Basic Petri Nets Research Articles

A Practical Exploration of the Integration of Civics into Student Education and Management in Colleges and Universities Empowered by Information Integration Technology in the Context of Three-Whole Parenting

Abstract Internet information technology has brought challenges to the integration of college and university Civics in student education and management work, and at the same time, it also provides an opportunity for the integration of information technology. In this paper, on the basis of two kinds of nodes of basic Petri nets, the library and change, we constructed the workflow of identification Petri nets oriented to the education and management of students in the Civic Government of colleges and universities. The workflow engine is designed as the center of gravity of the reference model, consisting of six basic elements of student management. In the information fusion workflow, a multi-source information fusion method based on CNN and LSTM is proposed to further integrate Civics into student education management. The response time of the student management action flow is shorter than the retrieval time based on the original mechanism, and the average response time is reduced by 57.4 ms when the workflow reaches 5000. The fusion of Civic Politics and education management in the context of three-whole-parenting optimizes the management work method.

A self-navigating robot using Fuzzy Petri nets

Petri nets (PNs) are capable of modeling nearly any conceivable system and can provide a better understanding of the idealized action sequence in which to most effectively describe or execute said system through their powerful analytical capabilities. However, because real world instances are rarely as consistent and ideal as simulated models, basic PN modeling and simulation properties may be insufficient in practical application. We remedy this through specialization in Fuzzy Petri nets (FPNs). Fuzzy logic is incorporated to better model a self-navigating robot algorithm, thanks to its versatile multi-valued logic reasoning. By using FPNs, it is possible to simulate, assess, and communicate the process and reasoning of the navigational algorithm and apply it to real world programming. In this paper, we propose a series of specific fuzzy algorithms intended to be implemented in concert on a mobile robot platform in order to optimize the sequence of actions needed for a given task, primarily the navigation of an unknown maze. A set of varied maze configurations were developed and simulated as PN and FPN models, providing a testing environment to examine the efficiency of several methodologies. Five methods, including an original proposal in this paper, were compared across 30,000 simulations, evaluating in particular performance in processing cost in time. Our experiments concluded with results suggesting a very competitive task completion time at a considerable fraction in processing cost compared to the closest performing alternatives.

CTL Model Repair for Bounded and Deadlock Free Petri Nets

Abstract: In dependable system design, formal techniques such as model checking are useful to perform property analysis of system models. Computation tree logic (CTL) model repair is an approach that complements model checking for obtaining new admissible models that can represent the correct behaviour of systems. In this paper a CTL model repair method for bounded and deadlock free Petri nets (PN) is presented. First, CTL semantics is defined for dealing with PN and a set of basic PN structure transformation operations are introduced. Then an algorithm to repair PN models for fulfilling CTL formulae is presented. The method is illustrated through an example regarding a system which must hold a safety property.

Extended knowledge attributed Petri Nets

Choosing the best way for describing physical reality has always been standing in focus of research. Several methodologies have been developed based on classical mathematics, or statistics and also new disciplines — such as soft-computing techniques — appeared. Petri Nets as one of the most naturalistic modeling methodologies are well suited to describe complex process in general. However in some fields of modeling the describing power of basic Petri Nets proved not to be robust enough, therefore several extensions were made to the original concept. Colored tokens (Colored Petri Nets), stochastic delayed streaming of mobile entities (Stochastic Petri Nets), object oriented architecture (Object Oriented Petri Nets), numerical (Numerical Petri Nets) and linguistic attributes (Fuzzy Petri Nets) broaden the range of capabilities. In some fields of problem solving, usage of static and mobile knowledge bases is needed: e.g., flexible manufacturing systems, or intelligent traffic simulation. These problems to be investigated involved new conceptual developments of Petri Nets and led to the introduction of Knowledge Attributed Petri Nets. At the same time distributed control in simulation appeared, intelligent agents supported the connection of mobile knowledge bases and static inference engines in an effective way. The mentioned extensions brought general support in model synthesis, but some unsolved questions remained related to the implementation of intelligent mobile entities. This paper highlights a new level of AI controlled simulation introducing the Extended Knowledge Attributed Petri Nets that offer the capability of easy implementation of mobile inference engines and knowledge base, providing general mobile AI in Petri Nets.

An Extended Stochastic Petri Nets Modeling Method for Collaborative Workflow Process

Workflow process modeling is important for BPR; some classic process modeling methods have many defects, such as weakness description ability, high modeling complex, and so on. In this paper, we explore an extended stochastic Petri Nets modeling method based on basic Petri Nets. This method can model concurrency collaborative workflow process under stochastic environment.

Modeling and Distributed Implementation of Synchronization and Coordination in Multi-Robot Systems

This paper deals with control system design and implementation problems encountered in multiple robot systems. A systematic method of constructing hierarchical net models is described for their direct implementation such that the net is translated into the detailed net by stepwise refinements from the highest task specification level to the lowest machine control level. Basic Petri nets are extended as a prototyping tool for expressing real-time control of robotic systems based on command response concept. The hierarchical and distributed coordinators are introduced to perform the synchronization and coordination of the robots and other machines in the system. The proposed method allows a direct coding of the inter-task cooperation from the net specification and can be implemented using off–the-shelf real-time executives.

실시간 임베디드 시스템 상황 정보 서비스를 위한 확장된 Petri-Net 모델링

컴퓨터 환경에서 한 가지 사건으로 상황이 특징 지워지기도 하지만, 일반적 상황 인식은 공간과 시간을 포함하는 다양한 사건들에 의해서 결정되어 진다. 상황 인식 서비스 관계 설정 방법으로 임베디드 시스템 상황 인식을 시공간적으로 취급하는 것이 요구된다. 물리 공간과 연동되는 시스템의 예외적 동작은 임베디드 시스템의 운영에 심각한 위험과 피해를 초래 할 수 있다. 본 논문은 상황 인식 모델에 시공간적 특성과 예외 관리가 포함 되도록 하는 방법을 제안하고, 이를 확장된 Petri-Net을 이용하여 효과를 확인한다. 실시간 임베디드 시스템 상황 인식을 위해 기본 Petri-Net, 패턴화된 Petri-Net 및 예외 동작을 위한 시공간 Petri-Net 모델 특성을 연구한다. 이 방법을 이용하여 응급의료지원 서비스에 적용 예를 보였다. 본 연구를 통해 시공간 Petri-Net을 사용한 응용 개발 뿐 만아니라 예외 처리를 위한 시공간 상황 인식 모델링에 기여 할 것이다. Some context is characterized by a single event in computing environment, but many other contexts are determined by a lot of things which occur with a space and a time. The Realtime Embedded System context-awareness service that interacts with the physical space can have property such as time. The exceptional behaviors of the system that interact with physical space can result in critical damage and cause danger to the operation of an embedded system. we propose an approach which should include spatio-temporal property and exceptional management in the context model, and verify its effectiveness using an expanded Petri-Net. The context-awareness service modeling of an embedded system is discussed the properties of model such as basic Petri-Net, patterned Petri-Net, or Spatio-temporal Petri-Net for the exceptional behaviors of the system. The proposed methodology demonstrated using an example that is emergency medical service. The use of expanded Petri-Net will contribute not only to develop the application but also to model the spatio-temporal context awareness for the exceptional handling.

Design of Service-Oriented Systems Using SODA

We propose a design methodology, Service-Oriented Design with Aspects (SODA), for service-oriented systems to address the need to continually upgrade and evolve services while maintaining various versions. Our approach treats aspects as first-class design elements and consistently applies the concept of aspect to all phases of design and evaluation. At the early design stages, crosscutting concerns are first separated out as aspects, and then, services are composed by weaving the different design elements together. The behavior of aspects and services is represented as basic Petri Nets and we present rules for weaving together Petri Nets so as to obtain behavior of the integrated system (with aspects crosscutting services). Even at the evaluation stages, performance and resource data are separated out as aspects to be woven in to the design so as to enable advanced analysis using Petri Net tools. A small order service example is used to illustrate our approach.

Mapping UML 2.0 Activities to Zero-Safe Nets

UML 2.0 activity diagrams (ADs) are largely used as a modeling language for flow-oriented behaviors in software and business processes. Unfortunately, their place/transition operational semantics is unable to capture and preserve semantics of the newly defined high-level activities constructs such as Interruptible Activity Region. Particularly, basic Petri nets do not preserve the non-locality semantics and reactivity concept of ADs. This is mainly due to the absence of global synchronization mechanisms in basic Petri nets. Zero-safe nets are a high-level variant of Petri nets that ensure transitions global coordination thanks to a new kind of places, called zero places. Indeed, zero-safe nets naturally address Interruptible Activity Region that needs a special semantics, forcing the control flow by external events and defining a certain priority level of executions. Therefore, zero-safe nets are adopted in this work as semantic framework for UML 2.0 activity diagrams.

A systematic approach for supply chain conflict detection with a hierarchical Petri Net extension

Coordinating and managing distributed entities in a supply chain is a challenging task due, in part, to conflicts present in such systems. If not handled effectively, the conflict can degrade the performance of the system as a whole due to the fact that each individual entity may be working towards goals that sub-optimize the integrated system. Therefore, the ability to discover conflicts would be a valuable asset, particularly if the discovery occurred proactively. This paper presents a methodology, extending the concept of basic Petri Nets, to discover supply chain conflict before they occur and cause detrimental effects to system performance. The approach involves linking hierarchical levels of the supply chain system and detecting conflicts occurring when the single entities, each optimized for it own operations, are combined together in a supply chain. These conflicts are not obvious or intuitive in examining the single entities of the supply chain, but when integrated the conflicts are discovered by the methodology. We applied the proposed methodology on a real-world supply chain to illustrate the validity of the tool. Although, further research is needed to fully explore this method of conflict detection, we believe that this research does indeed provide some much needed insight into the daunting task of conflict discovery and therefore proactive handling of these potentially negative occurrences in the supply chain.

Developing AGVS Petri net control models from flowpath nets

The paper presents a control-based Petri net (PN) modeling method that translates a high-level automated guided vehicle system (AGVS) flowpath net model into a low-level on/off control model systematically. The relation between a high-level AGVS flowpath net model and the equivalent low-level control net model is uniquely defined by introducing certain I/O control functions and station control macros into the net model. To ensure the uniqueness of the translation, the AGVS flowpath layout is first decomposed into constituent basic PN flowpath modules. By employing a modular concept, the wiring layout of each basic flowpath module is established. Proper I/O control functions and station control macros are introduced and incorporated into basic flowpath net modules to generate basic control net modules. The union of constituent basic control net modules systematically leads to a complete AGVS control PN model. A laboratory AGVS is used to verify the effectiveness of the proposed modeling method. The results indicate that the proposed method is capable of generating a control model directly from a given flowpath layout. Many by-products are generated by the method: wiring layout, minimum size and specification of the controller, scanning time of the control program, and so on. These features allow a designer to quickly conduct cost estimation and performance evaluation on any given flowpath layout.

Specification and analysis of parallel/distributed software and systems by Petri nets with transition enabling functions

An approach for visually specifying parallel/distributed software using Petri nets (PNs) extend with transition enabling functions (TEFs) is investigated. The approach is demonstrated to be useful in the specification of decision-making activities that control distributed computing systems. PNs are employed because of their highly visual nature that can give insight into the nature of the controller of such a system and because of their analytical properties. In order to increase the expressive power of PNs, the extension of TEFs is used. The main focus is the specification and analysis of parallel/distributed software and systems. A key element of this approach is a set of rules derived to automatically transform such an extended net into a basic PN. Once the rules have been applied to transform the specification, analytical methods can be used to investigate characteristic properties of the system and validate correct operation. >

Probabilistic delay evaluation in combinational digital circuits by petri nets

The present work considers the possibility of using Petri Nets (PN) as a systematic model to analyze delays in digital circuits. It has been found that PN's exhibit some interesting features in representing digital circuits at gate, element, unit or system level, whichever is needed. Furthermore, the logic verification can be achieved as a special case of the design verification because of the direct implementation of the thruth table of the circuit in the PN. In particular, a set of basic PN functions and a method of converting the circuit into the final PN, composed of the basic functions, are proposed. Moreover, an algorithm has been developed for the analysis of combinational circuits including also reconvergent fanouts and some examples are reported in the text. The algorithm may be employed to obtain the pdf of the overall circuit delay and to detect static hazards as well. The complexity of the model is directly related to that of the physical circuit to be analyzed, while the complexity of simulation does not increase with the timing precision required.