The role of visual management in collaborative integrated planning and control for engineer-to-order building systems

Visual Management is a key approach in the implementation of Lean Production. It emphasizes the importance of developing easy-to-understand visual devices for sharing knowledge within an organization. Such visual devices can play an important role in mitigating the complexity of engineer-to-order production systems. A major difficulty in managing engineer-to-order prefabricated building systems is the need to integrate planning and control of different processes, such as design, fabrication and assembly on site, in a multiple project environment. This paper reports preliminary findings on the implementation of visual devices for collaborative and integrated planning and control in a Steel Fabricator, which designs, fabricates and assembles steel structures. The aim of this paper is to understand how visual management tools can contribute to improve the effectiveness of planning and control in this environment. A set of visual devices have been used in the planning and control system in this company, including a panel that makes available information about 200 simultaneous contracts in an easy-to-understand way. The implementation of those tools has enhanced the participation of different people in the planning process from operational levels or from the different production units

Essays in International Economics and Labor Economics

University of Minnesota Ph.D. dissertation. August 2017. Major: Economics. Advisor: Timothy Kehoe. 1 computer file (PDF); x, 110 pages.The three chapters of this dissertation investigate major puzzles in international economics and labor economics. The first chapter investigates the macroeconomic effects of primary commodities trade flows across countries with different export composition. The second chapter studies labor flows of workers with similar skill-level and across countries with similar income. Lastly, the third chapter evaluates the macroeconomic effects of a health policy in the United States. Chapter 1 analyzes how the production and price volatility of primary commodities account for the co-movement between real GDP and terms of trade. Primary commodity exporter countries face large terms of trade fluctuations, largely driven by primary commodity price shocks and amplified by the relative importance of primary commodities in the countries’ exports. In this chapter, I document that an increase in the price of a primary commodity is usually followed by a decrease in terms of trade, defined as the relative price of imports over exports, and an increase in real GDP in these countries. Meanwhile, countries that do not export primary commodities enjoy more stable terms of trade, and their real GDP is positively correlated with terms of trade. Although the literature on primary commodity exporters has focused on developing countries, I show that this relation is independent of a country’s income level. Since standard models are unable to generate real aggregate fluctuations from price shocks if real GDP is correctly measured, this paper identifies a puzzle. I propose a class of mechanisms that is capable of explaining the heterogeneous impact of terms of trade fluctuations across countries. I show that a possible resolution is to incorporate the presence of idle resources and a production cost externality in the primary commodity producing sector in order to connect terms of trade fluctuations to real GDP fluctuations. When subjected to a primary commodity price shock, the model successfully accounts for the behavior of terms of trade and its relation to real GDP for different export compositions. Chapter 2, joint work with Maria Jose Rodriguez Garcia and Rocio Madera, revisits empirical evidence on migration within the European Union-15, disaggregated by occupation. We find that workers move to countries where their type is relatively more abundant among natives. This is at odds with traditional models of migration. We develop a model with external economies of scale that generates an agglomeration force in high-educated labor. Our main result is that a country that is relatively abundant in highly educated labor force will attract foreign labor of the same type. We argue this type of model is more suitable to analyze migration flows between countries of similar income level. Finally, Chapter 3, joint with Juan Carlos Conesa, Parisa Kamali, Timothy Kehoe, Vegard Nygard, Gajendran Raveendranathan, and Akshar Saxena, develops an overlapping generations model to study the macroeconomic effects of an unexpected elimination of Medicare. We find that a large share of the elderly respond by substituting Medicaid for Medicare. Consequently, the government saves only 46 cents for every dollar cut in Medicare spending. We argue that a comparison of steady states is insufficient to evaluate the welfare effects of the reform. In particular, we find lower ex-ante welfare gains from eliminating Medicare when we account for the costs of transition. Lastly, we find that a majority of the current population benefits from the reform but that aggregate welfare, measured as the dollar value of the sum of wealth equivalent variations, is higher with Medicare

História da habitação no Brasil (1850-2004)

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Using modularity to reduce complexity of industrialized building systems for mass customization

It is widely known that industrialized building systems can positively impact construction projects in terms of efficiency, duration, safety, and quality. Although the use of industrialized building systems can potentially simplify the production process on-site, the complexity of the overall delivery system tends to be high, especially in engineered-to-order (ETO) environments, due to factors such as uncertainty related to goals and methods, conflicts between different trades on-site, and interdependence between supply chain members. This paper explores the concept of modularity, which has proven to be useful in different industries as a way of dealing with complex systems. The aim of this paper is to illustrate how modularity can reduce the complexity of ETO industrialized building systems, in companies that adopt a mass customization strategy. This investigation is based on two descriptive case studies on the development of modular structural steel systems for buildings that have adopted innovative beam-to-column connections. The main contribution of this research is demonstrating the need to adopt an integrated product and process-oriented conceptualization of modularity in industrialized building systems. Moreover, the comparison between the two case studies pointed out that the management of tolerances plays a key role in achieving high productivity and short lead times in structural steel building systems. This investigation also illustrates how the adoption of a limited set of modular components can be used to decouple design decisions, and standardize different types of processes

Process Transparency on Construction Sites: Examples from Construction Companies in Brazil

Process transparency is the core concept in Visual Management (VM), which is one of the founding blocks of the Toyota Production System. This paper presents the preliminary results of a collaborative research conducted between Brazil and the UK, as part of a research effort focused on the application of Visual Management in construction. How process transparency is realized on construction sites is the main research question of the paper. The use of this concept and the implementation of the transparency theory were investigated through multiple case studies, carried out in nine different construction companies. The findings are explained through six theoretical transparency increasing approaches. The affecting parameters in the application of, the management’s perception of and several methods in process transparency in construction were identified. Further work, especially exploring the functions of process transparency on construction sites and reflecting the worker perception of the issue, is necessary to elaborate the process transparency concept

Characterization of cell integrity of Planctomycetes species : signaling and DNA protection

Dissertação de mestrado em Genética MolecularOs Planctomycetes são um grupo notável de bactérias que devido às suas características invulgares: divisão por gemulação, paredes celulares sem peptidoglicano e estrutura celular compartimentalizada apresentam relevância crescente em vários domínios científicos como a evolução, biologia celular, ecologia e genómica. Estudos de ecologia molecular microbiana evidenciaram que os Plancomycetes são organismos abundantes em habitats terrestres e aquáticos, desempenhando um papel preponderante nos equilíbrios dos mesmos. Embora seja conhecida a sua grande dispersão, os processos fisiológicos e metabólicos subjacentes a esta ubiquidade permanecem por esclarecer. As vias de sinalização celular permitem a adaptação a ambientes em constante mudança e são determinantes para sobrevivência dos organismos. Para os Planctomycetes, um aspecto importante a ter em conta no que se refere à ecologia prende-se com a resistência a radiação Ultravioleta (UV), principalmente para as espécies marinhas. O presente trabalho pretende caracterizar aspectos relacionados com a integridade celular de espécies marinhas de Planctomycetes após a exposição a radiação UV. Foi desenvolvido um novo método para detecção de danos de DNA em Planctomycetes, utilizado na caracterização da resistência à radiação UV de várias estirpes. Este trabalho foi complementado com testes de sobrevivência. O potencial efeito protector de extractos etanólicos de pigmentos de Planctomycetes foi também avaliado. Como as vias de sinalização mediadas por Mitogen-activated protein kinase (MAPK) regulam a resposta a diversos tipos de stress, espécies mutantes para componentes da via da Protein kinase C foram rastreados para resistência a radiação UVC para avaliar um possível envolvimento desta via na resposta à radiação UV. Potenciais homólogos de Planctomycetes foram também analisados. Este estudo multidisciplinar permitiu a caracterização de várias espécies marinhas de Planctomycetes quanto a danos de DNA e sobrevivência. Foi ainda demonstrado um possível envolvimento da via de sinalização mediada pela PKC na resposta de Saccharomyces cerevisiae a radiação UV. Os valores elevados de homologia entre os genes da levedura e de Planctomycetes podem indicar que este grupo depende de vias de sinalização complexas na manutenção da integridade celular.The phylum Planctomycetes is a remarkable group of bacteria with increasing relevance in numerous fields of research such as evolution, cell biology, ecology and genomics due to its unusual characteristics: division by budding, peptidoglycan-less cell walls and compartmentalized cell structure. Molecular microbial ecology studies repeatedly provided evidence that Planctomycetes are abundant in terrestrial and marine habitats, underlying that these organisms play an important role in the ecology of the habitats. Although this wide known dispersion, still little is known about the physiology and metabolism underlying the geographic ubiquity of Planctomycetes. Signalling pathways are essential for adaptation to a constantly changing environment that imposes exposure to several kinds of stress and are essential for organism’s survival. One important aspect of Planctomycetes ecology is ultra-violet radiation (UV) resistance, at least in marine species. In this work, we aimed to characterize aspects of cell integrity of marine Planctomycetes species upon exposure to UV radiation related to DNA damage and signalling. A new DNA damage detection method was developed for Planctomycetes and used to evaluate DNA damage resistance of several strains together with survival tests. In addition, the potential protective role of ethanolic extracts of Planctomycetes pigments was also evaluated. As signalling pathways mediated by Mitogen-activated protein kinase (MAPK) regulate response to several types of stress, several mutant strains for the Protein kinase C cascade components were screened for UV resistance to evaluate the possible involvement on this pathway in UV response. Furthermore, several predicted homologous kinases of Planctomycetes were analysed. This multi disciplinary approach allowed us to characterize several marine Planctomycetes strains comparatively to DNA damage and survival. Furthermore, we were able to demonstrate that PKC mediated pathway is probably involved in UV response in Saccharomyces cerevisiae. The high homology values between Planctomycetes and Saccharomyces cerevisiae may indicate that Planctomycetes rely on evolved signalling pathways to maintain cell integrity

A Biomassa Verde e Lenhosa dos Espaços Urbanos como Fonte Energética para os Edifícios Públicos da Cidade de Viseu

A biomassa gerada pelos espaços verdes urbanos constitui uma fonte de resíduos significativa que, muitas vezes, é direccionada directamente para aterros podendo ser aproveitada para fins energéticos, nomeadamente no aquecimento térmico de alguns edifícios públicos. O presente trabalho apresenta a quantificação da biomassa verde indiferenciada gerada pelos espaços verdes urbanos, depositada nos pontos de recolha específicos, e da biomassa lenhosa proveniente das podas realizadas nas árvores existentes na cidade de Viseu. Simultaneamente, estimam-se as necessidades energéticas (eléctricas e térmicas), no Verão e Inverno, dos principais edifícios públicos da cidade. A quantificação dos resíduos produzidos anualmente foi avaliada por inquéritos às empresas responsáveis pelas podas das árvores da cidade, à autarquia e ao centro de tratamento dos resíduos sólidos urbanos, para o período de 2004 a 2007. Fez-se também a estimativa a partir da caracterização dendrométrica do parque arbóreo existente, a qual serviu para comparar e validar os resultados obtidos. As necessidades energéticas médias anuais foram estimadas a partir do inquérito realizado, no período entre 2004 e 2006, em 49 edifícios públicos como escolas, unidades de saúde, edifícios da autarquia, entre outros. Os resultados mostram que as necessidades térmicas médias anuais dos edifícios estudados rondam os 109.245,78 GJ. A biomassa produzida ronda as 106,5 t/ano de resíduos lenhosos e 103,3 t/ano de resíduos verdes, os quais foram convertidos em valores de energia. A biomassa unicamente lenhosa poderia suprir cerca de 10,3% das necessidades térmicas de Inverno, das 19 escolas levantadas nestes estudo. Dado que muita da biomassa produzida na cidade não é contabilizada, uma vez que é depositada juntamente com os resíduos sólidos urbanos, o potencial energético destes resíduos poderia ser muito superior

Análise nutricional das dietas da moda

Introdução: analisou a divulgação e a realização de dietas da moda e o crescimento alarmante nos últimos anos, fatores estes associados e atribuídos pela mídia sejam por revistas não cientificas, livros periódicos ou por outros meios de comunicação. Objetivo: o estudo tem como objetivo discutir as consequências da prática de dietas da moda para o emagrecimento e seus efeitos adversos na saúde humana. Método: consiste em um estudo de revisão da literatura baseada em artigos científicos, revistas cientificas consultados nas bases de dados bireme, google acadêmico, scielo, pubmed, livros periódicos. Período da coleta de dados de agosto e finalizando no mês de novembro por meio das palavras chaves dieta da moda, dieta restritiva, obesidade, mídia, educação nutricional, Dukan e estética. Usando o Guia alimentar 2008 para a população brasileira para análise de cada dieta. Resultado: Dietas restritivas como a do Dr. Dukan, Dr. Ravenna trazem a ideologia de emagrecimento, porém o Guia alimentar mostra o quanto estão errôneas em relação a uma alimentação adequada. Por fim, a importância do profissional nutricionista perante a sociedade em mostrar que qualidade alimentar não é seguir uma dieta, mas educar de forma individualizada cada individuo

Model for planning and controlling the delivery and assembly of engineer-to-order prefabricated building systems : exploring synergies between Lean and BIM

The adoption of prefabricated building systems has grown due to the need to reduce duration and cost of construction projects, as well as to improve quality and working conditions. However, the adoption of those systems requires an intense exchange of information to integrate the production of components, logistics operations, and site assembly. This is particularly important in engineer-to-order environments, in which the level of uncertainty tends to be high. This research proposes a model for planning and controlling the delivery and assembly of ETO prefabricated building systems, emphasizing the integration between site installation and logistics operations. This model was devised in an empirical study carried out in a company that delivers and assembles prefabricated concrete structures. The main theoretical contribution is a set of approaches to implement the “pull production” and “reduce variability” principles in this particular context, exploring synergies that exist between Lean Production principles and Building Information Modeling (BIM) functionalities.L’adoption de procédés de préfabrication d’immeubles a augmenté en raison de la nécessité de réduire la durée et le coût des projets de construction, ainsi que d’améliorer la qualité et les conditions de travail. Toutefois, l’adoption de ces procédés nécessite un échange intense d’informations afin d’intégrer la production de composants, les opérations logistiques et l’assemblage sur chantier. Ceci est particulièrement important dans les environnements de fabrication pour projet, où le niveau d’incertitude a tendance à être élevé. Cette recherche propose un modèle de planification et de contrôle de la livraison et de l’assemblage des systèmes de préfabrication d’immeubles dans un environnement de fabrication pour projet, en mettant l’accent sur l’intégration entre l’installation du chantier et les opérations logistiques. Ce modèle a été conçu dans le cadre d’une étude empirique menée dans une entreprise qui fournit et assemble des structures préfabriquées en béton. La principale contribution théorique est un ensemble d’approches pour mettre en oeuvre les principes de « production tirée » et de « réduction de la variabilité » dans ce contexte particulier, en explorant les synergies qui existent entre les principes de production allégée et les fonctionnalités de la modélisation des données du bâtiment (MDI)