background: pemphigus is an autoimmune bullous disease and it is unclear what triggers and deteriorates it. the current study aimed to evaluate whether increasing the igg antibody titer represents a good indicator of the pemphigus recurrence. objectives: the current study aimed to evaluate whether increasing igg titer is an indicator of the expected recurrence. patients and methods: the current...

by KUSHEL RAI BELLIPADY (Under the Direction of John A. Miller) ABSTRACT The need for interoperability arises in the discipline of simulation and modeling, particularly when the components of a simulation environment need to communicate with each other or communicate with outside entities including other simulation environments. Ontologies can be used to facilitate this interoperability between...

DEVS (Discrete Event Systems Specification) models are widely employed for simulation-based performance evaluation of discrete event systems. Performance modeling of such a system requires a pruning of a set of components, or objects, within the system in its subset which are eventually transformed into simulation models. Such modeling is objective-driven in that simulation models may be abstra...

The topics of this paper are matrix factorizations and the minimal state space realization problem in the maxplus algebra, which is one of the modeling frameworks that can be used to model discrete event systems. We present a heuristic algorithm to compute a factorization of a matrix in the max-plus algebra. Next we use this algorithm to determine the minimal system order (and to construct a mi...

We introduce an extension of the classic Discrete Event System Specification (DEVS) formalism that includes stochastic features. Based on the use of the probability spaces theory we define the stochastic DEVS (STDEVS) specification, which provides a formal framework for modeling and simulation of general non-deterministic discrete event systems. The main theoretical properties of the STDEVS fra...

This paper describes the JDEVS modeling and simulation environment. JDEVS has been developed for over a year to serve as an experimental framework for natural systems modeling techniques. It enables discrete-event, general purpose, object-oriented, component based, GIS connected, collaborative, visual simulation model development and execution. The sample models implementation shows that this e...

The performance of different ATM switch buffer queuing schemes for round-robin and weighted round-robin didn‘t have too much difference. This paper presents the discrete-event simulation provides detailed, accurate network simulation results and it observed a wide variety of network statistics. The software simulation package, OPNET, which specializes in discrete-event simulation of communicati...

Hybrid technical systems combine discrete-state event-driven and continuous-state time-driven behavior. In this contribution, a general modeling formalism for such systems is proposed. The discrete subsystem is represented by an interpreted Petri net. In addition to external continuous inputs, discrete variables dependent on the net marking aaect the continuous subsystem which is a time-driven ...

Count data, or number of events per time interval, are discrete data arising from repeated time to event observations. Their mean count, or piecewise constant event rate, can be evaluated by discrete probability distributions from the Poisson model family. Clinical trial data characterization often involves population count analysis. This tutorial presents the basics and diagnostics of count mo...

Several formalisms have been defined to represent combined continuous and discrete event simulation models. In the “Theory of Modeling and Simulation” the DEV&DESS formalism was shown to have the properties expected from a universal representation of such models. Also it was shown that DEVS can provide accurate simulations of DESS (Differential Equation Specified System) models. In this paper, ...