Abstract: In the last few years we could perceive a great increase in interest in studying biologically inspired systems. Among these, we can emphasize artificial neural networks, evolutionary computation, DNA computation, and now artificial immune systems. The immune system is a complex of cells, molecules and organs which has proven to be capable of performing several tasks, like pattern recognition, learning, memory acquisition, generation of diversity, noise tolerance, generalization, distributed detection and optimization. Based on immunological principles, new computational techniques are being developed, aiming not only at a better understanding of the system, but also at solving engineering problems. In this report, after a brief introduction to the immune system, attaining a relevant level of details when necessary, we discuss the main strategies used by the immune system to problem solving, and introduce the concept of immune engineering. The immune engineering makes use of immunological concepts in order to create tools for solving demanding machine-learning problems using information extracted from the problems themselves. The text is concluded with the development of several immune engineering algorithms. These tools are extensively discussed and examples of their applications to artificial and real-world problems are presented.

Keywords: artificial immune system, intelligent systems, machine-learning, immune engineering

Abstract: In this report we discuss the DNA sequencing problem in a software platform that attempts to make use of the computing power represented by the thousands of computers interconected by Internet. Thus, we analyze the viability and scalability of a parallel processing tool to solve this problem, considering the specific characteristics presented by a massively parallel virtual computer. Initial results have shown that the DNA sequencing task can be performed in parallel and efficiently by such software platform

Keywords: Computational Biology, Parallel Processing, Virtual Computer

Abstract:The increase of the number of cellular mobile communications users in the world brought several operational and design problems, such as the system overload and the lack of new bands in the frequency spectrum. The Double Reuse of Frequency can solve these problems in a simple way. It consists on the reuse by microcells installed indoors of the same frequency bands used by conventional cells installed outdoors. Thus, it eliminates not only the need of new frequencies and their costs, but also the need to bear another equipment different from that used in a conventional cellular system. As the same frequencies will be used in the two systems, the cochannel interference increases. So, the project parameters have to be properly calculated in order to make the signal/interference ratio and the spectral efficiency higher than certain minimum values. The aim of this work is to develop a simplified tool to calculate interference between cochannel cells of a Double Reuse of Frequency system, and obtain the signal/interference ratio and the spectral efficiency, among other parameters. To do so, macro and microcell systems are represented in the form of matrixes, where each element correspond to a cell. Scanning the matrixes, each cochannel cell is identified and the distance between the cell and a reference point is calculated, and so, the interference level is determined. Compared to previous tools (that identify cochannel cells analytically), the tool proposed here is simpler, as it is based on the matrix scanning to find cochannel cells, and it is more precise, as many of the approximations used before are avoided. With this new tool, it is possible to evaluate, in a fast and precise way, the influence of each parameter on the design of a system with Double Reuse of Frequencies.

Keywords:Cellular Communitations, Double Reuse of Frequency, Microcells

Abstract:The explosion of the number of mobile phone users has overloaded many systems. Licensing new channels is not usually a viable solution either because of excessive cost or legal restrictions. The double reuse of frequency (DR) is a way of increasing the capacity of cell systems by allowing small radius, low power microcells to reuse the channels of the macrocells. Signal degradation is inevitable in DR systems and has to be carefully considered. This work introduces a new vectorial model for determining distances involved in interference calculation between cells. Based on this model, MAGIC (Much enhAnced Graphical Interference Calculator) a graphical tool for analysis and design of DR systems was developed. The new tool was written in Java, to allow execution in practically all kinds of platforms either as an independent program or applet.

Keywords: Double Reuse of Frequency, Cellular Telephony, Interference