Average reachability of continuous-time Markov jump linear systems and linear Markovian state observers

Stability of state estimators for Markov jump linear systems featuring time-varying and correlated noise processes are studied in this paper. Three conditions for stability are presented, starting with a more general one requiring positiveness of the covariance of the error estimate, and is applicable to a class of filters that contains the well known linear minimum mean square estimators. It is then derived a more strict condition based on the plant parameters only, which may be interpreted as requiring that the state additive noise pervades every system dynamics. Finally, we consider a structural notion linked with the reachability gramian and we show it is a sufficient condition for the previous ones to be fulfilled, thus linking the filter stability with the structure of the plant, and present a simple rank test. Illustrative examples are included

Average reachability of continuous-time Markov jump linear systems and the linear minimum mean square estimator

. In this paper we study the average reachability gramian for continuous-time linear systems with additive noise and jump parameters driven by a general Markov chain. We define a rather natural reachability concept by requiring that the average reachability gramian be positive definite. Aiming at a testable condition, we introduce a set of reachability matrices for this class of systems and employ invariance properties of the null space of the noise coefficient matrices to show that the system is reachable if and only if these matrices are of full rank. We also show for reachable systems that the state second moment is positive definite. One consequence of this result in the context of linear minimum mean square state estimation for reachable systems is that the expectation of the error covariance matrix is positive definite. Moreover, the average boundedness of the error covariance matrix is invariant to a type of perturbation in the noise model, meaning that the estimates are not overly sensitive, which consists in a property that is desirable in applications and sometimes referred to as stability of the estimator

Uma abordagem evolutiva para o problema de custo médio a longo prazo com saltos não-observados

Neste artigo propomos uma adaptação de um algoritmo baseado na evolução biológica para a obtenção do controle ótimo do problema do custo médio a longo prazo para sistemas lineares com saltos markovianos. Não há na literatura um método que forneça, comprovadamente, o controle ótimo do problema, nem estudos comparativos de diferentes métodos. O algoritmo empregado diferencia-se dos algoritmos genéticos básicos por substituir os operadores evolutivos por um sorteio de acordo com uma distribuição probabilística. Comparamos o algoritmo proposto com um método bastante utilizado para esta classe de problema, levando em consideração a relação entre os custos obtidos, o tempo de CPU e a quantidade de problemas em que o critério de parada estabelecido foi atingido

Potassium fertilization for long term no-till crop rotation in the central-southern region of Paraná, Brazil

Fertilization programs for annual crops in the state of Paraná, southern Brazil, are based on studies that focused on conventional tillage and were established more than 30 years ago. The primary purpose of this study was to assess potassium (K) fertilization on long-term (>30 years) no-tillage soybean, corn, wheat, and barley crops grown in rotation on Oxisols in the central-southern region of Paraná. A total of 47 experiments were carried out from 2008 to 2013, three of which addressed K calibration and the other 44, crop response to K fertilization. Critical K soil-test value and interpretation classes were established from the ratio between relative crop yield [RY = (yield without K/max yield) × 100] and soil K levels. Winter cereals were found to be more demanding of K than were soybean and corn; also, the former governed critical K soil-test value for crop rotation: 0.23 cmolc dm-3 in the 0.00-0.20 m soil layer. Recommended fertilization rates for soils in the low and medium soil K levels were established by using the build-up approach for soil correction; and those for the high and very high soil K levels were established by removing K at harvest and assessing economic return in crop response experiments. The K rates calculated for the high yield classes exceeded those currently recommended for use in Paraná

AVALIAÇÃO DA QUALIDADE DAS ÁGUAS SUBTERRÂNEAS EM ÁREAS DE PRESERVAÇÃO PERMANENTE (SISTEMA AQUÍFERO GUARANI – SAG), BACIA HIDROGRÁFICA DO RIO PARDO, RS, BRASIL

The aim of this research was to evaluate the quality of groundwater in areas of permanent preservation (Guarani Aquifer System – GAS) in the Rio Pardo Hydrographical Basin, RS, Brazil, using physical, chemical and microbiological variables, based on resolution no. 396/2008 of the National Council on the Environment - CONAMA. Nine sampling points were distributed throughout the basin, where groundwater was classified as the major ions through the Piper diagram. The results indicated that most of the wells evaluated were classified in Class 4, accounting for water uses less restrictive. However, it should be considered that the aquifers are characterize by different geological conditions, having intrinsical physical, chemical and biological variables with hydrogeochemical variations, requiring that their quality levels are often based on these characteristics, as noted in diagram Piper, where the samples P1, P2, P3, P5 and P9 were classified as calcium bicarbonate, the waters of the points P4, P6, P7 as sodium bicarbonate and P8 as sulfated. It was found that the quality of water from wells with depths less than 6 m are becoming more vulnerable due to anthropogenic activities, as showing by the concentration of nitrate, total and thermotolerant coliforms, while the quality of water from deeper wells basically depends on their hydrogeological and hydrogeochemical characteristics based on the concentration of sodium and sulfate variables. However, they also showed contamination by human activities, mainly by the nitrate variable.O objetivo principal deste estudo foi avaliar a qualidade das águas subterrâneas em áreas de preservação permanente (Sistema Aqüífero Guarani – SAG) da Bacia Hidrográfica do Rio Pardo, RS, Brasil, através de variáveis físicas, químicas e microbiológicas, tendo como base a resolução nº 396 do Conselho Nacional do Meio Ambiente – CONAMA. Nove pontos de coleta foram distribuídos ao longo da bacia, nos quais as águas subterrâneas foram classificadas quanto aos íons de maior ocorrência quantitativa através do diagrama de Piper. Os resultados indicaram que a maioria dos poços avaliados enquadraram-se na Classe 4 de usos da água, correspondendo a águas de usos menos restritivos. Entretanto, deve-se considerar que os aquíferos se apresentam em diferentes contextos geológicos, e que possuem características físicas, químicas e biológicas intrínsecas, com variações hidrogeoquímicas, sendo necessário que as suas classes de qualidade sejam pautadas nessas especificidades, como se observou no diagrama de Piper, onde as amostras P1, P2, P3, P5 e P9 classificaram-se como bicarbonatadas cálcicas, as águas dos pontos P4, P6, P7 como bicarbonatadas sódicas e P8 se classificou como sulfatada. Verificou-se que a qualidade das águas de poços com profundidade inferior a 6 m está mais vulnerável devido a alterações antrópicas em função da concentração de nitrato, coliformes totais e termotolerantes, enquanto que a qualidade das águas de poços mais profundos depende basicamente de suas características hidrogeológicas e hidrogeoquímicas naturais, em função das variáveis sulfato e sódio. Contudo, também apresentaram contaminação por atividade antrópica, principalmente pela variável nitrato

Phosphorus fertilization for high yield of soybean, maize, and winter cereal crops in rotation in oxisols under long-term no-till in the south central region of Parana, Brazil

O Estado do Paraná não dispõe de um sistema de recomendação de adubação para rotação de culturas em plantio direto (PD). Em razão disso, utiliza indicações geradas para culturas individuais há mais de 30 anos e em preparo convencional. Este estudo teve como objetivo consolidar a calibração de P e avaliar a resposta das culturas à adubação fosfatada, visando à proposição de um sistema de indicações técnicas para a adubação fosfatada das culturas da soja, do milho, do trigo e da cevada cultivadas em sistema de rotação em Latossolos com longo histórico de PD (>30 anos) na região centro-sul do Paraná, que se caracteriza por possuir alto potencial produtivo. Três experimentos de calibração foram conduzidos de 2008 a 2013 e consistiram na criação de níveis de P pela aplicação de doses a lanço de até 640 kg ha-1 de P2O5. Quarenta e quatro experimentos de resposta a P foram conduzidos entre as safras de 2011 a 2012/13, tendo como foco avaliar a resposta das culturas a P em solos com distinta disponibilidade do nutriente. Os rendimentos relativos [RR = (rendimento sem P/rendimento máximo) × 100] das culturas e os teores de P no solo (Mehlich-1) foram relacionados, obtendo-se os teores críticos e as classes de disponibilidade de P no solo. Para a estimativa das doses nas classes de disponibilidade Baixa e Média, foram utilizadas as curvas de resposta à adubação de P, seguindo a filosofia de suficiência (adubação de cultura) Nas classes de disponibilidade Alta e Muito Alta, as doses foram com base na exportação pelos grãos. Os cereais de inverno se evidenciaram mais exigentes e determinaram o teor crítico de P de 8 mg dm-3 para a rotação de culturas, considerando a camada de 0-20 cm. As doses de P indicadas para soja, milho, trigo e cevada em solos em PD de longa duração são superiores às de adubação atualmente indicadas no PR, o que, ao menos em parte, justificam-se pelas altas produtividades das culturas e alta capacidade de retenção de P dos solos da região. Embora adotada a filosofia de suficiência/adubação de cultura para a indicação das doses de adubação fosfatada em solos abaixo do teor crítico, estima-se que as doses estipuladas para as culturas elevem o teor de P no solo ao teor crítico após um ciclo da rotação de culturas (três anos).Although the State of Parana, Brazil, has adopted crop rotation and no-till (NT) systems, fertilizer application is still based on recommendations developed more than 30 years ago for monocropping under conventional tillage because fertilizer recommendations developed specifically for crop rotation under NT are lacking. The objective of our study was to consolidate P calibration and evaluate crop responses to P fertilization so as to propose a system of technical recommendations for P fertilization for soybean, maize, wheat, and barley grown in a crop rotation system in Oxisols under long-term (>30 years) NT systems in the high yield potential South-Central region of Parana. Three calibration trials were conducted from 2008 to 2013, consisting of P broadcast application rates of up to 640 kg ha-1 P2O5. Forty-four P fertilization trials were carried out over the 2011-2012/13 growing seasons to evaluate yield response to P fertilization rates in Oxisols with different levels of P availability. Relative crop yield [RR = (yield without P/maximum yield) × 100] and soil P availability (Mehlich-1) were compared to obtain P critical levels and generate soil P availability classes based on crop response. For soils in the Low and Medium availability classes, recommended P fertilizer application rates were based on the yield response curve following the nutrient sufficiency approach For soils in the High and Very High availability classes, P fertilizer recommendations were based on P removal through grain harvest. The winter cereal crops were more demanding to achieve maximum yields - the soil critical P level for the crop rotation system was determined at 8 mg dm-3 based on the requirement of these crops, considering the 0-20 cm soil layer. The recommended P fertilization rates for soybean, maize, wheat, and barley in Oxisols under long-term NT developed in our study are higher than the current P fertilization rates used in Parana, which is explained in part by the high crop yields and high P adsorption capacity of soils in the region. Although the nutrient sufficiency approach was used to determine P fertilization rates in the soils below the critical level, it is estimated that the P rates recommended for the crops will raise soil P availability above the critical level after a full crop-rotation cycle (3 years)

Gradient-based optimization techniques for the design of static controllers for Markov jump linear systems with unobservable modes

The paper formulates the static control problem of Markov jump linear systems, assuming that the controller does not have access to the jump variable. We derive the expression of the gradient for the cost motivated by the evaluation of 10 gradient-based optimization techniques. The numerical efficiency of these techniques is verified by using the data obtained from practical experiments. The corresponding solution is used to design a scheme to control the velocity of a real-time DC motor device subject to abrupt power failuresFAPESP (03 / 06736-7, 04 / 06947-0)CNPq (471557 / 2009-9, 304.856 / 2007-0, 304.429 / 2007-4, 306.466 / 2010-4)Fundación Carolina (Fundación Carolina - Programa "Movilidad de Professores e Investigadores Brasil-España. C.2010 "

AVALIAÇAO DA QUALIDADE DAS ÁGUAS SUBTERRÂNEAS DA BACIA HIDROGRÁFICA DO RIO PARDO, SISTEMA AQUÍFERO GUARANI, RS, BRASIL

O objetivo desta pesquisa foi avaliar a qualidade das águas subterrâneas em áreas de preservação permanente (Sistema Aquífero Guarani – SAG) da Bacia Hidrográfica do Rio Pardo, RS, Brasil, através de variáveis físicas, químicas e microbiológicas. Nove pontos de coleta foram distribuídos ao longo da bacia, nos quais as águas subterrâneas foram classificadas quanto aos íons de maior ocorrência quantitativa. Os resultados indicaram que a maioria dos poços avaliados enquadraram-se na Classe 4 de usos da água, correspondendo a águas de usos menos restritivos (como recreação de contato secundário). Entretanto, deve-se considerar que os aquíferos são caracterizados por diferentes condições geológicas, com características físicas, químicas e biológicas intrínsecas, e também variações hidrogeoquímicas, sendo necessário que as suas classes de qualidade sejam determinadas com base nessas especificidades. As amostras P1, P2, P3, P5 e P9 classificaram-se como bicarbonatadas cálcicas; as águas dos pontos P4, P6, P7 como bicarbonatadas sódicas; e P8 como sulfatada. Verificou-se que a qualidade das águas de poços com profundidade inferior a 6 m está mais vulnerável, devido a alterações antrópicas em função da concentração de nitrato, coliformes totais e termotolerantes, enquanto a qualidade das águas de poços mais profundos depende basicamente de suas características hidrogeológicas e hidrogeoquímicas naturais, em função das variáveis sulfato e sódio

Genomic-based surveillance reveals high ongoing transmission of multi-drug-resistant Mycobacterium tuberculosis in Southern Brazil

Funding Information: Funding: This study was funded, in part, by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (Grant No. 001) and supported by Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (Grant No. 17/1265–8 INCT-TB). JP is supported by Fundação para a Ciência e Tecnologia through Estímulo Individual ao Emprego Científico (CEECIND/00394/2017). Funding Information: The authors wish to thank TGen, C-Path and ReSeqTB for supporting WGS, and the Brazilian Network of Tuberculosis Research for enabling this partnership. The authors would also like to thank the Mycobacteria Laboratory at LACEN-RS/CEVS/SES-RS for performing and providing information on drug susceptibility testing. Funding: This study was funded, in part, by the Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - Brasil (Grant No. 001) and supported by Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul (Grant No. 17/1265?8 INCT-TB). JP is supported by Funda??o para a Ci?ncia e Tecnologia through Est?mulo Individual ao Emprego Cient?fico (CEECIND/00394/2017). Competing interests: None declared. Ethical approval: This project was approved by the Research Ethics Committee of the Funda??o Estadual de Produ??o e Pesquisa em Sa?de (Protocol No. 1.587.621 CAAE: 18269313.0.0000.5320). Data availability: M. tuberculosis genome data were deposited in the NCBI BioProject database (IDs: PRJNA535343, PRJNA639713 and PRJNA692642). Individual accession numbers for genomes analysed in this study are given in the online supplementary material. Publisher Copyright: © 2021 Elsevier LtdGenomic-based surveillance on the occurrence of drug resistance and its transmission dynamics has emerged as a powerful tool for the control of tuberculosis (TB). A whole-genome sequencing approach, phenotypic testing and clinical-epidemiological investigation were used to undertake a retrospective population-based study on drug-resistant (DR)-TB in Rio Grande do Sul, the largest state in Southern Brazil. The analysis included 305 resistant Mycobacterium tuberculosis strains sampled statewide from 2011 to 2014, and covered 75.7% of all DR-TB cases identified in this period. Lineage 4 was found to be predominant (99.3%), with high sublineage-level diversity composed mainly of 4.3.4.2 [Latin American and Mediterranean (LAM)/RD174], 4.3.3 (LAM/RD115) and 4.1.2.1 (Haarlem/RD182) sublineages. Genomic diversity was also reflected in resistance of the variants to first-line drugs. A large number of distinct resistance-conferring mutations, including variants that have not been reported previously in any other setting worldwide, and 22 isoniazid-monoresistant strains with mutations described as disputed in the rpoB gene but causing rifampicin resistance generally missed by automated phenotypic tests as BACTEC MGIT. Using a cut-off of five single nucleotide polymorphisms, the estimated recent transmission rate was 55.1%, with 168 strains grouped into 28 genomic clusters. The most worrying fact concerns multi-drug-resistant (MDR) strains, of which 73.4% were clustered. Different resistance profiles and acquisition of novel mutations intraclusters revealed important amplification of resistance in the region. This study described the diversity of M. tuberculosis strains, the basis of drug resistance, and ongoing transmission dynamics across the largest state in Southern Brazil, stressing the urgent need for MDR-TB transmission control state-wide.publishersversionpublishe