In this paper, we present a network flow based approach for network selection for secondary users in cognitive radio networks. Most approaches in the current literature on cognitive radio do not consider network selection. We present a network flow framework for network selection. We show that our approach can enable re-assignment of networks to secondary users and also re-assignment of channel...

The purpose of this paper is to analyze the flow field structure in transient state and performance of secondary injection system for thrust vectoring in divergent section of a two-dimensional nozzle. Secondary injection for thrust vectoring in a two-dimensional nozzle is studied by solving three-dimensional Reynolds-averaged equations by means of fluent solver. Spalart-allmaras model was used ...

In this paper we report experiments where we shear granular rods in split-bottom geometries, and find that a significant heap of height of least 40% of the filling height can form at the particle surface. We show that heaping is caused by a significant secondary flow, absent for spherical particles. Flow reversal transiently reverses the secondary flow, leading to a quick collapse and slower re...

in the past, mining activities have generated major acid drainage sources, which usually carry dissolved metals that flow into the main rivers of the affected basins. the study looks at natural attenuation processes in local, sub-basin and basin areas, in the el bierzo and odiel basins of spain, where coal and metal mining activities were formerly conducted. in this study, sampling and in situ ...

The incompressible boundary layer in the axial flow past a cylinder has been shown Tutty et. al.([11]) to be stabler than a two-dimensional boundary layer, with the helical mode being the least stable. In this paper the secondary instability of this flow is studied. The laminar flow is shown here to be always stable at high transverse curvatures to secondary disturbances, which, together with a...

Non-axisymmetric profiled endwalls have been shown to reduce losses and secondary flow both in cascades and in rig tests. This paper presents experimental results which quantify the benefits of loss reduction in the cascade with particular attention to accuracy. The paper compares the benefits achieved in experiment to the results predicted by computational fluid dynamics (CFD). The results sho...

An experimental investigation was carried out to examine the influence of the axial spacing between rotor and stator. The test facility of the Swiss Federal Institute of Technology is made up of an inlet guide vane (IGV), a rotor and a stator. Temperature and aerodynamic measurements determined the characteristics of the compressor stage. Data were acquired over a range of flow coefficients for...

New patterns of interaction emerge annually between the places where schoolchildren live and go to school. This paper concentrates on understanding the dynamics of the 'journey to learn'. It explains how PLASC data for Leeds, a city in northern England, can be used to measure daily pupil movements and to investigate school territories, but also to identify pupil movements between schools and be...