Ramón Puigjaner

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The Petri net modeling formalism allows for the convenient graphical visualization of system models, as well as the analysis of correctness and performance properties. Petri Nets theory has been widely used to implement a variety of modeling and evaluation tools. This paper surveys various of these tools and describes some recent extensions to a freely(More)
In this paper, we develop a performance model of a cell in a wireless communication network where the e ect of hando arrival and the use of guard channels is inlcuded. Fast recursive formulae for the loss probabilities of new calls and hando calls are developed. Monotonicity properties of the loss probabilities are proven. Algorithms to determine the(More)
In this paper, we develop a performance model of a cell in a wireless communication network where the effect of handoff arrival and the use of guard channels is inlcuded. Fast recursive formulas for the loss probabilities of new calls and handoff calls are developed. Monotonicity properties of the loss probabilities are proven. Algorithms to determine the(More)
This paper intends to present an overview of the main problems that appear when we wish to estimate the performance of a non existing system or a future situation of an existing system. The main techniques used for representing the workload and the system performance will be also presented. It will start with a definition of the main problems existing in(More)
In this article we intend to make an attempt to formalize the Software Performance Engineering Body of Knowledge (SPEBoK) by means of the formal semantics of an ontology written in OWL. We do not claim that our SPEBoK is complete nor the information contained correct. Rather we propose the structure of an ontological database to contain it. This structure(More)
Predictive algorithms play a crucial role in system management by alerting it to future events that may degrade the global performance of the system. Our paper proposes a predictive algorithm for a Web switch that manages a cluster of Web servers. Several throughput predictive techniques have been studied to balance the workload dynamically according to a(More)
This paper brings together the performance assessment of ambient intelligence architectures systems with ontology engineering. Thus, firstly appropriate description methods for distributed intelligent applications are summarized. Derived from the system characterization, typical software performance engineering techniques are based on the augmented(More)
In the computer science community there is a growing interest in the field of Ambient Intelligent Systems. This systems surround their human users with computing and networking technology unobtrusively embedded in their environment. This technology is aimed to provide the users with useful information and to take action to make the environment more(More)