796 research outputs found

    Invariant Submanifolds of Generalized Sasakian-Space-Forms

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    The object of this paper is to study the invariant submanifolds of generalized Sasakian-space-forms. Here, we obtain some equivalent conditions for an invariant submanifold of a generalized Sasakian-space-forms to be totally geodesic.Comment: 11 page

    Cross-Sender Bit-Mixing Coding

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    Scheduling to avoid packet collisions is a long-standing challenge in networking, and has become even trickier in wireless networks with multiple senders and multiple receivers. In fact, researchers have proved that even {\em perfect} scheduling can only achieve R=O(1lnN)\mathbf{R} = O(\frac{1}{\ln N}). Here NN is the number of nodes in the network, and R\mathbf{R} is the {\em medium utilization rate}. Ideally, one would hope to achieve R=Θ(1)\mathbf{R} = \Theta(1), while avoiding all the complexities in scheduling. To this end, this paper proposes {\em cross-sender bit-mixing coding} ({\em BMC}), which does not rely on scheduling. Instead, users transmit simultaneously on suitably-chosen slots, and the amount of overlap in different user's slots is controlled via coding. We prove that in all possible network topologies, using BMC enables us to achieve R=Θ(1)\mathbf{R}=\Theta(1). We also prove that the space and time complexities of BMC encoding/decoding are all low-order polynomials.Comment: Published in the International Conference on Information Processing in Sensor Networks (IPSN), 201

    Large Extra Dimension effects through Light-by-Light Scattering at the CERN LHC

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    Observing light-by-light scattering at the Large Hadron Collider (LHC) has received quite some attention and it is believed to be a clean and sensitive channel to possible new physics. In this paper, we study the diphoton production at the LHC via the process pppγγppγγp\rm pp\rightarrow p\gamma\gamma p\rightarrow p\gamma\gamma p through graviton exchange in the Large Extra Dimension (LED) model. Typically, when we do the background analysis, we also study the Double Pomeron Exchange (DPE) of γγ\gamma\gamma production. We compare its production in the quark-quark collision mode to the gluon-gluon collision mode and find that contributions from the gluon-gluon collision mode are comparable to the quark-quark one. Our result shows, for extra dimension δ=4\delta=4, with an integrated luminosity L=200fb1\rm {\cal L} = 200 fb^{-1} at the 14 TeV LHC, that diphoton production through graviton exchange can probe the LED effects up to the scale MS=5.06(4.51,5.11)TeV\rm M_S=5.06 (4.51, 5.11) TeV for the forward detector acceptance ξ1(ξ2,ξ3)\xi_1 (\xi_2, \xi_3), respectively, where 0.0015<ξ1<0.50.0015<\xi_1<0.5, 0.1<ξ2<0.50.1<\xi_2<0.5 and 0.0015<ξ3<0.150.0015<\xi_3<0.15.Comment: 25 pages. 7 figs. Change some grammatical error

    Degradation of Toxic Indigo Carmine Dye by Electrosynthesized Ferrate (VI)

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    Response surface methodology was applied for optimizing indigo carmine (IC) dye removal by electrochemically produced ferrate (VI). Box-Behnken design was employed in this study, and design parameters were pH, Fe (VI) dose and initial dye concentration (Co). R2 and adjusted R2 values were very high that indicated very good accuracy for the employed model. Optimum operational conditions were: 4.08-7.69 for pH, 24-118.83 mg/L for Fe (VI) dose and 60.68-99.13 mg/L for complete removal of IC. Produced by electrochemical method Ferrate (VI) provides high effectiveness for IC dye-containing synthetic wastewater

    A Comparative Study of Bioprocess Performance for Improvement of Bioethanol Production from Macroalgae

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    In the last decade, studies that have focused on biodiesel production from algal biomass have been replaced with bioethanol production from algae, because bioethanol production from algae seems more promising when assessed on economic terms. Most coastal areas are covered with macroalgae, which are considered as a waste, and thus become a great problem for the municipality. Instead of their disposal, they can be alternatively utilized for bioethanol production. In this study, macroalgae located in the coastal regions of the Marmara Sea were collected and utilized for bioethanol production, and effects of the concentration of pre-treatment chemicals, pre-treatment temperature, and pre-treatment time on bioethanol yield were investigated. The highest bioethanol yields for dilute acid and alkaline pre-treatments were obtained under the conditions of 2 N sulfuric acid and 0.15 N potassium hydroxide solutions at the pre-treatment temperature of 100 °C and pre-treatment time of 60 minutes

    Stabilization of self-coherent OFDM with injection locked laser

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    With the rebirth of coherent detection, various algorithms have come forth to alleviate phase noise, one of the main impairments for coherent receivers. These algorithms provide stable compensation, however they limit the DSP. With this key issue in mind, Fabry Perot filter based self coherent optical OFDM was analyzed which does not require phase noise compensation reducing the complexity in DSP at low OSNR. However, the performance of such a receiver is limited due to ASE noise at the carrier wavelength, especially since an optical amplifier is typically employed with the filter to ensure sufficient carrier power. Subsequently, the use of an injection-locked laser (ILL) to retrieve the frequency and phase information from the extracted carrier without the use of an amplifier was recently proposed. In ILL based system, an optical carrier is sent along with the OFDM signal in the transmitter. At the receiver, the carrier is extracted from the OFDM signal using a Fabry-Perot tunable filter and an ILL is used to significantly amplify the carrier and reduce intensity and phase noise. In contrast to CO-OFDM, such a system supports low-cost broad linewidth lasers and benefits with lower complexity in the DSP as no carrier frequency estimation and correction along with phase noise compensation is required
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