Hierarchical Forest Management Planning: A Bilevel Wood Supply Modelling Approach

Le processus de planification forestière hiérarchique présentement en place sur les terres publiques risque d’échouer à deux niveaux. Au niveau supérieur, le processus en place ne fournit pas une preuve suffisante de la durabilité du niveau de récolte actuel. À un niveau inférieur, le processus en place n’appuie pas la réalisation du plein potentiel de création de valeur de la ressource forestière, contraignant parfois inutilement la planification à court terme de la récolte. Ces échecs sont attribuables à certaines hypothèses implicites au modèle d’optimisation de la possibilité forestière, ce qui pourrait expliquer pourquoi ce problème n’est pas bien documenté dans la littérature. Nous utilisons la théorie de l’agence pour modéliser le processus de planification forestière hiérarchique sur les terres publiques. Nous développons un cadre de simulation itératif en deux étapes pour estimer l’effet à long terme de l’interaction entre l’État et le consommateur de fibre, nous permettant ainsi d’établir certaines conditions pouvant mener à des ruptures de stock. Nous proposons ensuite une formulation améliorée du modèle d’optimisation de la possibilité forestière. La formulation classique du modèle d’optimisation de la possibilité forestière (c.-à-d., maximisation du rendement soutenu en fibre) ne considère pas que le consommateur de fibre industriel souhaite maximiser son profit, mais suppose plutôt la consommation totale de l’offre de fibre à chaque période, peu importe le potentiel de création de valeur de celle-ci. Nous étendons la formulation classique du modèle d’optimisation de la possibilité forestière afin de permettre l’anticipation du comportement du consommateur de fibre, augmentant ainsi la probabilité que l’offre de fibre soit entièrement consommée, rétablissant ainsi la validité de l’hypothèse de consommation totale de l’offre de fibre implicite au modèle d’optimisation. Nous modélisons la relation principal-agent entre le gouvernement et l’industrie à l’aide d’une formulation biniveau du modèle optimisation, où le niveau supérieur représente le processus de détermination de la possibilité forestière (responsabilité du gouvernement), et le niveau inférieur représente le processus de consommation de la fibre (responsabilité de l’industrie). Nous montrons que la formulation biniveau peux atténuer le risque de ruptures de stock, améliorant ainsi la crédibilité du processus de planification forestière hiérarchique. Ensemble, le modèle biniveau d’optimisation de la possibilité forestière et la méthodologie que nous avons développée pour résoudre celui-ci à l’optimalité, représentent une alternative aux méthodes actuellement utilisées. Notre modèle biniveau et le cadre de simulation itérative représentent un pas vers l’avant en matière de technologie de planification forestière axée sur la création de valeur. L’intégration explicite d’objectifs et de contraintes industrielles au processus de planification forestière, dès la détermination de la possibilité forestière, devrait favoriser une collaboration accrue entre les instances gouvernementales et industrielles, permettant ainsi d’exploiter le plein potentiel de création de valeur de la ressource forestière.

Aplicación de la metodología Six Sigma para solucionar problemas de calidad en una empresa metalmecánica

En la actualidad muchas compañías enfocan sus esfuerzos en la chequera del cliente generando con esto una cortina de humo al interior de la empresa que hace que se descuiden los costos, se conviva con actividades que no agregan valor y se desconozcan las causas de los principales problemas de calidad que afectan al cliente. Este es el caso de la compañía metalmecánica objeto de esta investigación, la cual venía sobrellevando altos niveles de inventarios, reprocesos, problemas de calidad, falta de corresponsabilidad del personal, y otras situaciones que la estaban dejando vulnerable ante la competencia. Este fue el motivo que inspiró esta investigación en aras de validar una metodología de mejora continua para identificar, analizar, proponer, evaluar y reducir los costos de no calidad y sus implicaciones, de una forma ordenada, rigurosa y disciplinada. Posterior a la implementación del plan de acción los resultados no se hicieron esperar y la compañía mejoró su servicio al cliente sin incurrir en excesos de inventario, al igual que disminuyó sus sobrecostos de producción, los cuales eran generados en gran medida por problemas de calidad. Pero lo más significativo es que asimiló que esta metodología es un proceso continuo que no puede parar y que todo el personal de la empresa debe estar implicado.

Representation of odometry errors on occupancy grids

SOUZA, Anderson A. S. ; SANTANA, André M. ; BRITTO, Ricardo S. ; GONÇALVES, Luiz Marcos G. ; MEDEIROS, Adelardo A. D. Representation of Odometry Errors on Occupancy Grids. In: INTERNATIONAL CONFERENCE ON INFORMATICS IN CONTROL, AUTOMATION AND ROBOTICS, 5., 2008, Funchal, Portugal. Proceedings... Funchal, Portugal: ICINCO, 2008.

Localization of a mobile robot based on odometry and natural landmarks using extended kalman filter

SANTANA, André M.; SOUZA, Anderson A. S.; BRITTO, Ricardo S.; ALSINA, Pablo J.; MEDEIROS, Adelardo A. D. Localization of a mobile robot based on odometry and natural landmarks using extended Kalman Filter. In: INTERNATIONAL CONFERENCE ON INFORMATICS IN CONTROL, AUTOMATION AND ROBOTICS, 5., 2008, Funchal, Portugal. Proceedings... Funchal, Portugal: ICINCO, 2008.

Design and development of distributed feedback transistor lasers

The transistor laser is a unique three-port device that operates simultaneously as a transistor and a laser. With quantum wells incorporated in the base regions of heterojunction bipolar transistors, the transistor laser possesses advantageous characteristics of fast base spontaneous carrier lifetime, high differential optical gain, and electrical-optical characteristics for direct “read-out” of its optical properties. These devices have demonstrated many useful features such as high-speed optical transmission without the limitations of resonance, non-linear mixing, frequency multiplication, negative resistance, and photon-assisted switching. To date, all of these devices operate as multi-mode lasers without any type of wavelength selection or stabilizing mechanisms. Stable single-mode distributed feedback diode laser sources are important in many applications including spectroscopy, as pump sources for amplifiers and solid-state lasers, for use in coherent communication systems, and now as TLs potentially for integrated optoelectronics. The subject of this work is to expand the future applications of the transistor laser by demonstrating the theoretical background, process development and device design necessary to achieve singlelongitudinal- mode operation in a three-port transistor laser. A third-order distributed feedback surface grating is fabricated in the top emitter AlGaAs confining layers using soft photocurable nanoimprint lithography. The device produces continuous wave laser operation with a peak wavelength of 959.75 nm and threshold current of 13 mA operating at -70 °C. For devices with cleaved ends a side-mode suppression ratio greater than 25 dB has been achieved.

Tire inspection spreading machine

The aim of the project was to design in Solidworks and improve an existing Tire inspection machine. The project was developed in Gislotica - Mechanical Solutions, guided by ing. Rui Manuel Fazenda Silva who is a professor in ISEP. The designed device relates to the inspection of automobile tires for holes and weak places caused by punctures and usage. Such inspection includes careful examination of the inside surface of the tire which is difficult because of its cylindrical shape, stiff and resistant nature of the material out of which the tire is made. The whole idea is to provide a machine by which the walls of the tire may be spread and hold apart, presenting the inner surface for the worker to control. The device must also perform rotational and vertical movement of the tire. It is meant to provide inspection in hich there is no need for the controller to use force. It makes his work easier and more efficient.

Análise e modelagem do escoamento transitório de fluidos de perfuração

Drilling fluids present a thixotropic behavior and they usually gel when at rest. The sol-gel transition is fundamental to prevent the deposit of rock fragments, generated by drilling the well, over the drill bit during eventual stops. Under those conditions, high pressures are then required in order to break-up the gel when circulation is resumed. Moreover, very high pressures can damage the rock formation at the bottom of the well. Thus, a better understanding of thixotropy and the behavior of thixotropic materials becomes increasingly important for process control. The mechanisms that control thixotropy are not yet well defined and modeling is still a challenge. The objective of this work is to develop a mathematical model to study the pressure transmission in drilling fluids. This work presents a review of thixotropy and of different mathematical models found in the literature that are used to predict such characteristic. It also shows a review of transient flows of compressible fluids. The problem is modeled as the flow between the drillpipe and the annular region (space between the wall and the external part of the drillpipe). The equations that describe the problem (mass conservation, momentum balance, constitutive and state) are then discretized and numerically solved by using a computational algorithm in Fortran. The model is validated with experimental and numerical data obtained from the literature. Comparisons between experimental data obtained from Petrobras and calculated by three viscoplastic and one pseudoplastic models are conducted. The viscoplastic fluids, due to the yield stress, do not fully transmit the pressure to the outlet of the annular space. Sensibility analyses are then conducted in order to evaluate the thixotropic effect in pressure transmission.

Ecology, physiology and performance in high-rate anaerobic digestion

The design demands on water and sanitation engineers are rapidly changing. The global population is set to rise from 7 billion to 10 billion by 2083. Urbanisation in developing regions is increasing at such a rate that a predicted 56% of the global population will live in an urban setting by 2025. Compounding these problems, the global water and energy crises are impacting the Global North and South alike. High-rate anaerobic digestion offers a low-cost, low-energy treatment alternative to the energy intensive aerobic technologies used today. Widespread implementation however is hindered by the lack of capacity to engineer high-rate anaerobic digestion for the treatment of complex wastes such as sewage. This thesis utilises the Expanded Granular Sludge Bed bioreactor (EGSB) as a model system in which to study the ecology, physiology and performance of high-rate anaerobic digestion of complex wastes. The impacts of a range of engineered parameters including reactor geometry, wastewater type, operating temperature and organic loading rate are systematically investigated using lab-scale EGSB bioreactors. Next generation sequencing of 16S amplicons is utilised as a means of monitoring microbial ecology. Microbial community physiology is monitored by means of specific methanogenic activity testing and a range of physical and chemical methods are applied to assess reactor performance. Finally, the limit state approach is trialled as a method for testing the EGSB and is proposed as a standard method for biotechnology testing enabling improved process control at full-scale. The arising data is assessed both qualitatively and quantitatively. Lab-scale reactor design is demonstrated to significantly influence the spatial distribution of the underlying ecology and community physiology in lab-scale reactors, a vital finding for both researchers and full-scale plant operators responsible for monitoring EGSB reactors. Recurrent trends in the data indicate that hydrogenotrophic methanogenesis dominates in high-rate anaerobic digestion at both full- and lab-scale when subject to engineered or operational stresses including low-temperature and variable feeding regimes. This is of relevance for those seeking to define new directions in fundamental understanding of syntrophic and competitive relations in methanogenic communities and also to design engineers in determining operating parameters for full-scale digesters. The adoption of the limit state approach enabled identification of biological indicators providing early warning of failure under high-solids loading, a vital insight for those currently working empirically towards the development of new biotechnologies at lab-scale.

Influência do estímulo por PAF no perfil de abundância proteica em neutrófilos : uma abordagem proteômica

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Pós-Graduação em Biologia Molecular, 2015.

Redes interorganizacionais e inovação: o caso do pólo joalheiro de Belém

This work is a case study based on Belém Jewelry Pole, whose main issue is to understand how the social network (which the Pole is inserted) influences on innovation process on this area. The main objective is to analyze how interorganizational networks impacted/impact on the potential for innovation, creating both limits and opportunities for the companies development. The adopted method analyzed the historical jewelry industry trajectory since the beginning of mineral extraction in the city of Itaituba (in the Pará State) until nowadays. Primary and secondary data were used allowing the view of the dynamics of the network during transformation periods of the main involved actors in the process. The prospect of embeddedness structural as analysis technique allowed verifying the quality of interactors ties, as well as the visualization of their structures. During the jewelry industry trajectory was verified a change in the quality of social relations, modifying the information flow, trust and associations of various links in the production chain. Both direct and indirect ties facilitated the access to remote networks entering new information related to new products, processes and market aspects. This interaction has led to raising the innovation potential causing a qualitative and quantitative improvement in competitiveness of organizations. Some embedded ties allowed the formation of partnerships bringing various economic earnings for those involved in the relationship. Thus, it is understood how aspects related to the position, architecture and quality of ties in a wide social network influenced on the innovation process and eventual jewelry industry trajectory

Genetic algorithm seeding of idiotypic networks for mobile-robot navigation

Robot-control designers have begun to exploit the properties of the human immune system in order to produce dynamic systems that can adapt to complex, varying, real-world tasks. Jerne’s idiotypic-network theory has proved the most popular artificial-immune-system (AIS) method for incorporation into behaviour-based robotics, since idiotypic selection produces highly adaptive responses. However, previous efforts have mostly focused on evolving the network connections and have often worked with a single, preengineered set of behaviours, limiting variability. This paper describes a method for encoding behaviours as a variable set of attributes, and shows that when the encoding is used with a genetic algorithm (GA), multiple sets of diverse behaviours can develop naturally and rapidly, providing much greater scope for flexible behaviour-selection. The algorithm is tested extensively with a simulated e-puck robot that navigates around a maze by tracking colour. Results show that highly successful behaviour sets can be generated within about 25 minutes, and that much greater diversity can be obtained when multiple autonomous populations are used, rather than a single one.

Volatilidade dos retornos e governança: um estudo de eventos da crise do subprime

The financial crisis that occurred between the years 2007 and 2008, known as the subprime crisis, has highlighted the governance of companies in Brazil and worldwide. To monitor the financial risk, quantitative tools of risk management were created in the 1990s, after several financial disasters. The market turmoil has also led companies to invest in the development and use of information, which are applied as tools to support process control and decision making. Numerous empirical studies on informational efficiency of the market have been made inside and outside Brazil, revealing whether the prices reflect the information available instantly. The creation of different levels of corporate governance on BOVESPA, in 2000, made the firms had greater impairment in relation to its shareholders with greater transparency in their information. The purpose of this study is to analyze how the subprime financial crisis has affected, between January 2007 and December 2009, the volatility of stock returns in the BM&BOVESPA of companies with greater liquidity at different levels of corporate governance. From studies of time series and through the studies of events, econometric tests were performed by the EVIEWS, and through the results obtained it became evident that the adoption of good practices of corporate governance affect the volatility of returns of companies

Influência dos parâmetros de processo na deposição de nitreto de titânio por plasma em gaiola catódica

Titanium nitride films were grown on glass using the Cathodic Cage Plasma Deposition technique in order to verify the influence of process parameters in optical and structural properties of the films. The plasma atmosphere used was a mixture of Ar, N2 and H2, setting the Ar and N2 gas flows at 4 and 3 sccm, respectively and H2 gas flow varied from 0, 1 to 2 sccm. The deposition process was monitored by Optical Emission Spectroscopy (OES) to investigate the influence of the active species in plasma. It was observed that increasing the H2 gas flow into the plasma the luminescent intensities associated to the species changed. In this case, the luminescence of N2 (391,4nm) species was not proportional to the increasing of the H2 gas into the reactor. Other parameters investigated were diameter and number of holes in the cage. The analysis by Grazing Incidence X-Ray Diffraction (GIXRD) confirmed that the obtained films are composed by TiN and they may have variations in the nitrogen amount into the crystal and in the crystallite size. The optical microscopy images provided information about the homogeneity of the films. The atomic force microscopy (AFM) results revealed some microstructural characteristics and surface roughness. The thickness was measured by ellipsometry. The optical properties such as transmittance and reflectance (they were measured by spectrophotometry) are very sensitive to changes in the crystal lattice of the material, chemical composition and film thicknesses. Therefore, such properties are appropriate tools for verification of this process control. In general, films obtained at 0 sccm of H2 gas flow present a higher transmittance. It can be attributed to the smaller crystalline size due to a higher amount of nitrogen in the TiN lattice. The films obtained at 1 and 2 sccm of H2 gas flow have a golden appearance and XRD pattern showed peaks characteristics of TiN with higher intensity and smaller FWHM (Full Width at Half Maximum) parameter. It suggests that the hydrogen presence in the plasma makes the films more stoichiometric and becomes it more crystalline. It was observed that with higher number of holes in the lid of the cage, close to the region between the lid and the sample and the smaller diameter of the hole, the deposited film is thicker, which is justified by the most probability of plasma species reach effectively the sample and it promotes the growth of the film

Management of industrialization projects

Short time-to-market is a key success factor in the todays’ dynamic business environment and many companies are trying to improve their product development processes. A challenge is to develop products according to the time plan and at the same time keeping the cost low and the quality high. This study focuses on the project management within the product development process in an automotive industry. The background of this study started as a request from the research and development department at the automotive company, which led to the following questions; 1) what are the most crucial factors for project success? 2) How can these factors contribute to a more successful outcome? 3) How can project management decrease product development lead time by sharing knowledge? The research approach is a case study and the data collection consist of interviews and questioners at two companies connected to project management in product development projects. Spider charts are created from the collected data containing eleven dimensions to show similarities and differences between the project managers working within the research and development department as well as between the two companies. The main conclusions are that there is a need to allow a certain level of flexibility when managing projects, in order to more easily handle late changes. Being involved in a project from the concept phase could facilitate the product development activities later on, due to a deeper understanding regarding previous decisions. Further, knowledge sharing methods, such as databases, has to be designed to be suitable for a specific organization and user friendly which enables the users to more easily search for specific types of knowledge. Lastly, a low level on the detailed focus is shown to be another success factor, however, in some cases there is still a need of this detailed focus to solve specific problems but the details may never become a higher focus than the holistic view.