1,530 research outputs found

    Universality in the Gravitational Stretching of Clocks, Waves and Quantum States

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    There are discernible and fundamental differences between clocks, waves and physical states in classical physics. These fundamental concepts find a common expression in the context of quantum physics in gravitational fields; matter and light waves, quantum states and oscillator clocks become quantum synonymous through the Planck-Einstein-de Broglie relations and the equivalence principle. With this insight, gravitational effects on quantum systems can be simply and accurately analyzed. Apart from providing a transparent framework for conceptual and quantitative thinking on matter waves and quantum states in a gravitational field, we address and resolve with clarity the recent controversial discussions on the important issue of the relation and the crucial difference between gravimetery using atom interferometers and the measurement of gravitational time dilation.Comment: Gravity Research Foundation honorable mention, 201

    Space-Time Coded Spatial Modulated Physical Layer Network Coding for Two-Way Relaying

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    Using the spatial modulation approach, where only one transmit antenna is active at a time, we propose two transmission schemes for two-way relay channel using physical layer network coding with space time coding using Coordinate Interleaved Orthogonal Designs (CIOD's). It is shown that using two uncorrelated transmit antennas at the nodes, but using only one RF transmit chain and space-time coding across these antennas can give a better performance without using any extra resources and without increasing the hardware implementation cost and complexity. In the first transmission scheme, two antennas are used only at the relay, Adaptive Network Coding (ANC) is employed at the relay and the relay transmits a CIOD Space Time Block Code (STBC). This gives a better performance compared to an existing ANC scheme for two-way relay channel which uses one antenna each at all the three nodes. It is shown that for this scheme at high SNR the average end-to-end symbol error probability (SEP) is upper bounded by twice the SEP of a point-to-point fading channel. In the second transmission scheme, two transmit antennas are used at all the three nodes, CIOD STBC's are transmitted in multiple access and broadcast phases. This scheme provides a diversity order of two for the average end-to-end SEP with an increased decoding complexity of O(M3)\mathcal{O}(M^3) for an arbitrary signal set and O(M2M)\mathcal{O}(M^2\sqrt{M}) for square QAM signal set.Comment: 9 pages, 7 figure

    A probabilistic approach to reduce the route establishment overhead in AODV algorithm for manet

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    Mobile Ad-hoc Networks (MANETS) is a collection of wireless nodes without any infrastructure support. The nodes in MANET can act as either router or source and the control of the network is distributed among nodes. The nodes in MANETS are highly mobile and it maintains dynamic interconnection between those mobile nodes. MANTEs have been considered as isolated stand-alone network. This can turn the dream of networking "at any time and at any where" into reality. The main purpose of this paper is to study the issues in route discovery process in AODV protocol for MANET. Flooding of route request message imposes major concern in route establishment. This paper suggests a new approach to reduce the routing overhead during the route discovery phase. By considering the previous behaviour of the network, the new protocol reduces the unwanted searches during route establishment processComment: International Journal of Distributed and Parallel Systems (IJDPS) Vol.3, No.2, March 201

    Some Classes of Multivariate Life Distributions in Discrete Time

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    AbstractNew classes of multivariate survival distribution functions based on monotonic behaviour of a multivariate failure rate are developed in the discrete set up. Relationship among the classes along with multivariate geometric distributions that act as boundaries of the various classes are identified

    Initial wave packets and the various power-law decreases of scattered wave packets at long times

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    The long time behavior of scattered wave packets ψ(x,t)\psi (x,t) from a finite-range potential is investigated, by assuming ψ(x,t)\psi (x,t) to be initially located outside the potential. It is then shown that ψ(x,t)\psi (x,t) can asymptotically decrease in the various power laws at long time, according to its initial characteristics at small momentum. As an application, we consider the square-barrier potential system and demonstrate that ψ(x,t)\psi (x,t) exhibits the asymptotic behavior t−3/2t^{-3/2}, while another behavior like t−5/2t^{-5/2} can also appear for another ψ(x,t)\psi (x,t).Comment: 5 pages, 1 figur

    Ambulatory glucose profile as an educational tool in the management of patients with type 2 diabetes mellitus

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    A 60-year-old male patient with Type 2 Diabetes Mellitus (T2DM) since the last two years was presented in the clinic with repeated falls. He was on dietary treatment and was also taking metformin 500 mg twice daily, on and off. His Fasting Plasma Glucose (FPG) was 116 mg/dL, Postprandial Glucose (PPG) was 140 mg/dL and Glycosylated Haemoglobin (HbA1c) was 6.4%. The complete glycaemic profile obtained from the first Ambulatory Glucose Profile (AGP) revealed that the patient was not having hypoglycaemia and has very minimal glucose fluctuations without any post-prandial excursions. The visual cue obtained from Continuous Glucose Monitoring (CGM) / AGP enabled physicians to better inform the patient on the effects of medication and lifestyle on diabetes, thereby allowing the patient to make informed treatment and lifestyle modifications. This case study sheds light on the need to recommend AGP in such cases to provide insights on the glucose trends, thereby improve patient’s confidence in the therapy, with lifestyle modification

    An eyeshot on Kshudra Dhanya in Ayurveda

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    Kshudra Danya is a group of small seeded cereals used as human food since ages. They are popular by the name millets. As Millets are packed with nutrients, they have numerous health benefits. Ayurveda has a distinguished explanation of Kshudra Danya (millets) with their specific qualities and effects, based on which their indications and contraindications can be elicited. This analysis may help in understanding the right usage of Kshudra Danya (millets) to avail their complete health benefits

    Role of magnetic resonance spectroscopy in grading of gliomas- a tertiary care centre study

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    Background: Grading of gliomas is important for the determination of appropriate treatment strategies. MR spectroscopy has found increasing utility in grading of gliomas.Methods: MR spectroscopic imaging was done for the referred patients to obtain Cho/NAA and Cho/Cr ratios. After analyzing histopathology reports, gliomas were classified into low grade and high grade. Histologically proven 54 low grade and 54 high grade gliomas were included in the study. The mean and standard deviation of these variables were obtained and compared between two groups.  ROC curve analyses were performed in order to identify the optimal cut-off value for metabolite ratios for prediction purposes of high grade versus low grade gliomas.Results: The mean and SD of Cho/NAA ratio in low grade glioma was 1.93±1.19. The mean and SD of Cho /NAA ratio in high grade glioma was 3.16±1.73 was significantly higher. The optimal cut-off for differentiating low grade and high grade gliomas was 2.15 with a sensitivity of 74.07% and specificity of 66.67%. The mean and SD of CHO/Cr in low grade glioma was 2.05±0.76. The mean and SD of Cho/NAA in high grade glioma was 2.87±1.65 was significantly higher. The optimal cut-off for differentiating low grade and high grade gliomas was 1.98 with a sensitivity of 64.8% and specificity of 64.1%.Conclusions: MR spectroscopy imaging plays a pivotal role in prediction of glioma grade preoperatively and helps in deciding appropriate treatment strategies

    Free initial wave packets and the long-time behavior of the survival and nonescape probabilities

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    The behavior of both the survival S(t) and nonescape P(t) probabilities at long times for the one-dimensional free particle system is shown to be closely connected to that of the initial wave packet at small momentum. We prove that both S(t) and P(t) asymptotically exhibit the same power-law decrease at long times, when the initial wave packet in momentum representation behaves as O(1) or O(k) at small momentum. On the other hand, if the integer m becomes greater than 1, S(t) and P(t) decrease in different power-laws at long times.Comment: 4 pages, 3 figures, Title and organization changed, however the results not changed, To appear in Phys. Rev.
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