Search results for " communication"

Wireless Power Transmission for house appliances: A small-scale resonant coupling prototype

2016

This paper presents a low cost prototype of wireless power transfer system based on resonant coupling. The system here proposed can be useful for house appliances battery charging systems: as a matter of fact, it consists mainly of two copper wire coils or windings, placed one in front of the other on the same axis. By exploiting the coils resonance coupling effect, electric energy can be transferred from the inductor coil to the receiver in order to charge the batteries. Low cost experimental tests demonstrated the effectiveness of the proposed wireless power transfer prototype, being it capable to reach an efficiency of about 80% and more along a distance of 30 cm.

Control subsystem design for wireless power transfer

2014

Recently, the wireless power transfer has been increasingly employed. Particularly for the electric vehicles, the wireless solution is attractive for contactless battery charging, based on the Inductive Power Transfer (IPT). In this paper, a 150W prototype for IPT-based battery charging is presented and design criteria are reported. In addition to the power stage analysis, a proper control strategy is proposed. Simulation and experimental results are shown. The proposed control method aims at regulating the load current against variations in the magnetic coupling, so that the required amount of power can be supplied despite of unexpected decreases in the coupling efficiency.

On incorporating the paradigms of discretization and Bayesian estimation to create a new family of pursuit learning automata

2013

Published version of an article in the journal: Applied Intelligence. Also available from the publisher at: http://dx.doi.org/10.1007/s10489-013-0424-x There are currently two fundamental paradigms that have been used to enhance the convergence speed of Learning Automata (LA). The first involves the concept of utilizing the estimates of the reward probabilities, while the second involves discretizing the probability space in which the LA operates. This paper demonstrates how both of these can be simultaneously utilized, and in particular, by using the family of Bayesian estimates that have been proven to have distinct advantages over their maximum likelihood counterparts. The success of LA-…

A Comprehensive Survey on Cooperative Relaying and Jamming Strategies for Physical Layer Security

2019

Physical layer security (PLS) has been extensively explored as an alternative to conventional cryptographic schemes for securing wireless links. Many studies have shown that the cooperation between the legitimate nodes of a network can significantly enhance their secret communications performance, relative to the noncooperative case. Motivated by the importance of this class of PLS systems, this paper provides a comprehensive survey of the recent works on cooperative relaying and jamming techniques for securing wireless transmissions against eavesdropping nodes, which attempt to intercept the transmissions. First, it provides a in-depth overview of various secure relaying strategies and sch…

Relay selection in FDD amplify-and-forward cooperative networks

2017

In this paper, the problems of relay selection and distributed beamforming are investigated for bi-directional dual-hop amplify-and-forward frequency-division duplex cooperative wireless networks. When using individual per-relay maximum transmission power constraint, it has been proven that the relay selection and beamforming optimization problem becomes NP hard and requires exhaustive search to find the optimal solution. Therefore, we propose a computationally affordable sub-optimal multiple relay selection and beamforming optimization scheme based on the l1 norm squared relaxation. The proposed scheme performs the selection for the two transmission directions, simultaneously, while aiming…

Coordination in a multi-cell multi-antenna multi-user W-CDMA system: a beamforming approach

2008

The problem of designing joint power control and optimal beamforming (JPCOB) algorithms for the downlink of a coordinated multi-cell WCDMA system is considered throughout this paper. In this case, the JPCOB design is formulated as the problem of minimizing the total transmitted power in the coordinated multi-cell system, subject to a certain quality of service requirement for each user. In this paper, the performance of two JPCOB algorithms based on different beamforming approaches is compared over the coordinated multi-cell system. The first one, obtains local beamformers by means of the well-known virtual uplink-downlink duality. In contrast, the second algorithm implements multi-base bea…

Recurring sequences of multimodal non-verbal and verbal communication during a human psycho-social stress test: A temporal pattern analysis

2020

Abstract Background The Trier Social Stress Test (TSST) is a widely used protocol to study human psycho-social stress responses. Quantitative reports of non-verbal behaviors have been carried out by means of the Ethological Coding System for Interviews (ECSI). However, no data have described whether and how non-verbal and verbal behaviors take part in the composition of multimodal sequences of communication during the test. Method Five non-verbal ECSI categories and four verbal behaviors related with communication were included in the Ethogram. A focal sampling was employed to ensure a high temporal resolution of the behavioral annotation. T-Pattern Analysis was employed to detect statistic…

Local E-Government in Norway

2005

Managing Benefits in the Public Sector. Surveying Expectations and Outcomes in Norwegian Government Agencies

2008

Published version of a chapter in Lecture Notes in Computer Science, 5184, 98-110. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-540-85204-9_9 Government agencies currently experience increasing pressure to document benefits from spending on eGovernment efforts. Hence, structured methods for benefits management (BM) are being developed. However, hardly any studies have investigated how such approaches are used and experienced. This study addresses this practice-research gap by reporting a study of a project involving 30 Norwegian government agencies using a common BM approach.A questionnaire was answered by project managers. Results show that that some 80 % of the ma…

Wnt activity defines colon cancer stem cells and is regulated by the microenvironment.

2010

Despite the presence of mutations in APC or beta-catenin, which are believed to activate the Wnt signalling cascade constitutively, most colorectal cancers show cellular heterogeneity when beta-catenin localization is analysed, indicating a more complex regulation of Wnt signalling. We explored this heterogeneity with a Wnt reporter construct and observed that high Wnt activity functionally designates the colon cancer stem cell (CSC) population. In adenocarcinomas, high activity of the Wnt pathway is observed preferentially in tumour cells located close to stromal myofibroblasts, indicating that Wnt activity and cancer stemness may be regulated by extrinsic cues. In agreement with this noti…