Anisotropy-based performance analysis of linear discrete time invariant control systems

The anisotropic norm of a linear discrete-time-invariant system measures system output sensitivity to stationary Gaussian input disturbances of bounded mean anisotropy. Mean anisotropy characterizes the degree of predictability (or colouredness) and spatial non-roundness of the noise. The anisotropic norm falls between the H-2 and H-infinity norms and accommodates their loss of performance when the probability structure of input disturbances is not exactly known. This paper develops a method for numerical computation of the anisotropic norm which involves linked Riccati and Lyapunov equations and an associated special type equation.

Differential inclusions and robust control theory

Uncontrolled systems (x) over dot is an element of Ax, where A is a non-empty compact set of matrices, and controlled systems (x) over dot is an element of Ax + Bu are considered. Higher-order systems 0 is an element of Px - Du, where and are sets of differential polynomials, are also studied. It is shown that, under natural conditions commonly occurring in robust control theory, with some mild additional restrictions, asymptotic stability of differential inclusions is guaranteed. The main results are variants of small-gain theorems and the principal technique used is the Krasnosel'skii-Pokrovskii principle of absence of bounded solutions.

Stability of linear difference and differential inclusions

Any given n X n matrix A is shown to be a restriction, to the A-invariant subspace, of a nonnegative N x N matrix B of spectral radius p(B) arbitrarily close to p(A). A difference inclusion x(k+1) is an element of Ax(k), where A is a compact set of matrices, is asymptotically stable if and only if A can be extended to a set B of nonnegative matrices B with \ \B \ \ (1) < 1 or \ \B \ \ (infinity) < 1. Similar results are derived for differential inclusions.

Estimates of the real structured radius of stability of linear dynamic systems

A question is examined as to estimates of the norms of perturbations of a linear stable dynamic system, under which the perturbed system remains stable in a situation R:here a perturbation has a fixed structure.

Using clusters of computers for large QU-GENE simulation experiments

The QU-GENE Computing Cluster (QCC) is a hardware and software solution to the automation and speedup of large QU-GENE (QUantitative GENEtics) simulation experiments that are designed to examine the properties of genetic models, particularly those that involve factorial combinations of treatment levels. QCC automates the management of the distribution of components of the simulation experiments among the networked single-processor computers to achieve the speedup.

Development of a short-term model using petrophysical logging at Century Mine, North Queensland

Pasminco Century Mine has developed a geophysical logging system to provide new data for ore mining/grade control and the generation of Short Term Models for mine planning. Previous work indicated the applicability of petrophysical logging for lithology prediction, however, the automation of the method was not considered reliable enough for the development of a mining model. A test survey was undertaken using two diamond drilled control holes and eight percussion holes. All holes were logged with natural gamma, magnetic susceptibility and density. Calibration of the LogTrans auto-interpretation software using only natural gamma and magnetic susceptibility indicated that both lithology and stratigraphy could be predicted. Development of a capability to enforce stratigraphic order within LogTrans increased the reliability and accuracy of interpretations. After the completion of a feasibility program, Century Mine has invested in a dedicated logging vehicle to log blast holes as well as for use in in-fill drilling programs. Future refinement of the system may lead to the development of GPS controlled excavators for mining ore.

Rapid diagnosis in pediatric infectious diseases: The past, the present and the future

The focus of rapid diagnosis of infectious diseases of children in the last decade has shifted from variations of the conventional laboratory techniques of antigen detection, microscopy and culture to that of molecular diagnosis of infectious agents. Pediatricians will need to be able to interpret the use, limitations and results of molecular diagnostic techniques as they are increasingly integrated into routine clinical microbiology laboratory protocols. PCR is the best known and most successfully implemented diagnostic molecular technology to date. It can detect specific infectious agents and determine their virulence and antimicrobial genotypes with greater speed, sensitivity and specificity than conventional microbiology methods. Inherent technical limitations of PCR are present, although they are reduced in laboratories that follow suitable validation and quality control procedures. Variations of PCR together with advances in nucleic acid amplification technology have broadened its diagnostic capabilities in clinical infectious disease to now rival and even surpass traditional methods in some situations. Automation of all components of PCR is now possible. The completion of the genome sequencing projects for significant microbial pathogens, in combination with PCR and DNA chip technology, will revolutionize the diagnosis and management of infectious diseases.

Work domain analysis and sensors I: principles and simple example

In this paper we establish a foundation for understanding the instrumentation needs of complex dynamic systems if ecological interface design (EID)-based interfaces are to be robust in the face of instrumentation failures. EID-based interfaces often include configural displays which reveal the higher-order properties of complex systems. However, concerns have been expressed that such displays might be misleading when instrumentation is unreliable or unavailable. Rasmussen's abstraction hierarchy (AH) formalism can be extended to include representations of sensors near the functions or properties about which they provide information, resulting in what we call a sensor-annotated abstraction hierarchy. Sensor-annotated AHs help the analyst determine the impact of different instrumentation engineering policies on higher-order system information by showing how the data provided from individual sensors propagates within and across levels of abstraction in the AH. The use of sensor-annotated AHs with a configural display is illustrated with a simple water reservoir example. We argue that if EID is to be effectively employed in the design of interfaces for complex systems, then the information needs of the human operator need to be considered at the earliest stages of system development while instrumentation requirements are being formulated. In this way, Rasmussen's AH promotes a formative approach to instrumentation engineering. (C) 2002 Elsevier Science Ltd. All rights reserved.

Linguistic evaluation method for the environmental assessment of infrastructure projects

A soft linguistic evaluation method is proposed for the environmental assessment of physical infrastructure projects based on fuzzy relations. Infrastructure projects are characterized in terms of linguistic expressions of 'performance' with respect to factors or impacts and the 'importance' of those factors/impacts. A simple example is developed to illustrate the method in the context of three road infrastructure projects assessed against five factors/impacts. In addition, a means to include hard or crisp factors is presented and illustrated with respect to a sixth factor.

A uniform white-noise model for fixed-point roundoff errors in digital systems

Fixed-point roundoff noise in digital implementation of linear systems arises due to overflow, quantization of coefficients and input signals, and arithmetical errors. In uniform white-noise models, the last two types of roundoff errors are regarded as uniformly distributed independent random vectors on cubes of suitable size. For input signal quantization errors, the heuristic model is justified by a quantization theorem, which cannot be directly applied to arithmetical errors due to the complicated input-dependence of errors. The complete uniform white-noise model is shown to be valid in the sense of weak convergence of probabilistic measures as the lattice step tends to zero if the matrices of realization of the system in the state space satisfy certain nonresonance conditions and the finite-dimensional distributions of the input signal are absolutely continuous.

Robust model-order reduction of complex biological processes

This paper addresses robust model-order reduction of a high dimensional nonlinear partial differential equation (PDE) model of a complex biological process. Based on a nonlinear, distributed parameter model of the same process which was validated against experimental data of an existing, pilot-scale BNR activated sludge plant, we developed a state-space model with 154 state variables in this work. A general algorithm for robustly reducing the nonlinear PDE model is presented and based on an investigation of five state-of-the-art model-order reduction techniques, we are able to reduce the original model to a model with only 30 states without incurring pronounced modelling errors. The Singular perturbation approximation balanced truncating technique is found to give the lowest modelling errors in low frequency ranges and hence is deemed most suitable for controller design and other real-time applications. (C) 2002 Elsevier Science Ltd. All rights reserved.

Instrumentation used to measure residential magnetic fields and currents

The equipment used to measure magnetic fields and, electric currents in residences is described. The instrumentation consisted of current transformers, magnetic field probes and locally designed and, built signal conditioning modules. The data acquisition system was capable of unattended recording for extended time periods. The complete system was calibrated to verify its response to known physical inputs. (C) 2003 ISA-The Instrumentation Automation Society.

Gobernaciones y nueva gesti??n p??blica en Venezuela

A fines de los ???80, el Estado venezolano inici?? una descentralizaci??n pol??tico-territorial produciendo cambios en las gobernaciones, instancias receptoras de competencias en este proceso, las cuales realizan reformas a trav??s de la estrategia selectiva, incorporando algunas de la propuestas de la nueva gesti??n p??blica. Este trabajo explora estas reformas. Se observan: diferencias entre los servicios sociales y los relacionados directamente con la econom??a; privatizaci??n de ??stos; traspaso a la sociedad civil de algunos servicios sociales, creaci??n de entes descentralizados; automatizaci??n de procesos; flexibilizaci??n laboral; iniciativas con lento avance en rendici??n de cuentas por resultados y capacitaci??n para una nueva cultura administrativa. En conclusi??n: la tendencia es a la conformaci??n de una gesti??n p??blica eficiente sobre la base de la reducci??n del aparato estatal, de costos sociales, as?? como de costos y conflictos laborales y escasa incorporaci??n de las propuestas de participaci??n que permiten profundizar la democracia y promover el bienestar social.

Metodologia de representação identitária do patrimônio territorial : a água como elemento de identidade em Linhares/ES

Apresenta primeiramente o conceito de desenvolvimento local autossustentável dentro do enfoque territorialista. Mostra também o conceito de patrimônio territorial e o de representação identitária do território como instrumento de preservação do patrimônio, neste caso o territorial. O enfoque territorialista é adotado como base teórica para a construção do roteiro metodológico de representação identitária do território com vistas à preservação do patrimônio tendo como objeto empírico o município de Linhares/ES, que passa por um processo de intenso desenvolvimento de seu território e que apresenta um rico patrimônio, no que diz respeito aos recursos naturais, em especial o hídrico. Nos últimos anos tem-se registrado um crescimento forte dos instrumentos disponíveis para a produção de imagens do território, neste caso o uso da tecnologia de Sistemas de Informações Geográficas. Por meio deste recurso, adotado na Escola Territorialista Italiana, representa-se o patrimônio que constitui o território municipal, tendo como produtos finais o Atlas do patrimônio territorial no município de Linhares/ES e o Roteiro metodológico de representação identitária do patrimônio territorial.

Heterodox Autonomy Doctrine: realism and purposes, and its relevance

The Autonomy Doctrine, elaborated by Juan Carlos Puig, is a realist point of view of International Relations. It is an analysis, from the periphery, about the structure of world power, and a roadmap (from a theoretical point of view) for the longing process of autonomization-regarding hegemonic power-for a country whose ruling class would decide to overcome dependency. The elements its author took into account when analyzing its own context are explained in this text and, afterwards, are reflected over its relevance nowadays. For that purpose, it is necessary to answer certain questions, such as which are the concepts and categories that may explain its relevance, its applicability to regional integration and cooperation models and projects, and what would be the analytical method to compare reality versus ideas, among others. The methodological proposal to analyze the relevance of Puig's doctrine is to compare it to different visions of regionalism that are currently in effect in Latin America.