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Author Chierichetti, Flavio; Lattanzi, Silvio; Mari, Federico; Panconesi, Alessandro
Title On Placing Skips Optimally in Expectation Type Conference Article
Year 2008 Publication Web Search and Web Data Mining (WSDM 2008) Abbreviated Journal
Volume Issue Pages 15-24
Keywords Information Retrieval
Abstract We study the problem of optimal skip placement in an inverted list. Assuming the query distribution to be known in advance, we formally prove that an optimal skip placement can be computed quite efficiently. Our best algorithm runs in time O(n log n), n being the length of the list. The placement is optimal in the sense that it minimizes the expected time to process a query. Our theoretical results are matched by experiments with a real corpus, showing that substantial savings can be obtained with respect to the tra- ditional skip placement strategy, that of placing consecutive skips, each spanning sqrt(n) many locations.
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Corporate Author Thesis
Publisher Acm Place of Publication Editor Najork, M.; Broder, A.Z.; Chakrabarti, S.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ ChiLatMar08 Serial 94
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Author Coppo, Mario; Dezani-Ciancaglini, Mariangiola; Giovannetti, Elio; Salvo, Ivano
Title Mobility Types for Mobile Processes in Mobile Ambients Type Journal Article
Year 2003 Publication Electr. Notes Theor. Comput. Sci. Abbreviated Journal
Volume 78 Issue Pages
Keywords
Abstract We present an ambient-like calculus in which the open capability is dropped, and a new form of “lightweight  process mobility is introduced. The calculus comes equipped with a type system that allows the kind of values exchanged in communications and the access and mobility properties of processes to be controlled. A type inference procedure determines the “minimal  requirements to accept a system or a component as well typed. This gives a kind of principal typing. As an expressiveness test, we show that some well known calculi of concurrency and mobility can be encoded in our calculus in a natural way.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Coppo-Dezani-Giovannetti-Salvo:03 Serial 74
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Author Bobbio, Andrea; Ciancamerla, Ester; Di Blasi, Saverio; Iacomini, Alessandro; Mari, Federico; Melatti, Igor; Minichino, Michele; Scarlatti, Alessandro; Tronci, Enrico; Terruggia, Roberta; Zendri, Emilio
Title Risk analysis via heterogeneous models of SCADA interconnecting Power Grids and Telco networks Type Conference Article
Year 2009 Publication Proceedings of Fourth International Conference on Risks and Security of Internet and Systems (CRiSIS) Abbreviated Journal
Volume Issue Pages 90-97
Keywords
Abstract The automation of power grids by means of supervisory control and data acquisition (SCADA) systems has led to an improvement of power grid operations and functionalities but also to pervasive cyber interdependencies between power grids and telecommunication networks. Many power grid services are increasingly depending upon the adequate functionality of SCADA system which in turn strictly depends on the adequate functionality of its communication infrastructure. We propose to tackle the SCADA risk analysis by means of different and heterogeneous modeling techniques and software tools. We demonstrate the applicability of our approach through a case study on an actual SCADA system for an electrical power distribution grid. The modeling techniques we discuss aim at providing a probabilistic dependability analysis, followed by a worst case analysis in presence of malicious attacks and a real-time performance evaluation.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Fourth International Conference on Risks and Security of Internet and Systems (CRiSIS)
Notes Approved yes
Call Number (up) Sapienza @ mari @ crisis09 Serial 17
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Author Mazzini, Silvia; Puri, Stefano; Mari, Federico; Melatti, Igor; Tronci, Enrico
Title Formal Verification at System Level Type Conference Article
Year 2009 Publication In: DAta Systems In Aerospace (DASIA), Org. EuroSpace, Canadian Space Agency, CNES, ESA, EUMETSAT. Instanbul, Turkey, EuroSpace Abbreviated Journal
Volume Issue Pages
Keywords
Abstract System Level Analysis calls for a language comprehensible to experts with different background and yet precise enough to support meaningful analyses. SysML is emerging as an effective balance between such conflicting goals. In this paper we outline some the results obtained as for SysML based system level functional formal verification by an ESA/ESTEC study, with a collaboration among INTECS and La Sapienza University of Roma. The study focuses on SysML based system level functional requirements techniques.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Dasia09 Serial 20
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Author Cavaliere, Federico; Mari, Federico; Melatti, Igor; Minei, Giovanni; Salvo, Ivano; Tronci, Enrico; Verzino, Giovanni; Yushtein, Yuri
Title Model Checking Satellite Operational Procedures Type Conference Article
Year 2011 Publication DAta Systems In Aerospace (DASIA), Org. EuroSpace, Canadian Space Agency, CNES, ESA, EUMETSAT. San Anton, Malta, EuroSpace. Abbreviated Journal
Volume Issue Pages
Keywords
Abstract We present a model checking approach for the automatic verification of satellite operational procedures (OPs). Building a model for a complex system as a satellite is a hard task. We overcome this obstruction by using a suitable simulator (SIMSAT) for the satellite. Our approach aims at improving OP quality assurance by automatic exhaustive exploration of all possible simulation scenarios. Moreover, our solution decreases OP verification costs by using a model checker (CMurphi) to automatically drive the simulator. We model OPs as user-executed programs observing the simulator telemetries and sending telecommands to the simulator. In order to assess feasibility of our approach we present experimental results on a simple meaningful scenario. Our results show that we can save up to 90% of verification time.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Dasia11 Serial 13
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Author Della Penna, Giuseppe; Di Marco, Antinisca; Intrigila, Benedetto; Melatti, Igor; Pierantonio, Alfonso
Title Xere: Towards a Natural Interoperability between XML and ER Diagrams Type Conference Article
Year 2003 Publication Fundamental Approaches to Software Engineering, 6th International Conference, FASE 2003, Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2003, Warsaw, Poland, April 7-11, 2003, Proceedings Abbreviated Journal
Volume Issue Pages 356-371
Keywords
Abstract XML (eXtensible Markup Language) is becoming the standard format for documents on Internet and is widely used to exchange data. Often, the relevant information contained in XML documents needs to be also stored in legacy databases (DB) in order to integrate the new data with the pre-existing ones. In this paper, we introduce a technique for the automatic XML-DB integration, which we call Xere. In particular we present, as the first step of Xere, the mapping algorithm which allows the translation of XML Schemas into Entity-Relationship diagrams.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor Pezzè, M.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2621 Series Issue Edition
ISSN 3-540-00899-3 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Ddimp03 Serial 86
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Author Della Penna, Giuseppe; Di Marco, Antinisca; Intrigila, Benedetto; Melatti, Igor; Pierantonio, Alfonso
Title Interoperability mapping from XML schemas to ER diagrams Type Journal Article
Year 2006 Publication Data Knowl. Eng. Abbreviated Journal
Volume 59 Issue 1 Pages 166-188
Keywords
Abstract The eXtensible Markup Language (XML) is a de facto standard on the Internet and is now being used to exchange a variety of data structures. This leads to the problem of efficiently storing, querying and retrieving a great amount of data contained in XML documents. Unfortunately, XML data often need to coexist with historical data. At present, the best solution for storing XML into pre-existing data structures is to extract the information from the XML documents and adapt it to the data structures’ logical model (e.g., the relational model of a DBMS). In this paper, we introduce a technique called Xere (XML entity–relationship exchange) to assist the integration of XML data with other data sources. To this aim, we present an algorithm that maps XML schemas into entity–relationship diagrams, discuss its soundness and completeness and show its implementation in XSLT.
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Corporate Author Thesis
Publisher Elsevier Science Publishers B. V. Place of Publication Amsterdam, The Netherlands, The Netherlands Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-023x ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Ddimp06 Serial 77
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Minichino, Michele; Ciancamerla, Ester; Parisse, Andrea; Tronci, Enrico; Venturini Zilli, Marisa
Title Automatic Verification of a Turbogas Control System with the Mur$\varphi$ Verifier Type Conference Article
Year 2003 Publication Hybrid Systems: Computation and Control, 6th International Workshop, HSCC 2003 Prague, Czech Republic, April 3-5, 2003, Proceedings Abbreviated Journal
Volume Issue Pages 141-155
Keywords
Abstract Automatic analysis of Hybrid Systems poses formidable challenges both from a modeling as well as from a verification point of view. We present a case study on automatic verification of a Turbogas Control System (TCS) using an extended version of the Mur$\varphi$ verifier. TCS is the heart of ICARO, a 2MW Co-generative Electric Power Plant. For large hybrid systems, as TCS is, the modeling effort accounts for a significant part of the whole verification activity. In order to ease our modeling effort we extended the Mur$\varphi$ verifier by importing the C language long double type (finite precision real numbers) into it. We give experimental results on running our extended Mur$\varphi$ on our TCS model. For example using Mur$\varphi$ we were able to compute an admissible range of values for the variation speed of the user demand of electric power to the turbogas.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor Maler, O.; Pnueli, A.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2623 Series Issue Edition
ISSN 3-540-00913-2 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Dimmcptz03 Serial 88
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Author Della Penna, Giuseppe; Magazzeni, Daniele; Tofani, Alberto; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico
Title Automated Generation of Optimal Controllers through Model Checking Techniques Type Conference Article
Year 2006 Publication Icinco-Icso Abbreviated Journal
Volume Issue Pages 26-33
Keywords
Abstract We present a methodology for the synthesis of controllers, which exploits (explicit) model checking techniques. That is, we can cope with the systematic exploration of a very large state space. This methodology can be applied to systems where other approaches fail. In particular, we can consider systems with an highly non-linear dynamics and lacking a uniform mathematical description (model). We can also consider situations where the required control action cannot be specified as a local action, and rather a kind of planning is required. Our methodology individuates first a raw optimal controller, then extends it to obtain a more robust one. A case study is presented which considers the well known truck-trailer obstacle avoidance parking problem, in a parking lot with obstacles on it. The complex non-linear dynamics of the truck-trailer system, within the presence of obstacles, makes the parking problem extremely hard. We show how, by our methodology, we can obtain optimal controllers with different degrees of robustness.
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Corporate Author Thesis
Publisher INSTICC Press Place of Publication Editor Andrade-Cetto, J.; Ferrier, J.-L.; Pereira, J. M. C. D.; Filipe, J.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 972-8865-59-7 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Dimmtt06 Serial 79
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico
Title Exploiting Hub States in Automatic Verification Type Conference Article
Year 2005 Publication Automated Technology for Verification and Analysis: Third International Symposium, ATVA 2005, Taipei, Taiwan, October 4-7, 2005, Proceedings Abbreviated Journal
Volume Issue Pages 54-68
Keywords
Abstract In this paper we present a new algorithm to counteract state explosion when using Explicit State Space Exploration to verify protocol-like systems. We sketch the implementation of our algorithm within the Caching Mur$\varphi$ verifier and give experimental results showing its effectiveness. We show experimentally that, when memory is a scarce resource, our algorithm improves on the time performances of Caching Mur$\varphi$ verification algorithm, saving between 16% and 68% (45% on average) in computation time.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor D.A. Peled; Y.-K. Tsay
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 3707 Series Issue Edition
ISSN 3-540-29209-8 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number (up) Sapienza @ mari @ Dimt04 Serial 83
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