A hierarchy of adaptive (X)over-bar control charts

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Theory of non-steady state electrical characteristics of metal-insulator-metal structures with schottky barriers and exponentially distributed impurity states

We discuss non-steady state electrical characteristics of a metal-insulator-metal structure. We consider an exponential distribution (in energy) of impurity states in addition to impurity states at a single energy level within the depletion region. We discuss thermal as well as isothermal characteristics and present an expression for the temperature of maximum current (Tm) and a method to calculate the density of exponentially distributed impurity states. We plot the theoretical curves for various sets of parameters and the variation of Tm, and Im (maximum current) with applied potential for various impurity distributions. The present model can explain the available experimental results. Finally we compare the non-steady state characteristics in three cases: (i) impurity states only at a single energy level, (ii) uniform energetic distribution of impurity states, and (iii) exponential energetic distribution of impurity states.

Vibrational-rotational structure of supersingular plus Coulomb potential A/r4 - Z/r*

The vibrational-rotational states of the supersingular plus Coulomb potential A/r4 - Z/r are variationally constructed using a nonorthogonal basis of atomic hydrogenic eigenfunctions modulated by an exponential factor exp(- α/r), ensuring the correct behavior in the vicinity of the supersingularity. The construction is carried out in two successive stages. The first stage is restricted to trial functions without radial nodes, leading to a variational optimization of the parameters of the basis for each value of the angular momentum. The second stage uses the complete basis to construct linear trial functions and to formulate the variational problem in terms of secular equations, yielding the successive vibrational and rotational states. Numerical results for the corresponding energy levels are presented for different combinations of the intensity parameters of the potential. © 2001 Plenum Publishing Corporation.

Identification of structural parameters for active vibration control

The study of algorithms for active vibration control in flexible structures became an area of enormous interest for some researchers due to the innumerable requirements for better performance in mechanical systems, as for instance, aircrafts and aerospace structures. Intelligent systems, constituted for a base structure with sensors and actuators connected, are capable to guarantee the demanded conditions, through the application of diverse types of controllers. For the project of active controllers it is necessary, in general, to know a mathematical model that enable the representation in the space of states, preferential in modal coordinates to permit the truncation of the system and reduction in the order of the controllers. For practical applications of engineering, some mathematical models based in discrete-time systems cannot represent the physical problem, therefore, techniques of identification of system parameters must be used. The techniques of identification of parameters determine the unknown values through the manipulation of the input (disturbance) and output (response) signals of the system. Recently, some methods have been proposed to solve identification problems although, none of them can be considered as being universally appropriate to all the situations. This paper is addressed to an application of linear quadratic regulator controller in a structure where the damping, stiffness and mass matrices were identified through Chebyshev's polynomial functions.

Social Panorama of Latin America 2006

Includes bibliography

Methodology for the comparison of military expenditures

Includes bibliography

Contribution of energy services to the Millennium Development Goals and to poverty alleviation in Latin America and the Caribbean: executive summary

Includes bibliography

Contribution of energy services to the millennium development goals and to poverty alleviation in Latin America and the Caribbean

Includes bibliography

Quantum entanglement and information: The effect of entropy revisited

In non-extensive statistical mechanics [14], it is a nonsense statement to say that the entropy of a system is extensive (or not), without mentioning a law of composition of its elements. In this theory quantum correlations might be perceived through quantum information process. This article, that is an extension of recent work [4], is a comparative study between the entropies of Von Neumann and of Tsallis, with some implementations of the effect of entropy in quantum entanglement, important as a process for transmission of quantum information. We consider two factorized (Fock number) states, which interact through a beam splitter bilinear Hamiltonian with two entries. This comparison showed us that the entropies of Tsallis and Von Neumann behave differently depending on the reflectance of the beam splitter. © 2011 Academic Publications.

A virtual contradiction between international migration and human rights

Includes bibliography

International asymmetries and the design of the International Financial System

Includes bibliography

Asymmetries and cooperation in the Free Trade Area of the Americas

Includes bibliography

The North-South dimension of the environmental and cleaner technology industries

Includes bibliography

Report of the seminar on the results of the social vulnerability index

The Economic Commission for Latin America and the Caribbean (ECLAC); Subregional Headquarters for the Caribbean and secretariat of the Caribbean Development and Cooperation Committee (CDCC); has been involved for the past three years in the execution of a project NET/00/035: Development of the Social Statistical Databases and a methodological approach for a Social Vulnerability Index (SVI); funded by the Government of the Kingdom of the Netherlands. The project had been conceptualized to produce two outputs, one a social statistical database, and the other, the development of a methodological approach for an SVI. The project was in response to the articulated needs of governments in the subregion, specifically, and the wider international body of policy makers, in general, for greater availability and a better quality of social statistical data and indicators to measure the vulnerability of small States.

A virtual contradiction between international migration and human rights

Abstract If there is a geographical area that will be particularly affected by the tragedy of September 11, that will be the international borders of the United States. It is understandable that a country that enters in a state of war after been attacked with enormous losses, reacts by closing its international borders. Such immediate reaction has now been substituted by a more strict control over everything that crosses the border but, a fact remains, the border life is not going to be what it used to before September 11. In the short run, everything that crosses the border has slowed down by new controls. In the long run many things will return to what it was before that Tuesday, but for a long while, life at the border will not be the same. An intense interaction of more than twelve million people from the two sides of the U.S.-Mexico border have made us live in many instances as if the border does not exist. This is the case among many of us in the way we practice our family life. For the planning of weddings, birthdays, reunions, ceremonies, the border is more virtual than real. This is reversed as we get more serious in what it means to the space where institutions, the laws and the governments reminds us that there is a line that marks the beginning and the end of two different nations.