Networked PID control design : a pseudo-probabilistic robust approach

Networked Control Systems (NCS) are feedback/feed-forward control systems where control components (sensors, actuators and controllers) are distributed across a common communication network. In NCS, there exist network-induced random delays in each channel. This paper proposes a method to compensate the effects of these delays for the design and tuning of PID controllers. The control design is formulated as a constrained optimization problem and the controller stability and robustness criteria are incorporated as design constraints. The design is based on a polytopic description of the system using a Poisson pdf distribution of the delay. Simulation results are presented to demonstrate the performance of the proposed method

Reduction of unwanted swings and motions in floating wind turbines

A novel strategy to reduce unwanted swings and motions in floating wind turbines is presented. At above rated wind speeds, the platform, on which the wind turbine is mounted, causes the generator speed control loop to become unstable. The proposed strategy assures stability of the control loop by an additive adjustment of the measured generator speed using tower fictitious forces. The developed strategy is independent of the platform and wave dynamics

Gusts detection in a horizontal wind turbine by monitoring of innovations error of an extended Kalman filter

This paper presents a novel model-based detection scheme capable of detecting and diagnosing gusts. Detection is achieved by monitoring the innovations error (i.e., the difference between the estimated and measured outputs) of an extended discrete Kalman filter. It is designed to trigger a detection/confirmation alarm in the presence of wind anomalies. Simulation results are presented to demonstrate that both operating and coherent extreme wind gusts can successfully be detected. The wind anomaly is identified in magnitude and shape through maximum likelihood ratio and goodness of fit, respectively. The detector is capable of isolating extreme wind gusts before the turbine over speeds

Analysis of embedded CORBA middleware performance on urban distributed transportation equipments

The increasing number of ITS (Intelligent Transportation Systems) equipment spread across cities offers tre- mendous possibilities in the development of distributed smart environments. A middleware layer located be- tween the operating system and the fi nal application can be used for the communication among the equipment to spontaneously act and cooperate among themselves. However, this middleware layer has also a computational cost that should be quanti fi ed as it can affect the main application. This paper de fi nes a methodology for such quanti fi cation using as case example a modern ITS equipment related to vehicle tracking using arti fi cial vision. Experimental results illustrate the proposed methodology.Ministerio de Educación y Ciencia DPI2007-60128Consejería de Innovación, Ciencia y Empresa P07-TIC-0262

Viabilidade econômica agrícola e responsabilidade ambiental em unidades rurais de produção orgânica e convencional em Mundo Novo, MS.

bitstream/item/69064/1/099-recalde-viabilidade.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

A text categorisation tool for open source communities based on semantic analysis

Open source software (OSS) projects are supported by communities interacting through software repositories and mailing lists. Thousands of contributors participate in the development of the projects although they rarely meet each other. The result is a huge archived repository with thousands of questions, answers and contributions usually difficult to explore. We propose a tool based on semantic analysis for both performing an automatic knowledge discovery and a categorisation of the content of mailing lists repositories. Semantic analysis is a practical method for extracting and inferring relations of words in passages of discourse, producing measures of relations among words or passages that are well correlated with semantic similarity. The objective of this article is two-fold: (1) to develop a text categorisation tool based on indexing terms and semantic annotation, and (2) to apply the developed tool to extract the main dimensions related to knowledge sharing activities in virtual communities. Debian Linux ports to embedded processors are used as a case study to accomplish the proposed double objectiv

Executive functions and their relationship with intellectual capacity and age in schoolchildren with intellectual disability

Background: There is certain empirical evidence of, on the one hand, a positive correlation between executive functions (EFs) and intelligence in people with intellectual disability (ID) and, on the other hand, a slower rate of development of EFs in these people relative to people without ID. This evidence is not, however, unequivocal, and further studies are required. Methods: We analysed the relationship between development of EFs and both age and intellectual capacity, in a sample of 106 students with either ID or borderline intellectual functioning (BIF) at a special education centre [63 boys and 43 girls, 11-18 years old, mean total intelligence quotient (TIQ) of 59.6]. We applied nine instruments to evaluate both neuropsychological development (working memory, inhibitory control, cognitive flexibility, planning, processing speed and verbal fluency) and behavioural development [teachers' perceptions of the EFs of their students by Behavior Rating Inventory of Executive Function - Second Edition (BRIEF-2) School]. ID and BIF groups were statistically compared in terms of mean performance measures in EF tests. We looked at the correlation between EFs and age, and correlations between EFs and intelligence: TIQ, fluid intelligence [measured by the perceptual reasoning (PR) sub-index of Wechsler Intelligence Scale for Children-IV (WISC-IV)] and crystallised intelligence (measured by the verbal comprehension (VC) sub-index of WISC-IV). Regression models were built for variables with strong correlation. Results: In most of the tests used to evaluate EFs, the ID subgroup performed significantly worse than the subgroup with BIF. In general, teachers' thought that participants had 'medium-low' levels of EFs. TIQ, by WISC-IV scale, correlated significantly with scores in all tests for all EFs. The PR sub-index correlated significantly with 14 of the tests for EFs; 35% of the variation in PR can be explained by variation in performance in Picture Span (working memory) and Mazes (planning). The VC sub-index correlated weakly with seven of the EF tests. We found significant correlations in the ID group between age and scores in all tests of working memory and inhibitory control. Age - considering all participants - did not correlate with any of the variables of teachers' perception except for working memory, and this correlation was not strong. Conclusions: The results of our study are consistent with descriptions of the typical population: (1) fluid intelligence is more related to EFs than crystallised intelligence is; and (2) working memory capacity is the EF most strongly related with general, fluid and crystallised forms of intelligence. The results suggest that as children and adolescents with ID/BIF get older, their capacities for working memory and inhibitory control increase; development of the other EFs studied was less evident. Teachers' perceptions of the EFs of children with ID or BIF were independent of intellectual capacity and age. More research is needed to delve further into the development of EFs in people with ID/BIF

Propuesta de un modelo de programación por metas para la medición de la movilidad intergeneracional educativa en el departamento Central y Asunción, Paraguay

La medición de las variables que afectan el crecimiento económico de un país es de suma importancia para el análisis de la situación actual de una población, como también para la construcción de escenarios futuros. Además, una variable relevante a nivel mundial para la generación de políticas públicas, es el capital humano con sus componentes educación, salud y nutrición. En esta investigación se propone un modelo de programación por metas para la estimación de una matriz de probabilidades de transición, que refleje los niveles de movilidad intergeneracional educativa entre un individuo y su progenitor. Seguidamente, se calcula el índice de Shorrocks para describir el peso de la herencia entre generaciones. El modelo fue validado con datos oficiales de veinte años consecutivos de jefes de hogar de la ciudad de Asunción y del Departamento Central. Los resultados indican que se puede obtener una matriz de probabilidades de transición, para la medición de la movilidad intergeneracional educativa, aplicando un modelo de programación por metas basado en principios de cadenas de Markov.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Propuesta de un modelo de programación por metas para la medición de la movilidad intergeneracional educativa en el departamento Central y Asunción, Paraguay

La medición de las variables que afectan el crecimiento económico de un país es de suma importancia para el análisis de la situación actual de una población, como también para la construcción de escenarios futuros. Además, una variable relevante a nivel mundial para la generación de políticas públicas, es el capital humano con sus componentes educación, salud y nutrición. En esta investigación se propone un modelo de programación por metas para la estimación de una matriz de probabilidades de transición, que refleje los niveles de movilidad intergeneracional educativa entre un individuo y su progenitor. Seguidamente, se calcula el índice de Shorrocks para describir el peso de la herencia entre generaciones. El modelo fue validado con datos oficiales de veinte años consecutivos de jefes de hogar de la ciudad de Asunción y del Departamento Central. Los resultados indican que se puede obtener una matriz de probabilidades de transición, para la medición de la movilidad intergeneracional educativa, aplicando un modelo de programación por metas basado en principios de cadenas de Markov.Sociedad Argentina de Informática e Investigación Operativa (SADIO