291 research outputs found

    Thermodynamics of the FRW universe at the event horizon in Palatini f(R) gravity

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    In an accelerated expanding universe, one can expect the existence of an event horizon. It may be interesting to study the thermodynamics of the Friedmann-Robertson-Walker (FRW) universe at the event horizon. Considering the usual Hawking temperature, the first law of thermodynamics does not hold on the event horizon. To satisfy the first law of thermodynamics, it is necessary to redefine Hawking temperature. In this paper, using the redefinition of Hawking temperature and applying the first law of thermodynamics on the event horizon, the Friedmann equations are obtained in f(R) gravity from the viewpoint of Palatini formalisn. In addition, the generalized second law (GSL) of thermodynamics, as a measure of the validity of the theory, is investigated

    Modification of Truncated Expansion Method for Solving Some Important Nonlinear Partial Differential Equations

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    In this paper, we implemented modification of truncated expansion method for the exact solutions of the Konopelchenko-Dubrovsky equation the (n+1)-dimensional combined sinhcosh- Gordon equation and the Maccari system. Modification of truncated expansion method is a powerful solution method for obtaining exact solutions of nonlinear evolution equations. This method presents a wider applicability for handling nonlinear wave equations

    Analytic Investigation of the KP-Joseph-Egri Equation for Traveling Wave Solutions

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    By means of the two distinct methods, the cosine-function method and the (G /G ) expansion method, we successfully performed an analytic study on the KP-Joseph-Egri (KP-JE) equation. We exhibited its further closed form traveling wave solutions which reduce to solitary and periodic waves

    The Multisoliton Solutions of Some Nonlinear Partial Differential Equations

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    In this paper, we obtain multisoliton solutions of the Camassa-Holm equation and the Joseph- Egri (TRLW) equation by using the formal linearization method. The formal linearization method is an efficient instrument for constructing multisoliton solution of some nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones

    Exact Travelling Wave Solutions for Konopelchenko-Dubrovsky Equation by the First Integral Method

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    In this paper, the first integral method is used to construct exact travelling wave solutions of Konopelchenko-Dubrovsky equation. The first integral method is algebraic direct method for obtaining exact solutions of nonlinear partial differential equations. This method can be applied to non-integrable equations as well as to integrable ones. This method is based on the theory of commutative algebra

    A queuing location-allocation model for a capacitated health care system

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    International audienceThe aim of the present paper is to propose a location-allocation model for a capacitated health care system. This paper develops a discrete modeling framework to determine the optimal number of facilities among candidates and optimal allocations of the existing customers to operating health centers in a coverage distance. In doing so, the total sum of customer and operating facility costs is minimized. Our goal is to create a model that is more practical in the real world. Therefore, setup costs of hospitals are based on the costs of customers, xed costs of establishing health centers, and costs based on the available resources in each level of hospitals. In this paper, the idea of hierarchical structure has been used. There are two levels of service in hospitals, including low and high levels, and sections at diierent levels that provide diierent types of services. The patients refer to diierent sections of the hospital according to their requirements. To solve the model, two meta-heuristic algorithms, including genetic and simulated annealing algorithms and their combination, are proposed. To evaluate the performance of the three algorithms, some numerical examples are produced and analyzed using the statistical test in order to determine which algorithm works better

    Exact solutions of the nonlinear Schrödinger equation by the first integral method

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    AbstractThe first integral method is an efficient method for obtaining exact solutions of some nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones. In this paper, the first integral method is used to construct exact solutions of the nonlinear Schrödinger equation

    Exact Solutions of the Generalized- Zakharov (GZ) Equation by the Infinite Series Method

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    The infinite series method is an efficient method for obtaining exact solutions of some nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones. In this paper, the direct algebraic method is used to construct new exact solutions of generalized- Zakharov equation

    The First Integral Method to Nonlinear Partial Differential Equations

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    In this paper, we show the applicability of the first integral method for obtaining exact solutions of some nonlinear partial differential equations. By using this method, we found some exact solutions of the Landau-Ginburg-Higgs equation and generalized form of the nonlinear Schrödinger equation and approximate long water wave equations. The first integral method is a direct algebraic method for obtaining exact solutions of nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones. This method is based on the theory of commutative algebra
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