Analysis of acoustic feedback cancellation systems based on direct closed-loop identification

This work presents, using the least squares estimation theory, a theoretical and experimental analysis on the performance of the standard adaptive filtering algorithms when applied to acoustic feedback cancellation. Expressions for the bias and covariance matrix of the acoustic feedback path estimate provided by these algorithms are derived as a function of the signals statistics as well as derivatives of the cost function. It is demonstrated that, in general, the estimate is biased and presents a large covariance because the closed-loop nature of the system makes the cross-correlation between the loudspeaker and system input signals non-zero. Simulations are carried out to exemplify the results using speech signals, a long acoustic feedback path and the recursive least squares algorithm. The results illustrate that these algorithms converge very slowly to a solution that is not the true acoustic feedback path. The relationship between the performance of the adaptive filtering algorithms and the aforementioned cross-correlation is proven by varying the signal-to-noise ratio and the delay introduced by the forward path.info:eu-repo/semantics/publishedVersio

Review of SINAT’s technical guidelines for Light Wood Frame walls components in Brazil

Para regulamentar inovações tecnológicas da indústria da construção brasileira, em 2007, foi instituído o Sistema Nacional de Avaliação Técnica (SINAT). Neste programa, destaca-se o sistema construtivo Light Wood Frame (LWF), que possui como base a Diretriz SINAT nº 005 e o DATec nº 20. No entanto, observou-se que tais documentos dão respaldo para empresas solicitarem a avaliação e a aprovação de seus produtos específicos. As apresentações dos dados não são intuitivas para um público geral. Na dúvida sobre quais dados adotar, muitos técnicos e construtores continuam procurando guias internacionais. Assim, este estudo tem como objetivo resumir as principais diretrizes referentes ao LWF publicadas pelo SINAT. Como resultado, são apresentadas informações específicas para os componentes de paredes divididas em: quadro estrutural, face externa e face interna. Esta é a primeira etapa de uma pesquisa acadêmica que pretende usar estes dados para elaboração de guias técnicos mais didáticos e ilustrativos, auxiliando na propagação adequada do LWF no contexto brasileiro.In order to regulate technological innovations in the Brazilian construction industry, in 2007, the Nacional System of Technical Evaluation (SINAT) was instituted. In this program, this paper highlights the light wood frame (LWF) system, based on the SINAT No. 005 and DATec No. 20. However, it was observed that such documents provide support for companies to request the evaluation and approval of their specific products. The data presented are not intuitive for a general public. In doubt about which data to adopt, many professionals continue to seek international guides. Thus, this study aims to summarize the main guidelines for the LWF published by SINAT. As a result, specific information is presented for the components of walls divided into: structural frame, outer face and inner face. This is the first stage of an academic research that intends to use this data for the elaboration of more didactic and illustrative technical guides, to assist in the adequate propagation of LWF in the Brazilian context

Design for production of a children’s house in light wood frame

Para edificações estruturadas em madeira são necessários projetos bem detalhados, com etapas e especialidades relacionadas e dependentes entre si. Seu projeto para produção deve ocorrer simultaneamente ao projeto arquitetônico. O projeto para produção de edificações do tipo wood frame pode contribuir para uma disseminação de qualidade. Este artigo tem como objetivo apresentar o caso de um projeto para produção desenvolvido para uma casinha para crianças constituída com o sistema wood frame. As principais etapas do método aplicado foram: (1) dividir a edificação em painéis de piso, parede e cobertura; (2) detalhar os componentes constituintes de cada painel; (3) locar os painéis na sua posição para a montagem final. Os resultados apresentam desenhos e tabelas desenvolvidos para a manufatura dos elementos pré-fabricados e sua montagem final no canteiro. Neste caso, observou-se que a padronização e a identificação dos componentes facilitaram na execução, evitando retrabalhos e agilizando o processo.For wooden structures, the design must comprehend many details, including execution stages and related interdependent specialties. The design for production must occur simultaneously with the architectural design. The design for production of wood frame buildings may contribute to a quality dissemination. This article aims to present a case of a design for production developed for a children's house constituted with the wood frame system. The main steps of the method applied were: (1) divide the building into floor, wall and roof panels; (2) detail the components of each panel; (3) place the panels in their position for final assembly. The results present drawings and tables developed for the manufacture of prefabricated elements and their final assembly at the construction site. In this case, it was observed that the standardization and identification of the components facilitated the execution, avoiding rework and streamlining the process

Design for production of a children’s house in light wood frame

Para edificações estruturadas em madeira são necessários projetos bem detalhados, com etapas e especialidades relacionadas e dependentes entre si. Seu projeto para produção deve ocorrer simultaneamente ao projeto arquitetônico. O projeto para produção de edificações do tipo wood frame pode contribuir para uma disseminação de qualidade. Este artigo tem como objetivo apresentar o caso de um projeto para produção desenvolvido para uma casinha para crianças constituída com o sistema wood frame. As principais etapas do método aplicado foram: (1) dividir a edificação em painéis de piso, parede e cobertura; (2) detalhar os componentes constituintes de cada painel; (3) locar os painéis na sua posição para a montagem final. Os resultados apresentam desenhos e tabelas desenvolvidos para a manufatura dos elementos pré-fabricados e sua montagem final no canteiro. Neste caso, observou-se que a padronização e a identificação dos componentes facilitaram na execução, evitando retrabalhos e agilizando o processo.For wooden structures, the design must comprehend many details, including execution stages and related interdependent specialties. The design for production must occur simultaneously with the architectural design. The design for production of wood frame buildings may contribute to a quality dissemination. This article aims to present a case of a design for production developed for a children's house constituted with the wood frame system. The main steps of the method applied were: (1) divide the building into floor, wall and roof panels; (2) detail the components of each panel; (3) place the panels in their position for final assembly. The results present drawings and tables developed for the manufacture of prefabricated elements and their final assembly at the construction site. In this case, it was observed that the standardization and identification of the components facilitated the execution, avoiding rework and streamlining the process

Allergies and Diabetes as Risk Factors for Dengue Hemorrhagic Fever: Results of a Case Control Study

Dengue is an arboviral disease that affects large areas of countries in tropical and subtropical regions of the world. Around 500,000 cases and 22,000 deaths of dengue hemorrhagic fever (DHF)/Dengue Shock Syndrome (DSS), the most severe presentations of this disease, occur annually. It is unclear why some cases of dengue fever (0.5% to 4%) progress to DHF/DSS. There is weak evidence that some diseases could have a role in this process, such as diabetes, hypertension, and allergies. In epidemics most dengue fever cases are sent home as there are too many to be kept in observation, but if it were possible to identify those with a higher risk of progression to DHF, they could be kept for observation, for early detection of signs, symptoms and alterations in laboratory tests suggestive of DHF, to enable timely and effective clinical management and early intervention. We study this issue and we believe that the evidence produced in this study, when confirmed in other studies, suggests that screening criteria might be used to identify adult patients at a greater risk of developing DHF with a recommendation that they remain under observation and monitoring in a hospital

Serologic Survey of Hantavirus Infection, Brazilian Amazon

Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.Federal University of Maranhão. São Luís, MA, Brazil.State Department of Health. São Luís, MA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil

Epidemia de dengue em Fortaleza, Ceará: inquérito soro-epidemiológico aleatório

OBJECTIVE: A seroepidemiological random survey was carried out in Fortaleza city, State of Ceará, Brazil, following an epidemic of dengue virus type 2 (DEN 2), with the purpose of evaluating the frequency of clinical manifestations (signs and symptoms) and the prevalence of dengue infection. METHOD: A questionnaire calling for information on address, sex, age, clinical, epidemiological and economic status was applied to the population, followed by venupuncture collection of 5-10 ml of blood for testing by hemagglutination-inhibition (HI). The sample was calculated to obtain a prevalence of 20% with relative risk of 10% and confidence interval of 95%. All information obtained was analyzed by computer using Epi Info 5.0®, Lotus 123®, Excel 5.0®, and Stata® software. RESULTS AND CONCLUSIONS: A total of 1,341 serum samples were obtained from nine Health Districts (SD) and tested by hemagglutination inhibition. Of these, 589 (44%) were positive and 752 (56%) negative. Of the positive results, 93 primary responses (PR) (7%) to DEN-2 and 496 secondary responses (SR) (37%) were observed. The global prevalence in the SD ranged from 21% to 71%. There were 41% (243/589) asymptomatic infections and 59% (346/589) symptomatic infections. Data analysis showed no difference in frequency by sex, age, on schooling, although a highly statistically significant difference was found as between the different social classes, the infection most commonly observed being among people of better social status.The stratification of positive cases showed greater prevalence of AI (pOBJETIVO: Seguindo-se à epidemia de dengue (DEN), em 1994, em Fortaleza, Ceará, causada pelo sorotipo 2 (DEN-2), realizou-se inquérito soro-epidemiológico aleatório para avaliar e dimensionar o impacto da mesma e a prevalência do dengue por distrito sanitário. MÉTODO: Foi aplicado questionário contendo informações gerais, condições socio-econômicas, informações sobre o quadro clínico e tempo de doença. A amostra foi calculada para estimar uma prevalência de 20%, com erro relativo de 10%, e intervalo de confiança de 95% (erro a de 5%). O sorteio e as análises foram realizadas por meio de computador usando programas apropriados. RESULTADOS E CONCLUSÕES: Foram colhidas 1.341 amostras de soro de 9 distritos sanitários, testadas por inibição da hemaglutinação, sendo classificadas como negativas e positivas (respostas primária - RP e secundária - RS). Foram reativas 588 (44%) amostras, sendo 93 (7%) RP e 495 (37%) RS. A prevalência global em Fortaleza variou de 21% a 71%. Houve 41% (243/588) de infecções assintomáticas (IA) e 59% (346/588) sintomáticas (IS). Não houve diferença da prevalência quanto ao sexo, faixa etária e escolaridade, ao contrário da condição socioeconômica que apresentou diferenças estatisticamente significantes (p < 0,001). Ocorreram mais IA (

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised