33,500 research outputs found
Recommended from our members
A management architecture for active networks
No full textIn this paper we present an architecture for network and applications management, which is based on the Active Networks paradigm and shows the advantages of network programmability. The stimulus to develop this architecture arises from an actual need to manage a cluster of active nodes, where it is often required to redeploy network assets and modify nodes connectivity. In our architecture, a remote front-end of the managing entity allows the operator to design new network topologies, to check the status of the nodes and to configure them. Moreover, the proposed framework allows to explore an active network, to monitor the active applications, to query each node and to install programmable traps. In order to take advantage of the Active Networks technology, we introduce active SNMP-like MIBs and agents, which are dynamic and programmable. The programmable management agents make tracing distributed applications a feasible task. We propose a general framework that can inter-operate with any active execution environment. In this framework, both the manager and the monitor front-ends communicate with an active node (the Active Network Access Point) through the XML language. A gateway service performs the translation of the queries from XML to an active packet language and injects the code in the network. We demonstrate the implementation of an active network gateway for PLAN (Packet Language for Active Networks) in a forty active nodes testbed. Finally, we discuss an application of the active management architecture to detect the causes of network failures by tracing network events in time
Robust data gathering for wireless sensor networks
No full text2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications, Proceedings
Volume 1, 2005, Article number 1635527, Pages 469-474
2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications; Kuala Lumpur; Malaysia; 16 November 2005 through 18 November 2005; Category number05EX1235; Code 69262
Robust data gathering for wireless sensor networks (Conference Paper)
Ortolani, M. , Gatani, L. , Lo Re, G.
Dipartimento di Ingegneria Informatica, Università degli Studi di Palermo, Viale delle Scienze Parco d'Orleans, 90128 Palermo, Italy
View references (17)
Abstract
In this paper we propose a data gathering model for wireless sensor networks that provides a reasonable tradeoff between robustness and efficiency, with special regard to energy saving. We design a routing algorithm that exploits implicit acknowledgment of reception and smart caching of the data to implement an efficient strategy for retransmission of lost packets and alternative path discovery; in order to do that, we build upon the general framework presented in recent works, that provided a formulation of duplicate and order insensitive aggregation functions, taking advantage of some intrinsic characteristics of the wireless sensor networks. The advantages of the proposed approach become more evident when one parts from an ideal scenario in which all nodes have available data to transmit in favor of a more practical one in which data originates from only a subset of all sensors. In this practical case, the approach provides a better usage of the resources and a minimization of the traffic in the network, and, as a consequence, of the overall consumed energy
Urban Air Quality Monitoring Using Vehicular Sensor Networks
No full textThe quality of air is a major concern in modern cities as pollutants have been demonstrated to have significant impact on human health. Networks of fixed monitoring stations have been deployed in urban areas to provide authorities with data to define and enforce dynamically policies to reduce pollutants, for instance by issuing traffic regulation measures. However, fixed networks require careful placement of monitoring stations to be effective. Moreover, changes in urban arrangement, activities, or regulations may affect considerably the monitoring model, especially when budget constraints prevent from relocating stations or adding new ones to the network. In this chapter we discuss a different approach to environmental monitoring through mobile monitoring devices implementing a Vehicular Sensor Network (VSN) to be deployed on the public transport bus fleet of Palermo
Cystic lymphangioma of adrenal gland. Case report and review of the literature
No full textIl linfoangioma surrenalico cistico è una neoplasia beni-
gna rara che origina da una ectasia dei vasi linfatici; questa
lesione si localizza, più frequentemente, nella regione del collo,
ascellare e mediastinica.
Lo scopo di questo studio è descrivere il caso di una
donna di 60 anni con dolore addominale ricorrente che si è sot-
toposta ad un esame ecografico che ha mostrato la presenza di
una massa cistica in corrispondenza del polo superiore del
rene; quindi l’origine della massa, il surrene, è stata identificata
attraverso la Tomografia Compiuterizzata, eseguita con mezzo
di contrasto. Successivamente la paziente ha effettuato la
Risonanza Magnetica che ha meglio caratterizzato la lesione; la
Risonanza Magnetica ha suggerito la diagnosi di linfoangioma
cistico attraverso la diagnosi differenziale tra masse solide e
cistiche.Infine la diagnosi radiologica è stata confermata dalla
biopsiaCystic lymphangioma of adrenal gland (CL) is a rare benign neoplasm that begin from an ectasia of lynfatic vessel; this lesion is localized, most frequently, in neck, axillary and mediastinal region. The purpose of this study is to describe the case of a 60 years old patient with recurrent abdominal pain that underwent ultrasound scan that showed a cystic mass in upper renal pole; than the origin of the mass, the adrenal gland, was identify by Computer Tomography, performed using contrast material. Subsequently the patient underwent to Magnetic Resonance (MR) that better characterized the lesion; MR was enabled to suggest CL by differential diagnosis between solid and cystic mass of adrenal gland. Finally radiological diagnosis was confirmed from biopsy
DCFL: Dynamic Clustered Federated Learning under Differential Privacy Settings
No full textFederated Learning (FL) allows training machine learning models on a dataset distributed amongst multiple clients without disclosing sensitive data. Each FL client, however, might have a different data distribution, with a detrimental effect on the performance of the trained model. In this paper, we present a dynamic clustering algorithm (DCFL) that allows the server to cluster FL clients based on their model updates, letting the server adapt to changes in the data distribution and supporting the addition of new clients. Moreover, we propose a novel distance metric to estimate the distance between model updates by different clients. We evaluate our approach in a wide range of experimental settings, comparing it against the standard FedAvg algorithm and divisive clustering on the EMNIST dataset. Our approach outperforms the baselines, yielding higher accuracy and lower variance for the participating clients
Image processing techniques for the analysis of the micro-architecture of three-dimensional porous scaffolds
No full text- …
