Exploring signals and systems, this work develops continuous-time and discrete-time concepts, highlighting the differences and similarities. Two chapters deal with the Laplace transform and the Z-transform. Basic methods such as filtering, communication an

Representación de señales - Sistemas en tiempo continuo - Series de Fourier - La Transformada de Fourier - La Transformada de Laplace - Sistemas en tiempo discreto - Análisis de Fourier de sistemas en tiempo discreto - La Transformada Z - La Transformada discreta de Fourier - Diseño de filtros analógicos y digitales - Números complejos - Relaciones matemáticas - Teoría elemental de matrices - Descomposicón en fracciones simples.

This thesis (written in Spanish) presents the analysis, design and implementation of a four-quadrant power supply with high-frequency isolation, which is expected to be used to feed the low-energy correction magnet of a particle accelerator. In particle accelerator applications the magnetic field during beam acceleration may be either positive or negative, and true bipolar power converters are needed. The selected bipolar topology consists of a bidirectional three-phase to single-phase reduced matrix converter (RMC) with power factor correction and a bidirectional active rectifier. Main features of this power converter are the ability to regenerate energy back to the utility when the magnet acts as generator, unity power factor at the mains and reduction of volume and weight thanks to the inclusion of the isolation transformer at the switching frequency. A space vector modulation (SVM) technique was used to achieve unity power factor at the input and output current regulation simultaneously. This was done while a symmetrical pure AC profile is generated at the primary side of the isolation transformer. The secondary AC signal is then rectified into a positive or negative voltage, according to the desired output current sign, and later filtered to obtain the output DC current in both polarities. The active rectifier used permits reverse current flow to the primary side when driving an inductive load. By synchronising the commutation of both converters and adding a saturable inductor and a blocking capacitor it is possible to achieve soft commutation for most of the semiconductor elements. An all-digital control based on a Digital-Signal-Processor (DSP) and a Field-Programmed-Gate-Array (FPGA) was used to implement space vector modulation and output current regulation. Output current regulation is performed on a powerful 32-bit fixed-point DSP of Motorola, and was implemented by means of an observer based optimum state feedback control (LQR -- Linear Quadratic Regulator). A reduced order observer was implemented to estimate the output filter inductor current, reducing the number of sensors. Experimental results of a 1.5 kW, 20 kHz prototype are presented to illustrate the performance of the proposed topology.

A Deleuzian reading of Whitehead and a Whiteheadian reading of Deleuze open the possibility of a critical aesthetics of contemporary culture. In Without Criteria, Steven Shaviro proposes and explores a philosophical fantasy: imagine a world in which Alfred North Whitehead takes the place of Martin Heidegger. What if Whitehead, instead of Heidegger, had set the agenda for postmodern thought? Heidegger asks, “Why is there something, rather than nothing?” Whitehead asks, “How is it that there is always something new?” In a world where everything from popular music to DNA is being sampled and recombined, argues Shaviro, Whitehead's question is the truly urgent one. Without Criteria is Shaviro's experiment in rethinking postmodern theory, especially the theory of aesthetics, from a point of view that hearkens back to Whitehead rather than Heidegger. In working through the ideas of Whitehead and Deleuze, Shaviro also appeals to Kant, arguing that certain aspects of Kant's thought pave the way for the philosophical “constructivism” embraced by both Whitehead and Deleuze. Kant, Whitehead, and Deleuze are not commonly grouped together, but the juxtaposition of them in Without Criteria helps to shed light on a variety of issues that are of concern to contemporary art and media practices.

This second edition continues to emphasise learning by doing and the development of students' ability to use mathematics with understanding to solve engineering problems. Extensive treatment of some advanced engineering topics, particularly as tools for computer-based system modelling, analysis and design. *Follow on text from Modern Engineering Mathematics, 2E - over 20,000 copies sold *Changing student needs catered for by some easier examples and exercises plus new introductory sections on matrix algebra and vector spaces *New chapter on Numerical Solution of Ordinary Differential Equations *Engineering applications covered in specific sections in each chapter *The increasing importance of digital techniques and statistics is recognised throughout

Descended from a long and ancient lineage, tapirs are important tropical forest seed dispersers. However, today, all species of tapirs are threatened to various degrees by habitat destruction and hunting. This action plan was written with wildlife biologists, ecologists, administrators, educators and local conservation officials in mind and is aimed at those countries with tapir populations. It provides a brief natural history of each species and its objective is to aid in their conservation by catalyzing conservation action. In addition, it is hoped that the contents of the plan will stimulate further research into this fascinating group of animals.