<p>The purpose of this dissertation was to use an integrative theoretical framework to examine the individual and environmental factors associated with leisure-time physical activity (LTPA) for persons living with spinal cord injury (SCI). Using a systematic approach, three studies were conducted to: (1) survey the accessibility and availability of physical activity facilities for Canadians living with mobility disabilities, (2) test an integrative, theoretical framework for understanding LTPA among people with SCI, and (3) implement a theory-based intervention that focuses on helping beginner exercisers living with SCI cope with salient individual and environmental LTPA barriers. </p> <p>Study 1 involved two sub-studies. Study lA used a modified version of the AIMFREE instrument (Rimmer et al., 2004) and provided evidence of the limited accessibility of fitness and recreational facilities (n=44) for persons with mobility disabilities. Study lB applied a geographical technique, Geographical Information Systems (GIS), to develop an objective proximity measure specific to persons with SCI. Results indicated a small, negative association between the objective presence of physical activity facilities and L TPA in a sample of persons with SCI (n=50), suggesting that living in close proximity to a facility which provides adaptive programming and equipment does not necessarily translate into greater LTPA for persons with SCI.</p> <p>As an extension of Study 1, Study 2 used structural equation modeling to conduct a cross-sectional examination of whether an environmental factor --neighbourhood perceptions--could enhance the Theory of Planned ehaviour's (TPB; Ajzen, 1985) ability to explain LTPA intentions and behaviour in persons with SCI (n=246). Results indicated a small, negative association between perceived wheeling infrastructure and LTPA intentions. However, perceptions of neighbourhood aesthetics and wheeling infrastructure did not explain significant variance in either L TPA intentions or behaviour, beyond that accounted for by the TPB constructs, suggesting that these eighbourhood factors do not enhance the TPB's ability to explain LTPA behaviour.</p> <p>Lastly, Study 3 used a randomized, controlled design to examine the effects of a 10-week action and coping planning intervention on enhancing LTPA and coping self efficacy in exercise intenders living with SCI (n=47). Results indicated greater LTPA for participants who formed action plans and coping plans (A+C condition) than for the participants who only formed action plans (A condition). Furthermore, the A+C condition had greater confidence to schedule their L TPA and overcome L TPA-related barriers than the A condition. These findings provide evidence of the benefits of supplementing action plans with coping plans for enhancing L TP A and coping self-efficacy beliefs among exercise intenders living with SCI. </p> <p>Together, these three studies provide a broader understanding of L TPA correlates and determinants in people with SCI, and provide evidence of the efficacy of multiple planning strategics for promoting L TPA in persons with SCI. The results provide an impetus for extending the scope of the research on the physical environment and LTPA towards persons with mobility disabilities. Moreover, the findings demonstrate the value of theory-based research for identifying the multidimensional correlates and determinants of LTPA, and for designing effective LTPA-enhancing interventions in persons with SCI. </p> / Thesis / Doctor of Philosophy (PhD)

<p>Using a cross-sectional design, Bandura's (1986) Social Cognitive Theory and Self-Efficacy Theory (1977) were used as a framework to determine whether wheelchairuse self-efficacy and exercise barrier self-efficacy mediate the relationship between wheelchair mobility and leisure-time physical activity (LTPA) in people with spinal cord injury (SCI). Fourty-six manual wheelchair users (76.1 % male), with varying levels of SCI (80.4% paraplegic, 47.8% complete injuries) participated in this study. Participants completed The Wheelchair Skills Test version 4.1 (Wheelchair Skills Test Version 4.1 [WST 4.1],2008) which measured wheelchair mobility, a modified barrier self-efficacy questionnaire (McAuley & Mihalko, 1998) which measured exercise barrier self-efficacy, the Wheelchair Mobility Confidence Scale (WMCS; Rushton & Miller, 2009) which measured wheelchair-use self-efficacy, and the Physical Activity Recall Assessment for people with SCI (PARA-SCI; Martin Ginis, Latimer, Hicks & Craven, 2005) which measured LTPA. It was hypothesized that (1) there would be a positive relationship between wheelchair mobility and LTPA, and (2) wheelchair-use self-efficacy and exercise barrier self-efficacy would mediate this relationship. Using linear regression models, a positive association between wheelchair mobility and LTPA was established (β = .29, p < .05). Exercise barrier self-efficacy was a significant partial mediator, explaining 47.7% ofthe variance in the mobility-LTPA relationship. Wheelchair-use selfefficacy was a non-significant mediator. This thesis has practical and theoretical implications for understanding and improving LTPA participation and represents the first study to determine the relationship between wheelchair mobility, self-efficacy, and LTPA in people living with SCI.</p> / Master of Science (MS)

The purpose of this dissertation was to test the utility of theories across the development, implementation, and evaluation of three nationwide knowledge translation (KT) interventions in the physical disability community. Using a theory-based evaluation guided by the Theory of Planned Behaviour (TPB), Study 1 evaluates the effectiveness of an evidence-based, continuing education module designed to increase emergency health care professionals’ (HCPs) knowledge and use of clinical practice guidelines for managing patients with spinal cord injury (SCI) who present with autonomic dysrefexia. Findings suggest that behaviour change theory should be integrated into the intervention to change theory-based determinants of behaviour, and that information about intervention implementation may help explain observed outcomes. Study 2 examined the use of theory across three phases of research in the Canadian Paralympic Committee’s Changing Minds, Changing Lives (CMCL) intervention. Study 2.1 describes the restructuring of the CMCL curriculum to include research evidence and theory. Study 2.2 evaluates the short- and long-term effects of the CMCL intervention on HCPs’ social cognitions for discussing leisure-time physical activity (LTPA), and explores key implementation variables that predict changes in HCPs’ social cognitions. Overall Study 2 results suggest that: (1) using a KT framework and integrating stakeholders throughout intervention development increases the likelihood that interventionists will adopt and implement the intervention, and (2) real-world implementation is important to understanding intervention effectiveness. Study 3 examines the effectiveness, and its implementation correlates, of Get in Motion (GIM), a nationwide, LTPA-enhancing telephone counseling service for adults with SCI. Study 3 furthers our understanding of the relationship between implementation and effectiveness, and suggests key implementation ingredients that could be targeted in future refinements of GIM. Together, the dissertation studies contribute to our understanding of how to use theory when developing, implementing, and evaluating behaviour change interventions targeting HCPs and other end-users in the physical disability community. / Dissertation / Doctor of Philosophy (PhD)

O horário de atividade é um importante aspecto da vida de um animal, refletindo sua fisiologia, interações com o ambiente e com outros animais. Dentre os sinais exógenos que ajudam a determinar o início e fim de um dia para um animal estão a luz, temperatura, precipitação e disponibilidade de alimento. Em nosso estudo buscamos determinar o horário de atividade de duas espécies de roedores cricetídeos, Akodon montensis e Delomys dorsalis, verificando como este é influenciado por variáveis ambientais (temperatura e umidade) e pela disponibilidade da semente da araucária (pinhão). Para isso, utilizamos 21 armadilhas acopladas com relógios para determinar o horário de captura dos animais em oito grades de floresta com araucária nativa. As armadilhas permaneceram funcionando por cinco noites consecutivas em excursões bimestrais no período de março de 2010 a fevereiro de 2011. Para determinar a influência do pinhão no horário de atividade comparamos a época dentro e fora de sua produção. Também removemos o pinhão, experimentalmente, de quatro das grades para determinar como a ausência desse recurso sazonal afeta o comportamento dos animais (grades remoção). Encontramos um padrão de atividade bimodal para A. montensis e unimodal para D. dorsalis, sendo as duas espécies predominantemente noturnas e apresentando padrões de atividade noturnos distintos. Em A. montensis, verificamos diferenciações no horário de atividade entre o inverno e o verão, com a atividade nos meses mais frios apresentando um pico no início na noite e, nos meses mais quentes, apresentando um pico no fim da noite. A. montensis também apresentou horários médios de atividade diferentes entre as grades controle (21h35min) e remoção (23h51min). Em D. dorsalis verificamos uma relação positiva entre o horário de atividade e a temperatura ambiente. O efeito da remoção do pinhão sobre a atividade de A. montensis reforça a importância dessa espécie para a fauna de pequenos mamíferos. / An important aspect of an animal’s life is its activity pattern, which reflects its physiology, interactions with the environment and with other animals. Among the exogenous signs that help determine the beginning and end of a day to an animal are light, temperature, precipitation and food availability. In our study we aimed to determine the daily activity patterns of two species of cricetid rodents, Akodon montensis and Delomys dorsalis, analyzing how these are influenced by the availability of an important seasonal resource, the seed of the araucaria tree (Araucaria angustifolia), and by environmental variables (temperature and humidity). To do so, we used 21 live-traps equipped with clocks that determined the time an individual was captured in eight grids placed in native araucaria forest. The traps were set on the grids for five consecutive nights during six excursions, which took place between March 2010 and February 2011. To determine the influence of the araucaria seed on the daily activity of the two species, we compared the times of capture registered during the production season of the seed and outside of the production period. We also experimentally removed the araucaria seeds from four of the grids, to determine how the absence of this seasonal resource affects the behavior of the studied species (removal grids). We found a bimodal daily activity pattern for A. montensis and a unimodal pattern for D. dorsalis, and both species were considered predominantly nocturnal and presented distinct nocturnal activity patterns. A. montensis showed a differentiation in its daily activity pattern between winter and summer, presenting a peak of activity in the beginning of the night in the colder months and at the end of night during the warmer months. A. montensis also presented different average activity hours between the control grids (9:35 p.m.) and removal grids (11:51 p.m.). We found a positive relationship between the daily activity time of D. dorsalis and ambient temperature. The effect of the removal of the araucaria seed on the daily activity of A. montensis reinforces the importance of this tree species to the small mammal fauna.

O horário de atividade é um importante aspecto da vida de um animal, refletindo sua fisiologia, interações com o ambiente e com outros animais. Dentre os sinais exógenos que ajudam a determinar o início e fim de um dia para um animal estão a luz, temperatura, precipitação e disponibilidade de alimento. Em nosso estudo buscamos determinar o horário de atividade de duas espécies de roedores cricetídeos, Akodon montensis e Delomys dorsalis, verificando como este é influenciado por variáveis ambientais (temperatura e umidade) e pela disponibilidade da semente da araucária (pinhão). Para isso, utilizamos 21 armadilhas acopladas com relógios para determinar o horário de captura dos animais em oito grades de floresta com araucária nativa. As armadilhas permaneceram funcionando por cinco noites consecutivas em excursões bimestrais no período de março de 2010 a fevereiro de 2011. Para determinar a influência do pinhão no horário de atividade comparamos a época dentro e fora de sua produção. Também removemos o pinhão, experimentalmente, de quatro das grades para determinar como a ausência desse recurso sazonal afeta o comportamento dos animais (grades remoção). Encontramos um padrão de atividade bimodal para A. montensis e unimodal para D. dorsalis, sendo as duas espécies predominantemente noturnas e apresentando padrões de atividade noturnos distintos. Em A. montensis, verificamos diferenciações no horário de atividade entre o inverno e o verão, com a atividade nos meses mais frios apresentando um pico no início na noite e, nos meses mais quentes, apresentando um pico no fim da noite. A. montensis também apresentou horários médios de atividade diferentes entre as grades controle (21h35min) e remoção (23h51min). Em D. dorsalis verificamos uma relação positiva entre o horário de atividade e a temperatura ambiente. O efeito da remoção do pinhão sobre a atividade de A. montensis reforça a importância dessa espécie para a fauna de pequenos mamíferos. / An important aspect of an animal’s life is its activity pattern, which reflects its physiology, interactions with the environment and with other animals. Among the exogenous signs that help determine the beginning and end of a day to an animal are light, temperature, precipitation and food availability. In our study we aimed to determine the daily activity patterns of two species of cricetid rodents, Akodon montensis and Delomys dorsalis, analyzing how these are influenced by the availability of an important seasonal resource, the seed of the araucaria tree (Araucaria angustifolia), and by environmental variables (temperature and humidity). To do so, we used 21 live-traps equipped with clocks that determined the time an individual was captured in eight grids placed in native araucaria forest. The traps were set on the grids for five consecutive nights during six excursions, which took place between March 2010 and February 2011. To determine the influence of the araucaria seed on the daily activity of the two species, we compared the times of capture registered during the production season of the seed and outside of the production period. We also experimentally removed the araucaria seeds from four of the grids, to determine how the absence of this seasonal resource affects the behavior of the studied species (removal grids). We found a bimodal daily activity pattern for A. montensis and a unimodal pattern for D. dorsalis, and both species were considered predominantly nocturnal and presented distinct nocturnal activity patterns. A. montensis showed a differentiation in its daily activity pattern between winter and summer, presenting a peak of activity in the beginning of the night in the colder months and at the end of night during the warmer months. A. montensis also presented different average activity hours between the control grids (9:35 p.m.) and removal grids (11:51 p.m.). We found a positive relationship between the daily activity time of D. dorsalis and ambient temperature. The effect of the removal of the araucaria seed on the daily activity of A. montensis reinforces the importance of this tree species to the small mammal fauna.

O horário de atividade é um importante aspecto da vida de um animal, refletindo sua fisiologia, interações com o ambiente e com outros animais. Dentre os sinais exógenos que ajudam a determinar o início e fim de um dia para um animal estão a luz, temperatura, precipitação e disponibilidade de alimento. Em nosso estudo buscamos determinar o horário de atividade de duas espécies de roedores cricetídeos, Akodon montensis e Delomys dorsalis, verificando como este é influenciado por variáveis ambientais (temperatura e umidade) e pela disponibilidade da semente da araucária (pinhão). Para isso, utilizamos 21 armadilhas acopladas com relógios para determinar o horário de captura dos animais em oito grades de floresta com araucária nativa. As armadilhas permaneceram funcionando por cinco noites consecutivas em excursões bimestrais no período de março de 2010 a fevereiro de 2011. Para determinar a influência do pinhão no horário de atividade comparamos a época dentro e fora de sua produção. Também removemos o pinhão, experimentalmente, de quatro das grades para determinar como a ausência desse recurso sazonal afeta o comportamento dos animais (grades remoção). Encontramos um padrão de atividade bimodal para A. montensis e unimodal para D. dorsalis, sendo as duas espécies predominantemente noturnas e apresentando padrões de atividade noturnos distintos. Em A. montensis, verificamos diferenciações no horário de atividade entre o inverno e o verão, com a atividade nos meses mais frios apresentando um pico no início na noite e, nos meses mais quentes, apresentando um pico no fim da noite. A. montensis também apresentou horários médios de atividade diferentes entre as grades controle (21h35min) e remoção (23h51min). Em D. dorsalis verificamos uma relação positiva entre o horário de atividade e a temperatura ambiente. O efeito da remoção do pinhão sobre a atividade de A. montensis reforça a importância dessa espécie para a fauna de pequenos mamíferos. / An important aspect of an animal’s life is its activity pattern, which reflects its physiology, interactions with the environment and with other animals. Among the exogenous signs that help determine the beginning and end of a day to an animal are light, temperature, precipitation and food availability. In our study we aimed to determine the daily activity patterns of two species of cricetid rodents, Akodon montensis and Delomys dorsalis, analyzing how these are influenced by the availability of an important seasonal resource, the seed of the araucaria tree (Araucaria angustifolia), and by environmental variables (temperature and humidity). To do so, we used 21 live-traps equipped with clocks that determined the time an individual was captured in eight grids placed in native araucaria forest. The traps were set on the grids for five consecutive nights during six excursions, which took place between March 2010 and February 2011. To determine the influence of the araucaria seed on the daily activity of the two species, we compared the times of capture registered during the production season of the seed and outside of the production period. We also experimentally removed the araucaria seeds from four of the grids, to determine how the absence of this seasonal resource affects the behavior of the studied species (removal grids). We found a bimodal daily activity pattern for A. montensis and a unimodal pattern for D. dorsalis, and both species were considered predominantly nocturnal and presented distinct nocturnal activity patterns. A. montensis showed a differentiation in its daily activity pattern between winter and summer, presenting a peak of activity in the beginning of the night in the colder months and at the end of night during the warmer months. A. montensis also presented different average activity hours between the control grids (9:35 p.m.) and removal grids (11:51 p.m.). We found a positive relationship between the daily activity time of D. dorsalis and ambient temperature. The effect of the removal of the araucaria seed on the daily activity of A. montensis reinforces the importance of this tree species to the small mammal fauna.

This diploma thesis discusses the issue of Voice Activity Detection. There are two types of detectors described: energetic and statistics. Their funktionality is proved in the Matlab environment. Further, the implemetation of VADs is made through C language with standard libraries and GSL open-source libraries. The realized algorithms are compared in the scope of processing time of computation, memory management and a single mathematical operations stress. Also a comparism of the processing time according to segment length was made.

Participation in leisure-time physical activity (LTPA) is vital to ensure adequate physical work capacity for the demands of daily living and job performance. Due to work demand, most top and middle (executive) managerial employees become physically inactive and experience psychological and other health problems which may lead to hypokinetic diseases and even premature death. The purpose of this study was twofold: to determine leisure-time physical activity and psychological well-being status of executive employees; and to determine the relationship between leisure-time physical activity and psychological well-being status of executive employees in selected African countries. A cross-sectional study design was carried out on a group of 156 (mean age 41.22±10.17) available executive employees from selected African countries. Participants were grouped according to age (≤35 years; 36–46 years and ≥ 46 years). Standardised questionnaires were used to collect the data. Subsequently, total scores were calculated for all variables. Out of 156 participants in the study, 42.9% occupied top level management and 57.1% middle level management positions. When data was analysed according to age groups, 31.4% and 68.6% in the less than 35 years age group were in the top and the middle level management positions respectively. In the age group 36 to 46 years, 47.2% occupied the top level management position and 52.8% occupied the middle level management position. With regard to LTPA, top level managers (71.6%) scored low LTPA compared to the middle level managers (62.9%). In addition, both the top and middle level managers reported bad emotional index (49.3%; 56.2%) and happiness index (41.8%; 37.1%) respectively. Though not significant, LTPA was positively associated with psychological well-being parameters amongst top level managers. The study concluded that both top and middle level managers exhibited low LTPA, and with no participation in high physical activity among top level managers. In addition, more middle level managers reported bad emotional stage than the top level managers, while the top level managers were less happy than the middle level managers. The study therefore recommends urgent strategic intervention programmes for leisure-time physical activity and psychological well-being. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2014

Esta pesquisa versa sobre o tema decisão de mix de produtos que, em uma visão de Gestão de Produção e Operações, pode ser entendido como a definição da quantidade ideal a ser produzida de cada tipo de produto em um determinado período, considerando que estes competem por um número limitado de recursos, de forma a maximizar o resultado econômico (ex: lucro líquido) da empresa. Os modelos de decisão de mix produtos utilizam informações sobre rentabilidade que é determinada a partir de análises e confrontos entre os preços de vendas e os custos dos produtos, custos esses que são mensurados através de métodos de custeio. Dentre os métodos de custeio existentes na literatura, destacam-se o Custeio por Absorção, o Custeio Direto, o Custeio Baseado em Atividades (ABC) e o Custeio Baseado em Atividades e Tempo (TDABC). O TDABC, apesar de lançado na literatura em 2004 e detalhado em 2007 a partir de um livro publicado por Robert Kaplan e Steven Anderson, ainda não foi explorado diretamente pela literatura que versa sobre decisão de mix de produtos, ao contrário dos outros métodos de custeio mencionados. Nesse contexto, esta dissertação tem como objetivo primário construir um modelo quantitativo para alicerçar a decisão de mix de produtos que incorpore a lógica de custeio do TDABC. Para cumprir o objetivo primário, inicialmente, a dissertação é desenvolvida metodologicamente com a realização de uma pesquisa bibliográfica para discutir conceitos e posicionar a pesquisa sobre decisão de mix de produtos e sobre métodos de custeio, com destaque ao TDABC. Em seguida, utiliza-se modelagem quantitativa com vistas à proposição de um modelo baseado no TDABC para decisão de mix de produtos. A partir de um exemplo didático envolvendo um ambiente de manufatura, é ilustrada a aplicação do modelo proposto. Finalmente, conclui-se que o modelo proposto sob a ótica do TDABC é útil para fundamentar a decisão de mix de produtos. A dissertação possui, ainda, os objetivos secundários de posicionar teoricamente, de analisar criticamente e de caracterizar as publicações acadêmicas internacionais sobre decisão de mix de produtos no tocante (i) aos países nos quais os estudos foram originados, (ii) aos principais canais de publicação (periódicos) dos trabalhos, (iii) aos tipos de pesquisa utilizados e (iv) aos destaques em termos de autores e de publicações mais citados. Para cumprir os objetivos secundários, são realizados um levantamento bibliográfico em três portais de periódicos, uma análise bibliométrica dos artigos prospectados e uma análise crítica do conteúdo das publicações sobre decisão de mix de produtos. A partir dos resultados da análise bibliométrica, conclui-se que: (i) a produção acadêmica sobre decisão de mix de produtos apresentou um crescimento considerável a partir de 1991; (ii) 71% das publicações concentram-se em periódicos estritamente relacionados com o campo acadêmico da Gestão de Produção e Operações; (iii) há uma forte concentração das pesquisas em universidades dos Estados Unidos e é relevante o papel de pesquisadores vinculados a instituições de países orientais (Taiwan, Índia e China) na produção acadêmica internacional sobre decisão de mix de produtos; (iv) 77% das publicações foram trabalhados pelos autores a partir dos tipos de pesquisa Modelagem Matemática/Quantitativa e Teórico/Conceitual; e (v) Gerrard Plenert, pesquisador da Brigham Young University, foi o autor mais citado nos artigos analisados. / This research addresses the theme \"product-mix decision\" that, in a Production and Operations Management perspective, can be understood as the definition of the optimum quantity to be produced for each type of product in a given period, considering these products compete for limited resources in order to maximize the firm economic result (e.g. net profit). Product-mix decision models use information on profitability, which is determined from analysis and confrontation between sales prices and costs of the products supplied by the company. These products costs are measured by costing methods. Among the existing costing methods in the literature, Absorption Costing, the Direct Costing, the Activity Based Costing (ABC) and Time- Driven Activity-Based Costing (TDABC) are highlighted. TDABC, despite appearing in the literature in 2004 and detailed in 2007 from a book written by Robert Kaplan and Steven Anderson, has not been directly explored in the literature that deals with the product-mix decision, unlike the other costing methods mentioned. In this context, the dissertation aims primarily to build a quantitative model to underpin the productmix decision incorporating the TDABC approach. To meet the primary objective, firstly, the dissertation is methodologically developed from a literature research to discuss concepts and positioning the research on product-mix decision and on costing methods, emphasizing TDABC. Then, quantitative modeling is used in order to propose a model based on TDABC to assist product-mix decision. An application of the proposed model is illustrated from a didactic example involving a manufacturing environment. Finally, it is concluded that the model proposed from the perspective of TDABC can be helpful for decision making related to product-mix. Secondarily, the dissertation also aims to position theoretically, to analyze critically, and to characterize the academic literature on the product-mix decision published in international journals with respect to (i) the countries where the studies were originated, (ii) the main journals that publish the studies, (iii) the research approach used, and (iv) the highlights in terms of authors and publications cited. In order meet the secondary objectives, a bibliographic survey on three internet portals, a bibliometric analysis of the prospected papers, and a critical analysis of the content of product-mix decision publications are carried out. The bibliographic survey resulted in 70 academic articles on product-mix decision published in international journals. From the results of the bibliometric analysis, it was found that: (i) productmix decision academic research has grown since 1991; (ii) 71% of the publications focus on academic journals strictly related to the Production and Operations Management field; (iii) there is a strong concentration of research in American universities and the role of researchers from institutions in Eastern countries (Taiwan, India and China) is relevant in product-mix decision international publication; (iv) 77% of the publications were treated by the authors as from two research approaches: Mathematical/Quantitative Modeling and Theoretical/Conceptual; and (v) the most cited author in the articles analyzed is researcher Gerrard Plenert, from Brigham Young University.

Esta pesquisa versa sobre o tema decisão de mix de produtos que, em uma visão de Engenharia de Produção, pode ser entendido como a definição da quantidade ideal a ser produzida de cada tipo de produto em um determinado período, considerando que estes competem por um número limitado de recursos, de forma a maximizar o resultado econômico (ex: lucro operacional) da empresa. Os modelos de decisão de mix produtos utilizam informações sobre lucratividade que é determinada a partir de análises e confrontos entre os preços de vendas e os custos (gastos) dos produtos, custos esses que são mensurados através de métodos de custeio. Dentre os métodos de custeio existentes na literatura, destacam-se o Custeio por Absorção, o Custeio Direto/Variável, o Custeio Baseado em Atividades (ABC) e o Custeio Baseado em Atividades e Tempo (TDABC). O TDABC, a despeito de ter sido lançado na literatura em 2004 e detalhado em 2007 a partir de um livro publicado por Robert Kaplan e Steven Anderson, ainda não foi explorado diretamente pela literatura que versa sobre decisão de mix de produtos no contexto de operações com múltiplas restrições, ao contrário de alguns dos outros métodos de custeio mencionados, tal como o ABC. Para preencher essa lacuna teórica, esta tese tem como objetivo propor um modelo de decisão de mix de produtos sob a perspectiva do custeio baseado em atividades e tempo para operações com múltiplas restrições. Para cumprir este objetivo, inicialmente, a tese é desenvolvida metodologicamente com a realização de uma análise bibliométrica e de uma análise de citações das publicações realizadas em periódicos acadêmicos internacionais das áreas de Engenharia de Produção e de Contabilidade Gerencial sobre decisão de mix de produtos e sobre o TDABC. Em seguida, uma pesquisa bibliográfica é apresentada para discutir conceitos, analisar criticamente e posicionar a pesquisa sobre decisão de mix de produtos e sobre métodos de custeio, com destaque ao TDABC. Ainda, são apresentados exemplos didáticos para ilustrar a utilização de métodos de custeio na decisão de mix de produtos. Em seguida, utiliza-se de modelagem quantitativa com vistas à proposição do modelo para auxiliar a decisão de mix de produtos sob a perspectiva do TDABC, sendo este expresso na forma de um modelo de programação linear. No modelo proposto, são incorporados técnicas e conceitos relacionados com o controle gerencial de gastos, com a hierarquia de atividades, com o Overall Equipment Effectiveness (OEE) e com a programação matemática. Através de um exemplo didático envolvendo uma empresa de manufatura com múltiplas restrições do tipo hard e considerando parâmetros determinísticos, é apresentada a aplicação do modelo proposto na decisão de mix de produtos. Como principal resultado, tem-se a operacionalização do modelo proposto através do aplicativo Solver® incorporado ao software Microsoft Office Excel®, culminando na definição do mix de produtos que maximiza o lucro operacional esperado para a empresa no horizonte de planejamento analisado. Algumas reflexões críticas são realizadas no que tange aos limites de aplicação do modelo proposto. Finalmente, conclui-se que, sob a perspectiva do TDABC, o modelo proposto pode ser útil para auxiliar a decisão de mix de produtos no contexto de operações com múltiplas restrições. / This research addresses the theme \"product-mix decision\" that, in a Production Engineering perspective, can be understood as the definition of the optimum quantity to be produced for each type of product in a given period, considering these products compete for limited resources in order to maximize the firm economic result (e.g. operating income). Product-mix decision models use information on profitability, which is determined from analysis and confrontation between sales prices and costs (spending) of the products supplied by the company. These products costs are measured by costing methods. Among the existing costing methods in the literature, absorption costing, the direct costing, the activity based costing (abc) and time-driven activity-based costing (TDABC) are highlighted. TDABC, despite appearing in the literature in 2004 and detailed in 2007 from a book written by Robert Kaplan and Steven Anderson, has not been directly explored in the literature that deals with the product-mix decision considering multi-constrained operations context, unlike some of the other costing methods mentioned. In this context, to fill in this theoretical gap, the PhD thesis aims to propose a quantitative model to underpin the product-mix decision under the perspective of TDABC for multi-constrained operations. To meet this goal, initially, the thesis is developed methodologically from a bibliometric analysis and a citation analysis of papers on product mix decision and on TDABC published by international academic journals related to Production Engineering and Management Accounting research areas. Then the manuscript is methodologically developed from a literature research to discuss concepts and positioning the research on product-mix decision and on costing methods, emphasizing TDABC. Finally, quantitative modeling is employed in order to propose a model under the perspective of TDABC to assist product-mix decision, which is expressed as a linear programming model. The proposed model incorporates techniques and concepts related to management control over costs, the hierarchy of activities taxonomy, the Overall Equipment Effectiveness (OEE) and mathematical programming. An application of the proposed model is illustrated from a didactic example involving a multi-constrained manufacturing operation and considering deterministic parameters. The proposed model is operationalized through the Solver® and the Microsoft Office Excel® softwares, and, as main results, it was calculated the product-mix that maximizes the company\'s operating profit expected for the analyzed planning horizon. Some critical reflections are made regarding the proposed model application. Finally, it is concluded that, under the perspective of TDABC, the proposed model can be useful to support the product-mix decision of multiconstrained operations.