6,091 research outputs found

    On the Distribution of the Number of Points on Algebraic Curves in Extensions of Finite Fields

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    Let \cC be a smooth absolutely irreducible curve of genus g1g \ge 1 defined over \F_q, the finite field of qq elements. Let # \cC(\F_{q^n}) be the number of \F_{q^n}-rational points on \cC. Under a certain multiplicative independence condition on the roots of the zeta-function of \cC, we derive an asymptotic formula for the number of n=1,...,Nn =1, ..., N such that (# \cC(\F_{q^n}) - q^n -1)/2gq^{n/2} belongs to a given interval \cI \subseteq [-1,1]. This can be considered as an analogue of the Sato-Tate distribution which covers the case when the curve \E is defined over \Q and considered modulo consecutive primes pp, although in our scenario the distribution function is different. The above multiplicative independence condition has, recently, been considered by E. Kowalski in statistical settings. It is trivially satisfied for ordinary elliptic curves and we also establish it for a natural family of curves of genus g=2g=2.Comment: 14 page

    Looking for K\"ahler- Einstein Structure on Cartan Spaces with Berwald connection

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    A Cartan manifold is a smooth manifold M whose slit cotangent bundle T*M0 is endowed with a regular Hamiltonian K which is positively homogeneous of degree 2 in momenta. The Hamiltonian K defines a (pseudo)-Riemannian metric gij in the vertical bundle over T*M0 and using it a Sasaki type metric on T*M0 is constructed. A natural almost complex structure is also defined by K on T*M0 in such a way that pairing it with the Sasaki type metric an almost K\"ahler structure is obtained. In this paper we deform gij to a pseudo-Riemannian metric Gij and we define a corresponding almost complex K\"ahler structure. We determine the Levi-Civita connection of G and compute all the components of its curvature. Then we prove that if the structure (T*M0, G, J) is K\"ahler- Einstein, then the Cartan structure given by K reduce to a Riemannian one.Comment: This article is in 15 page. arXiv admin note: text overlap with this http URL and arXiv:1202.6202 by other autho

    Multiplicative Order of Gauss Periods

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    We obtain a lower bound on the multiplicative order of Gauss periods which generate normal bases over finite fields. This bound improves the previous bound of J. von zur Gathen and I. E. Shparlinski.Comment: 9 page

    Health concerns of Iranian adolescents: Protocol for a mixed methods study

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    Background: Adolescents have particular health and developmental needs that suggest they should neither be treated as older children nor younger adults. Objectives: The aim of this paper is to report the protocol for a mixed methods study that set out to investigate the health concerns of Iranian adolescents and their sources of health information with the goal of identifying suitable strategies to address their health concerns. Materials and Methods: This mixed methods study consists of an explanatory sequential design to be conducted in two phases. The first phase was a population-based cross-sectional survey of 915, 14-18 year old adolescents who were selected by stratified cluster random sampling method from the 22 main municipal sectors of Tehran, Iran. They completed a series of self-administered questionnaires which were analyzed using quantitative approaches. The second phase was a qualitative study in which adolescents were selected using purposeful sampling for individual in-depth semi-structured interviews on the basis of the quantitative findings from the first phase. These data, together with a literature review and data obtained through nominal group technique, would then be used to in the development of strategies to reduce adolescents' health concerns. Results: The findings of this mixed methods sequential explanatory study are expected to provide unique information about the health concerns of Iranian adolescents and their sources of information, which to date have received little attention. Conclusions: These data will provide a rich source of information that can be used by intervention programs, health professionals and policy makers in addressing the health concerns of adolescents, with the goal of facilitating a successful passage to adult life. © 2014, Iranian Red Crescent Medical Journal

    A Prioritised Traffic Embedding Mechanism enabling a Public Safety Virtual Operator

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    Public Protection and Distaster Relief (PPDR) services can benefit greatly from the availability of mobile broadband communications in disaster and emergency scenarios. While undoubtedly offering full control and reliability, dedicated networks for PPDR have resulted in high operating costs and a lack of innovation in comparison to the commercial domain. Driven by the many benefits of broadband communications, PPDR operators are increasingly interested in adopting mainstream commercial technologies such as Long Term Evolution (LTE) in favour of expensive, dedicated narrow-band networks. In addition, the emergence of virtualization for wireless networks offers a new model for sharing infrastructure between several operators in a flexible and customizable manner. In this context, we propose a virtual Public Safety (PS) operator that relies on shared infrastructure of commercial LTE networks to deliver services to its users. We compare several methods of allocating spectrum resources between virtual operators at peak times and examine how this influences differing traffic services. We show that it is possible to provide services to the PS users reliably during both normal and emergency operation, and examine the impact on the commercial operators.Comment: Accepted in VTC Fall 2015, 5 page

    Nonlocal communication with photoinduced structures at the surface of a polymer film

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    Nonlocal communication between two laser light beams is experimented in a photochromic polymer thin films. Information exchange between the beams is mediated by the self-induction of a surface relief pattern. The exchanged information is related to the pitch and orientation of the grating. Both are determined by the incident beam. The process can be applied to experiment on a new kind of logic gates.Comment: 7 pages, 4 figures, 2 table

    Comparison of efficacy Ephedrine and phenylephrine in Postoperative Vomiting in Cesarean section

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    Introduce: Postoperative nausea and vomiting (PONV) still is the most big problem event encountered in the PACU (Post Anesthesia Care Unit), despite advances in prevention and treatment. The incidence of PONV has remained high and has a major negative impact on patient satisfaction about the overall surgical experience. Method: In double-blind, clinical trial, 104 patients were undergoing cesarean section was randomizing into two groups: Group P (100μg Phenylephrine) and Group E (6μg Ephedrine). We compared the Vomiting parameters between the two groups. Result: Patients in the recovery were compared in 2 groups regarding occurrence of vomiting that no statistical difference between two group (P >0.05). The results show that vomiting was seen in ASA1, and in ASA2 no vomiting was observed. The incidence of vomiting was 2 patients in young group and 1 patient in middle-aged group. The incidence of vomiting was 2 patients in slim group, 1 in moderate group and no sign of vomiting has been seen in the obese group. Conclusion: We conclude that ephedrine is the best drug for antiemetic prophylaxis before cesarean surgery based on cost and lack of side effects
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