1,103 research outputs found
Automating the transformation-based analysis of visual languages
The final publication is available at Springer via http://dx.doi.org/10.1007/s00165-009-0114-yWe present a novel approach for the automatic generation of model-to-model transformations given a description of the operational semantics of the source language in the form of graph transformation rules. The approach is geared to the generation of transformations from Domain-Specific Visual Languages (DSVLs) into semantic domains with an explicit notion of transition, like for example Petri nets. The generated transformation is expressed in the form of operational triple graph grammar rules that transform the static information (initial model) and the dynamics (source rules and their execution control structure). We illustrate these techniques with a DSVL in the domain of production systems, for which we generate a transformation into Petri nets. We also tackle the description of timing aspects in graph transformation rules, and its analysis through their automatic translation into Time Petri netsWork sponsored by the Spanish Ministry of Science and Innovation, project METEORIC (TIN2008-02081/TIN) and by the Canadian Natural Sciences and Engineering Research Council (NSERC)
Reliability models for dataflow computer systems
The demands for concurrent operation within a computer system and the representation of parallelism in programming languages have yielded a new form of program representation known as data flow (DENN 74, DENN 75, TREL 82a). A new model based on data flow principles for parallel computations and parallel computer systems is presented. Necessary conditions for liveness and deadlock freeness in data flow graphs are derived. The data flow graph is used as a model to represent asynchronous concurrent computer architectures including data flow computers
Utilizing semantic networks to database and retrieve generalized stochastic colored Petri nets
Previous work has introduced the Planning Coordinator (PCOORD), a coordinator functioning within the hierarchy of the Intelligent Machine Mode. Within the structure of the Planning Coordinator resides the Primitive Structure Database (PSDB) functioning to provide the primitive structures utilized by the Planning Coordinator in the establishing of error recovery or on-line path plans. This report further explores the Primitive Structure Database and establishes the potential of utilizing semantic networks as a means of efficiently storing and retrieving the Generalized Stochastic Colored Petri Nets from which the error recovery plans are derived
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Modeling and analysis of concurrent systems
A survey of modeling and analysis techniques in common use for modeling and analyzing concurrent systems. The models surveyed are CSP (Communicating Sequential Processes), Path Expressions, CCS (Calculus of Communicating Systems), CIRCAL, Petri Nets, Coloured Petri Nets, Predicate-Action Nets, Numerical Petri Nets, Contour-Transition Nets, and several varieties of Timed Petri Nets. The analysis techniques are state-space analysis, temporal logic, structural analysis, and inductive analysis
A Framework for Formal Verification of DRAM Controllers
The large number of recent JEDEC DRAM standard releases and their increasing
feature set makes it difficult for designers to rapidly upgrade the memory
controller IPs to each new standard. Especially the hardware verification is
challenging due to the higher protocol complexity of standards like DDR5,
LPDDR5 or HBM3 in comparison with their predecessors. With traditional
simulation-based verification it is laborious to guarantee the coverage of all
possible states, especially for control flow rich memory controllers. This has
a direct impact on the time-to-market. A promising alternative is formal
verification because it allows to ensure protocol compliance based on
mathematical proofs. However, with regard to memory controllers no
fully-automated verification process has been presented in the state-of-the-art
yet, which means there is still a potential risk of human error. In this paper
we present a framework that automatically generates SystemVerilog Assertions
for a DRAM protocol. In addition, we show how the framework can be used
efficiently for different tasks of memory controller development.Comment: ACM/IEEE International Symposium on Memory Systems (MEMSYS 2022
COSMIC: A Model for Multiprocessor Performance Analysis
COSMIC, the Combined Ordering Scheme Model with Isolated Components, describes the execution of specific algorithms on multiprocessors and facilitates analysis of their performance. Building upon previous modeling efforts such as Petri nets, COSMIC structures the modeling of a system along several issues including computational and overhead costs due to sequencing of operations, synchronization between operations, and contention for limited resources. This structuring allows us to isolate the performance impact associated with each issue. Finally, studying the performance of a system while executing a specific algorithm gives insight into its performance under realistic operating conditions. The model also allows us to study realistically sized algorithms with ease, especially when they are regularly structured. During the analysis of a system modeled by COSMIC, a set timed Petri nets is produced. These Petri nets are then analyzed to determine measures of the systems performance. To facilitate the specification, manipulation, and analysis of large timed Petri nets, a set of tools has been developed. These tools take advantage of several special properties of the timed Petri nets that greatly reduce the computational resources required to calculate the required measures. From this analysis, performance measures show not only total performance, but also present a breakdown of these results into several specific categories
Performance evaluation and sequence control of an automatedmanufacturing system
In an automated sequential manufacturing system Programmable Logic Controllers (PLC) are widely used. As the control specification varies, the control software needs to be rewritten to accommodate the new specification. Since PLC has high flexibility, one can update the current system while it is running thereby making easier implementation. In order to design flexible, reusable and maintainable control software, a good modeling tool is required. Petri nets are such a tool. Which facilitates analysis of behavioral properties, performance evaluation, and systematic construction of discrete event simulators and controllers. In this thesis a system with one robot and five sequential work stations is used as an example of an automated system. To illustrate the Petri net method, performance and other properties of this system are evaluated. The PLC program is also developed for sequence control of the system
Representing Conversations for Scalable Overhearing
Open distributed multi-agent systems are gaining interest in the academic
community and in industry. In such open settings, agents are often coordinated
using standardized agent conversation protocols. The representation of such
protocols (for analysis, validation, monitoring, etc) is an important aspect of
multi-agent applications. Recently, Petri nets have been shown to be an
interesting approach to such representation, and radically different approaches
using Petri nets have been proposed. However, their relative strengths and
weaknesses have not been examined. Moreover, their scalability and suitability
for different tasks have not been addressed. This paper addresses both these
challenges. First, we analyze existing Petri net representations in terms of
their scalability and appropriateness for overhearing, an important task in
monitoring open multi-agent systems. Then, building on the insights gained, we
introduce a novel representation using Colored Petri nets that explicitly
represent legal joint conversation states and messages. This representation
approach offers significant improvements in scalability and is particularly
suitable for overhearing. Furthermore, we show that this new representation
offers a comprehensive coverage of all conversation features of FIPA
conversation standards. We also present a procedure for transforming AUML
conversation protocol diagrams (a standard human-readable representation), to
our Colored Petri net representation
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