In this study we consider a two-echelon supply chain with a nonstationary demand process. The retailer batches the customer demand for a predetermined number of periods before placing an order to the supplier. We show that the demand process for the supplier is more variable than that for the retailer. It is observed that the supplier can reduce the variability of orders by tracking the exogenous demand occurring at the retailer&#039 / s side.

A dificuldade técnica enfrentada pelas firmas em seu cotidiano é frequentemente atribuída ao grau de complexidade das tecnologias, produtos ou processos de produção utilizados. Não obstante, a repetida referência ao termo complexidade em estudos sobre gestão da tecnologia e da inovação parece haver uma lacuna no que diz respeito a uma definição formal desse conceito. Por outro lado, capacidade tecnológica, o grau de acúmulo e domínio tecnológico que permite à firma adaptar tecnologias em variadas circunstâncias de mercado (LALL, 1992), é um conceito que vem sendo utilizado por diversos autores ao longo das últimas duas décadas (PANDA E RAMANATHAN, 1996; KIM, 1999; FIGUEIREDO, 2009). Enquanto o esforço das pesquisas dos últimos anos permitiu avançar na compreensão das capacidades tecnológicas nas firmas de diferentes setores industriais, todavia pouco se compreende a respeito da complexidade do conteúdo tecnológico que as firmas carregam, além da respectiva relação com o desenvolvimento das capacidades tecnológicas. Este trabalho tem como objetivo avançar na direção de uma definição de complexidade tecnológica, bem como no estabelecimento da relação entre o grau de complexidade da tecnologia de uma firma e as capacidades tecnológicas existentes na mesma. Mediante uma pesquisa de levantamento com 303 empresas de 5 setores da indústria metal mecânica, buscou-se estabelecer a relação entre estes dois conceitos. Os resultados indicam que a capacidade tecnológica não se apresenta exclusivamente vinculada à adaptação da tecnologia e à busca de soluções tecnológicas inéditas. Um nível elevado de complexidade na tecnologia manipulada pelas firmas pode exigir também o desenvolvimento de capacidades tecnológicas. / The technical difficulty faced by firms in its routine activities is often attributed to the complexity of technologies, products or production processes applied. Despite the repeated references to the term complexity in studies on technology management and innovation, there seems to be a gap with respect to a formal definition of this concept. On the other hand, technological capacity, i.e. the degree of accumulation and technological mastery that allows the firm to adapt technologies in different market circumstances (Lall, 1992), is a concept that has been successfully applied by several authors in this area of research over the past two decades (Panda and Ramanathan, 1996; Kim, 1999; Figueiredo, 2009). While the research effort in recent years has allowed us to advance the understanding of the technological capabilities of firms in different industries, little is explained about the technological complexity that firms carry and its relationship with firm technological capability acquisition process. This paper aims to move forward a definition of technological complexity, and also the establishment of the relationship between the degree of complexity of a technology and the technological capabilities existing in the firm. Through a research survey of 303 companies in five sectors of the metalworking industry, sought to establish the relationship between these two concepts. The results indicate that technological capability seems not only to be linked to technology adaptation and the search for novel technological solutions. A high level of complexity in the technology manipulated by firms can also provoke the development of technological capabilities.

A dificuldade técnica enfrentada pelas firmas em seu cotidiano é frequentemente atribuída ao grau de complexidade das tecnologias, produtos ou processos de produção utilizados. Não obstante, a repetida referência ao termo complexidade em estudos sobre gestão da tecnologia e da inovação parece haver uma lacuna no que diz respeito a uma definição formal desse conceito. Por outro lado, capacidade tecnológica, o grau de acúmulo e domínio tecnológico que permite à firma adaptar tecnologias em variadas circunstâncias de mercado (LALL, 1992), é um conceito que vem sendo utilizado por diversos autores ao longo das últimas duas décadas (PANDA E RAMANATHAN, 1996; KIM, 1999; FIGUEIREDO, 2009). Enquanto o esforço das pesquisas dos últimos anos permitiu avançar na compreensão das capacidades tecnológicas nas firmas de diferentes setores industriais, todavia pouco se compreende a respeito da complexidade do conteúdo tecnológico que as firmas carregam, além da respectiva relação com o desenvolvimento das capacidades tecnológicas. Este trabalho tem como objetivo avançar na direção de uma definição de complexidade tecnológica, bem como no estabelecimento da relação entre o grau de complexidade da tecnologia de uma firma e as capacidades tecnológicas existentes na mesma. Mediante uma pesquisa de levantamento com 303 empresas de 5 setores da indústria metal mecânica, buscou-se estabelecer a relação entre estes dois conceitos. Os resultados indicam que a capacidade tecnológica não se apresenta exclusivamente vinculada à adaptação da tecnologia e à busca de soluções tecnológicas inéditas. Um nível elevado de complexidade na tecnologia manipulada pelas firmas pode exigir também o desenvolvimento de capacidades tecnológicas. / The technical difficulty faced by firms in its routine activities is often attributed to the complexity of technologies, products or production processes applied. Despite the repeated references to the term complexity in studies on technology management and innovation, there seems to be a gap with respect to a formal definition of this concept. On the other hand, technological capacity, i.e. the degree of accumulation and technological mastery that allows the firm to adapt technologies in different market circumstances (Lall, 1992), is a concept that has been successfully applied by several authors in this area of research over the past two decades (Panda and Ramanathan, 1996; Kim, 1999; Figueiredo, 2009). While the research effort in recent years has allowed us to advance the understanding of the technological capabilities of firms in different industries, little is explained about the technological complexity that firms carry and its relationship with firm technological capability acquisition process. This paper aims to move forward a definition of technological complexity, and also the establishment of the relationship between the degree of complexity of a technology and the technological capabilities existing in the firm. Through a research survey of 303 companies in five sectors of the metalworking industry, sought to establish the relationship between these two concepts. The results indicate that technological capability seems not only to be linked to technology adaptation and the search for novel technological solutions. A high level of complexity in the technology manipulated by firms can also provoke the development of technological capabilities.

A dificuldade técnica enfrentada pelas firmas em seu cotidiano é frequentemente atribuída ao grau de complexidade das tecnologias, produtos ou processos de produção utilizados. Não obstante, a repetida referência ao termo complexidade em estudos sobre gestão da tecnologia e da inovação parece haver uma lacuna no que diz respeito a uma definição formal desse conceito. Por outro lado, capacidade tecnológica, o grau de acúmulo e domínio tecnológico que permite à firma adaptar tecnologias em variadas circunstâncias de mercado (LALL, 1992), é um conceito que vem sendo utilizado por diversos autores ao longo das últimas duas décadas (PANDA E RAMANATHAN, 1996; KIM, 1999; FIGUEIREDO, 2009). Enquanto o esforço das pesquisas dos últimos anos permitiu avançar na compreensão das capacidades tecnológicas nas firmas de diferentes setores industriais, todavia pouco se compreende a respeito da complexidade do conteúdo tecnológico que as firmas carregam, além da respectiva relação com o desenvolvimento das capacidades tecnológicas. Este trabalho tem como objetivo avançar na direção de uma definição de complexidade tecnológica, bem como no estabelecimento da relação entre o grau de complexidade da tecnologia de uma firma e as capacidades tecnológicas existentes na mesma. Mediante uma pesquisa de levantamento com 303 empresas de 5 setores da indústria metal mecânica, buscou-se estabelecer a relação entre estes dois conceitos. Os resultados indicam que a capacidade tecnológica não se apresenta exclusivamente vinculada à adaptação da tecnologia e à busca de soluções tecnológicas inéditas. Um nível elevado de complexidade na tecnologia manipulada pelas firmas pode exigir também o desenvolvimento de capacidades tecnológicas. / The technical difficulty faced by firms in its routine activities is often attributed to the complexity of technologies, products or production processes applied. Despite the repeated references to the term complexity in studies on technology management and innovation, there seems to be a gap with respect to a formal definition of this concept. On the other hand, technological capacity, i.e. the degree of accumulation and technological mastery that allows the firm to adapt technologies in different market circumstances (Lall, 1992), is a concept that has been successfully applied by several authors in this area of research over the past two decades (Panda and Ramanathan, 1996; Kim, 1999; Figueiredo, 2009). While the research effort in recent years has allowed us to advance the understanding of the technological capabilities of firms in different industries, little is explained about the technological complexity that firms carry and its relationship with firm technological capability acquisition process. This paper aims to move forward a definition of technological complexity, and also the establishment of the relationship between the degree of complexity of a technology and the technological capabilities existing in the firm. Through a research survey of 303 companies in five sectors of the metalworking industry, sought to establish the relationship between these two concepts. The results indicate that technological capability seems not only to be linked to technology adaptation and the search for novel technological solutions. A high level of complexity in the technology manipulated by firms can also provoke the development of technological capabilities.

Orientador: Alfredo Rocha de Faria / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T21:18:25Z (GMT). No. of bitstreams: 1 Aguado_ClodoaldoGarcia_M.pdf: 53529976 bytes, checksum: c01081cee3de72ee7fd5c2ac1f9d0612 (MD5) Previous issue date: 2011 / Resumo: As simulações dentro do ambiente de projeto devem prever a utilização de novas variáveis, especialmente de processos, de forma a aumentar a proximidade entre os modelos virtual e real e, com isso, aumentar a precisão das simulações. O objetivo deste trabalho foi o de estudar um modelo pelo Método dos Elementos Finitos que incluísse os efeitos da variação de espessura provenientes do processo de estampagem para a análise de vida em fadiga de um componente do sistema de exaustão automotivo. Primeiramente foi realizada a simulação do processo de estampagem, onde foi possível identificar as mudanças de espessura na geometria do componente estudado. O resultado dessa simulação foi transportado para a malha de elementos finitos, de forma que as análises posteriores, estrutural e de fadiga, considerassem os efeitos da redução e aumento da espessura local. Como base de comparação, as mesmas análises foram realizadas para a condição de espessura constante, tradicionalmente adotada durante a fase de projeto. Utilizando o modelo de Wöhler-Goodman-Miner para o cálculo do Dano acumulado e comparando com dados experimentais aquisitados em simulador veicular, os resultados cálculo de fadiga demonstraram que ambas as condições de espessura atingem vida infinita. Entretanto, após a seleção e análise de algumas regiões consideradas críticas nas simulações precedentes (estampagem e estrutural), pôde-se notar que na maior parte das regiões os valores de dano acumulado eram inferiores para a condição de espessura constante. Já a condição de espessura variável se aproximou mais ao resultado medido. Pôde-se concluir com os resultados que a variação de espessura, como efeito do processo de estampagem, desempenha um papel importante na vida do componente estudado, indicando que a utilização dos dados de processo auxilia na aproximação entre os resultados do cálculo de vida e a condição real / Abstract: The simulations within the Product Development environment must give the chance to use new variables, particularly from processes, in order to improve the correlation between the virtual and real models, and thus enhance the accuracy of the simulations. The objective of this work was to study a model by the finite element method (FEM) that includes the effects of thickness variation from stamping process for the fatigue life prediction in an automotive exhaust system component. Firstly it was carried out a simulation of the stamping process, where it was possible to identify the thickness distribution all along the geometry of selected component. Then, the result of this simulation was transported to the finite element mesh, so that further analyses, structural and fatigue, could consider the effects of reduction and increasing in local thickness. As a basis for comparison, the same analyses were performed for the homogeneous geometry (uniform thickness), which are typically taken during the design phase. Using the model proposed by Wöhler-Goodman-Miner to calculate the accumulated damage and comparing with real data acquisited from a vehicle, the calculation results of fatigue showed that both conditions (equal and unequal thickness) reached infinite life. However, after the selection and analysis of some critical regions in the previous simulations (stamping and structural), it might be noted that, in most regions, the values of accumulated damage were lower for the uniform thickness condition. Besides, for the unequal thickness condition, the results got closer to those measured in vehicle. With these results, it could be demonstrated that the unequal thickness, as a process variable, plays an important role in the component life, indicating that the use of process data helps in bringing together the results from fatigue calculation and real condition / Mestrado / Manufatura / Mestre em Engenharia Automobilistica

The biological treatment of metalworking fluids (MWFs) is a cost effective alternative to conventional waste disposal processes. While research has proven that this process is capable of treating large volumes of wastes with high organic concentrations, there are uncertainties about the mechanisms by which the treatment occurs, and there are limitations that must be overcome. There is a need to understand the importance of the mechanisms by which carbon (and hence COD) is removed from the wastewater. This will allow for waste practitioners to make better decisions for optimizing the process, and for disposing of waste (i.e sludge) that is generated. The biological treatment process is also susceptible to biocides present within formulations. These compounds either need to be removed before the treatment process, or the bioreactors need to be made more resistant to them to ensure that their presence does not hinder the reactor functioning. This study aims to answer the uncertainties about the carbon removal mechanisms involved in the treatment of oil-containing MWFs. In the first experimental chapter, it is shown that the predominant mechanism of carbon removal is oil/water separation induced by emulsifier degradation, and hence the bioprocess treatment rate is significantly affected by the biodegradability of surfactants and by the presence of cations found naturally in the water that used to prepare the emulsions. The study then provides insights into the potential that coagulation and coalescence has for removing inhibitory components commonly found in MWFs. Coagulation and coalescence is shown to effectively remove biocides with low aqueous solubility (iodopropynyl butylcarbamate) and those that partition themselves into the oil phase (o-phenyl phenate and its sodium salt). Finally, to improve the resistance of reactors to inhibitory compounds, factors influencing the development of fixed-film reactors are investigated. A micro-cosmic system is used to study the both physico-chemical effects and nutritional factors on the development of biofilm reactors. It is shown that biofilm yields can be controlled through pH adjustment, and that these yields are maximized with phosphate stimulation and ammonium limitation. It is then shown that fixed-film reactors are able to treat metalworking fluids even under conditions deemed to be inhibitory. In summary, this project provides insights into further understanding and enhancing the biological treatment of MWFs.

The problem of this study was to determine the type of metals used in the foundries in the high schools of Texas and the treatment of these metals. The data for this study were provided by thirty metalworking instructors of Texas high schools. Of the Texas high schools offering foundry as part of their metalworking curriculum, all included aluminum as a basic metal. In addition, the amount of metals used and their treatment varied from school to school.

The purpose of this study was to determine the required knowledge and skills of mobile home metalworkers in the Dallas-Fort Worth area as compared to the Industrial Arts metalworking curriculum presented in Texas Education Agency, Bulletin 615. Items of significance in Chapter IV appear in findings, conclusions, and recommendations. The "use of basic hand tools" and "safety concepts" were consistently emphasized and required by manufacturing firms. It was found that educational requirements were quite often "some high school" or less. It was found that Industrial Arts metalworking curriculum was closely related to required knowledge and skills of mobile home metalworkers. It was recommended that Industrial Arts course work be extended into lower levels of education.

Monitoring of emulsion properties is important in many applications, like in foods and pharmaceutical products, or in emulsion polymerization processes, since aged and broken emulsions perform worse and may affect product quality. In machining processes, special types of emulsions called metalworking fluids (MWF) are widely used, because of its combined characteristics of cooling and lubrication, increasing the productivity, enabling the use of higher cutting speeds, decreasing the amount of power consumed and increasing tool life. Even though emulsion quality monitoring is a key issue in manufacturing processes, traditional methods are far from accurate and generally fail in providing the tools for determining the optimal useful life of these emulsions, with high impact in costs. The present study is dedicated to the application of a spectroscopic sensor to monitor MWF emulsion destabilization, which is related to changes in its droplet size distribution. Rapeseed oil emulsions, artificially aged MWF and MWF in machining application were evaluated, using optical measurements and multivariate calibration by neural networks, for developing a new method for emulsion destabilization monitoring. The technique has shown good accuracy in rebuilding the droplet size distribution of emulsions for monomodal and bimodal distributions and different proportions of each droplet population, from the spectroscopic measurements, indicating the viability of this method for monitoring such emulsions. This study is part of a joint project between the University of São Paulo and the University of Bremen, within the BRAGECRIM program (Brazilian German Cooperative Research Initiative in Manufacturing) and is financially supported by FAPESP, CAPES, FINEP and CNPq (Brazil), and DFG (Germany). / Sem resumo em português.

O monitoramento de emulsões utilizadas na indústria metalmecânica compõe uma importante atividade para o controle da qualidade das peças trabalhadas, proporcionando também o aumento da vida útil de ferramentas e maquinários utilizados neste setor através da lubrificação e refrigeração da região de corte. Em grande parte dos casos, estas emulsões são preparadas pela diluição de um fluido de corte em meio aquoso, constituindo assim um conjunto de gotículas estabilizadas em um meio contínuo devido à presença de compostos emulsificantes, estando constantemente sujeitas a ciclos de aquecimento e resfriamento durante os processos de usinagem. Apesar do acompanhamento deste material ser realizado através de análises periódicas usuais, não há um método eficiente estabelecido para verificar sua qualidade em tempo real e em linha de processo. Neste contexto, torna-se possível aplicar técnicas relacionadas à espectroscopia UV-Vis para se obterem informações sobre a estabilidade destes sistemas, correlacionando intensidades de espalhamento de luz com as dimensões das gotas presentes no meio. Dessa forma, tornou-se possível o estudo da desestabilização térmica de emulsões de um fluido de corte comercial, a qual mostrou-se, através do acompanhamento do cálculo do expoente do comprimento de onda, dependente do tempo de exposição ao aquecimento e de sua temperatura média temporal, não sendo influenciada pela perda de meio contínuo por processos evaporativos ou sua posterior reposição. Também se verificou que parâmetros típicos do processo de preparo de emulsões, como a temperatura do meio dispersante e o tempo de repouso do fluido de corte sobre a superfície do mesmo, apresentam fundamental importância para a definição do tamanho médio de gota inicial destes sistemas, o que forneceu evidência da possibilidade de se relacionar a área sob espectros de extinção de luz com tamanhos médios de gota. / The monitoring of emulsions used in the metal-mechanical industry comprise an important activity to the quality control of the products manufectured, also providing an increase in the working life of the tools and machinery employed in this sector through the lubrication and refrigeration of the cutting zone. In the majority of cases, these emulsions are prepared diluting a metalworking fluid in an aqueous media, constituting a collection of particles stabilized by emulsifiers and undergoing heating and cooling cycles during metalworking processes. Currently, monitoring routines are based on regular analyses of samples taken from the process fluid, and an effective in-line method is not available to monitor emulsion quality in real time. In this context, it is possible to apply techniques related to UV-Vis spectrocopy in order to obtain information concerning the stability of those systems, correlating light scattering intensities to the droplet dimensions. In this study, it was possible to investigate the thermal destabilisation of a commercial metalworking fluid emulsion, which showed, through the evaluation of the wavelength exponent, to be dependant on the exposure time to heating and its time-averaged temperature. It was also noted that the loss of continuous phase by evaporation and its reposition do not affect the emulsion stability. Moreover, it was observed that important emulsion preparation parameters, such as continuous phase temperature and the time span between the addition of the metalworking fluid on the water surface and the stirring, have fundamental roles in defining the initial average droplet size, which made possible to correlate the area under the light extinction spectra with average droplet sizes.