Search results for "Distributed"
showing 10 items of 1260 documents
Developing business networking opportunities for SMEs through business ecosystem and ICT
2010
Globalisation is a new challenge for European small and medium enterprises; indeed, on one hand, it represents a threat, since new emerging companies are entering their domestic market, but on the other hand, it represents the opportunity to enter new emerging and growing markets. In order to win this challenge, European SMEs need to play the networking card; in fact, it is well acknowledged that networking can improve SMEs effectiveness and efficiency which is absolutely necessary to win the globalisation battle. Many public regional institutions are thinking about how to improve the networking capacity of their SMEs through specific programs and investments. This paper reports the results…
Optimal Operating Point Calculation for Medium Voltage Distribution Systems
2007
The paper deals with the calculation of the optimal working point of a distribution system, equipped with several distributed generators, able to operate also autonomously, i.e. disconnected from the main grid. When connected to the main grid, it appears in general convenient to assign the slack bus role to the bus that represents such a connection. The problem becomes more complex when maximum power transfer constraints through the connection must be taken into account. The adequate slack bus treatment is even more important when the optimal operating condition must refer to the condition subsequent to an intentional or unintentional disconnection from the main grid. The paper presents an …
Evaluating the Performance of Real Time Videoconferencing in Ad Hoc Networks Through Emulation
2008
The validation of new video protocols and applications for mobile ad hoc networks in a real environment is an important task. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for ad hoc networks using low-cost, off-the-shelf devices and open source software. We use this tool to test a videocall using the OLSR protocol in different scenarios, varying the number of hops between the caller and the receiver. The results obtained in this paper show that, for an ad hoc network with a large number of hops, the quality of videocalls suffers a significant degradation even in the absence of mobility.
Software Defined Machine-to-Machine Communication for Smart Energy Management in Power Grids
2020
The successful realization of smart energy management relies on ubiquitous and reliable information exchange among millions of sensors and actuators deployed in the field with little or no human intervention. This motivates us to introduce a unified communication framework for smart energy management by exploring the integration of software-defined networking (SDN) with M2M communication. In this chapter, the overall design of the software-defined M2M (SD-M2M) framework is presented, with an emphasis on its technical contributions to cost reduction, fine granularity resource allocation, and end-to-end QoS guarantee. Then, a case study is conducted for a electric vehicle energy management sy…
Technical-economical evaluation for distributed storage applications. An Italian case study for a medium-scale public facility
2014
Time-of-use energy cost management involves the use of storage by customers to reduce their electricity bills. This can be accomplished by charging the storage during off-peak time periods, when electricity energy prices are low, and discharging it during times when on-peak energy prices are applied. This article addresses the question whether it is economically viable to install medium-scale distributed storage devices in the power system designed to lower the electricity cost for a customer-side application, assuming flexible electricity tariffs. The technical/economical evaluation is carried out referring to Lithium ion (Li-ion), Sodium Sulphur (NaS) and Vanadium Redox Battery (VRB) tech…
GPCALMA, a mammographic CAD in a GRID connection
2003
Purpose of this work is the development of an automatic system which could be useful for radiologists in the investigation of breast cancer. A breast neoplasia is often marked by the presence of microcalcifications and massive lesions in the mammogram: hence the need for tools able to recognize such lesions at an early stage. GPCALMA (Grid Platform Computer Assisted Library for MAmmography), a collaboration among italian physicists and radiologists, has built a large distributed database of digitized mammographic images (at this moment about 5500 images corresponding to 1650 patients). This collaboration has developed a CAD (Computer Aided Detection) system which, installed in an integrated…
Coupled hydraulic and electronic regulation of cross-flow turbines in hydraulic plants
2017
The potential benefit of coupling hydraulic and electronic regulation to maximize the energy production of a cross-flow turbine in hydraulic plants is analyzed and computed with reference to a specific case. Design criteria of the cross-flow turbine inside hydraulic plants are first summarized, along with the use of hydraulic regulation in the case of constant water head and variable discharge. Optimal turbine impeller rotational speed is derived, and traditional as well as innovative systems for electrical regulation are presented. A case study is analyzed to evaluate the potential energy production according to the expected monthly mean flow distribution and two possible choices: CFT1 wit…
Smart interface devices for distributed generation in smart grids: The case of islanding
2017
With the increasing presence of distributed generators (DGs), the implementation of a smart sensors and actuators network in distribution grids has become crucial for different monitoring, management and protection functionalities. For DGs monitoring and control, sensors and actuators are usually embedded in so-called interface devices (IDs) or interface protection systems (IPSs). Existing IDs lack in communication interfaces both to the electrical energy Distribution System Operators (DSOs) and to the DGs inverter. In this framework, the authors have developed a new ID solution and a proper communication architecture, which allow implementing new smart functionalities based on the interact…
A novel frequency reuse scheme for coordinated multi-point transmission
2010
La transmisión multipunto coordinada (CoMP) se considera en 3GPP LTE-Advanced como una técnica clave para mejorar el rendimiento en el borde de la célula. Con el fin de apoyar la asignación conjunta de asignación de recursos entre células coordinadas en sistemas CoMP, es necesario diseñar esquemas eficientes de reutilización de frecuencias. Sin embargo, la mayoría de los esquemas de reutilización de frecuencias existentes no son adecuados para transmisión CoMP debido a que no consideran el escenario de transmisión conjunta multicelular en su regla de reutilización de frecuencias. Para resolver este problema, en este trabajo se propone un esquema de reutilización de frecuencias que divide el…
Fault Tolerant Ancillary Function of Power Converters in Distributed Generation Power System within a Microgrid Structure
2013
Distributed generation (DG) is deeply changing the existing distribution networks which become very sophisticated and complex incorporating both active and passive equipment. The simplification of their management can be obtained assuming a structure with small networks, namely, microgrids, reproducing, in a smaller scale, the structure of large networks including production, transmission, and distribution of the electrical energy. Power converters in distributed generation systems carry on some different ancillary functions as, for example, grid synchronization, islanding detection, fault ride through, and so on. In view of an optimal utilization of the generated electrical power, fault to…