Alberto Sangiovanni-Vincentelli

Bio: Alberto Sangiovanni-Vincentelli is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Logic synthesis & Finite-state machine. The author has an hindex of 99, co-authored 934 publications receiving 45201 citations. Previous affiliations of Alberto Sangiovanni-Vincentelli include National University of Singapore & Lawrence Berkeley National Laboratory.

JPEG encoding on the Intel MXP5800: a platform-based design case study

Abstract: Multimedia systems are becoming increasingly complex and concurrent. The platform-based design (PBD) methodology (Keutzer et al., 2000) tackles these issues by recommending the use of formal models, carefully defined abstraction layers and the separation of concerns. Models of computation (Lee and Sangiovanni-Vincentelli, 1998) (MoCs) can be used within this methodology to enable specialized synthesis and verification techniques. In this paper, these concepts are leveraged in an industrial case study: the JPEG encoder application deployed on the Intel MXP5800 imaging processor. The modeling is carried out in the Metropolis (Balarin et al., 2003) design framework. We show that the system-level model using our chosen model of computation allows performance estimation within 5% of the actual implementation. Moreover, the chosen MoC is amenable to automation, which enables future synthesis techniques.

Rialto: a bridge between description and implementation of control algorithms for wireless sensor networks

Abstract: Rialto is a design framework that allows separating the description of a control application for wireless sensor networks from its physical network implementation. The methodology supported by Rialto consists of two steps:An application is described in a Rialto Model in terms of logical components queries and commands.The description is translated into an internal format called RialtoNet that is used to explore all the possible sequence of queries and commands that the application may lead to. The RialtoNet is executed and a set of constraints on the communication and sensing infrastructure is generated.The semantics of RialtoNet is based on a MoC that takes inspiration from Kahn Process Networks, but blocking rules are conveniently modified to exploit the domain specificity.Our approach offers a clear interface to the application designer as Rialto automatically bridges the gap between application and implementation. Hence, Rialto facilitates the adoption of wireless sensor networks technology in application domains, such as industrial control, where the application designer is not a communication engineer.

Controller synthesis for hybrid systems with a lower bound on event separation

Abstract: A systematic procedure for synthesizing all full-state feedback controllers for a hybrid system subject to a safety (state-invariance) specification has been proposed in the literature. The interaction between the controller and a non- deterministic hybrid plant is viewed as a two-person game. The controller wins if it keeps the state of the closed-loop system within a specified set of good states; its adversarial environment tries to force the system outside the good set. The synthesis procedure iteratively augments the set of states from which the environment wins via either one additional discrete step, or one additional continuous flow. The key difficulty in carrying out the synthesis procedure lies in the computations for continuous flows. One must essentially solve a differential game in which the environment is trying to drive the system into its target set at the same time as avoiding the target set of the controller. In this paper, we study hybrid systems with lower bounds on the separation betwe...

On the temporal equivalence of sequential circuits

Abstract: The authors extend the abstract notion of temporal behavior to compare arbitrary circuits with arbitrary multiphase clocking schemes. They consider the input-output behavior of circuits with respect to time. Properties are discussed that remain invariant under certain transformations. Constraints are derived that permit a legal retiming in the case of multiphase sequential circuits with edge triggered and/or transparent latches. For a particular design style an efficient procedure is described to check for temporal equivalence of sequential circuits. A model and a formal definition for the temporal behavior of an arbitrary multiphase circuits and an algorithm for formal verification of the temporal behavior of circuits are outlined. >

Models of computation for system design

Abstract: In the near future, most objects of common use will contain electronics to augment their functionality, performance, and safety. Hence, time-to-market, safety, low-cost, and reliability will have to be addressed by any system design methodology. A fundamental aspect of system design is the specification process. We advocate using an unambiguous formalism to represent design specifications and design choices. This facilitates tremendously efficiency of specification, formal verification, and correct design refinement, optimization, and implementation. This formalism is often called model of computation. There are several models of computation that have been used, but there is a lack of consensus among researchers and practitioners on the “right” models to use. To the best of our knowledge, there has also been little effort in trying to compare rigorously these models of computation. In this paper, we review current models of computation and compare them within a framework that has been recently proposed. This analysis demonstrates both the need for heterogeneity to capture the richness of the application domains, and the need for unification for optimization and verification purposes. We describe in detail our CFSM model of computation, illustrating its suitability for design of reactive embedded systems and we conclude with some general considerations about the use of models of computations in future design systems.

Gradient-based learning applied to document recognition

Abstract: Multilayer neural networks trained with the back-propagation algorithm constitute the best example of a successful gradient based learning technique. Given an appropriate network architecture, gradient-based learning algorithms can be used to synthesize a complex decision surface that can classify high-dimensional patterns, such as handwritten characters, with minimal preprocessing. This paper reviews various methods applied to handwritten character recognition and compares them on a standard handwritten digit recognition task. Convolutional neural networks, which are specifically designed to deal with the variability of 2D shapes, are shown to outperform all other techniques. Real-life document recognition systems are composed of multiple modules including field extraction, segmentation recognition, and language modeling. A new learning paradigm, called graph transformer networks (GTN), allows such multimodule systems to be trained globally using gradient-based methods so as to minimize an overall performance measure. Two systems for online handwriting recognition are described. Experiments demonstrate the advantage of global training, and the flexibility of graph transformer networks. A graph transformer network for reading a bank cheque is also described. It uses convolutional neural network character recognizers combined with global training techniques to provide record accuracy on business and personal cheques. It is deployed commercially and reads several million cheques per day.

Differential Evolution – A Simple and Efficient Heuristic for Global Optimization over Continuous Spaces

Abstract: A new heuristic approach for minimizing possibly nonlinear and non-differentiable continuous space functions is presented. By means of an extensive testbed it is demonstrated that the new method converges faster and with more certainty than many other acclaimed global optimization methods. The new method requires few control variables, is robust, easy to use, and lends itself very well to parallel computation.

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Graph-Based Algorithms for Boolean Function Manipulation

Abstract: In this paper we present a new data structure for representing Boolean functions and an associated set of manipulation algorithms. Functions are represented by directed, acyclic graphs in a manner similar to the representations introduced by Lee [1] and Akers [2], but with further restrictions on the ordering of decision variables in the graph. Although a function requires, in the worst case, a graph of size exponential in the number of arguments, many of the functions encountered in typical applications have a more reasonable representation. Our algorithms have time complexity proportional to the sizes of the graphs being operated on, and hence are quite efficient as long as the graphs do not grow too large. We present experimental results from applying these algorithms to problems in logic design verification that demonstrate the practicality of our approach.

Principles of Model Checking

Abstract: Our growing dependence on increasingly complex computer and software systems necessitates the development of formalisms, techniques, and tools for assessing functional properties of these systems. One such technique that has emerged in the last twenty years is model checking, which systematically (and automatically) checks whether a model of a given system satisfies a desired property such as deadlock freedom, invariants, and request-response properties. This automated technique for verification and debugging has developed into a mature and widely used approach with many applications. Principles of Model Checking offers a comprehensive introduction to model checking that is not only a text suitable for classroom use but also a valuable reference for researchers and practitioners in the field. The book begins with the basic principles for modeling concurrent and communicating systems, introduces different classes of properties (including safety and liveness), presents the notion of fairness, and provides automata-based algorithms for these properties. It introduces the temporal logics LTL and CTL, compares them, and covers algorithms for verifying these logics, discussing real-time systems as well as systems subject to random phenomena. Separate chapters treat such efficiency-improving techniques as abstraction and symbolic manipulation. The book includes an extensive set of examples (most of which run through several chapters) and a complete set of basic results accompanied by detailed proofs. Each chapter concludes with a summary, bibliographic notes, and an extensive list of exercises of both practical and theoretical nature.