Petri Net Graph Research Articles

Kyrtos: A methodology for automatic deep analysis of graphic charts with curves in technical documents

Deep Understanding of Technical Documents (DUTD) has become a very attractive field with great potential due to large amounts of accumulated documents and the valuable knowledge contained in them. In addition, the holistic understanding of technical documents depends on the accurate analysis of its particular modalities, such as graphics, tables, diagrams, text, etc. and their associations. In this paper, we introduce the Kyrtos methodology for the automatic recognition and analysis of charts with curves in graphics images of technical documents. The recognition processing part adopts a clustering based approach to recognize middle-points that delimit the line-segments that construct the illustrated curves. The analysis processing part parses the extracted line-segments of curves to capture behavioral features such as direction, trend and etc. These associations assist the conversion of recognized segments’ relations into attributed graphs, for the preservation of the curves’ structural characteristics. The graph relations are also are expressed into natural language (NL) text sentences, enriching the document’s text and facilitating their conversion into Stochastic Petri-net (SPN) graphs, which depict the internal functionality represented in the chart image. Extensive evaluation results demonstrate the accuracy of Kyrtos’ recognition and analysis methods by measuring the structural similarity between input chart curves and the approximations generated by Kyrtos for charts with multiple functions.

Pinakas: A Methodology for Deep Analysis of Tables in Technical Documents

The holistic understanding of the information contained in technical documents depends on the understanding of the document’s individual modalities. These modalities are tables, graphics, diagrams, formulas, etc. and each of them is a standalone research topic that requires a different way of processing and understanding. These modalities, processed and combined with the document text, can introduce new techniques for visual question answering in documents. Thus, in this paper we present Pinakas, a methodology for automatic analysis of the internal tabular information that appears in technical documents and its modeling to stochastic Petri-net graphs. We focus only on tables that strictly abide by the IEEE format rules. The methodology presented here is divided into the following steps: (1) table detection, (2) table recognition, (3) table understanding. Qualitative results of Pinakas are demonstrated as proof of concept for the accurate extraction of information from three different types of tables.

Development, research of a model and an algorithm for organizing data transfer in a monitoring device

The article examines the use of the graph theory method, in particular, the Petri net graph, for the development of microprocessor devices for remote continuous monitoring of the state of railway automation control equipment using Internet of Things technologies. Based on it, the model of the behavior of a set of modules that determines the state of automatic blocking signal point devices was studied.

Robust Diagnosability Analysis Using Basis Reachability Graph

Fault-freeness is one of the necessary guarantees for healthy and stable operations of discrete event systems. Traditional diagnostic models may fail since sensors may suffer electronic component failures, communication failures, or atmospheric electromagnetic interference. Robust diagnosis problem has attracted more and more attention since it improves reliability of the diagnosis technology. When generating the Petri net reachability graph necessary for constructing a reachability diagnoser, one may face the state explosion problem. As a Petri net gets more complicated, the complexity of its reachability graph also increases exponentially. With the basis reachability graph, a lightweight diagnoser named a basis reachability diagnoser is developed, together with a robust basis reachability diagnoser obtained by dilating the basis reachability graph. Compared with reachability graphs, the advantages of basis reachability graphs in construction complexity are confirmed and the efficiency in robust diagnosability analysis is improved.

From strong to exact Petri net computers

Petri net paradigm of computing is concerned discussing basic types of Petri net computers and their relations. We developed a technique of parametric specification of Petri nets, built of a few connected components which are repeated depending on a parameter or a set of parameters, and composition of software to generate automatically the corresponding models in a vivid graphical form. We construct explicitly a Petri net that is a strong computer of double exponent after R.J. Lipton. Its nondeterministic computation is represented by a Petri net reachability graph to which a successful branch belongs. Then we minimise and transform the net to obtain twice smaller construct than the original one. Moreover, the obtained net possesses such a marvellous property that addingto it four priority arcs makes it an exact (deterministic) computer having a single firable sequence only. Same as the Lipton’s net, the minimized net allows the proof that the Petri net reachability problem is exponential in space. Besides, it represents an example when simple transformations allow guessing the successful branch of a nondeterministic computation. The practical significance of the approach in applications consists in a state-of-art heuristic technique of solving some NP problems in polynomial time.

Deep Understanding of Technical Documents: An Enhancement on Diagrams Understanding

Humans are capable of understanding the knowledge that is included in technical documents automatically by consciously combining the information that is presented in the document’s individual modalities. These modalities are mathematical formulas, charts, tables, diagram images and etc. In this paper, we significantly enhance a previously presented technical document understanding methodology3 that emulates the way that humans also perceive information. More specifically, we make the original diagram understanding methodology adaptive to larger architectures with more complex structures and modules. The overall understanding methodology results in the generation of a Stochastic Petri-net (SPN) graph that describes the system’s functionality. Finally, we conclude with the introduction of the hierarchical association of different diagram images from the same technical document. This processing step aims to provide a holistic understanding of all illustrated diagram information.

BEHAVIORAL HIDDENTESTING OF DISTRIBUTED INFORMATION SYSTEMSTAKING INTO ACCOUNTOF ENERGY

The introduction of new energy-consuming properties for positions and transitions into the checked properties of the extended reference Petri net, for which the deviations of the tested Petri net are determined and a testing model is developed, provides new diagnostic possibilities. Keeping the class of checked properties in the composition of deviations of incidence relations, correspondences and marking functions of positions and transitions for the checked and reference Petri nets, the new properties make it possible to record the appearance of critical temperature regimes that are a consequence of errors or directly leading to their appearance. Thisversatility of testing helps to increase its completeness, accuracy and efficiency. The energy-heavy testing model is based on verification of incidence, correspondence, and markup functions. Checking the markup functions when generating events in positions, performing actions in transitions, as well as the proposed checking of the energy consumption indicators accumulated in the monitor tokens, is performed when checking the incidence, correspondences. The features of the testingmodel include the input of generalized energy-loaded Petri nets recorders, accumulating information about energy consumption in the behavior of positions/transitions, topological componentsand subnets, the entire Petri net in the process of its functioning. The testingmodel is also distinguished by the recognition of the reference energy-loaded behavior when checking the Petri net based on behavioral identification and coincidenceof subsets of positions/transitions, the determination of behavior, the use of checkprimitives and transactions. The behavioral testingmodel defines the formal conditions for behavioral testingprocedures, including the analysis of the correctness of energy consumption. The dimensionality of the testingmodel was estimated using the representation of Petri net graphs, special graphs of attainable states, including Rabin-Scott automata, using list structures. These estimates define the limits of applicability of the formal testingmodel.

Model of Process Synchronization in Through Analysis

Synchronization of parallel processes of distributed information systems (DIS) has been largely determined by decisions taken at the stages of their design. Having already been in structural and functional models, when determining cause- and-effect relationships for events and actions in DIS components, it becomes necessary to coordinate them. In the proposed multilevel systemic, structural and functional synchronization model, a hierarchy of such causal relationships with interlevel mappings, inheritance and encapsulation of events and actions have been formed. The model has been also based on hierarchical extended Petri nets, which make it possible to represent various aspects of a special analysis of technical diagnostics, in particular, analysis of correctness, verification, testing, for the adopted display of the asynchronous-behavioral nature of the multilevel interaction of DIS processes. Features of the synchronization model include mapping operations for cross- level inheritance and encapsulations that synchronize events and actions, as well as end-to-end synchronized quasi-order relationships and compatibility for them. The synchronization model is also distinguished by the possibility of specializing its objects, operations and relations for the tasks of check and recognition of behavioral properties set for analysis and verification, basic in technical diagnostics, including in online and offline testing. The synchronization model has allowed one to determine the formal conditions for methods of end-to-end asynchronous coordination of events and actions of multi-level models, that represent design solutions for DIS, in particular, for technical diagnostics methods, and also to reduce the computational complexity of a special synchronization analysis due to an end-to-end decomposition approach. The dimension of the synchronization model has been estimated using the representation of Petri net graphs and special graphs of reachable states using list structures. The above estimates determine the limits of applicability of the formal synchronization model.

Development of a New Strategy to Extract Dangerous Scenarios from Petrochemical Industry Installation

The use of Petri net reachability graph remains one of the most popular methods to extract critical scenarios that lead the system to a dangerous state. However, in complex systems, explosion states space and confusion between causality and precedence relationship between events are the two major limits making reachability graph inefficient to perform such analysis. In the last decade, the first limitation was tackled by an approach that uses the Petri net structure. It considers only the last normal state and ignores the rest of the network. Nevertheless, no research work appears in the literature, to consider the second limitation. In this sense, this paper proposes a novel approach based on Petri net and linear logic, to overcome the two limits. To prove the effectiveness of this proposal, the approach was applied on a petrochemical installation consisting of a cooling flammable fluids storage bins system. The obtained results are compared with the two existing approaches, the first using reachability graph and the second using the Petri net structure. The new proposed approach has shown higher performances compared to the previously mentioned methods.

Improving Business Process Efficiency for Supply Chain Finance: Empirical Analysis and Optimization Based on Stochastic Petri Net

Efficient business process is important to the operations of supply chain finance (SCF). Many deficiencies exist in the processes of SCF such as complicated workflows and high time-consuming steps. However, few studies have paid attention to evaluate and improve the performance of SCF processes. We empirically model and investigate the processes of supply chain finance by constructing a Stochastic Petri Net based on the field survey of a focal firm. Two critical indices, place busy rate and transition utilization rate, are evaluated. The results demonstrate that some places (transitions) of the Petri Net have high busy rates (utilization rates). By integrating the Petri Net and dependency graph, several key places and transitions in the Petri Net of SCF processes are identified for further optimization. To improve the performance of SCF processes, we propose three optional adjusting schemes on the basis of information sharing perspective (for the first half of the Petri Net) and risk sharing perspective (for the second half of the Petri Net). The proposed optimization strategies have further been proven to reduce the place busy rates, shorten the process, and improve the process efficiency of the supply chain finance.

Robust Deadlock Control for Automated Manufacturing Systems With Unreliable Resources Based on Petri Net Reachability Graphs

Resource failures may happen in automated manufacturing systems (AMSs) because of different reasons in the real world, making most existing deadlock control policies unapplicable. This paper develops methods for the robust deadlock control of AMSs with unreliable resources based on Petri nets. The considered AMSs are modeled with generalized systems of simple sequential processes with resources (GS3PR). First, a method based on reachability graph partition technique is provided to analyze the robust legal markings and the forbidden ones in an unreliable GS3PR (U-GS3PR), in which resource failures and recovery procedures are modeled with recovery subnets. Then, the control problem for such a system is converted into a problem for controlling the forbidden states in a U-GS3PR and control places can be designed by solving the maximal number of forbidden markings problems. Since the robust legal reachability spaces computed may be nonconvex and such a system cannot be optimally controlled by the conjunctions of linear constraints, we propose an interval-inhibitor-arc-based robust deadlock control policy for a system with nonconvex legal reachability spaces by solving the maximal number of ${t_{q}}$ -critical marking/transition separation instances problems (MNTMPs( ${t_{q}}$ )). Finally, examples are presented to demonstrate the proposed methods.

Security Assessment for Cyber Physical Distribution Power System Under Intrusion Attacks

A cyber physical distribution power system (CPDS) is a large and complex infrastructure that coordinates the cyber communication system and the physical distribution power system. Because of the increasingly advanced information communication technology, the development of cyber physical distribution power system has caused key cyber security issues related to system operation. This paper is focused on realizing a unified system attack modeling and security assessment of an active distribution power system. In this paper, first we present an overview of the system operation from the fusion system perspective. The significant effects of network intrusion attacks on operational security are evaluated. A new unified cyber physical network model is established using a limited stochastic Petri net graph theory that considers refined firewalls and password components. Then, a security effectiveness evaluation method is proposed to analyze channel throughput variation and system robustness. Overall CPDS security risk values are determined based on physical influence coefficients. Finally, simulations of an improved IEEE-33 bus distribution power system and security assessment under intrusion attacks are described. The research work could raise awareness of the cyber intrusion threats and provide the basis for security defense.

Data-driven scheduling optimization under uncertainty using Renyi entropy and skewness criterion

Abstract In order to deal with the resource cost uncertainties, this paper introduces a Renyi mean-entropy-skewness (RMES) information criterion for the scheduling optimization problems in flexible manufacturing systems (FMSs). Motivated by potential limitations in the existing measures, this third-order information criterion is carefully integrated to be more general and more robust in representing the schedule dispersion under uncertainties. The RMES information criterion is estimated using data-driven techniques so that it does not rely on the assumptions of exact probability distributions which are usually unknown in practice. Modeled with Petri net (PN) and system state reachable graph (RG), the RG-based dynamic programming (DP) algorithm and an approximate dynamic programming (ADP) algorithm are presented to solve the proposed model. The effectiveness of the introduced information criterion is verified by both technical proofs and extensive simulation studies of systems with a wide range of scales and data types. A real stamping industrial case study is also conducted as a justification of the model’s practical applicability.

Using information flow analysis to detect implicit information leaks for web service composition

Information leak, which can undermine the compliance of web-service-composition business processes for some policies, is one of the major concerns in web service composition. We present an automated and effective approach for the detection of implicit information leaks in business process execution language (BPEL) based on information flow analysis. We introduce an adequate meta-model for BPEL representation based on a Petri net for transformation and analysis. Building on the concept of Petri net place-based noninterference, the core contribution of this paper is the application of a Petri net reachability graph to estimate Petri net interference and thereby to detect implicit information leaks in web service composition. In addition, a case study illustrates the application of the approach on a concrete workflow in BPEL notation.

Coexistence Plant Model for an Automated Coexistence Management

For data transmission of industrial applications parallel operations of various wireless communication systems are required in an industrial application environment. For guaranteeing that every application communication requirement of each wireless communication system is fulfilled, those systems have to be coexistent between each other. The process ensuring coexistence is called coexistence management process. In current approaches this holistic management is not considered yet. We want to develop an automated coexistence management with control engineering considerations. In this contribution we propose a basic model approach for a coexistence plant. For describing the structure and the time behaviour of a coexistence plant, Petri-net graphs are used. Therefore we split the state space into two description types. The first one describes the transfer of messages and the second one describes the time behaviour of state transition in the coexistence plant. Finally, the derived model on measurements in a 2:4 GHz frequency spectrum within a WiFi test environment is parametrised and validated.

Petri net siphon analysis and graph theoretic measures for identifying combination therapies in cancer.

Epidermal Growth Factor Receptor (EGFR) signaling to the Ras-MAPK pathway is implicated in the development and progression of cancer and is a major focus of targeted combination therapies. Physiochemical models have been used for identifying and testing the signal-inhibiting potential of targeted therapies, however, their application to larger multi-pathway networks is limited by the availability of experimentally-determined rate and concentration parameters. An alternate strategy for identifying and evaluating drug-targetable nodes is proposed. A physiochemical model of EGFR-Ras-MAPK signaling is implemented and calibrated to experimental data. Essential topological features of the model are converted into a Petri net and nodes that behave as siphons-a structural property of Petri nets-are identified. Siphons represent potential drug-targets since they are unrecoverable if their values fall below a threshold. Centrality measures are then used to prioritize siphons identified as candidate drug-targets. Single and multiple drug-target combinations are identified which correspond to clinically relevant drug targets and exhibit inhibition synergy in physiochemical simulations of EGF-induced EGFR-Ras-MAPK signaling. Taken together, these studies suggest that siphons and centrality analyses are a promising computational strategy to identify and rank drug-targetable nodes in larger networks as they do not require knowledge of the dynamics of the system, but rely solely on topology.

A novel memory management method for multi-core processors

This study examines a multicore processor based on a system-on-chip (SoC) and configured by a Tensilica Xtensa® LX2. The multicore processor is a heterogeneous, configurable dual-core processor. In this study, one core was used as the host to control the processor chip, and the other was used as a slave to extend digital signal processing applications. Each core not only owned its local memory, but also shared common data memory. In addition, the proposed multicore processors had a virtual memory. This additional memory supported the processor by enabling it to easily manage complex programs; it also allowed the two cores to access data from the unified data memory of different tasks. For bus management, a bus arbitration mechanism was added to handle the cores and to distribute the priority of asynchronous access requests. The benefits of the proposed structure include avoiding hardwired memory and reducing interface handshaking. To verify the proposed processor, it was simulated on the model level using a Petri net graph, and on the system level using ARM SoC designer tools. In the performance simulation, we found that the lowest latency-to-cost ratios were achieved using a 32-bit bus interface and a 4-entry data queue.

Control Design for Trajectory Tracking With Untimed Petri Nets

This technical note is about trajectory tracking for discrete event systems. The main contribution is to compute incrementally control sequences with minimal or near-minimal length based on a partial exploration of the Petri net (PN) reachability graph and inspired by the model predictive control approach. The method is suitable for bounded and unbounded PNs, for PNs with weighted arcs and with some uncontrollable transitions. Finally forbidden markings or regions of markings are easily avoided with the proposed approach that can be used for supervisory control issues.

Demos

In today's dynamic network environments like smart cities, information evolves in distributed resources and in different forms or modalities. An agent or a system that wants to be actively part of this evolution has to be interactive, adaptive, autonomous and intelligent. The paper presents a new version of a distributed model-framework (called Demos) based on autonomous, intelligent agents with anticipatory responses. The first version of the system was proposed by , and the new features (LG Graphs, SPNs and NNs) were embedded in the version presented here. The Demos model is mainly based on the development of an adaptive distributed knowledge base system. Knowledge is represented in a form of frames with internal stochastic Petri-net graph for local representations (KR). A major advantage for the Demos model having a distributed (possibly across the net) is the adaptive knowledge base. Here the authors present the design of an adaptive knowledge model and its challenge, which lays principally on how to learn new knowledge by synthesising SPN forms, and how to develop anticipatory responses at an agent's site. The development of the Demos prototype has a great range of applicability, such as in autonomous negotiating teams, autonomous distributed units for energy efficient distribution, autonomous multiple mobile robots space exploration and maps generation, autonomous intelligent information agents (WWW), automatic information synthesis and fusion, etc. Here the authors have used this model for management of the electric power on a grid of a smart city.

A cloud resource management model for the creation and orchestration of social communities

Managing resources, context and data in mobile clouds is a challenging task. Specific aspects of spontaneity, large interaction space and dynamic interaction share a metaphorical resemblance to chemistry, chemical reactions and solutions. In this paper, it is argued that by adopting a nature-inspired chemical computing model, a mobile cloud resource management model can be evolved to serve as the basis for novel service modelling and social computing in mobile clouds. To support the argument, a chemistry inspired computation model, Chemistry for Context Awareness (C2A), is extended with Higher Order Chemical Language (HOCL) and High Level Petri-net Graph (HLPNG) formalisms. A scenario and simulation-based evaluation of the proposed model, focusing on two applications dynamic service composition and social communities identification, is also presented in this paper. The formal encoding of C2A validates its assumptions, enabling formal execution and analysis of context-based interactions that are derived using C2A principles.