Critical success factors in mobile communictions: a comparative roadmap for Germany and India

The world of telecommunications, especially mobile communications, continues to evolve with innovative technologies and high-speed data services. In many economies, mobile phones have overtaken fixed lines. In this dynamic context, we have envisaged to study mobile communication diffusion in Germany and India, from a historical comparative perspective. The basic standard for comparison has been Global Systems for Mobile Communications (GSM) and its data services, which was adopted by both economies. Subsequently, critical success factors in each economy is drawn and compared with the other, to elicit future directions.

Speed control and policing in a cellular mobile network: speedNet

In this paper, we describe SpeedNet, a GSM network variant which resembles an ad hoc wireless mobile network where base stations keep track of the velocities of mobile users (cars). SpeedNet is intended to track mobile users and their speed passively for both speed policing and control of traffic. The speed of the vehicle is controlled in a speed critical zone by means of an electro-mechanical control system, suitably referred to as VVLS (Vehicular Velocity Limiting System). VVLS is mounted on the vehicle and responds to the command signals generated by the base station. It also determines the next base station to handoff, in order to improve the connection reliability and bandwidth efficiency of the underlying network. Robust Extended Kalman Filter (REKF) is used as a passive velocity estimator of the mobile user with the widely used proportional and integral controller speed control. We demonstrate through simulation and analysis that our prediction algorithm can successfully estimate the mobile user’s velocity with low system complexity as it requires two closest mobile base station measurements and also it is robust against system uncertainties due to the inherent deterministic nature in the mobility model.

Speed control and policing in a cellular mobile network: SpeedNet

In this paper, we describe SpeedNet, a GSM network variant which resembles an ad hoc wireless mobile network where base stations (possibly other vehicles in the network) keep track of the velocities of mobile users (cars). SpeedNet is intended to track mobile users and their speed passively for both speed policing and control of traffic. The speed of the vehicle is controlled in a speed critical zone by means of an electro-mechanical control system, suitably referred to as VVLS (vehicular velocity limiting system). VVLS is mounted in the vehicle and responds to the command signals generated by the base station. It also determines the next basestation to handoff, in order to improve the connection reliability and bandwidth efficiency of the underlying network. Robust extended Kalman filter (REKF) is used as a passive velocity estimator of the mobile user with the widely used proportional and integral controller speed control. We demonstrate through simulation and analysis that our prediction algorithm can successfully estimate the mobile users velocity with low system complexity as it requires two closet mobile-base station measurement and also it is robust against system uncertainties due to the inherent deterministic nature in the mobility model.

A survey on mechanisms and critical parameters on solidification of selective laser melting during fabrication of Ti-6Al-4V prosthetic acetabular cup

Additive Manufacturing (AM) includes a range of approaches that correlate with computer aided design (CAD) and manufacturing by fabrication via precise layers and is a promising method for the production of medical tools. In this study, different aspects and mechanisms of solidification for curved surfaces based on equilibrium at curved interfaces, Monge patch, interfacial and Gibbs energy will be discussed. Also, the effect of capillarity, geometry, substrate temperature, cooling rate and scanning parameters in the solidification of a prosthetic acetabular cup (PAC) using selective laser melting (SLM) is analysed. The contributions of this work are analysing solidification and effective factors in this process to produce parts with a higher quality and mechanical properties such as strength, strain, porosity, relative density and hardness. Results indicate that due to the surface to volume (S/V) ratio, and the increasing effect of the radius on Monge patch, thermal stresses and surface forces are more prevalent on outer surfaces. Moreover, solidification and mechanical properties are related to capillarity, geometry, substrate temperature, cooling rate, scanning power and speed. The results also indicate the interaction of solute diffusion and heat transfer with interatomic forces in large S/V ratio and at small scales tend to improve solidification.