Cooperative Modeling and Design History Tracking Using Design Tracking Matrix

This thesis suggests a new framework for cooperative modeling which supports concurrency design protocol with a design history tracking function. The proposed framework allows designers to work together while eliminating design conflicts and redundancies, and preventing infeasible designs. This framework provides methods to track optimal design path and redundant design history in the overall design process. This cooperative modeling architecture consists of a modeling server and voxel-based multi-client design tool. Design change among server and multiple clients are executed using the proposed concurrency design protocol. The design steps are tracked and analyzed using Design Tracking Graph and Design Tracking Matrix (DTM), which provide a design data exchange algorithm allowing seamless integration of design modifications between participating designers. This framework can be used for effective cooperative modeling, and helps identify and eliminate conflicts and minimize delay. The proposed algorithm supports effective cooperative design functions. First, it provides a method to obtain the optimal design path which can be stored in a design library and utilized in the future design. Second, it helps capture modeling pattern which can be used for analyzing designer's performance. Finally, obtained redundancies can be used to evaluate designer?s design efficiency

An approach to distributed state space exploration for coloured Petri nets

Abstract. We present an approach and associated computer tool support for conducting distributed state space exploration for Coloured Petri Nets (CPNs). The distributed state space exploration is based on the introduction of a coordinating process and a number of worker processes. The worker processes are responsible for the storage of states and the computation of successor states. The coordinator process is responsible for the distribution of states and termination detection. A main virtue of our approach is that it can be directly implemented in the existing single-threaded framework of Design/CPN and CPN Tools. This makes the distributed state space exploration and analysis largely transparent to the analyst. We illustrate the use of the developed tool on an example.

Coping with the State Explosion Problem in Formal Methods: Advanced Abstraction Techniques and Big Data Approaches.

Formal verification of dynamic, concurrent and real-time systems has been the focus of several decades of software engineering research. Formal verification requires high-performance data processing software for extracting knowledge from the unprecedented amount of data containing all reachable states and all transitions that systems can make among those states, for instance, the extraction of specific reachable states, traces, and more. One of the most challenging task in this context is the development of tools able to cope with the complexity of real-world models analysis. Many methods have been proposed to alleviate this problem. For instance, advanced state space techniques aim at reducing the data needed to be constructed in order to verify certain properties. Other directions are the efficient implementation of such analysis techniques, and studying ways to parallelize the algorithms in order to exploit multi-core and distributed architectures. Since cloud-based computing resources have became easily accessible, there is an opportunity for verification techniques and tools to undergo a deep technological transition to exploit the new available architectures. This has created an increasing interest in parallelizing and distributing verification techniques. Cloud computing is an emerging and evolving paradigm where challenges and opportunities allow for new research directions and applications. There is an evidence that this trend will continue, in fact several companies are putting remarkable efforts in delivering services able to offer hundreds, or even thousands, commodity computers available to customers, thus enabling users to run massively parallel jobs. This revolution is already started in different scientific fields, achieving remarkable breakthroughs through new kinds of experiments that would have been impossible only few years ago. Anyway, despite many years of work in the area of multi-core and distributed model checking, still few works introduce algorithms that can scale effortlessly to the use of thousands of loosely connected computers in a network, so existing technology does not yet allow us to take full advantage of the vast array of compute power of a "cloud" environment. Moreover, despite model checking software tools are so called "push-button", managing a high-performance computing environment required by distributed scientific applications, is far from being considered such, especially whenever one wants to exploit general purpose cloud computing facilities. The thesis focuses on two complementary approaches to deal with the state explosion problem in formal verification. On the one hand we try to decrease the exploration space by studying advanced state space methods for real-time systems modeled with Time Basic Petri nets. In particular, we addressed and solved several different open problems for such a modeling formalism. On the other hand, we try to increase the computational power by introducing approaches, techniques and software tools that allow us to leverage the "big data" trend to some extent. In particular, we provided frameworks and software tools that can be easily specialized to deal with the construction and verification of very huge state spaces of different kinds of formalisms by exploiting big data approaches and cloud computing infrastructures

Sixth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools Aarhus, Denmark, October 24-26, 2005

This booklet contains the proceedings of the Sixth Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 24-26, 2005. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop0