Minimization of Reactive Probabilistic Automata

The problem of finite automata minimization is important for software and hardware designing. Different types of automata are used for modeling systems or machines with finite number of states. The limitation of number of states gives savings in resources and time. In this article we show specific type of probabilistic automata: the reactive probabilistic finite automata with accepting states (in brief the reactive probabilistic automata), and definitions of languages accepted by it. We present definition of bisimulation relation for automata's states and define relation of indistinguishableness of automata states, on base of which we could effectuate automata minimization. Next we present detailed algorithm reactive probabilistic automata’s minimization with determination of its complexity and analyse example solved with help of this algorithm

Użycie czasowych automatów probabilistycznych do modelowania protokołów zabezpieczających

Probabilistic timed automata can be used for modeling and verification of systems whose characteristic is real-time and probabilistic. Analyzing stochastic behavior of network communication, many common points of security protocols and automata can be easily found. Modeling with automata allows to use relations and algorithms, such as bisimulation or minimization. This can lead to verification/simplification protocols.Czasowe automaty probabilistyczne mogą zostać użyte do modelowania i weryfikacji systemów przetwarzanych w czasie rzeczywistym i posiadających cechy probabilistyczne. Biorąc pod uwagę stochastyczne zachowania komunikacji w sieci, można znaleźć wspólne cechy protokołów i automatów. Modelowanie z wykorzystaniem automatów umożliwia użycie relacji i algorytmów, takich jak bisymulacja czy minimalizacja. To może ułatwić weryfikację/uproszczenie protokołów

Towards Most Efficient Method for Untimed Security Protocols Verification

Security protocols are a crucial point of more complicated communication protocols that are responsible for keeping security during data transmission in computer networks. From a security point of view, proper verification of such protocols properties is a significant challenge. In the last decades, many concepts and connected with them verification tools were developed and successfully used for checking protocols correctness conditions. In this area of research, much attention is paid for suitable methods of protocols modelling and a low as possible a computational complexity of algorithms used. The last property is important because it allows practical use of such structures and algorithms for automatic verification. Adding timestamps for protocols schemes caused a need for time modelling in solutions of security protocols verification. Time models added into considerations introduce more complicated structures and increase the complexity of structures and algorithms used in the verification process. According to this, there is still a need of looking for more and more efficient ways for modelling of untimed versions of the protocols, for which adding time will be effective from the verification process point of view. In this paper, we propose a new method for modelling and verification of untimed security protocols properties. We present an idea, examples, an algorithm and experimental results for several protocols. We also compare our results with the best, well-known verification tools

SAT and SMT-Based Verification of Security Protocols Including Time Aspects

For many years various types of devices equipped with sensors have guaranteed proper work in a huge amount of machines and systems. For the proper operation of sensors, devices, and complex systems, we need secure communication. Security protocols (SP) in this case, guarantee the achievement of security goals. However, the design of SP is not an easy process. Sometimes SP cannot realise their security goals because of errors in their constructions and need to be investigated and verified in the case of their correctness. Now SP uses often time primitives due to the necessity of security dependence on the passing of time. In this work, we propose and investigate the SAT-and SMT-based formal verification methods of SP used in communication between devices equipped with sensors. For this, we use a formal model based on networks of communicating timed automata. Using this, we show how the security property of SP dedicated to the sensors world can be verified. In our work, we investigate such timed properties as delays in the network and lifetimes. The delay in the network is the lower time constraint related to sending the message. Lifetime is an upper constraint related to the validity of the timestamps generated for the transmitted messages

The utility of inflammation and platelet biomarkers in patients with acute coronary syndromes

Introduction: Thrombotic and inflammatory mechanisms are involved in the pathophysiology of acute coronary syndrome (ACS). The aim of the study was the evaluation of inflammation (white blood cells count/WBC, C-reactive protein/CRP, interleukin-6/IL-6) and platelet (platelet count/PLT, mean platelet volume/MPV, large platelet/LPLT, beta-thromboglobulin/β-TG) biomarkers in the groups of ACS patients depending on the severity of signs and symptoms and compared to controls without coronary artery disease. Materials and methods: The study group included 93 patients categorized into 3 subgroups depending on the severity of signs and symptoms of ACS. PLT, MPV, LPLT, and WBC were determined on hematological analyzer, IL-6 and β-TG were measured using the ELISA method. Results: In the whole group of ACS patients WBC, CRP, IL-6, MPV, and β-TG were significantly higher as compared to controls. Analyzing the inflammation and platelet biomarkers depending on the severity of signs and symptoms in comparison to controls, statistically significant differences for above-mentioned parameters were also found. There were no significant differences between the advancement of coronary artery changes and inflammation as well as platelet parameters, except for CRP concentrations. The AUCs for all inflammation parameters tested were similar, however the highest AUCs showed WBC and CRP. Among platelet parameters the highest AUC revealed β-TG. Conclusion: Markers of inflammation and platelet activation may be associated to myocardial ischemia and myocardial injury. WBC, CRP and IL-6 as inflammation parameters and MPV and β-TG as platelet biomarkers may be useful indicators of the presence of coronary artery disease. Keywords: Acute coronary syndrome, Beta-thromboglobulin, Inflammation biomarkers, Activated platele

Molecular Mechanisms Leading from Periodontal Disease to Cancer

Periodontitis is prevalent in half of the adult population and raises critical health concerns as it has been recently associated with an increased risk of cancer. While information about the topic remains somewhat scarce, a deeper understanding of the underlying mechanistic pathways promoting neoplasia in periodontitis patients is of fundamental importance. This manuscript presents the literature as well as a panel of tables and figures on the molecular mechanisms of Porphyromonas gingivalis and Fusobacterium nucleatum, two main oral pathogens in periodontitis pathology, involved in instigating tumorigenesis. We also present evidence for potential links between the RANKL-RANK signaling axis as well as circulating cytokines/leukocytes and carcinogenesis. Due to the nonconclusive data associating periodontitis and cancer reported in the case and cohort studies, we examine clinical trials relevant to the topic and summarize their outcome

METHOD AND ALGORITHM FOR MINIMIZATION OF PROBABILISTIC AUTOMATA

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