Alisson Pontes

The main goal of RouteFlow is to develop an open-source framework for virtual IP routing solutions over commodity hardware implementing the OpenFlow API. RouteFlow aims at a commodity routing architecture that combines the line-rate performance of commercial hardware with the flexibility of open source routing stacks (remotely) running on general purpose computers. As an outcome of this point in the design space of routing solutions, we expect: Migration path from legacy IP deployments to purely software-defined networks (i.e. OpenFlow) Open-Source framework to support the different flavours of network virtualization (e.g., logical routers, router aggregation / multiplexation). IP Routing-as-a-Service models of networking Simplified intra- and inter-domain routing interoperable with legacy equipments.

Wireless ad hoc networks do not have radio base stations and the entire task to access the channel is distributed among the nodes (or users). Such networks are extremely versatile and have huge potential to be used. Furthermore, Ad hoc networks protocols must be decentralized and make little use of computer resources and energy.

In this context, the effect of mobility in ad hoc networks has been studied by several authors interested in investigating the systems of communication and procolocos conditions of use to reproduce the situations of users moving and using the network. The mobility can interfere strongly in the results of analysis of performance of the protocols. For example, the results of any simulation of the network must be obtained under steady state to be considered valid.

It has been shown recently that the instantaneous average nodal speed in the Random Waypoint (RWP) mobility model may not reach a stationary regime which can cause inaccurate results in simulations and communication protocol validations for wireless ad hoc networks. In this work we presented a modification in the RWP model and demonstrates analytically and by simulations that our modification stabilizes the instantaneous average nodal speed in the network whichever is the chosen set of parameters. The proposed change in the RWP model can be easily incorporated in the current simulators by doing a simple alteration in the function called to choose the velocity of the nodes.

Here I make a brief description of the system developed by me during my internship in the Federal Service of Data Processing - SERPRO. My duties were to implement and maintain the system of communications support between the board of directors and enployees spread all over Brasil. Also study of new techniques and tools that make such activities more efficient.

Investing in internal communication is to invest in the organizational climate and also in marketing. Thus, it becomes evident, for a company the size of Serpro, the importance of investing in a tool like Babassu. The process of internal communication needs to be cherished and the channels it offers made in an effective and attractive manner to actually integrate the entire framework of a functional organization.

Babassu (Broadcast System Based Suport) is an application that sends messages via Broadcast for a specific user or groups of users or all users on the Serpro's internal network...

Handwritten Character Recognition approaches innumerous situations, such as automatic reading of bank checks; recognition of postal addresses; automatic indexing of documents, among others. This work addresses the problem of handwritten characters recognition in historical documents. We will treat here of procedures for the text segmentation, with emphasis on the character segmentation algorithm proposed during this work, called the sliding window; features extraction using the histograms projection method, and artificial neural networks (RNA) for classification.

During this work I developed studies related to the Cooperative Multimedia Streaming Research Group, headed by Prof. Dr. Günter Schäfer. One of the lines of research of this group concerns of studying overlay network topologies to enable resources sharing through a P2P network. That was my main object of study.

Most of this time I studied a network simulator called OMNeT++. This is a general purpose simulator that uses INET/OMNeT framework for network simulations support. I was also dedicated to the study of distributed hash tables (DHT). DHT is a class of distributed systems that provide a search service where each node of the network has a group of resources. To facilitate the search for any resources in the network, each node contains information about some other peers, so any resource can be found traveling throught a small fraction of all nodes of the network.

In implementation of simulation in OMNeT, in addition to the INET platform to support the simulation of networks, were used the C language for creating classes that represent the components of the network and a call NED own language to describe the topology of network components.