Modeling behavioral design patterns of concurrent objects

ABSTRACT Object-oriented software development practices are being rapidly adopted within increasingly complex systems, including reactive, real-time and concurrent system applications. While data modeling is performed very well under current objectoriented development practices, behavioral modeling necessary to capture critical information in real-time, reactive, and concurrent systems is often lacking. Addressing this deficiency, we offer an approach for modeling and analyzing concurrent object-oriented software designs through the use of behavioral design patterns, allowing us to map stereotyped UML objects to colored Petri net (CPN) representations in the form of reusable templates. The resulting CPNs are then used to model and analyze behavioral properties of the software architecture, applying the results of the analysis to the original software design

Formal and efficient verification techniques for Real-Time UML models

The real-time UML profile TURTLE has a formal semantics expressed by translation into a timed process algebra: RT-LOTOS. RTL, the formal verification tool developed for RT-LOTOS, was first used to check TURTLE models against design errors. This paper opens new avenues for TURTLE model verification. It shows how recent work on translating RT-LOTOS specifications into Time Petri net model may be applied to TURTLE. RT-LOTOS to TPN translation patterns are presented. Their formal proof is the subject of another paper. These patterns have been implemented in a RT-LOTOS to TPN translator which has been interfaced with TINA, a Time Petri Net Analyzer which implements several reachability analysis procedures depending on the class of property to be verified. The paper illustrates the benefits of the TURTLE->RT-LOTOS->TPN transformation chain on an avionic case study

A structured approach for the engineering of biochemical network models, illustrated for signalling pathways

http://dx.doi.org/10.1093/bib/bbn026Quantitative models of biochemical networks (signal transduction cascades, metabolic pathways, gene regulatory circuits) are a central component of modern systems biology. Building and managing these complex models is a major challenge that can benefit from the application of formal methods adopted from theoretical computing science. Here we provide a general introduction to the field of formal modelling, which emphasizes the intuitive biochemical basis of the modelling process, but is also accessible for an audience with a background in computing science and/or model engineering. We show how signal transduction cascades can be modelled in a modular fashion, using both a qualitative approach { Qualitative Petri nets, and quantitative approaches { Continuous Petri Nets and Ordinary Differential Equations. We review the major elementary building blocks of a cellular signalling model, discuss which critical design decisions have to be made during model building, and present ..

Modelling Requirements for Content Recommendation Systems

This paper addresses the modelling of requirements for a content Recommendation System (RS) for Online Social Networks (OSNs). On OSNs, a user switches roles constantly between content generator and content receiver. The goals and softgoals are different when the user is generating a post, as opposed as replying to a post. In other words, the user is generating instances of different entities, depending on the role she has: a generator generates instances of a "post", while the receiver generates instances of a "reply". Therefore, we believe that when addressing Requirements Engineering (RE) for RS, it is necessary to distinguish these roles clearly. We aim to model an essential dynamic on OSN, namely that when a user creates (posts) content, other users can ignore that content, or themselves start generating new content in reply, or react to the initial posting. This dynamic is key to designing OSNs, because it influences how active users are, and how attractive the OSN is for existing, and to new users. We apply a well-known Goal Oriented RE (GORE) technique, namely i-star, and show that this language fails to capture this dynamic, and thus cannot be used alone to model the problem domain. Hence, in order to represent this dynamic, its relationships to other OSNs' requirements, and to capture all relevant information, we suggest using another modelling language, namely Petri Nets, on top of i-star for the modelling of the problem domain. We use Petri Nets because it is a tool that is used to simulate the dynamic and concurrent activities of a system and can be used by both practitioners and theoreticians.Comment: 28 pages, 7 figure

A technique for detecting wait-notify deadlocks in Java

Deadlock analysis of object-oriented programs that dynamically create threads and objects is complex, because these programs may have an infinite number of states. In this thesis, I analyze the correctness of wait - notify patterns (e.g. deadlock freedom) by using a newly introduced technique that consists in an analysis model that is a basic concurrent language with a formal semantic. I detect deadlocks by associating a Petri Net graph to each process of the input program. This model allows to check if a deadlock occur by analysing the reachability tree. The technique presented is a basic step of a more complex and complete project, since in my work I only consider programs with one object

Deterministic Petri net languages as business process specification language.

Today, a wide variety of techniques have been proposed to model the process aspects of business processes. The problem, however, is that many of these are focused on providing a clear graphical representation of the models and give almost no support for complex verification procedures. Alternatively, the use of Petri Nets as a business process modeling language has been repeatedly proposed. In complex business processes the use of Petri Nets has been criticized and the technique is believed to be unable to capture such processes in all aspects. Therefore, in this paper, we introduce the application of Petri Net language theory for business process specification. Petri Net languages are an extension to the Petri Net theory, and they provide a set of techniques to describe complex business processes more efficiently. More specifically, we advocate the application of deterministic Petri Net languages to model the control flow aspects of business processes. The balance between modeling power and analysis possibilities makes deterministic Petri Nets a highly efficient technique, used in a wide range of domains. The proof of their usability, as business process specification language, is given by providing suitable solutions to model the basic and more complex business process patterns [4]. Additionally, some points of particular interest are concisely discussed.Business; Business process modeling; Control; Model; Models; Patterns; Petri Net theory; Power; Process modeling; Processes; Representation; Theory; Verification;