Wireless network system aims to provide dedicated links to the users for improving the quality of services. Particularly in heterogeneous network seamless connectivity is the important requirement for the users utilizing multimedia services. Vertical handover (VH) mechanism provides uninterrupted service to the users in a multiple wireless network region by selecting the best available network. Unlike horizontal handover (one base station to another or nearby access point) VH chooses the wireless access technologies (Wi-Fi to 4G). To improve the QoS of VH model the decision phase needs efficient metrics for providing excellent service. In general a fuzzy based operating model is most suitable for decision making and to implement a seamless handover, neural network is used in the proposed research work. An experimental result describes the best decision making module by comparing the proposed hybrid model with existing models.
A theory describing the behavior of chemically non-reacting binary mixtures can be based on a detailed formulation of the governing equations for the individual components of the mixture or on treating the mixture as a single homogenized continuous medium. We argue that if we accept that both approaches can be used to describe the behavior of the given mixture, then the requirement on the equivalence of these approaches places restrictions on the possible structure of the internal energy, entropy, Helmholtz potential, and also of the diffusive, energy, and entropy fluxes. (The equivalence of the approaches is understood in the sense that the quantities used in one approach can be interpreted in terms of the quantities used in the other approach and vice versa. Further, both approaches must lead to the same predictions concerning the evolution of the physical system under consideration). In the case of a general chemically non-reacting binary mixture of components at the same temperature, we show that these restrictions can indeed be obtained by purely algebraic manipulations. An important outcome of this analysis is, for example, a general form of the evolution equation for the diffusive flux. The restrictions can be further exploited in the specification of thermodynamically consistent constitutive relations for quantities such as the interaction (drag) force or the Cauchy stress tensor. As an example of the application of the current framework, we derive, among others, a generalization of Fick’s law and we recover several non-trivial results obtained by other techniques. The qualitative features of the derived generalization of Fick’s law are demonstrated by a numerical experiment. 相似文献
The paper explores results based on the concept of the Reservoir Integral for understanding pressure analysis under multiphase flow. A theoretical framework is developed, and the use of the theory is demonstrated by considering a model problem namely that of the pressure behavior of injection wells. Limiting forms are derived. The theory provides a basis for understanding conclusions derived by numerical results for multiphase flow. 相似文献
In this short note, we develop a new class of “quasi-linear” viscoelastic models wherein the linearized strain is expressed in terms of a nonlinear measure of the stress. The class of models that is developed could be regarded as counterpart to the class of models referred to popularly as “quasi-linear” models, proposed by Fung to describe the response of viscoelastic bodies; however, now the strain is expressed as an integral of a nonlinear measure of the stress. The class of models that are developed can describe response that cannot be described by the class of models proposed by Fung, and moreover, these models are more reasonable from the point of view of causality. 相似文献
Efficient control of RF MEMS switches is a very important issue as it is correlated to main failure mechanisms/modes such as the impact force and bouncing phenomena, which degrade their dynamic performance and longevity. This paper presents the control of specific ohmic RF MEMS switches under three different actuation modes, a tailored pulse optimization method based on Taguchi's technique (voltage mode actuation control), resistive damping (charge mode actuation control) and finally the Hybrid actuation mode, which is a combination of the tailored pulse, the resistive damping and Taguchi's optimization technique. Coventorware simulations indicate that under optimized Tailored pulse and Hybrid actuation modes, the impact velocity is reduced by around 90%, the initial impact force by around 75% and the maximum bouncing displacement during the release phase by around 95%, while the switching speed is increased by around 20% compared with the step pulse control mode. The resistive damping control mode is inappropriate for this type of switch and only partial improvement during the pull-down phase has been achieved. Finally, a comparison between Hybrid and optimized tailored modes shows that Hybrid actuation mode excels with better switching characteristics and most importantly offers immunity to manufacturing and operation tolerances. 相似文献
This study is concerned with the constitutive modeling of asphalt concrete. Unlike most constitutive models for asphalt concrete that do not take into account the evolution of the microstructure of the material, this study incorporates the evolution of the microstructure by using a framework that recognizes that a body’s natural configurations can evolve as the microstructure changes. The general framework, on which this study is based, is cast within a full thermomechanical setting. In this paper, we develop models within the context of a mechanical framework that stems from the general framework for models based on the full thermodynamic framework and the resulting equations represent a nonlinear rate type viscoelastic model. The creep and stress relaxation experiments of Monismith and Secor are used for validating the efficacy of the model, and it is found that the predictions of the theory agree very well with the available experimental results. The advantages of using such a framework are many, especially when one wants to model the diverse mechanical and thermodynamic response characteristics of asphalt and asphalt concrete. 相似文献