Passive exoskeletons hold promise in reducing the risk of work-related musculoskeletal disorders, however further research is essential before widespread adoption can occur. This study explores the feasibility of using subjective measures of physical demand in place of costly and less practical objective measures. Normalized electromyography (nEMG) data and ratings of perceived exertion (RPE) were collected from seven different studies conducted by the Occupational Ergonomics and Biomechanics Lab (OEB lab). Employing a repeated measures three-way ANOVA, we assessed the influence of nEMG, gender, and exoskeleton type on RPE. Additionally, mean nEMG and RPE from seven passive exoskeleton-based studies conducted outside the OEB lab were assessed in order to determine if the findings from the OEB lab existed across other research environments. The results demonstrated a general positive linear trend between nEMG and RPE for both the individual and mean results. Substantial inconsistencies emerged when considering the influence of gender, exoskeleton type, and task conditions on the relationship between nEMG and RPE. These discrepancies underscore the need for more in-depth research into this topic, specifically investigating the effects of gender and exoskeleton design. / Master of Science / Passive exoskeletons, devices designed to improve safety and provide support to the body, offer the potential for reducing muscle strain and reducing work-related injury risk. However, before these devices can be widely adopted, more research is necessary. Subjective measures of exertion, an affordable and user-friendly alternative to objective measures, require further investigation before replacing traditional methods in exoskeleton research. This study explores the possible connection between subjective and objective assessments of physical demand during passive exoskeleton usage. We analyzed data from seven studies conducted by the Occupational Ergonomics and Biomechanics Lab (OEB lab), focusing on muscle activity (an objective measure) and perceived exertion (a subjective measure). Our analysis examined the relationship between these objective and subjective measures, as well as how gender, exoskeleton type, and task conditions influenced this relationship. Additionally, we considered mean values from seven passive exoskeleton studies conducted outside the OEB lab, to investigate whether our findings existed in other research environments. The results revealed that as muscle activity increased, perceived exertion tended to increase as well. Moreover, our findings demonstrated that gender, exoskeleton type, and task conditions did influence the relationship, although there was significant variability in how these factors affected it. This research sheds light on the potential for using subjective measures in exoskeleton studies, bringing us closer to making exoskeletons more practical and accessible for real-world applications while acknowledging the complexities of this relationship.

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No. of bitstreams: 1 DissFCB.pdf: 2039382 bytes, checksum: deb6e0cfa82a6110cc30a62b7c764d4c (MD5) Previous issue date: 2016-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Background: Office work is associated with prolonged awkward postures, overloading body structures when associated with improper ergonomic conditions, and may be associated with musculoskeletal disorders. Effective ergonomic interventions for reducing biomechanical exposure are not documented. Therefore it is necessary to identify effective preventive measures, using objective measurements of occupational exposure, for controlling and preventing these disorders. Objective: This study aimed to evaluate the effectiveness of an ergonomic intervention by a cluster randomized and controlled design using objective measures to evaluate head, cervical spine, thoracic spine and shoulders postures during work, perceived discomfort and musculoskeletal pain, among office workers. Methods: Sixty one administrative employees were evaluated at a university sector where 95 employees work. The allocation of subjects to the groups was performed by cluster randomization. The clusters was the rooms in which the subjects work. Thus, two groups (experimental group [EG; n = 31] and control group [CG; n = 30]) were compared before (T1) and 30 minutes (T2) after the application of the intervention. Assessment of perceived discomfort, musculoskeletal pain and postures of the head, cervical spine, thoracic spine and shoulders, and in addition, photos were taken for both groups at T1 and T2 was held. The EG received a workstation ergonomic intervention since the CG took a 15-minute break, but received no intervention in the workplace. Kolmogorov-Smirnov test were used to test the data distribution and Levene test for homogeneity of variances between groups. Then, a linear mixed model analysis was performed to compare groups at the two assessments. Mann Whitney test was applied to compare the groups for discomfort, pain and the final score of the ROSA. The data were analyzed using SPSS (version 22.0) and the significance level was set at 5%. The photos were analyzed descriptively and were also punctuated using the ROSA tool. Results: A significant interaction between group and time was found only for shoulders. The EG presented an arm lowering regarding the elevation on T2, on P90 it lowered 8,81º and 8.46, on right and left shoulders, respectively, since the CG had similar values in T1 and T2, with the P90 raising 0,88º and 1,97º on the right and left shoulders. For the upper back was found a significant difference in relation to time, showing a reduction on flexion in both groups at T2. The head and neck postures were similar between the time in both groups. On T2, the EG showed a significant reduction on perceived discomfort (2.2 mm), and pain on neck (0.07 points), shoulders (0.16 points) and upper back (0.32 points) regions; and for CG there was an increase of the same variables (0.72, 1.73, 0.82 mm and 1.06 points, respectively). Conclusion: The furniture adjustment was important to reduce the exposure of shoulders and perceived discomfort and pain referred to neck, shoulders and upper back areas. The pause was beneficial to improve superior trunk posture, probably due to postural changes. These results highlight the importance of using objective measures to evaluate the effectiveness of ergonomics interventions. / Contextualização: O trabalho de escritório implica ao trabalhador tempo prolongado na postura sentada, gerando sobrecarga quando associado a condições ergonômicas inadequadas, podendo causar distúrbios musculoesqueléticos. Intervenções ergonômicas efetivas para redução da exposição biomecânica ainda não estão documentadas. Portanto é necessário identificar medidas preventivas efetivas, utilizando medidas objetivas da exposição no trabalho, para prevenção e controle destes distúrbios. Objetivo: Este estudo teve por objetivo avaliar a efetividade de uma intervenção ergonômica randomizada por cluster e controlada utilizando medidas objetivas de avaliação das posturas da cabeça, coluna cervical, coluna torácica e ombros durante o trabalho, desconforto percebido e dor musculoesquelética em trabalhadores de escritório. Método: Foram avaliados 61 trabalhadores administrativos de uma universidade, em uma secretaria na qual trabalham 95 funcionários. A alocação dos sujeitos aos grupos foi realizada de forma aleatorizada por cluster. A unidade de agrupamento (cluster) foram as salas nas quais os sujeitos trabalhavam. Desta forma, dois grupos (grupo experimental [GE; n=31] e grupo controle [GC; n=30]) foram comparados antes (T1) e 30 minutos após (T2) a aplicação da intervenção. Foi realizada avaliação do desconforto percebido, dor musculoesquelética e posturas da cabeça, coluna cervical, coluna torácica e ombros, além da realização de fotos de ambos os grupos em T1 e T2 para aplicação do instrumento Rapid Office Strain Assessement (ROSA). O GE recebeu uma intervenção ergonômica nos postos de trabalho, já o GC realizou uma pausa de 15 minutos, mas não recebeu nenhuma intervenção no posto de trabalho. O modelo linear misto foi utilizado para comparar os grupos e os tempos. Para testar a diferença entre os grupos em relação à dor, desconforto e pontuação final do ROSA foi aplicado o teste Mann Whitney. Os dados foram analisados utilizando o programa SPSS (versão 22.0) e o nível de significância adotado foi de 5%. Resultados: Foi encontrada interação significativa entre grupo e tempo apenas para a postura dos ombros. O GE apresentou redução na elevação dos ombros, sendo que no percentil 90 o ombro direito e esquerdo reduziram 8,8º e 8,5o, respectivamente, já o GC apresentou valores semelhantes em T1 e T2, com um aumento de 0,9º e 2º para os ombros direito e esquerdo no percentil 90. Para o tronco superior, houve diferença significativa em relação ao tempo, com redução da flexão de tronco superior em ambos os grupos. As posturas de cabeça e cervical foram semelhantes entre os tempos em ambos os grupos. O GE apresentou redução significativa do desconforto percebido (22 mm) e da dor no pescoço (0,07 pontos), ombros (0,16 pontos) e parte superior das costas (0,32 pontos); já para o GC houve um aumento das mesmas variáveis (0,72 mm; 1,73; 0,82 e 1,06 pontos, respectivamente). Conclusão: A intervenção ergonômica reduziu a exposição dos ombros, o desconforto percebido e a dor no pescoço, ombros e parte superior das costas. A pausa foi benéfica para melhorar a postura de tronco superior, provavelmente devido à variação postural. Estes resultados destacam também a importância e necessidade do uso de medidas objetivas para avaliar a eficácia das intervenções ergonômicas.

Purpose: Listening effort has traditionally been measured using subjective rating scales and behavioral measures. Recent physiological measures of listening effort have utilized pupil dilation. Using a combination of physiological and subjective measures of listening effort, this study aimed to identify differences in listening effort during 2 auditory tasks: sentence recognition and word recognition. Method: Pupil dilation and subjective ratings of listening effort were obtained for auditory tasks utilizing AzBio sentences recognition and Northwestern University Auditory Test No. 6 words recognition, across 3 listening situations: in quiet, at +6 dB signal-to-noise ratio, and at 0 dB signal-to-noise ratio. Task accuracy was recorded for each of the 6 conditions, as well as peak pupil dilation and a subjective rating of listening effort. Results: A significant impact of listening situation (quiet vs. noise) and task type (sentence recognition vs. word recognition) on both physiological and subjective measures was found. There was a significant interaction between listening situation and task type, suggesting that contextual cues may only be beneficial when audibility is uncompromised. The current study found no correlation between the physiological and subjective measures, possibly suggesting that these measures analyze different aspects of cognitive effort in a listening task.

Dans un contexte fortement concurrentiel, l'un des principaux enjeux pour les opérateurs et les fournisseurs de services de visiophonie est de garantir aux utilisateurs une qualité d'expérience (QoE) optimale. Il existe un fort besoin d'une mesure qui reflète la satisfaction et la perception des utilisateurs de ces services. La qualité audiovisuelle d'un appel vidéo doit être contrôlée pour répondre à deux besoins principaux. Le premier concerne la planification de nouvelles technologies en cours de développement. Le second est axé sur le contrôle des communications existantes en évaluant la qualité des services offerts. Aujourd'hui, deux approches sont utilisées pour évaluer la qualité audiovisuelle : les tests subjectifs en collectant des notes données par des participants sur des échelles de qualité, après visualisation et écoute de séquences audiovisuelles et les métriques objectives basées sur des algorithmes automatiques d'évaluation de la qualité d'un signal audio, vidéo ou audiovisuel. Concernant les services de téléphonie, des décennies de recherche, de standardisation et d'exploitation des réseaux ont permis aux opérateurs de maîtriser les outils de diagnostic et de déterminer les métriques représentatives de la qualité vocale. Cependant, les méthodes de mesure de la qualité audiovisuelle des services conversationnels ne sont pas encore matures et peu exploitées par les opérateurs de télécommunication. Le présent travail est centré sur la recherche de métriques représentatives de la perception de la qualité des nux associés aux services de visiophonie et de visioconférence. Ces métriques objectives sont calculées à partir du signal audio et vidéo. Des tests subjectifs sont menés afin de collecter le jugement des utilisateurs du service sur la qualité perçue en fonction de différents niveaux de dégradations. Nous avons étudié l'impact des conditions réseau (perte de paquet, gigue et désynchronisation) sur la QoE d'un appel vidéo. Le principe général est ensuite d'établir une corrélation forte entre les métriques objectives sélectionnées et la qualité perçue telle qu'elle est exprimée par les utilisateurs. Les résultats ont montré que les nouvelles métriques de qualité globale audiovisuelle qui prennent en compte l'aspect temporel de la vidéo sont plus performantes que les métriques basées qualité d'images. D'autre part l'utilisation d'une approche machine learning représente une solution pour générer un modèle de prédiction de la qualité globale à partir des métriques de dégradation (flou, pixellisation, gel d'images, ... ) / In a highly competitive environment, one of the key challenges for operators and providers of video telephony services is to ensure the highest quality of experience (QoE). There is a strong need for a measure that reflects users satisfaction and perception of these services. The audio-visual quality of a video call must be controlled to meet two main needs. The first concerns the planning of new technologies under development. The second is focused on the control of existing communications by assessing the quality of the services offered and evaluating them. Two approaches are used to evaluate audio-visual quality: subjective tests by collecting scores given by participants on quality scales, after viewing and listening to audiovisual sequences and objective metrics based on automatic audio/ video or audiovisual quality evaluation algorithms. Concerning telephony services, decades of research, standardization work and network exploitation, have allowed operators to master the automatic monitoring tools and to determine the representative metrics of voice quality. However, the metrics for measuring the audiovisual quality of a conversational services are not yet mature and not exploited by telecommunication operators. The present work focuses on finding representative metrics of the perception of the video telephony anc videoconferencing services quality. These objective metrics are calculated from the audio and video signals. Subjective tests are conducted to collect the judgment of service users on the perceived quality according to different levels of degradation. We studied the impact of network conditions (packet loss, jitter and desynchronization) on the QoE of a video call. The general principle is then to establish a correlation between the selected objective metrics and the perceived quality as expressed by the users. The results showed that new metric of overall audiovisual quality that take into account the temporal aspect of video are more powerful than image quality based metrics. On the other hand, the use of a machine learning approach represents a solution to generat a global quality prediction model from the degradation metrics (blur, pixelization, image freezing, ... )

O processo de mineração de dados tem como objetivo encontrar o conhecimento implícito em um conjunto de dados para auxiliar a tomada de decisão. Do ponto de vista do usuário, vários problemas podem ser encontrados durante a etapa de pós-processamento e disponibilização do conhecimento extraído, como a enorme quantidade de padrões gerados por alguns algoritmos de extração e a dificuldade na compreensão dos modelos extraídos dos dados. Além do problema da quantidade de regras, os algoritmos tradicionais de regras de associação podem levar à descoberta de conhecimento muito específico. Assim, pode ser realizada a generalização das regras de associação com o intuito de obter um conhecimento mais geral. Neste projeto é proposta uma metodologia interativa que auxilie na avaliação de regras de associação generalizadas, visando melhorar a compreensibilidade e facilitar a identificação de conhecimento interessante. Este auxílio é realizado por meio do uso de técnicas de visualização em conjunto com a aplicação medidas de avaliação objetivas e subjetivas, que estão implementadas no módulo de visualização de regras de associação generalizados denominado RulEE-GARVis, que está integrado ao ambiente de exploração de regras RulEE (Rule Exploration Environment). O ambiente RulEE está sendo desenvolvido no LABIC-ICMC-USP e auxilia a etapa de pós-processamento e disponibilização de conhecimento. Neste contexto, também foi objetivo deste projeto de pesquisa desenvolver o Módulo de Gerenciamento do ambiente de exploração de regras RulEE. Com a realização do estudo dirigido, foi possível verificar que a metodologia proposta realmente facilita a compreensão e a identificação de regras de associação generalizadas interessantes / The data mining process aims at finding implicit knowledge in a data set to aid in a decision-making process. From the users point of view, several problems can be found at the stage of post-processing and provision of the extracted knowledge, such as the huge number of patterns generated by some of the extraction algorithms and the difficulty in understanding the types of the extracted data. Besides the problem of the number of rules, the traditional algorithms of association rules may lead to the discovery of very specific knowledge. Thus, the generalization of association rules can be realized to obtain a more general knowledge. In this project an interactive methodology is proposed to aid in the evaluation of generalized association rules in order to improve the understanding and to facilitate the identification of interesting knowledge. This aid is accomplished through the use of visualization techniques along with the application of objective and subjective evaluation measures, which are implemented in the visualization module of generalized association rules called RulEE-GARVis, which is integrated with the Rule Exploration Environment RulEE. The RulEE environment is being developed at LABIC-ICMC-USP and aids in the post-processing and provision of knowledge. In this context, it was also the objective of this research project to develop the Module Management of the rule exploration environment RulEE. Through this directed study, it was verified that the proposed methodology really facilitates the understanding and identification of interesting generalized association rules

O processo de mineração de dados tem como objetivo encontrar o conhecimento implícito em um conjunto de dados para auxiliar a tomada de decisão. Do ponto de vista do usuário, vários problemas podem ser encontrados durante a etapa de pós-processamento e disponibilização do conhecimento extraído, como a enorme quantidade de padrões gerados por alguns algoritmos de extração e a dificuldade na compreensão dos modelos extraídos dos dados. Além do problema da quantidade de regras, os algoritmos tradicionais de regras de associação podem levar à descoberta de conhecimento muito específico. Assim, pode ser realizada a generalização das regras de associação com o intuito de obter um conhecimento mais geral. Neste projeto é proposta uma metodologia interativa que auxilie na avaliação de regras de associação generalizadas, visando melhorar a compreensibilidade e facilitar a identificação de conhecimento interessante. Este auxílio é realizado por meio do uso de técnicas de visualização em conjunto com a aplicação medidas de avaliação objetivas e subjetivas, que estão implementadas no módulo de visualização de regras de associação generalizados denominado RulEE-GARVis, que está integrado ao ambiente de exploração de regras RulEE (Rule Exploration Environment). O ambiente RulEE está sendo desenvolvido no LABIC-ICMC-USP e auxilia a etapa de pós-processamento e disponibilização de conhecimento. Neste contexto, também foi objetivo deste projeto de pesquisa desenvolver o Módulo de Gerenciamento do ambiente de exploração de regras RulEE. Com a realização do estudo dirigido, foi possível verificar que a metodologia proposta realmente facilita a compreensão e a identificação de regras de associação generalizadas interessantes / The data mining process aims at finding implicit knowledge in a data set to aid in a decision-making process. From the users point of view, several problems can be found at the stage of post-processing and provision of the extracted knowledge, such as the huge number of patterns generated by some of the extraction algorithms and the difficulty in understanding the types of the extracted data. Besides the problem of the number of rules, the traditional algorithms of association rules may lead to the discovery of very specific knowledge. Thus, the generalization of association rules can be realized to obtain a more general knowledge. In this project an interactive methodology is proposed to aid in the evaluation of generalized association rules in order to improve the understanding and to facilitate the identification of interesting knowledge. This aid is accomplished through the use of visualization techniques along with the application of objective and subjective evaluation measures, which are implemented in the visualization module of generalized association rules called RulEE-GARVis, which is integrated with the Rule Exploration Environment RulEE. The RulEE environment is being developed at LABIC-ICMC-USP and aids in the post-processing and provision of knowledge. In this context, it was also the objective of this research project to develop the Module Management of the rule exploration environment RulEE. Through this directed study, it was verified that the proposed methodology really facilitates the understanding and identification of interesting generalized association rules

Theoretical background indicates that ownership structure and the type of management can influence performance of companies. According to the typology model of Westhead and Howorth (2007), we analyzed the relationship between management control and ownership structure in the performance of the family owned hotels. The data was collected from surveys applied to managers and owners. We surveyed 92.51% of accommodation options in Costa Esmeralda, Santa Catarina / Brazil. In addition to calculate average scores, a factor analysis was also conducted. Results were classified into five types of family owned businesses. We identified a greater use of objective performance indicators in businesses hiring managers, showing positive financial indicators in this type of business. Subjective indicators related to the hotel industry, from the model of Haber and Reichel (2005), proved to be useful to explain performance. Reaching income goals and maintaining financial health had the highest average in the sample; as well as achieving visitor satisfaction and developing a good reputation, which were the most prioritized goals of the companies surveyed. This work contributes to the research on the classification and organizational analysis of family businesses, and the development of performance indicators in the hotel industry. / Los antecedentes teóricos indican que la estructura de la propiedad y el tipo de gestión pueden influir en el rendimiento de las empresas. Según el modelo tipológico de Westhead y Howorth (2007), se analizó la relación entre el control y la estructura de la propiedad en el desempeño de las empresas hoteleras familiares. Se obtuvo información de los cuestionarios aplicados a los administradores y propietarios. Se encuestó al 92.51% de alojamientos en la Costa Esmeralda, Santa Catarina / Brasil. Además del cálculo de promedios también se utilizó un análisis factorial. Los resultados se clasificaron en cinco tipos de negocios hoteleros familiares y se identificó un mayor uso de los indicadores de desempeño objetivos en las empresas que contratan administradores, demostrando una relación positiva entre los indicadores financieros en este tipo de empresas. Los indicadores subjetivos específicos al sector hostelero, según el modelo de Haber y Reichel (2005), demostraron ser útiles para entender el rendimiento. Los indicadores para alcanzar los objetivos de ingresos y mantener la salud financiera alcanzada tuvieron el promedio más alto en la muestra; del mismo modo, la satisfacción de los usuarios y la creación de una buena reputación fueron las metas más priorizados por las empresas encuestadas. Este trabajo contribuye a la investigación sobre la clasificación y el análisis organizacional de las empresas familiares, eldesarrollo de indicadores de desempeño en las organizaciones del sector hotelero y de servicio. / Antecedentes teóricos apontam que a estrutura de propriedade e tipo de gestão podem influenciar no desempenho das empresas. Baseados no modelo tipológico de Westhead e Howorth (2007), foi analisada a relação do controle de gestão eestrutura de propriedade no desempenho de empresas hoteleiras familiares. Os dados foram obtidos a partir de questionários aplicados a gestores e proprietários. Foram pesquisados 92,51% dos meios de hospedagem da Costa Esmeralda, Santa Catarina/Brasil. Além do cálculo de médias também foi utilizada a análise fatorial. Como resultados foram classificados cinco diferentes tipos de empreendimentos hoteleiros familiares e identificado maior uso de indicadores de desempenho objetivos nas empresas que contratam gestores, constatando-se uma relação positiva entre os indicadores financeiros dessestipos de empresas. Indicadores subjetivos específicos do setor hoteleiro, do modelo de Haber e Reichel (2005), mostraramse úteis para explicar a performance; atingir metas de lucro e manter a saúde financeira conquistada foram os com maior média na amostra, da mesma forma o sucesso em satisfazer o consumidor e em criar reputação positiva foram os mais priorizados pelas empresas pesquisadas. Este trabalho contribui para as pesquisas sobre classificação e análise organizacional de empresas familiares, construção de indicadores de desempenho das organizações do setor hoteleiro e serviços.