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Development of distribution network and power consumption growth, increase voltage drop on the line impedance and therefore voltage drop in system buses. In some cases consumption is so high that voltage in some buses exceed from standard. In this paper, effect of the fuel cell and photovoltaic hybrid system on distribution network for solving expressed problem is studied. For determining the capacity of each distributed generation source, voltage limitation on the bus voltages under different conditions is considered. Simulation is done by using DIgSILENT software on the part of the 20 kV real life Sirjan distribution system. In this article, optimum location with regard to system and environmental conditions are studied in two different viewpoints.

A critical issue in monitoring and controlling geo-distributed dual-stack networks may be the following one: if a Remote Component has to send all the gathered traffic to the Central Component, the information is doubled with a consequent significant waist of bandwidth. This is particularly true if the gathered information is repeated and redundant. In this case, the information might be preprocessed on the Remote Component to obtain and propagate to the Central Component only the essential part of information useful for the network management. In a distributed statistical-based monitoring tool (i.e. that uses statistics to synthesize the whole information gathered, extracting only the essential pieces of information), the goal of minimizing the exchanged traffic, can be achieved by using a caching mechanism and by processing the gathered information on the Remote Components using simple and efficient algorithms to reduce the flow of information, before sending it to the Central Component.This report describes how to address the latter issue on a Remote Component, introducing a threshold-based caching mechanism for minimizing the transmission of the gathered information to the Central Component and proving its efficiency by showing results obtained by taking some measurements on a real network. This mechanism has been implemented and is used to minimize information exchange in the distributed components of 6MoN.

In this paper, a solution for the pervasive monitoring of large monumental structures based on the use of Wireless Sensor Networks is presented. In particular, the paper focuses on the case of the Ancient City Walls of the city of Siena, Italy, that still surround the whole historic centre and require a real time monitoring of the cracks present in several points.

This letter proposes a fast retry limit adaptation algorithm for the 802.11e distributed networks. Different from existing solutions, which manage a unique access category, the presented method jointly estimates the retry limits associated with both voice and video packets. The algorithm that operates in saturated and non-saturated traffic conditions is validated adopting an 802.11n physical layer and comparing its performance with a proper extension of an existing solution.

[ES] En este proyecto se ha implementado una red distribuida. Ha sido construida con placas Arduino Uno y conectada mediante el uso de shields Ethernet. El objetivo de la red es que los nodos que la componen lleguen al consenso de tres valores predefinidos para cada nodo, simulando una entrada de datos de un sensor de cualquier tipo. Junto con la topología distribuida de la red, cada nodo sólo conoce la existencia de sus vecinos inmediatos y sólo es capaz de comunicarse con estos. Cada uno de los nodos van a estar compuestos, además de por una placa Arduino Uno con su correspondiente Shield Ethernet, de un led RGB, con el que se mostrará el valor de las variables con las que se está realizando el consenso., [EN] In this project, we have implemented a distributed network. The network has been built with Arduino Uno boards connected with Ethernet Shields. The objective of the network is that all the nodes involved find a consensus for three preset values on each node, simulating an input from a generic sensor. With the distributed topology of the network, we have nodes that only know the existence of their immediate neighbors. Also, they are only able to communicate with them. Each of the nodes will be built, in addition of the Arduino Uno and the Ethernet shield, with a RGB led. The led has to show the values of the variables involved in the consensus.

In the last decade the world has seen a steadily increasing number of Cube Satellites deployed to Low Earth Orbit. Traditionally, these cubesats rely on Amateur Radio communications technology that are proven to work from space. However, as data volumes increase, the existing Amateur Radio protocols, combined with the restrictions of use for the Amateur Radio Spectrum, as well as the trend to build one control station per cubesat, result in a bottle neck effect whereby existing communications methods are no longer sufficient to support the increasing data volumes of the spacecraft. This Masters Thesis work explores the concept of deploying a network of distributed ground station receiver nodes for the purposes of increasing access time to the spacecraft, and thereby increasing the potential amount of data that can be transferred from orbit to the ground. The current trends in cubesat communications will be analyzed and an argument will be made in favor of transitioning to more modern digital communications approaches for on orbit missions. Finally, a candidate ground station receiver node design is presented a possible design that could be used to deploy such a network. Master of Science

Instead of being static and waiting passively for instructions, software systems are required to take a more proactive approach in their behavior in order to anticipate and to adapt to the needs of their users. To design and develop such systems in an affordable, predictable and timely manner is a great engineering challenge. Even though there have been notable steps towards distributed self-adaptive and context-aware systems, there is still a lack of methodologies on how to model and implement applications which have to distribute and to manage large amounts of information. In this work-in-progress, we address this issue by proposing a self-adaptive and context-aware model with a structure that allows the system to learn from the user’s behavior by using Proactive Computing. The novelty comes from the possibility of having a distributed network of Proactive Engines in which the exchange of contextual information would help each system to take smart decisions.

We study the compressive diffusion strategies over distributed networks based on the diffusion implementation and adaptive extraction of the information from the compressed diffusion data. We demonstrate that one can achieve a comparable performance with the full information exchange configurations, even if the diffused information is compressed into a scalar or a single bit. To this end, we provide a complete performance analysis for the compressive diffusion strategies. We analyze the transient, steady-state and tracking performance of the configurations in which the diffused data is compressed into a scalar or a single-bit. We propose a new adaptive combination method improving the convergence performance of the compressive diffusion strategies further. In the new method, we introduce one more freedom-of-dimension in the combination matrix and adapt it by using the conventional mixture approach in order to enhance the convergence performance for any possible combination rule used for the full diffusion configuration. We demonstrate that our theoretical analysis closely follow the ensemble averaged results in our simulations. We provide numerical examples showing the improved convergence performance with the new adaptive combination method., Comment: Submitted to IEEE Transactions on Signal Processing

In this paper the problem of distributed target tracking is considered. A network of heterogeneous sensing agents is used to observe a maneuvering target and, at each iteration, all the agents are able to agree about the estimate of the target position, despite the fact that only a small percentage of agents can sense the target at each time instant. Our Consensus-based Distributed Target Tracking (CDTT) is a fully distributed iterative tracking algorithm, in which each iteration is based on two phases: an estimation phase and a consensus one. As a result, the estimated trajectories are identical for all the agents at each time instant. Numerical simulations and comparison with another target tracking algorithm are carried out to show the effectiveness and feasibility of our approach. © 2011 IEEE.

The paper provides a global architectural and decision support solution for a reaction after alert detection mechanisms in the frame of information systems security applied to telecom infrastructures. Therefore, the architecture is developed in a distributed perspective and is composed of three basic layers: the low level that constitutes the interface between the architecture and the infrastructure. The intermediate level that is responsible of correlating the alerts coming from different domains of the infrastructure and to deploy the reaction actions. The architecture is elaborated using a MAS associated to the OntoBayes model for decision mechanism. This model helps agents to make decisions according to preference values and is built upon ontology based knowledge sharing, Bayesian networks based uncertainty management and influence diagram. The major novelty of this Decision Support System is the layered view of the infrastructure thanks to MAS architecture, which enables the decision making with different levels of knowledge.

The main objective of this paper is to provide a global decision-reaction architectural built on the requirements for a reaction after alert detection mechanisms in the frame of information systems security and more particularly applied to telecom infrastructures security. These infrastructures are distributed in nature, therefore the architecture is elaborated using the multi-agents system that provides the advantages of autonomous and interaction facilities, and has been associated to the ontoBayes model for decision support mechanism. This model helps agents to make decisions according to preference values and is built upon ontology based knowledge sharing, bayesian networks based uncertainty management and influence diagram based decision support. The Multi-Agent System decision-reaction architecture is developed in a distributed perspective and is composed of three basic layers: low level, intermediate level and high level. The proposed approach has been illustrated based on the network architecture for heterogeneous mobile computing developed by the BARWAN project. Accordingly: the Building Area constitutes the low level and aims to be the interface between the main architecture and the targeted infrastructure. The Campus-Area is the intermediate level responsible of correlating the alerts coming from different domains of the infrastructure and to smartly deploy the reaction actions.

In this paper a new approach to design frequency triplers is introduced. The technique is based on the closed-form synthesis of distributed matching networks which synthesize the desired load values at fundamental, second and third harmonic frequencies. Then to validate the introduced approach an active frequency tripler is designed and the resulting performances are reported.

Published in: Proceeding RoboComm '07 Proceedings of the 1st international conference on Robot communication and coordination; Article No. 39; Athens, Greece - October 15 - 17, 2007 This paper describes the experimental design, implementation, and testing of a network for tele-command, control, and communications of micro robots over long distances. The system utilizes commercial low bandwidth satellites to transmit near real-time video and leverages micro-robot platform synergies for command-communications relays. The system is capable of controlling micro ground vehicles and micro air vehicles (MAVs) over long distances using a small UAV as a communications relaying device. System elements meet size, power and mass constraints such that they may interface with control and power subsystems on micro robotic platforms and are scalable to control several entities simultaneously. We report the successful testing of the system in intercontinental experiments for control of both aerial and terrestrial micro robots between the Naval Postgraduate School (NPS) in Monterey, CA, USA, The University of Southampton, UK, and Space Warfare Systems Command (SPAWAR) in San Diego, CA, USA. We believe this research will serve as a proof of concept for future testing for a wide range of micro robotic command and control applications.

In this paper a closed-form synthesis of distributed networks for harmonic matching is presented. Taking into account the fundamental frequency and its second and third harmonics, all the possible circuital solutions are examined and the synthesis relationships for the optimum solution are inferred. Finally some matching network examples, designed according to the proposed approach, are presented.

In this paper a sensor data fusion procedure for electromagnetic field monitoring is proposed. Distributed sensing and remote processing are the basic features of the employed architecture. In fact, in order to obtain meaningful information about the temporal and spatial variations, which characterize the electromagnetic field levels, a distributed network of wireless and mobile smart-sensors has been designed. The monitored region is a wide urban area, partitioned in small local zones. Each mobile station has the task to explore a specific zone. The qualification of the sensor network is achieved by the possibility to configure dynamically the partitioning of investigated area according to the needs. The refresh time of monitoring map, the thickness of the grid, the choice of sampling points and their locations are consequence of an experiment design and function of several influence parameters. Acquired data are sent in a short time to a processing unit for performing the fusion procedure. A two-level decision approach has been employed. For each local zone, a first algorithm extracts a local decision concerning warning or alert situations. This step permits to reduce data amount and perform a preliminary data fusion starting from the reliability information on the single sensor. A second procedure realizes the final aggregation of data extracting a global decision and a 'picture' about the behaviour of electromagnetic field levels. Local decisions and correlated information are aggregated in order to obtain a meaningful and a higher-quality 'image' of monitored phenomenon according to desired performances.

2004 IEEE MITT-S International Microwave Symposium Digest -- 6 June 2004 through 11 June 2004 -- Fort Worth, TX -- 63477 In this paper, a parametric approach to construct two-variable positive real driving point impedance functions characterizing lossless ladder networks with mixed lumped and distributed elements is presented. The proposed approach is based on the generation of two-variable positive real impedance functions from the single variable boundary conditions. Utilizing the proposed parametric construction algorithm, real frequency matching technique is extended to the design of matching networks with mixed lumped and distributed elements. The application of the approach is illustrated by a broadband microwave amplifier design incorporating mixed lumped and distributed type matching networks. The resultant design has been compared with the AWR Microwave Office software simulation. Institute of Electrical and Electronics Engineers, IEEE,IEEE Microwave Theory and Techniques Society Publisher's Version

Information Technologies (IT s) are making possible the integration of different information systems used by geographically dispersed organizations. An integration model must facilitate the combination of internet, intranet and extranet concepts with a high fiability security policy and it ought to be perfectly adapted to the organizational structure. An adequate security policy must consider the establishment of a Virtual Private Network (VPN) identifying different potential clients: clients connected to the intranet by modem, by isdn, etc; clients connected to the VPN; or teleworking stations accessing through the extranet. Thus, this study aims to define the function of all those elements which provide security in an VPN such as firewalls and encryptation systems and to reduce the vulnerability of the elements taking part in an information exchange.