Context awareness by unit-type evolutionary Petri net for team medical care support

A set of non-negative integral vectors is said to be right-closed if the presence of a vector in the set implies all term-wise larger vectors also belong to the set. A set of markings is control invariant with respect to a Petri Net (PN) structure if the firing of any uncontrollable transition at any marking in this set results in a new marking that is also in the set. Every right-closed set of markings has a unique supremal control invariant subset, which is the largest subset that is control invariant with respect to the PN structure. This subset is not necessarily right-closed. In this paper, we present an algorithm that computes the supremal right-closed control invariant subset of a right-closed of markings with respect to an arbitrary PN structure. This set plays a critical role in the synthesis of Liveness Enforcing Supervisory Policies (LESPs) for a class of PN structures, and consequently, the proposed algorithm plays a key role in the synthesis of LESPs for this class of PN structures.

This article addresses expressiveness problems for Petri nets and their useful extension for modeling and control of a system that can be modeled with Petri nets. We construct some Petri net modules, namely, an enabling module, an inhibitor module and a Modulo-N counter, which are useful for system operations. We also present the simplifications for the enabling and inhibitor modules. Then, we propose two new types of arcs, namely, enabling and inhibitor arcs, with a weighted function set. The arcs with the weighted function set from places to transitions are the marked arcs. A function set is employed to denote the weight of an arc according to the system requirements. They are very useful to solve the resource reallocation problem in a resource allocation system, where resource sharing contributes to the occurrences of deadlocks. Finally, two examples are used to show the advantages of the presented new types of arcs.

Petri net as a modeling tool

Objective To describe and analyze the status quo of the doctor and nurse configuration in Heilongjiang Province, and to study their cultivation condition while predicting the number of medical staff. Methods Through the health workforce database of Heilongjiang Province in 2014, using Excel 2007 statistical software, the status quo of doctor and nurse configuration was analyzed. The grey prediction model was also used to analyze the number of medical staff in Heilongjiang province from 2004 to 2014, and the number of medical staff in Heilongjiang province from 2016 to 2018 was predicted. Results Up to 2015, the number of doctors and nurses in Heilongjiang Province accounted for 0.42% of the total population, composed of mainly young and middle-aged staff and mostly with bachelor’s degree and junior college cer-tificate. Doctor-to-nurse ratio was 1∶0.96. The grey prediction model indicated that the number of medical staff in Heilongjiang Province would increase year by year, and the inversion of doctor-to-nurse ratio would be eased. Conclusion The reform and development of medical education in Heilongjiang Province has promoted the optimization of the professional title structure and educational structure. It is expected that by 2016 Heilongjiang medical care ratio inversion problem will be completely resolved. Key words: Heilongjiang Province; Doctors and nurses; Configuration; Grey prediction model; Doctor-to-nurse ratio

IntroductionAs Divisional Medical Director from September 2018 to May 2022 and College Tutor for Medicine from September 2018 to December 2021, I had a unique opportunity to collaborate with senior...

This paper presents an approach to modeling aircraft airline maintenance circuit through a particular Petri Nets structures, called Treble transitions Petri Nets. In order to meet the requirements of the simulation of aircraft airline maintenance circuit, several enhancements were proposed. The first of them consider the characteristic of circuit, the places, transitions and arcs of classical Petri Nets are extended. In the Second enhancement, the rules of transitions were modified. Finally, the relating matrix and the state transfer equation are redefined. One case is included illustrating the applicability and efficiency of the proposed modeling method.

The paper addresses the fault detection problem for discrete event systems modeled by Petri nets (PN). Assuming that the PN structure and initial marking are known, faults are modeled by unobservable transitions. The paper recalls a previously proposed diagnoser that works online and employs an algorithm based on the definition and solution of some integer linear programming problems to decide whether the system behavior is normal or exhibits some possible faults. To reduce the on-line computational effort, we prove some results showing that if the unobservable subnet enjoys suitable properties, the algorithm solution may be obtained with low computational complexity. We characterize the properties that the PN modeling the system fault behavior has to fulfill and suitably modify the proposed diagnoser.

In this paper we introduce an approach for defining semantics for AUML agent interaction protocol diagrams using Petri net code structures. This approach is based on the usage of net components which provide basic tasks and the structure for Petri nets. Agent interaction protocol diagrams are used to model agent conversations on an abstract level. By mapping elements of the diagrams to net components we are able to translate the diagrams into Petri nets, i.e to generate code structures from the drawings. We provide tool support for this approach by combining a tool for net components with a tool for drawing agent interaction protocol diagrams. This combined tool is available as a plug-in for Renew (Reference Net Workshop).Keywordsagentsagent interaction protocolsAUML Capa high-level Petri nets Mulan net componentsoperational semanticsreference nets Renew

Petri Nets (PNs) are an effective structure for modeling and analyzing asynchronous systems with concurrent and parallel activities. A Petri net models the static properties of a discrete event system concentrating on two basic concepts: events and conditions. Most of the theoretical work on Petri nets is a formal definition of Petri nets structures, which consist of a set of places, representing conditions, a set of transitions, representing events, an input function and an output function. For practical purposes, a graphical representation is more useful. Two types of nodes portray places and transitions. A circle is a place and a bar is a transition. There is no inherent measure of time in a classical Petri net. To approach time-based evaluation of system performances, Timed Petri Nets (TPNs) were introduced. Modeling the notion of time is not straightforward. There are several possibilities for introducing time in PNs, among them timed transitions and timed places. This paper reviews several published examples where Petri Nets were used in different circumstances such as estimating expected utilization of processing resources at steady state in open queueing networks, verifying computerized simulations and batch planning in textile industry.

Many tools for online collaboration, information and file sharing are currently employed to facilitate the process of online education. However, as stated in [14] the existing E-learning environments are not mature enough and only a small set of them provide functionality for defining reusable learning entities, reliable publishing and republishing mechanisms and possibilities for the teachers to give feedback to or receive feedback from the E-students. In order to improve E-learning experience [14] presents PeU 2.0, a system that enables the graphical representation and editing of the learning workflow without the execution environment of a workflow management system. The present paper examines the current executability of Petri Nets and gives a mapping of the visual elements in the PeU 2.0 graphs onto Petri Net structures. An interesting approach is introduces for the physical execution of the Petri Nets.

A new heuristic search approach for scheduling two classes of flexible manufacturing systems (FMSs) that contains assembly operations is proposed. The FMSs are modeled by two classes of Petri nets, called generalized symmetric and asymmetric nets. In the paper, the problem of minimizing makespan is transformed into searching the reachability graph for the optimal (minimal time) firing sequence from the initial marking (state) to the goal marking. A solution of the state equation constitutes a part of the heuristic function. The dynamic information of the nets, such as concurrency and synchronization, is used to adjust the heuristic function since the solution of the state equation may over-estimate the real cost.

The understanding of the molecular mechanism of cell-to-cell communication is fundamental for system biology. Up to now, the main objectives of bioinformatics have been reconstruction, modeling and analysis of metabolic, regulatory and signaling processes, based on data generated from high-throughput technologies. Cell-to-cell communication or quorum sensing (QS), the use of small molecule signals to coordinate complex patterns of behavior in bacteria, has been the focus of many reports over the past decade. Based on the quorum sensing process of the organism Aliivibrio salmonicida, we aim at developing a functional Petri net, which will allow modeling and simulating cell-to-cell communication processes. Using a new editor-controlled information system called VANESA (http://vanesa.sf.net), we present how to combine different fields of studies such as life-science, database consulting, modeling, visualization and simulation for a semi-automatic reconstruction of the complex signaling quorum sensing network. We show how cell-to-cell communication processes and information-flow within a cell and across cell colonies can be modeled using VANESA and how those models can be simulated with Petri net network structures in a sophisticated way.

Differential responses to market competition by private and public hospitals in China: a longitudinal analysis

Introduction: In the Democratic Republic of Congo, there are two types of pricing for medical care in hospitals: Flat Rate Pricing and Pricing per Act. This study focuses on the evaluation of pricing methods and its impact on accessibility to care in public hospitals. This study specifically aims to determine the pricing method that allows the GRH/Makiso and the GRH/Mangobo to maximize revenue. Methodology: This is a retrospective analytical study, conducted over a period of three years, i.e. from 2019 to 2021, and which concerned the maximization of revenues in the General Reference Hospitals of Makiso and Mangobo. The documentary analysis allowed us to collect the data and the use of average and percentage calculations made it possible to analyze the data. The comparison of the results was certified by the Chi2 test at the threshold of 0.05. Results: The annual revenues produced by the Pricing per Act at the GRH/Mangobo from 2019 to 2021 are relatively lower than the annual revenues generated by the Flat Rate Pricing at the GRH/Makiso, i.e. respectively, 129,013,100.00 FC, compared to 706,501,460.00 FC. Finally, it is the Flat Rate Pricing which is advantageous for the hospital in being able to maximize revenue. Conclusion: The Congolese State is obliged to finance the health system accordingly to allow public hospitals to operate efficiently. It is therefore up to hospitals to choose the type of pricing that allows them to generate revenue.

Public bicycle sharing systems control and performance evaluation: A Petri net-based approach