in this paper we investigate the long memory of tehran securities price index and fit arfima model using 970 daily data since 1382/1/6 until 1386/4/17. furthermore, we compare the forecasting performance of arfima and arima models. the results show that the series is a long memory one and therefore it can become stationary by fractional differencing. we obtaine the fractional differencing param...

in this paper, static performance characteristics for a finite lenght two-lobe journal bearing lubricated with micropolar fluid is studied. using finite element method, steady-state film pressure is obtained by solving modified reynolds equation, based on micropolar lubrication theory. with the help of film pressure in bearing, the static performance characteristics in terms of load carrying ca...

In this paper, the shape influence of piezoelectric beams including triangle, trapezoid, rectangle, inverted trapezoid, convex parabola, concave parabola, and comb-shaped (a combination of two triangular beams with a connector of 4 mm length) are addressed and analyzed by FEM. The analysis is performed for a bimorph piezoelectric beam. The analyzed parameters include the beam length, thickness ...

In this paper, the performance of a Ring Laser Gyro based inertial navigation is investigated. Dynamic and stochastic modeling are applied to gyro simulation and performance evaluation. In the dynamic model, some parameters such as scale factor and environmental sensitivity have been determined, whereas in the stochastic model, the other parameters such as random drift and measurement noise...

in this paper, we study the estimation problems for the two-parameter exponentiated gumbel distribution based on lower record values. an exact confidence interval and an exact joint confidence region for the parameters are constructed. a simulation study is conducted to study the performance of the proposed confidence interval and region. finally, a numerical example with real data set is given...

Database queries within a component framework usually take the form of a string passed to an operation in a component’s interface. The interface operation accepts a value of type string as an actual parameter and implements the necessary support to resolve the query. In such an approach, a component’s interface does not explicitly state the queries supported by that component. In this paper, we...

Soft glassy materials exhibit the so-called glassy transition which means that the behavior of the model at low shear rate changes when a certain parameter (which we call the glass parameter) crosses a critical value. This behavior goes from a Newtonian behavior to a HerschelBulkley behavior through a power-law-type behavior at the transition point. In a previous paper we rigorously proved that...

Combined logics have recently deserved much attention. In this paper we develop a detailed study of a form of combination that generalises the temporalisation construction proposed in 9]. It consists of replacing an atomic part (formal parameter) of one (parameterised) logic by another (actual parameter) logic. We provide a categorial char-acterisation of parameterisation and illustrate it with...

Scientific theories are hard to find, and once scientists have found a theory H, they often believe that there are not many distinct alternatives to H. But is this belief justified? What should scientists believe about the number of alternatives to H, and how should they change these beliefs in the light of new evidence? These are some of the questions that we will address in this paper. We als...