toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author (down) Chierichetti, Flavio; Lattanzi, Silvio; Mari, Federico; Panconesi, Alessandro pdf  doi
openurl 
  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.  
  Address  
  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 Sapienza @ mari @ ChiLatMar08 Serial 94  
Permanent link to this record
 

 
Author (down) Cavaliere, Federico; Mari, Federico; Melatti, Igor; Minei, Giovanni; Salvo, Ivano; Tronci, Enrico; Verzino, Giovanni; Yushtein, Yuri pdf  openurl
  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.  
  Address  
  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 Sapienza @ mari @ Dasia11 Serial 13  
Permanent link to this record
 

 
Author (down) Bobbio, Andrea; Ciancamerla, Ester; Di Blasi, Saverio; Iacomini, Alessandro; Mari, Federico; Melatti, Igor; Minichino, Michele; Scarlatti, Alessandro; Tronci, Enrico; Terruggia, Roberta; Zendri, Emilio pdf  doi
openurl 
  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.  
  Address  
  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 Sapienza @ mari @ crisis09 Serial 17  
Permanent link to this record
 

 
Author (down) Barbanera, Franco; Dezani-Ciancaglini, Mariangiola; Salvo, Ivano; Sassone, Vladimiro pdf  doi
openurl 
  Title A Type Inference Algorithm for Secure Ambients Type Journal Article
  Year 2002 Publication Electronic Notes in Theoretical Computer Science Abbreviated Journal  
  Volume 62 Issue Pages 83-101  
  Keywords  
  Abstract We consider a type discipline for the Ambient Calculus that associates ambients with security levels and constrains them to be traversed by or opened in ambients of higher security clearance only. We present a bottom-up algorithm that, given an untyped process P, computes a minimal set of constraints on security levels such that all actions during runs of P are performed without violating the security level priorities. Such an algorithm appears to be a prerequisite to use type systems to ensure security properties in the web scenario.  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier 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 TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types Approved yes  
  Call Number Sapienza @ mari @ Barbanera-Dezani-Salvo-Sassone:01 Serial 73  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico pdf  doi
isbn  openurl
  Title A Map-Reduce Parallel Approach to Automatic Synthesis of Control Software Type Conference Article
  Year 2013 Publication Proc. of International SPIN Symposium on Model Checking of Software (SPIN 2013) Abbreviated Journal International SPIN Symposium on Model Checking of Software  
  Volume Issue Pages 43-60  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Springer - Verlag Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title  
  Series Volume 7976 Series Issue Edition  
  ISSN 0302-9743 ISBN 978-3-642-39175-0 Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Sapienza @ melatti @ Serial 112  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico pdf  doi
isbn  openurl
  Title On-the-Fly Control Software Synthesis Type Conference Article
  Year 2013 Publication Proceedings of International SPIN Symposium on Model Checking of Software (SPIN 2013) Abbreviated Journal International SPIN Symposium on Model Checking of Software  
  Volume Issue Pages 61-80  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Springer - Verlag Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title  
  Series Volume 7976 Series Issue Edition  
  ISSN 0302-9743 ISBN 978-3-642-39175-0 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Sapienza @ melatti @ Serial 111  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico url  openurl
  Title Automatic Control Software Synthesis for Quantized Discrete Time Hybrid Systems Type Report
  Year 2012 Publication Abbreviated Journal  
  Volume abs/1207.4098 Issue Pages  
  Keywords  
  Abstract Many Embedded Systems are indeed Software Based Control Systems, that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of embedded systems control software. This paper addresses control software synthesis for discrete time nonlinear systems. We present a methodology to overapproximate the dynamics of a discrete time nonlinear hybrid system H by means of a discrete time linear hybrid system L(H), in such a way that controllers for L(H) are guaranteed to be controllers for H. We present experimental results on the inverted pendulum, a challenging and meaningful benchmark in nonlinear Hybrid Systems control.  
  Address  
  Corporate Author Thesis  
  Publisher CoRR, Technical Report 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 Sapienza @ mari @ Serial 103  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico url  openurl
  Title On Model Based Synthesis of Embedded Control Software Type Report
  Year 2012 Publication Abbreviated Journal  
  Volume abs/1207.4474 Issue Pages  
  Keywords  
  Abstract Many Embedded Systems are indeed Software Based Control Systems (SBCSs), that is control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for control software. Given the formal model of a plant as a Discrete Time Linear Hybrid System and the implementation specifications (that is, number of bits in the Analog-to-Digital (AD) conversion) correct-by-construction control software can be automatically generated from System Level Formal Specifications of the closed loop system (that is, safety and liveness requirements), by computing a suitable finite abstraction of the plant.
With respect to given implementation specifications, the automatically generated code implements a time optimal control strategy (in terms of set-up time), has a Worst Case Execution Time linear in the number of AD bits $b$, but unfortunately, its size grows exponentially with respect to $b$. In many embedded systems, there are severe restrictions on the computational resources (such as memory or computational power) available to microcontroller devices.
This paper addresses model based synthesis of control software by trading system level non-functional requirements (such us optimal set-up time, ripple) with software non-functional requirements (its footprint). Our experimental results show the effectiveness of our approach: for the inverted pendulum benchmark, by using a quantization schema with 12 bits, the size of the small controller is less than 6% of the size of the time optimal one.
 
  Address  
  Corporate Author Thesis  
  Publisher CoRR, Technical Report 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 Sapienza @ mari @ Serial 102  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico file  url
openurl 
  Title A Map-Reduce Parallel Approach to Automatic Synthesis of Control Software Type Report
  Year 2012 Publication Abbreviated Journal  
  Volume abs/1210.2276 Issue Pages  
  Keywords  
  Abstract Many Control Systems are indeed Software Based Control Systems, i.e. control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of control software.
Available algorithms and tools (e.g., QKS) may require weeks or even months of computation to synthesize control software for large-size systems. This motivates search for parallel algorithms for control software synthesis.
In this paper, we present a map-reduce style parallel algorithm for control software synthesis when the controlled system (plant) is modeled as discrete time linear hybrid system. Furthermore we present an MPI-based implementation PQKS of our algorithm. To the best of our knowledge, this is the first parallel approach for control software synthesis.
We experimentally show effectiveness of PQKS on two classical control synthesis problems: the inverted pendulum and the multi-input buck DC/DC converter. Experiments show that PQKS efficiency is above 65%. As an example, PQKS requires about 16 hours to complete the synthesis of control software for the pendulum on a cluster with 60 processors, instead of the 25 days needed by the sequential algorithm in QKS.
 
  Address  
  Corporate Author Thesis  
  Publisher CoRR, Technical Report 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 Sapienza @ mari @ Serial 101  
Permanent link to this record
 

 
Author (down) Alimguzhin, Vadim; Mari, Federico; Melatti, Igor; Salvo, Ivano; Tronci, Enrico pdf  doi
isbn  openurl
  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 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  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: