Mathematical modeling and control of population systems: Applications in biological pest control

The aim of this paper is to apply methods from optimal control theory, and from the theory of dynamic systems to the mathematical modeling of biological pest control. The linear feedback control problem for nonlinear systems has been formulated in order to obtain the optimal pest control strategy only through the introduction of natural enemies. Asymptotic stability of the closed-loop nonlinear Kolmogorov system is guaranteed by means of a Lyapunov function which can clearly be seen to be the solution of the Hamilton-Jacobi-Bellman equation, thus guaranteeing both stability and optimality. Numerical simulations for three possible scenarios of biological pest control based on the Lotka-Volterra models are provided to show the effectiveness of this method. (c) 2007 Elsevier B.V. All rights reserved.

Field-theoretic approach for systems of composite hadrons

Systems containing simultaneously hadrons and their constituents are most easily described by treating composite hadron field operators on the same kinematical footing as the constituent ones. Introduction of a unitary transformation allows redescription of hadrons by elementary-particle field operators. Transformation of the microscopic Hamiltonian leads to effective Hamiltonians describing all possible processes involving hadrons and their constituents.

A petri net based timing model for hardware/software co-design of digital systems

We have recently proposed an extension to Petri nets in order to be able to directly deal with all aspects of embedded digital systems. This extension is meant to be used as an internal model of our co-design environment. After analyzing relevant related work, and presenting a short introduction to our extension as a background material, we describe the details of the timing model we use in our approach, which is mainly based in Merlin's time model. We conclude the paper by discussing an example of its usage. © 2004 IEEE.

Management of vomplex systems: Modeling the biological pest control

The aim of this paper is to study the cropping system as complex one, applying methods from theory of dynamic systems and from the control theory to the mathematical modeling of the biological pest control. The complex system can be described by different mathematical models. Based on three models of the pest control, the various scenarios have been simulated in order to obtain the pest control strategy only through natural enemies' introduction. © 2008 World Scientific Publishing Company.

Social protection systems in Latin America and the Caribbean: Plurinational State of Bolivia

Includes bibliography

Introduction of a non-conventional solution for Amazon transmission system: Analysis of the electric aspects

This article shows an analysis of the longitudinal electric parameters of a three-phase transmission line/section using a 280-meter high steel tower. This characteristic, the height of the line conductors and distance between them, are intrinsic related to the longitudinal and transversal parameters of the line. By this means, an accurate study was carried out in order to show the electric variations between a transmission line using the new technology and a three-phase conventional 440 kV line for a wide range of frequencies and a variable soil resistivity. In addition, by using a digital line model, simulations are carried out in time domain to analyze critical overvoltage transients on the studied line. © 2011 IEEE.

Population ageing and pension systems in Latin America

Includes bibliography

The Contribution of the Economic Commission for Latin America and the Caribbean (ECLAC) to the Physical Integration of Transport Systems in South America: A Historical Overview

For over a quarter of a century, the Economic Commission for Latin America and the Caribbean (ECLAC) has been in the vanguard of the search for greater physical integration among South American countries, especially in the area of transport, including road, rail, river and multimodal transport.Its activities in this field have ranged from drafting agreements to the design and introduction of concrete measures and have been carried out, either individually, at the request of the Governments of member States, or in collaboration with other organizations, such as the Institute for the Integration of Latin America and the Caribbean (INTAL), which is part of the Inter-American Development Bank (IDB).

Public transport fares in Latin American cities: systems, values and problems

Although public transport has undergone a series of changes over the last few decades, fares are still strongly affecting the budget of low-income families. This is despite the fact that, with very few exceptions, public transport fares are one of the few prices still fixed by the government authorities. The introduction of integrated networks made up of trunk lines and feeder services is not guaranteed to reduce the cost for users. It would be possible to reduce fares if free transport provided by the authorities to various groups of citizens were financed by the authorities themselves, and not by other groups of passengers.

Cleaner Production initiatives and challenges for a sustainable world: an introduction to this special volume

This special volume of the Journal of Cleaner Production is comprised of articles presented at the 3rd International Workshop Advances in Cleaner Production held in Sao Paulo, Brazil, in 2011. The content underscores the recognition of the pressing and inescapable need for making changes from unsustainable to sustainable production and consumption patterns. The 48 articles from 15 countries provide different, but complimentary approaches to help industrial and societal sectors in advancing on their paths towards sustainability. Initiatives and challenges are included, which systematically address problems affecting raw material changes, technological modifications, product and policy changes. The findings range from proposals for alternative uses of wastes, substitution of raw materials for environmentally friendlier substances, optimization of industrial processes by source reductions of wastes and emissions and documented economic and environmental advantages of a wide array of initiatives. The roles of operational and managerial practices are also stressed, highlighting the role of diverse stakeholders as promoters of implementation and internalization of innovative cleaner technologies within companies. Systemic assessment tools are employed and experimented with in order to more effectively evaluate the environmental performance of systems on the biosphere scale. The methodological procedures and proposals presented can help in the design and management of production systems, for governmental and corporate policy development, for implementing and monitoring CP Programs, prevention and mitigation strategies, and evaluation of the outcomes of CP initiatives in the production and service sectors. (C) 2013 Elsevier Ltd. All rights reserved.

Clinical Comparison of the Effectiveness of Single-file Reciprocating Systems and Rotary Systems for Removal of Endotoxins and Cultivable Bacteria from Primarily Infected Root Canals

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

Análise crítica da implementação de sistema ERP à perspectiva da metodologia de gestão de projetos

Management information systems such as ERP can bring to businesses many competitive advantages. There is a great demand for systems projects to consulting firms that have knowledge to manage this particular type of project. However, the rate of system projects that cannot achieve success is very high. The methodology of Project Management, standardized by the Project Management Institute, is a globally recognized standard and used even in projects involving information technology. In the present study, was made a case study of an ERP system implementation project in a large company, by a consulting firm. From this analysis and on contributions from the literature, recommendations were proposed for the project management, in order to better direct the PMI methodology in large projects involving systems like ERP

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals

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

Introduction to the Software-defined Radio Approach

Telecommunications have been in constant evolution during past decades. Among the technological innovations, the use of digital technologies is very relevant. Digital communication systems have proven their efficiency and brought a new element in the chain of signal transmitting and receiving, the digital processor. This device offers to new radio equipments the flexibility of a programmable system. Nowadays, the behavior of a communication system can be modified by simply changing its software. This gave rising to a new radio model called Software Defined Radio (or Software-Defined Radio - SDR). In this new model, one moves to the software the task to set radio behavior, leaving to hardware only the implementation of RF front-end. Thus, the radio is no longer static, defined by their circuits and becomes a dynamic element, which may change their operating characteristics, such as bandwidth, modulation, coding rate, even modified during runtime according to software configuration. This article aims to present the use of GNU Radio software, an open-source solution for SDR specific applications, as a tool for development configurable digital radio.

A regional multirnodulus algorithm for blind equalization of QAM signals: Introduction and steady-state analysis

It is well known that constant-modulus-based algorithms present a large mean-square error for high-order quadrature amplitude modulation (QAM) signals, which may damage the switching to decision-directed-based algorithms. In this paper, we introduce a regional multimodulus algorithm for blind equalization of QAM signals that performs similar to the supervised normalized least-mean-squares (NLMS) algorithm, independently of the QAM order. We find a theoretical relation between the coefficient vector of the proposed algorithm and the Wiener solution and also provide theoretical models for the steady-state excess mean-square error in a nonstationary environment. The proposed algorithm in conjunction with strategies to speed up its convergence and to avoid divergence can bypass the switching mechanism between the blind mode and the decision-directed mode. (c) 2012 Elsevier B.V. All rights reserved.