Recommendations Based QoS Trust Aggregation and Routing in Mobile Adhoc Networks

In mobile adhoc netwotk (MANET), a node’s quality of service (QoS) trust represents how much it is reliable in quality. QoS trust of a node is computed based on its multiple quality parameters and it is an interesting and challenging area in MANETs. In this work, QoS trust is evaluated by taking into consideration quality parameters like node residual energy, bandwidth and mobility. The proposed method “Recommendations Based QoS Trust Aggregation and Routing in Mobile Adhoc Networks-QTAR” is a frame work. Where the trust is established through four phases like QoS trust computation, aggregation, propagation and routing. The Dempster Shafer Theory (DST) is used for aggregation of trust recommendations. In the network, trust information is propagated through HELLO packets. Each node stores the QoS trust information of other nodes in the form of trust matrices. We applied matrix algebra operations on trust matrices for route establishment from source to destination. The time and space complexity of proposed method is discussed theoretically. The simulation is conducted for the varying of node velocity and network size, where the proposed method shown considerable improvement over existing protocols

Application of Fuzzy Reasoning Spiking Neural P Systems to Fault Diagnosis

This paper discusses the application of fuzzy reasoning spiking neural P systems with trapezoidal fuzzy numbers (tFRSN P systems) to fault diagnosis of power systems, where a matrix-based fuzzy reasoning algorithm based on the dynamic firing mechanism of neurons is used to develop the inference ability of tFRSN P systems from classical reasoning to fuzzy reasoning. Some case studies show the effectiveness of the presented method. We also briefly draw comparisons between the presented method and several main fault diagnosis approaches from the perspectives of knowledge representation and inference process

An advanced fuzzy Bayesian-based FMEA approach for assessing maritime supply chain risks

This paper aims to develop a novel model to assess the risk factors of maritime supply chains by incorporating a fuzzy belief rule approach with Bayesian networks. The new model, compared to traditional risk analysis methods, has the capability of improving result accuracy under a high uncertainty in risk data. A real case of a world leading container shipping company is investigated, and the research results reveal that among the most significant risk factors are transportation of dangerous goods, fluctuation of fuel price, fierce competition, unattractive markets, and change of exchange rates in sequence. Such findings will provide useful insights for accident prevention

A new paradigm for uncertain knowledge representation by Plausible Petri nets

This paper presents a new model for Petri nets (PNs) which combines PN principles with the foundations of information theory for uncertain knowledge representation. The resulting framework has been named Plausible Petri nets (PPNs). The main feature of PPNs resides in their efficiency to jointly consider the evolution of a discrete event system together with uncertain information about the system state using states of information. The paper overviews relevant concepts of information theory and uncertainty representation, and presents an algebraic method to formally consider the evolution of uncertain state variables within the PN dynamics. To illustrate some of the real-world challenges relating to uncertainty that can be handled using a PPN, an example of an expert system is provided, demonstrating how condition monitoring data and expert opinion can be modelled

Modelagem e simulação de sistemas de gerenciamento de processos de negócios baseadas em workflow net temporais com mecanismos de alocação de recursos híbridos fuzzy

The main objective of this doctoral research is to propose a new business process model for efficient (and realistic) resources and time management in Workflow nets. This research had as its starting point the validation of the fuzzy resource allocation model presented in (JESKE, 2006). In particular, a specialized inference mechanism of the token player type adapted to a fuzzy hybrid resource allocation model was implemented in the modeling, analysis and simulation tool of colored Petri nets called CPN Tools. Such simulations have shown that the new model in relation to a simple resource allocation mechanism with an earlier firing policy (FIFO) allows an improvement in the proportion of cases that meet the established deadlines. To solve the scheduling problem in Workflow Management Systems, important characteristics inherent to these systems should be considered. In particular, when many cases are run concurrently, conflict situations due to shared resource can occur and must be resolved in real time (without a backward mechanism). Also, temporary restrictions regarding the deadlines for delivery of specific cases should be considered. For that, a fuzzy time associated to the activities of the processes was defined as well as a mechanism of propagation of restrictions whose role is to guarantee the consistency of the time constraints to carry out the activities respecting the expected delivery times. With the objective of making the behavior of the new model the closest and consistent with the behavior of the human collaborators involved in the execution of business process activities, the notion of joint possibility was inserted in the model. This notion involves the uncertain and nebulous character of the execution times of the activities of the processes and the intensity of the resources used to carry out the activities. New firing rules for transitions were then defined based on the concept presented. Token players based on the new model presented were defined, implemented, simulated and validated in the CPN Tools, whose main role is to show the execution of the new models presented. Using the CPN Tools, it was possible to evaluate the system behavior considering the expected or most critical operating. It is important to point out that through the simulation results it is possible to predict how the system will behave and, from this, to evaluate several possible resource distribution scenarios in order to be able, in the future, to carry out the sizing of the system based on a modeling and simulation tool that approximates of the way employees work in an office environment.Tese (Doutorado)O principal objetivo desta pesquisa de doutorado é propor um novo modelo de processo de negócios para uma gestão eficiente (e realista) dos recursos e do tempo em Workflow nets. Esta pesquisa teve como ponto de partida a validação do modelo de alocação de recursos fuzzy apresentado em (JESKE, 2006). Em particular, um mecanismo de inferência especializado do tipo token player adaptado a um modelo de alocação de recurso híbrido fuzzy foi implementado na ferramenta de modelagem, análise e simulação de redes de Petri coloridas chamada CPN Tools. Tais simulações mostraram que o novo modelo em relação a um mecanismo simples de alocação de recurso com uma política de disparo mais cedo (FIFO) permite uma melhoria da proporção de casos que respeitam os prazos estabelecidos. Para resolver o problema do escalonamento em Sistemas de Gerenciamento de Workflow deverão ser consideradas características importantes inerentes a estes sistemas. Em particular, quando muitos casos são executados simultaneamente, situações de conflito por recursos compartilhados podem ocorrer e devem ser resolvidas em tempo real (sem um mecanismo de retrocesso). Também, deverão ser consideradas restrições temporais relativas aos prazos de entrega de casos específicos. Para tanto, definiu-se um tempo fuzzy associado às atividades dos processos bem como um mecanismo de propagação de restrições cujo papel é garantir a consistência das restrições de tempo para realização das atividades respeitando os prazos de entrega previstos. Com o objetivo de tornar o comportamento do novo modelo o mais próximo e consistente com o comportamento de funcionários humanos envolvidos na execução de atividades de processos de negócios, a noção de possibilidade conjunta que envolve o caráter incerto e nebuloso tanto dos tempos de execução das atividades dos processos quanto das intensidades de carga dos recursos utilizados para a realização de atividades foi inserida no modelo. Novas regras de disparo de transições foram então definidas baseadas no conceito apresentado. Jogadores de rede de Petri do tipo token player baseados no novo modelo apresentado foram definidos, implementados, simulados e validados na ferramenta CPN Tools, cujo papel principal é mostrar a execução dos novos modelos apresentados. Com o uso da ferramenta CPN Tools foi possível avaliar o comportamento do sistema em funcionamento esperado ou em situação mais crítica. É importante salientar que através dos resultados de simulação é possível prever como o sistema se comportará, isso a fim de avaliar diversos cenários possíveis de distribuição de recursos para poder, no futuro, realizar o dimensionamento do sistema baseado numa ferramenta de modelagem e simulação próxima da forma de trabalhar dos funcionários em ambiente de escritório