On lag controllers: Design and implementation

Sometimes it is inconvenient or expensive to open the loop of a system to insert lag controllers-for instance, when this system is an open-loop system. A new controller structure where the loop is not opened, and that allows the design of lag controllers as in the case where one can open the loop, is presented. This result can be used by educators in undergraduate courses that deal with classic control system theory, because it allows a better comprehension of the concept of lag compensation and provides a new method for its design and implementation. An example illustrates the application of the proposed method.

Use of genetic algorithms and solvation potential to study peptides structure

In this work, genetic algorithms concepts along with a rotamer library for proteins side chains and implicit solvation potential are used to optimize the tertiary structure of peptides. We starting from the known PDB structure of its backbone which is kept fixed while the side chains allowed adopting the conformations present in the rotamer library. It was used rotamer library independent of backbone and a implicit solvation potential. The structure of Mastoporan-X was predicted using several force fields with a growing complexity; we started it with a field where the only present interaction was Lennard-Jones. We added the Coulombian term and we considered the solvation effects through a term proportional to the solvent accessible area. This paper present good and interesting results obtained using the potential with solvation term and rotamer library. Hence, the algorithm (called YODA) presented here can be a good tool to the prediction problem. (c) 2007 Elsevier B.V. All rights reserved.

Characterization of micro-bubble size distribution and flow configuration in DAF contact zone by a non-intrusive image analysis system and tracer tests

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Design and implementation of a dc-dc converter based on variable structure control of switched systems

This paper presents a control method for a class of continuous-time switched systems, using state feedback variable structure controllers. The method is applied to the control of a non-trivial dc-dc power converter and a simple and inexpensive control circuit design, that was simulated using the software PSpice, is proposed. The design is based on Lyapunov-Metzler-SPR systems and the performance of the resulting control system is superior to that afforded by a recently proposed alternative sliding-mode control technique. © 2011 IFAC.

A single-phase single-stage buck-boost inverter intended for low power alternative energy conversion systems: Analysis, design and experimentation

This paper presents the operational analysis of the single-phase integrated buck-boost inverter. This topology is able to convert the DC input voltage into AC voltage with a high static gain, low harmonic content and acceptable efficiency, all in one single-stage. Main functionality aspects are explained, design procedure, system modeling and control, and also component requirements are detailed. Main simulation results are included, and two prototypes were implemented and experimentally tested, where its results are compared with those corresponding to similar topologies available in literature. © 2012 IEEE.

Quantitative analysis of the implementation of economic plans in Latin America

Includes bibliography

Resolution 654(XXXIII) Activities of the Economic Commission for Latin America and the Caribbean in relation to follow-up to the Millennium Development Goals and implementation of the outcomes of the major United Nations conferences and summits in the economic, social and related fields

Includes bibliography

Resolution 639(XXXII) Activities of the Economic Commission for Latin America and the Caribbean in relation to follow-up to the Millennium Development Goals and implementation of the outcomes of the major United Nations conferences and summits in the economic, social and related fields

Includes bibliography

Resolution 669(XXXIV) Activities of the Economic Commission for Latin America and the Caribbean in relation to follow-up to the Millennium Development Goals and implementation of the outcomes of the major United Nations conferences and summits in the economic, social and related fields

Spanish version available

Proposal for a code of good practice in statistics in Latin America and the Caribbean and implementation plan for 2012-2013

Incluye Bibliografía