187 research outputs found

    Integração de um sensor a laser a um manipulador cartesiano de soldagem para o seguimento automático de juntas

    Get PDF
    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2015O presente trabalho aborda a integração de um sensor óptico a laser a um robô para automação da soldagem. O sensor é fabricado por uma empresa estrangeira, a Meta Vision Systems. O manipulador robótico faz parte da família TARTILOPES, desenvolvido pelo Laboratório de Soldagem da UFSC, LABSOLDA. Esse sensor é capaz de reconhecer e medir o perfil da junta de soldagem durante a execução da união, disponibilizando informações em tempo real sobre o posicionamento da tocha de soldagem ao longo da junta soldada. A utilização destes dados torna possível a realização do seguimento de junta, situação em que o manipulador é comandado para manter sempre o mesmo posicionamento em relação ao centro da junta. O sistema desenvolvido neste trabalho demandou a aplicação de um protocolo de comunicação entre o software para seguimento de junta e o controlador do robô. Os algoritmos de correção de trajetória foram criados contemplando duas situações distintas, de movimentação com e sem oscilação da tocha de soldagem. Os dois algoritmos foram testados em quatro ensaios diferentes. Nos ensaios foram abordados desde a calibração destes até a comparação do sistema desenvolvido com um manipulador comercial para seguimento de junta. Os corpos de prova projetados para ensaio dos algoritmos contemplaram diversas variações geométricas acentuadas, impondo ao sistema a necessidade de contínua correção da trajetória de soldagem. Ao final dos ensaios, o sistema desenvolvido neste trabalho se mostrou capaz de realizar o seguimento de junta em situações de extrema solicitação.This work discusses the integration of an optical laser sensor to a robot for welding automation. The sensor is manufactured by a foreign company, Meta Vision Systems. The robotic manipulator is part of the TARTILOPES family, developed by Welding Laboratory of UFSC, LABSOLDA. This sensor is able to recognize and measure the profile of the weld joint while the union is made, providing real-time information about the positioning of the welding torch along the weld joint. Using such data makes it possible to have the seam tracking, in which the manipulator is operated to always maintain the same relative position to the joint center. The system developed in this study required the implementation of a communication protocol between the software for seam tracking and the robot controller. The trajectory correction algorithms were created considering two distinct situations, handling with and without oscillation of the welding torch. Both algorithms were tested in four different experiments. The tests included from the calibration of these algorithms to the comparison with a commercial system designed for seam tracking. The specimens designed to test the algorithms included several sharp geometric variations, demanding the system the need for continuous adjustment of the welding trajectory. At the end of the tests, the system developed in this paper proved to be able to perform the seam-tracking request in extreme situations

    Towards Optimal Graph Coloring Using Rydberg Atoms

    Get PDF
    Quantum mechanics is expected to revolutionize the computing landscape in the near future. Among the many candidate technologies for building universal quantum computers, Rydberg atoms-based systems stand out for being capable of performing both quantum simulations and working as gate-based universal quantum computers while operating at room temperature through an optical system. Moreover, they can potentially scale up to hundreds of quantum bits (qubits). In this work, we solve a Graph Coloring problem by iteratively computing the solutions of Maximal Independent Set (MIS) problems, exploiting the Rydberg blockade phenomenon. Experimental results using a simulation framework on the CINECA Marconi-100 supercomputer demonstrate the validity of the proposed approach

    Deep Learning for real-time neural decoding of grasp

    Full text link
    Neural decoding involves correlating signals acquired from the brain to variables in the physical world like limb movement or robot control in Brain Machine Interfaces. In this context, this work starts from a specific pre-existing dataset of neural recordings from monkey motor cortex and presents a Deep Learning-based approach to the decoding of neural signals for grasp type classification. Specifically, we propose here an approach that exploits LSTM networks to classify time series containing neural data (i.e., spike trains) into classes representing the object being grasped. The main goal of the presented approach is to improve over state-of-the-art decoding accuracy without relying on any prior neuroscience knowledge, and leveraging only the capability of deep learning models to extract correlations from data. The paper presents the results achieved for the considered dataset and compares them with previous works on the same dataset, showing a significant improvement in classification accuracy, even if considering simulated real-time decoding

    Facial filling with polymethylmethacrylate in patients with acquired immunodeficiency syndrome

    Get PDF
    INTRODUCTION: Patients with acquired immunodeficiency syndrome (AIDS) who use highly active antiretroviral therapy (HAART) can develop lipodystrophy syndrome, for which facial filling with polymethylmethacrylate is a treatment option. The objective is to analyze the procedure of facial filling and evaluate patients in relation to their perception, discomfort, revelation of the diagnosis to third parties, expectation concerning facial filling, and satisfaction with the treatment outcome and its impact on their lives. METHODS: Sixty-three patients who underwent facial filling were evaluated. Procedures performed between January and July 2009 were assessed, the records of the patients were analyzed, and the outpatient lipodystrophy protocol of the STD/AIDS and Viral Hepatitis Municipal Program of SĂŁo Bernardo do Campo was used. RESULTS: All the 63 patients who agreed to participate in the research completed the study. Only 6 patients (9.5%) were from other municipalities, while 57 patients (90.5%) were residents of SĂŁo Bernardo. Of the patients, 68.2% were men and 100% were Caucasian. The mean age of the patients was 49.7 years. Human immunodeficiency virus was diagnosed 11.5 years prior on average, with 10-year average use of HAART and 3.8-year average time of facial lipoatrophy. Most of the patients used stavudine and/or efavirenz. The patients themselves felt more uncomfortable with facial changes. Among the patients, 85.7% did not reveal the diagnosis to third parties. CONCLUSION: All of the patients were satisfied or very satisfied with the result obtained, which had a favorable impact on their lives. The filling surgical procedure had no adverse effects

    RNA Editing Genes Associated with Extreme Old Age in Humans and with Lifespan in C. elegans

    Get PDF
    The strong familiality of living to extreme ages suggests that human longevity is genetically regulated. The majority of genes found thus far to be associated with longevity primarily function in lipoprotein metabolism and insulin/IGF-1 signaling. There are likely many more genetic modifiers of human longevity that remain to be discovered.Here, we first show that 18 single nucleotide polymorphisms (SNPs) in the RNA editing genes ADARB1 and ADARB2 are associated with extreme old age in a U.S. based study of centenarians, the New England Centenarian Study. We describe replications of these findings in three independently conducted centenarian studies with different genetic backgrounds (Italian, Ashkenazi Jewish and Japanese) that collectively support an association of ADARB1 and ADARB2 with longevity. Some SNPs in ADARB2 replicate consistently in the four populations and suggest a strong effect that is independent of the different genetic backgrounds and environments. To evaluate the functional association of these genes with lifespan, we demonstrate that inactivation of their orthologues adr-1 and adr-2 in C. elegans reduces median survival by 50%. We further demonstrate that inactivation of the argonaute gene, rde-1, a critical regulator of RNA interference, completely restores lifespan to normal levels in the context of adr-1 and adr-2 loss of function.Our results suggest that RNA editors may be an important regulator of aging in humans and that, when evaluated in C. elegans, this pathway may interact with the RNA interference machinery to regulate lifespan

    Adaptação cultural em Português Brasileiro da Derriford Appearance Scale – 24 (DAS-24) para pessoas vivendo com HIV/AIDS

    Get PDF
    Introduction: Body image can be defined as the representation of beliefs, emotions and perceptions about the body itself, manifested in behaviors directed to the body. When the body changes because of a disease and does not seem healthy, the self-concept may be severely challenged. People living with HIV/AIDS (PLHA) are particularly vulnerable to the distress and psychosocial impact of appearance, but in Brazil the assessment of those body image changes was subjective because there was not an available scale in Brazilian Portuguese to assess body image changes in clinical practice or research. Objective: To carry out the cross-cultural adaptation to the Brazilian Portuguese of the Derriford Appearance Scale 24 (DAS-24), with the verification of the linguistic, semantic, conceptual and cultural equivalence of the people living with HIV/AIDS in Brazil. Methods: We followed the five stages of culturally sensitive translation: direct translations, synthesis of translations, back-translations, expert committee meeting and pre-tests. The process of cultural adaptation was presented in a descriptive and analytical way, following patterns of methodological studies. The minimum, maximum and median values of the responses of each item were calculated from the pool of data from the third pretest group of 50 participants. The median of the item scores, the correlation on each item with the total score and the internal reliability, were calculated using the Cronbach alpha test. Results: The analysis of the responses of the last pre-test group indicated that attention must be given to itemsA, H, T and V in a future psychometric study. The present study is not enough for this scale to be used in clinical practice. To ensure that the culturally adapted instrument generates valid and reliable data, a subsequent study investigating its psychometric properties should be conducted. Conclusion: The cross-cultural adaptation of the Derriford Appearance Scale 24 (DAS-24) in its components of linguistic, semantic, conceptual and cultural equivalence to Brazilian Portuguese for the population of people living with HIV/AIDS was fully carried out. Despite this achievement, it is emphasized that the use of the Brazilian versionof DAS-24 in research and clinical routine is advised only after a psychometric study with this instrument.Introdução: A imagem corporal pode ser definida como a representação das crenças, emoções e percepções a respeito do prĂłprio corpo, manifesta em comportamentos voltados ao corpo. Quando o corpo muda como consequĂŞncia de doença e nĂŁo parece mais saudável, a definição de si mesmo pode ser severamente desafiada. As pessoas vivendo com HIV/AIDS (PVHA) sĂŁo um pĂşblico especialmente vulnerável quando se trata do “distress” e do impacto psicossocial da aparĂŞncia, mas a avaliação destas alterações de imagem corporal era subjetiva porque nĂŁo havia nenhuma escala em PortuguĂŞs Brasileiro para avaliar alterações da imagem disponĂ­vel para uso clĂ­nico ou para pesquisa. Objetivo: Realizar a adaptação transcultural para o portuguĂŞs Brasileiro da Derriford Appearance Scale 24 (DAS-24), com a verificação da equivalĂŞncia idiomática, semântica, conceitual e cultural, para o pĂşblico-alvo pessoas vivendo com HIV/AIDS (PVHA) no Brasil. MĂ©todo: Seguiu-se guia de cinco etapas para adaptação de escala transcultural: traduções, sĂ­ntese de traduções, retrotraduções, reuniĂŁo de comitĂŞ de especialistas e prĂ©-testes. O processo de adaptação cultural foi apresentado de forma descritiva e analĂ­tica, seguindo padrões de estudos metodolĂłgicos. Os valores mĂ­nimo, máximo e mediano das respostas de cada item foram calculados a partir do pool de dados do terceiro grupo de prĂ©-teste de 50 participantes. A mediana dos escores dos itens, a correlação de cada item com o escore total e a confiabilidade interna foram calculados pelo teste alfa de Cronbach. Resultado: A análise das respostas do Ăşltimo grupo prĂ©-teste indicou que deve ser dada atenção aos itens A, B, G, H e K em um futuro estudo psicomĂ©trico. O presente estudo nĂŁo Ă© suficiente para que essa escala seja utilizada na prática clĂ­nica. Para garantir que o instrumento culturalmente adaptado gere dados válidos e confiáveis, um estudo subsequente que investigue suas propriedades psicomĂ©tricas deve ser conduzido. ConclusĂŁo: A adaptação transcultural da Derriford Appearance Scale 24 (DAS-24), em seus componentes de equivalĂŞncia linguĂ­stica, semântica, conceitual e cultural para o portuguĂŞs brasileiro para a população de pessoas vivendo com HIV/AIDS foi plenamente realizada. Apesar dessa conquista, ressalta-se que o uso da versĂŁo brasileira do DAS-24 em pesquisa e rotina clĂ­nica Ă© aconselhado somente apĂłs um estudo psicomĂ©trico com este instrumento
    • …
    corecore