| Records |
| 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 |
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| Volume |
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Issue |
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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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| Publisher |
Acm |
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Editor |
Najork, M.; Broder, A.Z.; Chakrabarti, S. |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ ChiLatMar08 |
Serial |
94 |
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| Author |
Bucciarelli, Antonio; de Lorenzis, Silvia; Piperno, Adolfo; Salvo, Ivano |
| Title |
Some Computational Properties of Intersection Types (Extended Abstract) |
Type |
Journal Article |
| Year |
1999 |
Publication |
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Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
109-118 |
| Keywords |
lambda calculusCurry types, intersection types, lambda-definability, lambda-terms, strong normalization |
| Abstract |
This paper presents a new method for comparing computation-properties of λ-terms typeable with intersection types with respect to terms typeable with Curry types. In particular, strong normalization and λ-definability are investigated. A translation is introduced from intersection typing derivations to Curry typeable terms; the main feature of the proposed technique is that the translation is preserved by β-reduction. This allows to simulate a computation starting from a term typeable in the intersection discipline by means of a computation starting from a simply typeable term. Our approach naturally leads to prove strong normalization in the intersection system by means of purely syntactical techniques. In addition, the presented method enables us to give a proof of a conjecture proposed by Leivant in 1990, namely that all functions uniformly definable using intersection types are already definable using Curry types. |
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IEEE Computer Society |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ bucciarelli-delorenzis-piperno-salvo:99 |
Serial |
71 |
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| Author |
Tronci, Enrico |
| Title |
Equational Programming in lambda-calculus |
Type |
Conference Article |
| Year |
1991 |
Publication |
Sixth Annual IEEE Symposium on Logic in Computer Science (LICS) |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
191-202 |
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| Publisher |
IEEE Computer Society |
Place of Publication |
Amsterdam, The Netherlands |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ lics91 |
Serial |
58 |
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| Author |
Tronci, Enrico |
| Title |
Automatic Synthesis of Controllers from Formal Specifications |
Type |
Conference Article |
| Year |
1998 |
Publication |
Proc of 2nd IEEE International Conference on Formal Engineering Methods (ICFEM) |
Abbreviated Journal |
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Issue |
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Pages |
134-143 |
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| Abstract |
Many safety critical reactive systems are indeed embedded control systems. Usually a control system can be partitioned into two main subsystems: a controller and a plant. Roughly speaking: the controller observes the state of the plant and sends commands (stimulus) to the plant to achieve predefined goals. We show that when the plant can be modeled as a deterministic finite state system (FSS) it is possible to effectively use formal methods to automatically synthesize the program implementing the controller from the plant model and the given formal specifications for the closed loop system (plant+controller). This guarantees that the controller program is correct by construction. To the best of our knowledge there is no previously published effective algorithm to extract executable code for the controller from closed loop formal specifications. We show practical usefulness of our techniques by giving experimental results on their use to synthesize C programs implementing optimal controllers (OCs) for plants with more than 109 states. |
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Place of Publication |
Brisbane, Queensland, Australia |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ icfem98 |
Serial |
52 |
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| Author |
Cecconi, Michele; Tronci, Enrico |
| Title |
Requirements Formalization and Validation for a Telecommunication Equipment Protection Switcher |
Type |
Conference Article |
| Year |
2000 |
Publication |
Hase |
Abbreviated Journal |
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Issue |
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Pages |
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| Publisher |
IEEE Computer Society |
Place of Publication |
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Edition |
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| ISSN |
0-7695-0927-4 |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ CeTro00 |
Serial |
29 |
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| Author |
Tronci, Enrico |
| Title |
Formally Modeling a Metal Processing Plant and its Closed Loop Specifications |
Type |
Conference Article |
| Year |
1999 |
Publication |
4th IEEE International Symposium on High-Assurance Systems Engineering (HASE) |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
151 |
| Keywords |
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| Abstract |
We present a case study on automatic synthesis of control software from formal specifications for an industrial automation control system. Our aim is to compare the effectiveness (i.e. design effort and controller quality) of automatic controller synthesis from closed loop formal specifications with that of manual controller design followed by automatic verification. The system to be controlled (plant) models a metal processing facility near Karlsruhe. We succeeded in automatically generating C code implementing a (correct by construction) embedded controller for such a plant from closed loop formal specifications. Our experimental results show that for industrial automation control systems automatic synthesis is a viable and profitable (especially as far as design effort is concerned) alternative to manual design followed by automatic verification. |
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| Publisher |
IEEE Computer Society |
Place of Publication |
Washington, D.C, USA |
Editor |
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Series Issue |
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Edition |
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| ISSN |
0-7695-0418-3 |
ISBN |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ hase99 |
Serial |
50 |
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| Author |
Tronci, Enrico |
| Title |
Automatic Synthesis of Control Software for an Industrial Automation Control System |
Type |
Conference Article |
| Year |
1999 |
Publication |
Proc.of: 14th IEEE International Conference on: Automated Software Engineering (ASE) |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
247-250 |
| Keywords |
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| Abstract |
We present a case study on automatic synthesis of control software from formal specifications for an industrial automation control system. Our aim is to compare the effectiveness (i.e. design effort and controller quality) of automatic controller synthesis from closed loop formal specifications with that of manual controller design, followed by automatic verification. Our experimental results show that for industrial automation control systems, automatic synthesis is a viable and profitable (especially as far as design effort is concerned) alternative to manual design, followed by automatic verification. |
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Place of Publication |
Cocoa Beach, Florida, USA |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ ase99 |
Serial |
49 |
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| Author |
Tronci, Enrico; Della Penna, Giuseppe; Intrigila, Benedetto; Venturini Zilli, Marisa |
| Title |
A Probabilistic Approach to Automatic Verification of Concurrent Systems |
Type |
Conference Article |
| Year |
2001 |
Publication |
8th Asia-Pacific Software Engineering Conference (APSEC) |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
317-324 |
| Keywords |
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| Abstract |
The main barrier to automatic verification of concurrent systems is the huge amount of memory required to complete the verification task (state explosion). In this paper we present a probabilistic algorithm for automatic verification via model checking. Our algorithm trades space with time. In particular, when memory is full because of state explosion our algorithm does not give up verification. Instead it just proceeds at a lower speed and its results will only hold with some arbitrarily small error probability. Our preliminary experimental results show that by using our probabilistic algorithm we can typically save more than 30% of RAM with an average time penalty of about 100% w.r.t. a deterministic state space exploration with enough memory to complete the verification task. This is better than giving up the verification task because of lack of memory. |
| Address |
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Thesis |
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| Publisher |
IEEE Computer Society |
Place of Publication |
Macau, China |
Editor |
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Summary Language |
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Original Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0-7695-1408-1 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ apsec01 |
Serial |
43 |
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| Author |
Bucciarelli, Antonio; Piperno, Adolfo; Salvo, Ivano |
| Title |
Intersection types and λ-definability |
Type |
Journal Article |
| Year |
2003 |
Publication |
Mathematical Structures in Computer Science |
Abbreviated Journal |
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| Volume |
13 |
Issue |
1 |
Pages |
15-53 |
| Keywords |
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| Abstract |
This paper presents a novel method for comparing computational properties of λ-terms that are typeable with intersection types, with respect to terms that are typeable with Curry types. We introduce a translation from intersection typing derivations to Curry typeable terms that is preserved by β-reduction: this allows the simulation of a computation starting from a term typeable in the intersection discipline by means of a computation starting from a simply typeable term. Our approach proves strong normalisation for the intersection system naturally by means of purely syntactical techniques. The paper extends the results presented in Bucciarelli et al. (1999) to the whole intersection type system of Barendregt, Coppo and Dezani, thus providing a complete proof of the conjecture, proposed in Leivant (1990), that all functions uniformly definable using intersection types are already definable using Curry types. |
| Address |
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Thesis |
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| Publisher |
Cambridge University Press |
Place of Publication |
New York, NY, USA |
Editor |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0960-1295 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ Bucciarelli-Piperno-Salvo:MSCS-03 |
Serial |
69 |
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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 |
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| Volume |
78 |
Issue |
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Pages |
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| Keywords |
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| 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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Edition |
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| Notes |
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Approved |
yes |
| Call Number |
Sapienza @ mari @ Coppo-Dezani-Giovannetti-Salvo:03 |
Serial |
74 |
| Permanent link to this record |
