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Author Melatti, Igor; Palmer, Robert; Sawaya, Geoffrey; Yang, Yu; Kirby, Robert Mike; Gopalakrishnan, Ganesh
Title Parallel and distributed model checking in Eddy Type Journal Article
Year 2009 Publication Int. J. Softw. Tools Technol. Transf. Abbreviated Journal
Volume 11 Issue 1 Pages 13-25
Keywords
Abstract Model checking of safety properties can be scaled up by pooling the CPU and memory resources of multiple computers. As compute clusters containing 100s of nodes, with each node realized using multi-core (e.g., 2) CPUs will be widespread, a model checker based on the parallel (shared memory) and distributed (message passing) paradigms will more efficiently use the hardware resources. Such a model checker can be designed by having each node employ two shared memory threads that run on the (typically) two CPUs of a node, with one thread responsible for state generation, and the other for efficient communication, including (1) performing overlapped asynchronous message passing, and (2) aggregating the states to be sent into larger chunks in order to improve communication network utilization. We present the design details of such a novel model checking architecture called Eddy. We describe the design rationale, details of how the threads interact and yield control, exchange messages, as well as detect termination. We have realized an instance of this architecture for the Murphi modeling language. Called Eddy_Murphi, we report its performance over the number of nodes as well as communication parameters such as those controlling state aggregation. Nearly linear reduction of compute time with increasing number of nodes is observed. Our thread task partition is done in such a way that it is modular, easy to port across different modeling languages, and easy to tune across a variety of platforms.
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Corporate Author Thesis
Publisher Springer-Verlag Place of Publication Berlin, Heidelberg Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1433-2779 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Mpsykg09 Serial 80
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Author Intrigila, Benedetto; Melatti, Igor; Tofani, Alberto; Macchiarelli, Guido
Title Computational models of myocardial endomysial collagen arrangement Type Journal Article
Year 2007 Publication Computer Methods and Programs in Biomedicine Abbreviated Journal
Volume 86 Issue 3 Pages 232-244
Keywords
Abstract Collagen extracellular matrix is one of the factors related to high passive stiffness of cardiac muscle. However, the architecture and the mechanical aspects of the cardiac collagen matrix are not completely known. In particular, endomysial collagen contribution to the passive mechanics of cardiac muscle as well as its micro anatomical arrangement is still a matter of debate. In order to investigate mechanical and structural properties of endomysial collagen, we consider two alternative computational models of some specific aspects of the cardiac muscle. These two models represent two different views of endomysial collagen distribution: (1) the traditional view and (2) a new view suggested by the data obtained from scanning electron microscopy (SEM) in NaOH macerated samples (a method for isolating collagen from the other tissue). We model the myocardial tissue as a net of spring elements representing the cardiomyocytes together with the endomysial collagen distribution. Each element is a viscous elastic spring, characterized by an elastic and a viscous constant. We connect these springs to imitate the interconnections between collagen fibers. Then we apply to the net of springs some external forces of suitable magnitude and direction, obtaining an extension of the net itself. In our setting, the ratio forces magnitude /net extension is intended to model the stress /strain ratio of a microscopical portion of the myocardial tissue. To solve the problem of the correct identification of the values of the different parameters involved, we use an artificial neural network approach. In particular, we use this technique to learn, given a distribution of external forces, the elastic constants of the springs needed to obtain a desired extension as an equilibrium position. Our experimental findings show that, in the model of collagen distribution structured according to the new view, a given stress /strain ratio (of the net of springs, in the sense specified above) is obtained with much smaller (w.r.t. the other model, corresponding to the traditional view) elasticity constants of the springs. This seems to indicate that by an appropriate structure, a given stiffness of the myocardial tissue can be obtained with endomysial collagen fibers of much smaller size.
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Corporate Author Thesis
Publisher Elsevier North-Holland, Inc. Place of Publication New York, NY, USA Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0169-2607 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Imtm07 Serial 82
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Author Della Penna, Giuseppe; Magazzeni, Daniele; Tofani, Alberto; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico
Title Automatic Synthesis of Robust Numerical Controllers Type Conference Article
Year 2007 Publication Icas '07 Abbreviated Journal
Volume Issue Pages 4
Keywords
Abstract A major problem of numerical controllers is their robustness, i.e. the state read from the plant may not be in the controller table, although it may be close to some states in the table. For continuous systems, this problem is typically handled by interpolation techniques. Unfortunately, when the plant contains both continuous and discrete variables, the interpolation approach does not work well. To cope with this kind of systems, we propose a general methodology that exploits explicit model checking in an innovative way to automatically synthesize a (time-) optimal numerical controller from a plant specification and apply an optimized strengthening algorithm only on the most significant states, in order to reach an acceptable robustness degree. We implemented all the algorithms within our CGMurphi tool, an extension of the well-known CMurphi verifier, and tested the effectiveness of our approach by applying it to the well-known truck and trailer obstacles avoidance problem.
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Corporate Author Thesis
Publisher IEEE Computer Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0-7695-2859-5 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Dmtimt07 Serial 89
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico; Venturini Zilli, Marisa
Title Exploiting Transition Locality in Automatic Verification of Finite State Concurrent Systems Type Journal Article
Year 2004 Publication Sttt Abbreviated Journal
Volume 6 Issue 4 Pages 320-341
Keywords
Abstract In this paper we show that statistical properties of the transition graph of a system to be verified can be exploited to improve memory or time performances of verification algorithms. We show experimentally that protocols exhibit transition locality. That is, with respect to levels of a breadth-first state space exploration, state transitions tend to be between states belonging to close levels of the transition graph. We support our claim by measuring transition locality for the set of protocols included in the Mur$\varphi$ verifier distribution. We present a cache-based verification algorithm that exploits transition locality to decrease memory usage and a disk-based verification algorithm that exploits transition locality to decrease disk read accesses, thus reducing the time overhead due to disk usage. Both algorithms have been implemented within the Mur$\varphi$ verifier. Our experimental results show that our cache-based algorithm can typically save more than 40% of memory with an average time penalty of about 50% when using (Mur$\varphi$) bit compression and 100% when using bit compression and hash compaction, whereas our disk-based verification algorithm is typically more than ten times faster than a previously proposed disk-based verification algorithm and, even when using 10% of the memory needed to complete verification, it is only between 40 and 530% (300% on average) slower than (RAM) Mur$\varphi$ with enough memory to complete the verification task at hand. Using just 300 MB of memory our disk-based Mur$\varphi$ was able to complete verification of a protocol with about $10^9$ reachable states. This would require more than 5 GB of memory using standard Mur$\varphi$.
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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 (down) Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ DIMTZ04j Serial 91
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Author Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico; Alvisi, Lorenzo; Clement, Allen; Li, Harry
Title Model Checking Nash Equilibria in MAD Distributed Systems Type Conference Article
Year 2008 Publication FMCAD '08: Proceedings of the 2008 International Conference on Formal Methods in Computer-Aided Design Abbreviated Journal
Volume Issue Pages 1-8
Keywords Model Checking, MAD Distributed System, Nash Equilibrium
Abstract We present a symbolic model checking algorithm for verification of Nash equilibria in finite state mechanisms modeling Multiple Administrative Domains (MAD) distributed systems. Given a finite state mechanism, a proposed protocol for each agent and an indifference threshold for rewards, our model checker returns PASS if the proposed protocol is a Nash equilibrium (up to the given indifference threshold) for the given mechanism, FAIL otherwise. We implemented our model checking algorithm inside the NuSMV model checker and present experimental results showing its effectiveness for moderate size mechanisms. For example, we can handle mechanisms which corresponding normal form games would have more than $10^20$ entries. To the best of our knowledge, no model checking algorithm for verification of mechanism Nash equilibria has been previously published.
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Corporate Author Thesis
Publisher IEEE Press Place of Publication Piscataway, NJ, USA Editor Cimatti, A.; Jones, R.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 978-1-4244-2735-2 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ MarMelSalTroAlvCle08 Serial 93
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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 (down) Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ ChiLatMar08 Serial 94
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Author Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico
Title Automatic Control Software Synthesis for Quantized Discrete Time Hybrid Systems Type Conference Article
Year 2012 Publication Proceedings of the 51th IEEE Conference on Decision and Control, CDC 2012, December 10-13, 2012, Maui, HI, USA Abbreviated Journal
Volume Issue Pages 6120-6125
Keywords
Abstract
Address
Corporate Author Thesis
Publisher IEEE Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN ISBN 978-1-4673-2065-8 Medium
Area Expedition Conference
Notes Techreport version can be found at http://arxiv.org/abs/1207.4098 Approved yes
Call Number Sapienza @ mari @ cdc12 Serial 96
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Author Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico
Title On Model Based Synthesis of Embedded Control Software Type Conference Article
Year 2012 Publication Proceedings of the 12th International Conference on Embedded Software, EMSOFT 2012, part of the Eighth Embedded Systems Week, ESWeek 2012, Tampere, Finland, October 7-12, 2012 Abbreviated Journal
Volume Issue Pages 227-236
Keywords
Abstract
Address
Corporate Author Thesis
Publisher ACM Place of Publication Editor Ahmed Jerraya and Luca P. Carloni and Florence Maraninchi and John Regehr
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN ISBN 978-1-4503-1425-1 Medium
Area Expedition Conference
Notes Techreport version can be found at arxiv.org Approved yes
Call Number Sapienza @ mari @ emsoft12 Serial 97
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Author Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico
Title Linear Constraints as a Modeling Language for Discrete Time Hybrid Systems Type Conference Article
Year 2012 Publication Proceedings of ICSEA 2012, The Seventh International Conference on Software Engineering Advances Abbreviated Journal
Volume Issue Pages 664-671
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Abstract
Address
Corporate Author Thesis
Publisher ThinkMind Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ icsea12 Serial 98
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Author Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico
Title Control Software Visualization Type Conference Article
Year 2012 Publication Proceedings of INFOCOMP 2012, The Second International Conference on Advanced Communications and Computation Abbreviated Journal
Volume Issue Pages 15-20
Keywords
Abstract
Address
Corporate Author Thesis
Publisher ThinkMind Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 978-1-61208-226-4 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ infocomp2012 Serial 100
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