Modeling a New AQM Model for Internet Chaotic Behavior Using Petri Nets

Formal modeling is considered one of the fundamental phases in the design of network algorithms, including Active Queue Management (AQM) schemes. This article focuses on modeling with Petri nets (PNs) a new scheme of AQM. This innovative AQM is based on a discrete dynamical model of random early detection (RED) for controlling bifurcations and chaos in Internet congestion control. It incorporates new parameters (α,β) that make possible better stability control over oscillations of an average queue length (AQL) at the router. The PN is validated through the matrix equation approach, reachability tree, and invariant analysis. The correctness is validated through the key properties of reachability, boundedness, reversibility, deadlock, and liveness.

ALGORITHM FOR CONSTRUCTING A REACHABILITY TREE FOR STOCHASTIC PETRI NETS

Описываются основные определения дерева достижимости сетей Петри. Также рассматриваются различные примеры стохастических сетей Петри, в которых после выставления начальных маркировок в первых позициях определяются значения во всех остальных позициях. Показаны примеры определения маркировок при помощи высчитывания вектора диагональной свертки. Для каждого примера стохастической сети Петри проводится анализ данной сети. Данный анализ необходим для различных распределительных систем и процессов, особенно на заключительном этапе. Основными методами анализа являются дерево достижимости и матричные уравнения. Рассматривается один из таких методов анализа сетей Петри. С использованием дерева достижимости можно проанализировать, выявить и исправить сбои в процессах, которые могут произойти при наличии тупиковых состояний и при неправильной последовательности срабатывания переходов. Исходя из рассмотренных примеров предлагается обобщенный алгоритм построения дерева достижимости для стохастических сетей Петри. Предложенный алгоритм построения дерева достижимости стохастических сетей Петри можно применять для всех сетей как с конечным, так и с бесконечным множеством достижимости. Данный алгоритм будет являться полезным инструментом при анализе стохастических сетей Петри The article describes the basic definitions of the reachability tree of Petri nets. It also considers various examples of stochastic Petri nets, in which, after setting the initial markings in the first positions, the values in all other positions are determined. The work shows examples of determining markings by calculating the vector of the diagonal convolution. Each example of a stochastic Petri net is analyzed. This analysis is necessary for various distribution systems and processes, especially in the final stage. The main analysis methods are reachability tree and matrix equations. I consider one of such methods for analyzing Petri nets. Using the reachability tree, you can analyze, identify, and correct process failures that can occur when there are deadlocks and when transitions are fired incorrectly. Based on the examples considered, I propose a generalized algorithm for constructing a reachability tree for stochastic Petri nets. The proposed algorithm for constructing the reachability tree of stochastic Petri nets can be applied to all nets with both finite and infinite reachability sets. This algorithm will be a useful tool for analyzing stochastic Petri nets

Existence of Forbidden Digraphs for Crisp Boolean Petri Nets

Boolean Petri net (BPN) and Crisp Boolean Petri net (CBPN) is a well-studied graph model since 2010 which has several applications in mathematical modeling of complex or tricky networks. Modeling any network with Petri net which can generate binary numbers as marking vectors in its reachability tree is still has much uses. In CBPN with a minimum number of transition and minimum number of steps of reachability tree, minimal execution time to run the machine has not been noted till date, thus it’s necessary to sort out this problem. Possibly it may occur due to some forbidden structure which hinders any 1-safe Petri net to be a CBPN. In this paper, we present some forbidden digraphs whose presence interrupts the generation of binary n-vectors exactly once. Any 1-safe Petri net is not a CBPN if it contains any of the subnet induced to the four forbidden structures discussed in this paper.

Petri Net Recommender System for Generating of Perfect Binary Tree

In modeling a discrete event driven system, Petri net recommender systems can play a very important role in describing the structural and behavioral properties of complex and tricky networks. The finite and infinite perfect binary tree forms a predictive model which can map the input information to output information based on the inputs' attributes. A perfect binary tree can be used for three types of recommender systems such as: collaborative filtering, a content-based approach, and a hybrid approach. In this article, the authors show the existence of a Petri net whose reachability tree is a Perfect Infinite Binary Tree (PIBT).

An Automatic Algorithm to Generate a Reachability Tree for Large-Scale Fuzzy Petri Net by And/Or Graph

Fuzzy Petri net (FPN) is widely used to repre sent, model and analyse knowledge-based systems (KBSs). Meanwhile, a reachability tree is an important tool to fully represent the flow relationship of FPN and is widely applied to implement inference in industrial areas. However, the traditional reachability ignores recording the dependence relationships (‘and/or’ relationship) among the places in the neighbouring layers. This paper develops a modified reachability tree based on an and/or graph and presents a three-phase generation algorithm to model the reachability tree for the corresponding FPN automatically via fuzzy production rules (FPRs). Four cases are used to verify the correctness and feasibility of the proposed algorithm from different viewpoints, such as general FPRs, FPRs with a condition-sharing situation, FPRs with a conclusion-sharing situation, and FPRs with multi-conclusions. Simulation results reveal that the proposed approach has the ability to automatically generate the reachability tree for the corresponding FPN correctly.