S. Cavalieri

University of Catania, Catania, Sicily, Italy

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Publications (86)59.1 Total impact

  • Salvatore Cavalieri
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    ABSTRACT: Location detection is a very important issue in a wireless environment, allowing realisation of several useful services linked to the knowledge of the position of a mobile user (e.g. path optimisation, management of field crew in a large plant, providing a mobile robot with autonomous capabilities). Literature presents many approaches for location detection of a mobile device in a WLAN. One of these is based on the use of a pattern matching algorithm which provides for the position of the mobile device given the Radio Signal Strength (RSS) values received by it. Generally, localisation in WLAN environment is limited to indoor scenarios. Although GPS is commonly used for outdoor location detection, localisation in a WLAN communication infrastructure may be realised also for outdoor areas. The main advantage is a save in the hardware needed for the localisation, as it only requires the use of the WLAN communication card; further, the current limits of GPS, which may introduce not negligible errors in outdoor location detection, encourages the investigation of other techniques for outdoor localisation. On account of what said, the first aim of the paper is to investigate the feasibility of outdoor localisation of a mobile device in a WLAN environment; an IEEE 802.11b-based WLAN will be considered. Outdoor localisation has been realised using a pattern matching algorithm and the relevant performance, measured in terms of location errors, has been evaluated and compared with that commonly provided for by a GPS device. Then the paper will present a proposal for localisation, aimed to reduce the complexity typically featured by the pattern matching algorithm based approach when used for wide areas; the proposal is based on the use of a signal propagation model able to predict the RSS values available in each position of a IEEE 802.11b WLAN. Performance of the novel approach has been evaluated for outdoor localisation and the main results achieved will be shown in the paper. Finally, use of a Kalman filter for the location detection, will be presented in order to improve the performance of the pattern matching algorithm, making this technique very attractive for outdoor use.
    International Journal of Wireless Information Networks 11/2007; 14:265-279.
  • S. Cavalieri
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    ABSTRACT: Use of pattern matching algorithm for location detection in a wireless LAN is well known in literature. It allows to achieve good performances in terms of localisation errors, but it may require a very long and time-consuming start-up phase, during which a set of measurements of the radio signal strength values received in different positions inside the area involved in the localisation, must be taken. The complexity of this procedure increases with the size of the area involved in the localisation; this clearly happens for large outdoor areas, where a huge set of measurements must be taken during the start-up phase. The paper aims to present an approach for localisation in outdoor areas covered by a wireless network; this approach is still based on the use of pattern matching algorithm, but use of a signal propagation model during the start-up phase has been introduced in order to reduce its complexity. Performances of the proposal have been evaluated for outdoor localisation and the main results achieved will be shown in the paper
    Emerging Technologies and Factory Automation, 2006. ETFA '06. IEEE Conference on; 10/2006
  • Salvatore Cavalieri
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    ABSTRACT: The paper deals with the scheduling of information flow in a CAN ISO IS-11898 communication system. It mainly features a bus access arbitration protocol based on a priority assigned to each message to be transmitted; if two or more messages are transmitted at the same time by different communication nodes, only the message with the highest priority continues to be transmitted, the other being stopped. In real-time applications, messages contain information which must be transmitted within strict time constraints; according to the CAN ISO IS-11898 bus arbitration protocol, respect of real-time constraints of time critical information depends on the priority assigned to the message conveying it. The aim of the paper is to propose a procedure for dynamic assignment of priorities to messages to be transmitted, in such a way the real-time requirements of the information conveyed are fulfillled. Although many other approaches can be found in literature, the proposal is original as It is based on standard full CAN communication stacks.
    Computer Standards & Interfaces 06/2006; 28:531-552. · 0.98 Impact Factor
  • S. Cavalieri, A. Di Stefano, O. Mirabella
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    ABSTRACT: In the context of the Packet Switching Networks, the main need is to optimize the paths connecting the source and the destination. In this paper the authors deal with the problem of routing by means of a neural approach. This is based on the assumption that each switching node is made up by a Hopfield network which is capable to determine the optimal path which connects the local node with a generic node in the packet switching network. On this basis, the suitable output link on which each incoming packet must be routed is chosen.
    01/2006: pages 583-592;
  • Salvatore Cavalieri
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    ABSTRACT: IEEE 802.11b standard, also known as Wi-Fi, is one of the most used wireless communication system. Location of a mobile device using IEEE 802.11b communication infrastructure has a lot of advantages, first of all the use of the same hardware/software needed by the mobile device to communicate. Literature presents many approaches for localisation based on Wi-Fi; one of the most known features the use of the pattern-matching algorithm. Localisation based on pattern-matching algorithm is mainly realised in indoor environment; outdoor localisations based on Wi-Fi and pattern matching algorithm is currently missing in literature. For this reason, one of the aims of the paper is to present and evaluate outdoor use of this algorithm based on IEEE 802.11b communication system. Further, the paper present a novel approach for localisation, aimed to reduce the complexity of the pattern-matching algorithm. Performance evaluations were presented in the paper in order to clearly assess the outdoor localisation errors achievable when using the proposed approach
    01/2006;
  • Salvatore Cavalieri
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    ABSTRACT: Literature presents many approaches for location detection of a mobile device in a IEEE 802.11 LAN; one of them is based on the use of a pattern matching algorithm. Although it's generally used in indoor environment, the first aim of the paper is to investigate the feasibility of outdoor localisation of a mobile device in a IEEE 802.11b environment. Then the paper presents a proposal aimed to reduce the complexity typically featured by the location detection approach based on pattern matching algorithm. The proposal is based on the use of a signal propagation model. Performance of the novel approach has been evaluated for outdoor localisation and the main results achieved is shown in the paper
    01/2006;
  • S. Cavalieri
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    ABSTRACT: Literature presents many approaches for location detection of a mobile user using IEEE 802.11b wireless communication standard; generally localisation is limited to indoor scenarios, where GPS cannot be used, and is based on pattern matching algorithm. The paper aims to reach two different goals. The first is the proposal of the use of IEEE 802.11b standard for outdoor location detection; this choice is mainly justified by the large availability of communication cards at very low costs and by the limits of GPS, which may introduce not negligible errors in location detection. The second aim of the paper is the proposal of a new approach for outdoor wireless localisation, aimed to reduce the complexity featuring by the well-known localisation approaches based on pattern matching algorithm.
    Emerging Technologies and Factory Automation, 2005. ETFA 2005. 10th IEEE Conference on; 10/2005
  • S. Cavalieri
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    ABSTRACT: IEEE 802.11b standard, also known as Wi-Fi, is one of the most used wireless communication systems. Location of a mobile user by IEEE 802.11b has a lot of advantages, mainly due to the use of the same hardware/software needed for the communication. Literature presents many approaches for localisation based on Wi-Fi; among them there is the pattern matching algorithm. The paper aims to present outdoor use of this algorithm, due to the lack in literature of relevant examples. Further, the paper will present a new approach for wireless localisation, aimed to reduce the complexity of the pattern matching algorithm.
    Industrial Informatics, 2005. INDIN '05. 2005 3rd IEEE International Conference on; 09/2005
  • S. Cavalieri
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    ABSTRACT: This paper deals with the problem of information flow scheduling in a communication system based on CAN ISO IS-11898 physical medium access mechanism. It mainly features a bus access arbitration protocol based on a priority assigned to each message to be transmitted; if two or more messages are transmitted at the same time by different communication nodes, only the message with the highest priority continues to be transmitted, the other being stopped. In real-time applications, messages are relevant to process variables which must be transmitted within strict time constraints; according to the CAN ISO IS-11898 bus arbitration protocol, respect of real-time constraints depends on the priority assigned to each variable. The aim of the paper is to propose a procedure for dynamic assignment of priorities to variables to be transmitted, in such a way the relevant real-time requirements are fulfilled. Although many other approaches can be found in literature, the proposal is original as it is based on standard full CAN communication stacks.
    IEEE Transactions on Industrial Informatics 06/2005; · 8.79 Impact Factor
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    ABSTRACT: One of the main limits of the current technology for the management of large plant (like those concerning water, gas, power distribution) is the lack of vertical and/or horizontal integration of information. Vertical integration refers to the need to integrate systems implemented at different administrative level of an organisation. Horizontal integration improves the concept of integration, allowing the user of large plant to execute very complex transformations on data coming from several real applications, also of different types. The Mobicossum EU project, IST 1999-57455, is a CRAFT project, aimed to define a middleware between (mobile) user and lower level applications, based on vertical and horizontal integrations of information.
    Industrial Technology, 2004. IEEE ICIT '04. 2004 IEEE International Conference on; 01/2005
  • R. Mita, G. Palumbo, S. Cavalieri, A. Palumbo
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    ABSTRACT: In this paper the authors present an hardware implementation of interbus-S protocol sub-blocks which include an extension of the protocol that manage the fault recovery capability. The fault recovery protocol is based on the definition of a novel device called master/slave able to recover any occurring fault. The master/slave device will be implemented into an FPGA chip. It contains the physical layer and a portion of data link and they are described through VHDL language. Gate level simulations are carried out to verify the functionality and compatibility with interbus-S of the fault recovery protocol.
    Industrial Electronics Society, 2004. IECON 2004. 30th Annual Conference of IEEE; 12/2004
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    ABSTRACT: The paper aims to point out the main results obtained during the European project Mobicossum IST 1999-57455, still running. This project aims to realise a horizontal and vertical integration of SCADA/GIS and DSS applications. Definition of horizontal and vertical integration would be clearly pointed out in the paper highlighting its relevant advantages. The paper focus only on some the results achieved at the date of the writing of the paper. These results able to point out the advantages coming from their adoption and their further improvement, for users of the main applications used in large plants (such that of water and gas distribution).
    Industrial Electronics, 2004 IEEE International Symposium on; 06/2004
  • 01/2004
  • S. Cavalieri
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    ABSTRACT: Fieldbuses are communication systems used in industrial environments to convey information on which process control is based. Due to the nature of this information, the presence of fault tolerance mechanisms is required. This letter proposes a fault recovery protocol compliant with Interbus-S, one of the most widely used fieldbuses.
    IEEE Transactions on Industrial Electronics 09/2003; · 6.50 Impact Factor
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    ABSTRACT: The paper deals with the scheduling of periodic information flow in a FieldBus environment. The scheduling problem is defined from an analytical point of view, giving a brief survey of the most well-known solutions. One of these is called multicycle polling scheduling, which is based on the hypothesis that all the production periods of the periodic processes to be scheduled are harmonic. Although in some process control or manufacturing scenarios, this hypothesis may be acceptable, there are many real industrial processes to which it cannot be applied. The aim of the paper is to make a contribution towards solving the scheduling problem. It essentially concerns extension of the theory on which multicycle polling scheduling is based to a much more realistic and general scenario, where the periods of all the processes to be scheduled have arbitrary values. The authors present a new formulation of multicycle polling scheduling, called extended multicycle polling scheduling, and demonstrate that it comprises the scenario currently considered in the literature. Two algorithmic solutions for extended multicycle polling scheduling are then proposed, giving a computational complexity analysis which will highlight the capability of the algorithmic scheduling solutions to be performed on-line. The paper concludes by comparing the multicycle polling scheduling approach known in literature and the one presented in the paper. Comparison is performed by evaluating the use of available bandwidth to serve both periodic and asynchronous traffic in the two approaches.
    Real-Time Systems 08/2003; 25(2):157-185. · 0.55 Impact Factor
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    ABSTRACT: The paper deals with the scheduling of periodic information flow in single and multi FieldBus environments. The problem is defined from an analytical point of view, giving a brief survey of the most well-known solutions. Then the authors make their contribution to the problem. More specifically, a modification to a well-known single FieldBus scheduling solution is introduced, in order to make its applicability wider. As far as multi FieldBus scheduling is concerned, a genetic approach is presented.
    03/2003;
  • Salvatore Cavalieri, Salvatore Monforte, Fabio Scibilia
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    ABSTRACT: Distributed computing addresses workload challenges by aggregating and allocating computing resources to provide for unlimited processing power. In the last ten years, it has grown from a concept that would enable organizations to simply balance workloads across heterogeneous computer resources, to an ubiquitous solution that has been embraced by some of the world’s leading organizations across multiple industry sectors. And while distributed computing harnesses the full potential of existing computer resources by effectively matching the supply of processing cycles with the demand created by applications, even more importantly it has paved the way for grid computing — a more powerful, yet global approach to resource sharing. The aim of this paper is to propose new allocation algorithms for workload management in a computing grid environment. A simulation tool is used to validate and estimate performance of these algorithms. The paper is organized as follows. After a brief introduction about grid environment and on the DataGrid Project in Section 1, Section 2 presents the proposal for novel allocation policies. Finally, Section 3 provides for a performance evaluation of the algorithms proposed, comparing their performances it with those offered by the actual solution adopted in the DataGrid Project.
    Computational Science - ICCS 2003, International Conference, Melbourne, Australia and St. Petersburg, Russia, June 2-4, 2003. Proceedings, Part III; 01/2003
  • S. Cavalieri
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    ABSTRACT: Object oriented software design is getting more and more common in the field of industrial control. In particular, Java seems extremely versatile for the development of distributed control applications. One of the main requirements of control application is a deterministic execution of the tasks, which generally feature real-time constraints. When Java language has been conceived, a little weight to the real-time requirements of applications has been given. In the last few years the limits to the use of Java for real-time applications has led to the definition of Java Real-Time platform specifications. Real-time capability of a Java virtual machine (VM) depends on a very large number of elements, among which the task scheduling algorithm, the memory management, the garbage collector algorithm and its execution policy. Knowledge of how each single internal mechanism of a Java VM influence its performance is very important to improve its real-time behaviour. This paper must be considered as a first step toward this direction, as its aim is to try to understand how real-time performance of a Java VM may be influenced by each its single component.
    IECON 02 [Industrial Electronics Society, IEEE 2002 28th Annual Conference of the]; 12/2002
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    ABSTRACT: Profibus networks are often used as the communication infrastructure for supporting distributed computer-controlled applications. Very often these applications impose strict real-time requirements. A widely used class of Profibus networks is the Profibus-DP profile, which may be implemented as mono or multi- master network. The aim of this paper is to analyse the real-time behaviour of both mono and multi- master Profibus-DP networks. The authors present a novel methodology for evaluating the worst-case message response time in systems where high-priority and cyclic low-priority Profibus traffic coexist. The proposal constitutes a powerful tool to guarantee, prior to runtime, the real-time behaviour of a distributed computer-controlled system based on a Profibus network.
    11/2002;
  • S. Cavalieri, N. Di Lisi, S. Monforte
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    ABSTRACT: Fieldbus systems were developed in order to overcome the very huge number of limits featured by the point-to-point links in distributed process control systems, by adopting a shared communication medium. This paper provides an analysis of the real-time behaviour of the multi-master Profibus DP network. The analysis presented represents a step toward the capability to perform a more accurate evaluation of the performance of the Profibus network.
    Intelligent Control, 2002. Proceedings of the 2002 IEEE International Symposium on; 02/2002