional two-dimensional confinement for the QWR structure, have a blocking effect on relaxation mechanisms for certain structures within the v-groove. Time-resolved PL measurements show that efficient carrier relaxation from excited QWR states into the ground state, occurs only at temperatures > 30 K. Values for the low temperature radiative lifetimes of the ground- and first excited-state excitons have been obtained (340 ps and 160 ps respectively), and their corresponding localization lengths along the wire estimated.Comment: 9 pages, 8 figures, submitted to Phys. Rev. B Attempted to correct corrupt figure
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