107 research outputs found

    Mechanical Attributes of Fractal Dragons

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    Fractals are ubiquitous natural emergences that have gained increased attention in engineering applications, thanks to recent technological advancements enabling the fabrication of structures spanning across many spatial scales. We show how the geometries of fractals can be exploited to determine their important mechanical properties, such as the first and second moments, which physically correspond to the center of mass and the moment of inertia, using a family of complex fractals known as the dragons

    DFT based spatial multiplexing and maximum ratio transmission for mm-wawe large MIMO

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    Frequency Bin Entangled Photons

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    A monochromatic laser pumping a parametric down conversion crystal generates frequency entangled photon pairs. We study this experimentally by addressing such frequency entangled photons at telecommunication wavelengths (around 1550 nm) with fiber optics components such as electro-optic phase modulators and narrow band frequency filters. The theory underlying our approach is developed by introducing the notion of frequency bin entanglement. Our results show that the phase modulators address coherently up to eleven frequency bins, leading to an interference pattern which can violate a Bell inequality adapted to our setup by more than five standard deviations.Comment: 10 pages, 4 figures (extended version

    One-loop expressions for h→llˉγh\rightarrow l\bar{l}\gamma in Higgs extensions of the Standard Model

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    A systematic study of one-loop contributions to the decay channels h→llˉγh\rightarrow l\bar{l}\gamma with l=νe,μ,τ,e,μl=\nu_{e,\mu, \tau}, e, \mu, performed in Higgs extended versions of the Standard Model, is presented in the 't Hooft-Veltman gauge. Analytic formulas for one-loop form factors are expressed in terms of the logarithm and di-logarithmic functions. As a result, these form factors can be reduced to those relating to the loop-induced decay processes h→γγ,Zγh\rightarrow \gamma\gamma, Z\gamma, confirming not only previous results using different approaches but also close relations between the three kinds of the loop-induced Higgs decay rates. For phenomenological study, we focus on the two observables, namely the enhancement factors defined as ratios of the decay rates calculated between the Higgs extended versions and the standard model, and the forward-backward asymmetries of fermions, which can be used to search for Higgs extensions of the SM. We show that direct effects of mixing between neutral Higgs bosons and indirect contributions of charged Higg boson exchanges can be probed at future colliders.Comment: 39 pages, 9 Figures, 11 Tables of dat

    The effect of nocturnal wear of dentures on the sleep quality: A systematic review and meta-analysis

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    Purpose The effect of nocturnal wear of denture on sleep quality and integrity is still not well understood. Therefore, this systematic review was conducted to provide evidence on this topic. Methods Electronic searches were conducted from 1964 up to September 2015, using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. Only publications in English or French, in which sleep quality of edentate adult individuals wearing dentures at night was compared to those not wearing were included in the review. Random effects models were used to pool the effect sizes. Results A total of 10 studies were included in the systematic review and 5 in the meta-analysis. No statistically significant difference between sleeping with denture and without denture was found for the Apnea-Hypopnea Index (AHI; Standard Mean Difference = −0.60, 95 % CI −1.67–0.47; Z = −1.10; p = 0.27). However, there was considerable heterogeneity in the studies included in the meta-analysis (Tau2 = 1.34; Q-value = 59.32, df = 4 (P < 0.0001); I2 = 93.3 %). When results from randomized controlled trials (RCTs) were pooled in subgroup analyses of AHI, there was a tendency towards favoring sleeping without dentures (P = 0.059) and no evidence of heterogeneity between studies (Tau2 = 0.000; Q-value = 0.06, df = 1 (P = 0.80); I2 = 0.000 %). Conclusion The current evidence suggests that there is no difference in the sleep quality and integrity of individuals wearing or not wearing their denture during sleep. However, the results of randomized controlled trials favoring sleeping without dentures and the likely presence of bias in the previous studies indicate the need for further randomized controlled trials for the development of clinical guideline

    Experimental quantum tossing of a single coin

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    The cryptographic protocol of coin tossing consists of two parties, Alice and Bob, that do not trust each other, but want to generate a random bit. If the parties use a classical communication channel and have unlimited computational resources, one of them can always cheat perfectly. Here we analyze in detail how the performance of a quantum coin tossing experiment should be compared to classical protocols, taking into account the inevitable experimental imperfections. We then report an all-optical fiber experiment in which a single coin is tossed whose randomness is higher than achievable by any classical protocol and present some easily realisable cheating strategies by Alice and Bob.Comment: 13 page

    A Schr\"odinger Equation for Evolutionary Dynamics

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    We establish an analogy between the Fokker-Planck equation describing evolutionary landscape dynamics and the Schr\"{o}dinger equation which characterizes quantum mechanical particles, showing how a population with multiple genetic traits evolves analogously to a wavefunction under a multi-dimensional energy potential in imaginary time. Furthermore, we discover within this analogy that the stationary population distribution on the landscape corresponds exactly to the ground-state wavefunction. This mathematical equivalence grants entry to a wide range of analytical tools developed by the quantum mechanics community, such as the Rayleigh-Ritz variational method and the Rayleigh-Schr\"{o}dinger perturbation theory, allowing us to not only make reasonable quantitative assessments but also explore fundamental biological inquiries. We demonstrate the effectiveness of these tools by estimating the population success on landscapes where precise answers are elusive, and unveiling the ecological consequences of stress-induced mutagenesis -- a prevalent evolutionary mechanism in pathogenic and neoplastic systems. We show that, even in a unchanging environment, a sharp mutational burst resulting from stress can always be advantageous, while a gradual increase only enhances population size when the number of relevant evolving traits is limited. Our interdisciplinary approach offers novel insights, opening up new avenues for deeper understanding and predictive capability regarding the complex dynamics of evolving populations

    A Conceptual Design and Numerical Analysis for a Small-Scale and Low-Cost Plastic Recycling Machine

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    A new conceptual design for a small-scale and low-cost plastic recycling machine is generated by combining melting part and compression process. Starting with one of the outstanding requirements is in terms of an affordable-priced machine that can perform two processes with high accuracy and capacity, some issues related to balancing among quality, capacity and cost of machine occurred during a discussion. After implementing various designing methods such as Quality Function Deployment, Reverse Engineering, Morphological Matrix and Pugh Method, an idea of final concept about using an electric oven and hydraulic system to melt down and compress plastic tile which has a dimension of 300x300x9 mm was created. The design of concept is divided into two parts which are mechanical and electrical systems. In a mechanical section, the technical drawing and simulation are made to see how machine performs under operation. Besides, we examined the forces that applied in the moulds to evaluate the strength of the system. In heating and electricity section, we chose electrical components, designed oven parameters and conducted the heating simulation on the mould. In addition, the heating and cooling time was calculated based on the principles of thermodynamics and heat transfer. Furthermore, the manufacturing plan is created to estimate the essential resources producing a certain number of heat-forming machines. In general, the machine needs to be prototyped for controlling its main function and finding practical issues. After that, some improvements could be made to enhance efficiency and increase capacity by designing an optimal mould to more heat absorb and reduce post process, calculate and design more efficient oven, create faster lock mechanism and other improvements for an automatizing machine

    Reconfigurable Intelligent Surfaces vs. Relaying: Differences, Similarities, and Performance Comparison

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    Reconfigurable intelligent surfaces (RISs) have the potential of realizing the emerging concept of smart radio environments by leveraging the unique properties of meta-surfaces. In this article, we discuss the potential applications of RISs in wireless networks that operate at high-frequency bands, e.g., millimeter wave (30-100 GHz) and sub-millimeter wave (greater than 100 GHz) frequencies. When used in wireless networks, RISs may operate in a manner similar to relays. This paper elaborates on the key differences and similarities between RISs that are configured to operate as anomalous reflectors and relays. In particular, we illustrate numerical results that highlight the spectral efficiency gains of RISs when their size is sufficiently large as compared with the wavelength of the radio waves. In addition, we discuss key open issues that need to be addressed for unlocking the potential benefits of RISs.Comment: Submitted for journal publication (revised version
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