Leu-M

Time dependant models have been intensively studied for many reasons, among others because of their applications in software verification and due to the development of embedded platforms where reliability and safety depend to a large extent on the time features. Many of the time dependant models were suggested as real-time extensions of several well-known untimed models. The most studied formalisms include Networks of Timed Automata which extend the model of communicating finite-state machines with a finite number of real-valued clocks, and timed extensions of Petri nets where the added time constructs include e.g. time intervals that are assigned to the transitions (Time Petri Nets) or to the arcs (Timed-Arc Petri Nets). In this paper, we shall semi-formally introduce these models, discuss their strengths and weaknesses, and provide an overview of the known results about the relationships among the models.

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Comparing the Expressiveness of Timed Automata and Timed Extensions of Petri Nets

Performance and cost analysis are the two main purposes of business process modeling, where the Petri net extended with time information is an effective tool for performance analysis, but not for cost analysis. This paper proposes a time Petri net extended with price information—Price Time Petri Net. Firstly, this paper associates a price with a time transition, and gives the semantics for price time Petri net in terms of priced timed transition systems. Then it defines a priced state class as an extension of state class, and discusses the soundness and completeness for this extension. An algorithm is given to prove that the minimum-cost reachability problem for bounded price time Petri net is decidable. Finally, this paper gives an example and draws a conclusion that incorporating price information in time Petri net and applying price time Petri net to business process management

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A Time Petri Net Extended with Price Information

A process for expressing extracellular beta -glucosidase in a filamentous fungus by expressing a fungal DNA sequence encoding enhanced, deleted or altered beta -glucosidase in a recombinant host microorganism is disclosed. Recombinant fungal cellulase compositions containing enhanced, deleted or altered expression of beta -glucosidase is also disclosed.

Workflow Management Coalition.

How the internet of things technology enhances emergency response operations

Preface. 1. Introduction. 2. Petri Nets. 3. Deterministic Timed Petri Nets. 4. Time Petri Nets. 5. Stochastic Timed Petri Nets and Stochastic Petri Nets. 6. Generalized Stochastic Petri Nets. 7. High-Level Stochastic Petri Nets. 8.Semi-Markovian Stochastic Petri Nets. 9. Arbitrary Stochastic Petri Nets. Bibliography. Index.

Timed Petri Nets: Theory and Application

Time Petri nets (TPNs) are a popular Petri net model for specification and verification of real-time systems. A fundamental and most widely applied method for analyzing Petri nets is reachability analysis. The existing technique for reachability analysis of TPNs, however, is not suitable for timing property verification because one cannot derive end-to-end delay in task execution, an important issue for time-critical systems, from the reachability tree constructed using the technique. In this paper, we present a new reachability based analysis technique for TPNs for timing property analysis and verification that effectively addresses the problem. Our technique is based on a concept called clock-stamped state class (CS-class). With the reachability tree generated based on CS-classes, we can directly compute the end-to-end time delay in task execution. Moreover, a CS-class can be uniquely mapped to a traditional state class based on which the conventional reachability tree is constructed. Therefore, our CS-class-based analysis technique is more general than the existing technique. We show how to apply this technique to timing property verification of the TPN model of a command and control (C2) system.

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Reachability analysis of real-time systems using time Petri nets

Hand gestures are a natural way for human-robot interaction. Vision based dynamic hand gesture recognition has become a hot research topic due to its various applications. This paper presents a novel deep learning network for hand gesture recognition. The network integrates several well-proved modules together to learn both short-term and long-term features from video inputs and meanwhile avoid intensive computation. To learn short-term features, each video input is segmented into a fixed number of frame groups. A frame is randomly selected from each group and represented as an RGB image as well as an optical flow snapshot. These two entities are fused and fed into a convolutional neural network &#x0028 ConvNet &#x0029 for feature extraction. The ConvNets for all groups share parameters. To learn long-term features, outputs from all ConvNets are fed into a long short-term memory &#x0028 LSTM &#x0029 network, by which a final classification result is predicted. The new model has been tested with two popular hand gesture datasets, namely the Jester dataset and Nvidia dataset. Comparing with other models, our model produced very competitive results. The robustness of the new model has also been proved with an augmented dataset with enhanced diversity of hand gestures.

Dynamic hand gesture recognition based on short-term sampling neural networks

Petri Nets for Dynamic Event-Driven System Modeling

Security system architecture governs the composition of components in security systems and interactions between them. It plays a central role in the design of software security systems that ensure secure access to distributed resources in networked environment. In particular, the composition of the systems must consistently assure security policies that it is supposed to enforce. However, there is currently no rigorous and systematic way to predict and assure such critical properties in security system design. A systematic approach is introduced to address the problem. We present a methodology for modeling security system architecture and for verifying whether required security constraints are assured by the composition of the components. We introduce the concept of security constraint patterns, which formally specify the generic form of security policies that all implementations of the system architecture must enforce. The analysis of the architecture is driven by the propagation of the global security constraints onto the components in an incremental process. We show that our methodology is both flexible and scalable. It is argued that such a methodology not only ensures the integrity of critical early design decisions, but also provides a framework to guide correct implementations of the design. We demonstrate the methodology through a case study in which we model and analyze the architecture of the Resource Access Decision (RAD) Facility, an OMG standard for application-level authorization service.

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Jiacun Wang

Papers

Timed Petri Nets: Theory and Application

Reachability analysis of real-time systems using time Petri nets

Dynamic hand gesture recognition based on short-term sampling neural networks

Petri Nets for Dynamic Event-Driven System Modeling

An approach for modeling and analysis of security system architectures