A new proposal of an efficient algorithm for routing and wavelength assignment in optical networks.

The routing and wavelength assignment (RWA) algorithms used in optical networks are critical to achieve good network performance. However, despite several previous studies to optimize the RWA, which is classified as an NP-Hard, it seems that there is not, a priori, any solution that would lead to standardization of this process. This article presents the proposed RWA algorithm based on a Generic Objective Function (GOF) which aims to establish a base from which it is possible to develop a standard or multiple standards for optical networks. The GOF algorithm introduces the concept of implicit constraint, which guarantees a simple solution to a problem not as trivial as the RWA

PERFORMANCE EVALUATION OF AN ADHOC WIRELESS NETWORK IN A TYPICAL SCENERIO OF AN AMAZONIAN AREA (REGIONS IN AMAZON)

ABSTRACT This paper aims at verifying the viability of the application of an ad-hoc network for medical services rendered in a typical scenery of an Amazonian area. It had been evaluated the performance of an ad-hoc net considering the current technology. Four routing protocols (DSR, LOG, AODV and DSDV) were used and two radio propagation models (Two-ray Ground and Shadowing) were tested. Furthermore, two transport protocols (TCP -Transmission Control Protocol and UDP -User Datagram Protocol) were involved in the process. The analysis was made by means of simulation using the Network Simulator. Throughput, delay, blocking probability, number of established connections and scalability were the performance measures used

A feasibility study of powerline communication technology for digital inclusion

ABSTRACT In the current national scene, many actions point at projects of digital inclusion and citizenship. In this context, providing access technologies as a requisite for the implementation of these actions is primordial. In this way, many innovative experiences have been presented in the past few years. This paper presents a study on the Powerline Communication -PLC technology; as a proposal for a feasible access network for Brazilian Amazon. First, the characteristics of the PLC technology are studied from an implanted indoor prototype at Federal University of Pará. The measures used in this prototype serve as input for a created model, from which it is intended to study the system more widely, considering factors such as: scalability, reliability and the physical characteristics

Strategies for Improving the Interpretability of Bayesian Networks Using Markovian Time Models and Genetic Algorithms

One of the main factors for the success of the knowledge discovery process is related to the comprehensibility of the patterns discovered by the data mining techniques used. Among the many data mining techniques found in the literature, we can point the Bayesian networks as one of most prominent when considering the easiness of knowledge interpretation achieved in a domain with uncertainty. However, the static Bayesian networks present two basic disadvantages: the incapacity to correlate the variables, considering its behavior throughout the time; and the difficulty of establishing the optimum combination of states for the variables, which would generate and/or achieve a given requirement. This paper presents an extension for the improvement of Bayesian networks, treating the mentioned problems by incorporating a temporal model, using Markov chains, and for intermediary of the combination of genetic algorithms with the networks obtained from the data