Orientador: Amauri Hassui / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T20:30:13Z (GMT). No. of bitstreams: 1 Correa_FabianodosSantos_M.pdf: 5805847 bytes, checksum: 1e46e12c4b86d23df66529c421067901 (MD5) Previous issue date: 2013 / Resumo: A vida da ferramenta juntamente com o tempo gasto para acertos quando a mesma é substituída pode representar uma significativa parcela do custo total do produto. Desta forma, a redução destes custos é de fundamental importância para o processo. Quando se utiliza ferramentas de metal duro com coberturas, ou ferramentas com geometria definida, o desgaste mais comum que determina sua vida útil é o desgaste de flanco (VB). Este trabalho tem como principais objetivos estudar os esforços existentes na usinagem de fresamento de topo com insertos intercambiáveis redondos do aço inoxidável aeronáutico 15-5 PH e relacioná-los com o tempo de vida das ferramentas testadas. Analisar estes esforços no regime do tempo e da frequência a fim de verificar as principais forças responsáveis pelas possíveis vibrações do sistema. Tais vibrações podem ter grande parcela na contribuição dos desgastes e avarias das ferramentas. Todos os ensaios deste trabalho mantiveram constante a largura fresada (ae) de 14 mm, o corte em movimento predominantemente discordante e assimétrico com ae > D/2 (diâmetro da fresa), a profundidade de corte (ap) de 1 mm e fluido de corte em abundância. Para os parâmetros que variaram tem-se a velocidade de corte (vc) de 195 m/min e 170 m/min, os avanços por dente da fresa (fz) de 0,15 mm/dente e 0,25 mm/dente além de duas geometrias diferentes de insertos. Nas análises dos esforços foi utilizada a RMS para melhor interpretação da magnitude destes esforços. Observou-se que o aumento do avanço faz os esforços aumentarem, o mesmo aumento de esforços se deu para geometrias positivas (com quebra-cavaco) quando comparadas as geometrias neutras. No entanto, para as velocidades de corte usadas não se teve uma correlação significativa nos esforços. Para a vida da ferramenta, a vc teve influência direta na vida, o que era de se esperar, os avanços fz maiores apresentaram um comportamento inverso na vida. O maior contribuinte para o desgaste da ferramenta foi o alto atrito causado pelos esforços elevados, medidos na entrada do dente, onde a espessura do cavaco inicia-se com zero. Este comportamento do cavaco é um fenômeno comum ao corte discordante. Dentre os mecanismos de desgastes constatados, o predominante foi o desgaste conhecido como aderência (attrition) / Abstract: Tool life along with the setup time whenever it is changed may represent a big amount of the total cost of the product. This way, reducing these costs plays a fundamental role in the process. When using coated carbide tools, or designed geometry tools, the most common type of wear that determines the end of a tools life is flank wear (VB). This work has as main goals evaluate the machining forces in round inserts face milling of aerospace stainless steel 15-5 PH and relate these forces with the tool life. Evaluate the forces in time and frequency domain to check the main responsible for vibrations of the machining system. The vibrations may contribute in tool wear and failure. In all the tests, cutting width (ae) of 14 mm, up milling an asymmetric cut (with radial immersion of ae > D/2), cutting depth (ap) of 1 mm and cutting fluid conditions were kept constant. Cutting speed (vc) of 170 m/min and 195 m/min, feed per tooth (fz) of 0.15 mm/tooth and 0.25 mm/tooth, and two different insert geometries were the tests inputs. For analysis, the RMS value was used for better understanding of forces magnitude. It was observed that an increase in feed per tooth causes an increase of forces. The same behavior occurred for positive geometries (with chipbreaker) than for neutral geometry. However, the relationship between cutting speeds and forces was not significant. In tool life, cutting speed had high influence (as expected). High feed per tooth showed an inverse impact in tool life, increasing tool life. The main factor for tool wear was the high friction caused by high forces, measured in the beginning of the cut, when chip width was zero. This behavior of the chip is common in up milling. Attrition was the main mechanism of wear among all types observed / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Ontologies have become an important tool for representing data in a structured manner. Merging ontologies allows for the creation of ontologies that later can be composed into larger ontologies as well as for recognizing patterns and similarities between ontologies. Ontologies are being used nowadays in many areas, including bioinformatics. In this thesis, we present a desktop version of SAMBO, a system for merging ontologies that are represented in the languages OWL and DAML+OIL. The system has been developed in the programming language JAVA with JDK (Java Development Kit) 1.4.2. The user can open a file locally or from the network and can merge ontologies using suggestions generated by the SAMBO algorithm. SAMBO provides a user-friendly graphical interface, which guides the user through the merging process.

Many maintenance policies have been proposed for refreshing a warehouse. The difficulties of selecting an appropriate maintenance policy for a specific scenario with specific source characteristics, user requirements etc. has triggered researcher to develop algorithms and cost-models for predicting cost associated with a policy and a scenario. In this dissertation, we develop a benchmarking tool for testing scenarios and retrieve real world data that can be compared against algorithms and cost-models. The approach was to support a broad set of configurations, including the support of source characteristics proposed in [ENG00], to be able to test a diversity set of scenarios.

A database, AmyProt, was developed that collated details of 32 human amyloid proteins associated with disease and 488 associated mutations and polymorphisms, of which 316 are classified as amyloid. A detailed profile of the mutations was developed in terms of location within domains and secondary structures of the proteins and functional effects of the mutations. The data was used to test the hypothesis that mutations enhance amyloidosis in human amyloid proteins have distinctive characteristics, in terms of specific location within proteins and physico-chemical characteristics, which differentiate them from non-amyloid forming polymorphisms in amyloid proteins and from disease mutations and polymorphisms in non-amyloid disease linked proteins. The aim was to use these characteristics to train a prediction algorithm for amyloid mutations that will provide a more accurate prediction than current general disease prediction tools and amyloid prediction tools that focus on aggregating regions. 66 location specific features and changes upon mutation of 366 amino acids propensities, derived from the amino acid index database AAindex, were analysed. A significant proportion of mutations were located with aggregating regions, however the majority of mutations were not associated with these regions. An analysis of motifs showed that amyloid mutations had a significant association with transmembrane helix motifs such as GxxxG. Statistical analysis of substitutions mutations, using substitution matrices, showed that amyloid mutations have a decrease in α-helix propensity and overall secondary structure propensity compared to the disease mutations and disease and amyloid polymorphisms. Machine learning was used to reduce the large set of features to a set of 18 features. These included location near transmembrane helices, secondary structure features; transmembrane and extracellular domains and 4 amino acid propensities: knowledge-based membrane propensity scale from 3D helix; α-helix propensity; partition coefficient; normalized frequency of coil. The AmyProt mutations and non-amyloid polymorphisms were used to train and test the novel amyloid mutation prediction tool, AmyPred, the first tool developed purely to predict amyloid mutations. AmyPred predicts the amyloidogenicity of mutations as a consensus by majority vote (CMV) and mean probability (CMP) of 5 classifiers. Validation of AmyPred with 27 amyloid mutations and 20 non-amyloid mutations from APP, Tau and TTR proteins, gave classification accuracies of 0.7/0.71 (CMV/CMP) and with an MCC of 0.4 (CMV) and 0.41 (CMP). AmyPred out performed other tools such as SIFT (0.37) and PolyPhen (0.36) and the amyloid consensus prediction tool, MetAmyl (0.13). Finally, AmyPred was used to analyse p53 mutations to characterize amyloid and non-amyloid mutations within this protein.

The efficacy of combined diamond and diamond like carbon coatings, to allow for effective and efficient dry turning of aluminium alloy Al 6082, has been investigated. Optimised diamond and diamond-like carbon (DLC) coatings were combined and deposited onto a WC-Co insert using chemical vapour deposition (CVD) methods. DLC coatings were developed by testing the effects of bias voltage, deposition time and gas pressure. During the development of the DLC layer, the effects of substrate geometry and positioning in the deposition chamber were investigated. It was discovered that coating characteristics could vary significantly across the samples as a result of geometrical effects. This contradicted claims that, as plasma enhanced CVD is a non-line of sight deposition method, any variation in the coating due to geometry would be negligible. SEM analysis revealed coating thickness to increase by over 50%. AFM measurements showed coating roughness to increase by up to 30 times, whilst Raman spectroscopy highlighted a significant decrease in sp3 bonding. This variation in characteristics was seen, through the use of scratch testing, to translate into significantly reduced tribological performance. Friction was increased by 60% and critical load was only half of that of the coating applied to flat surface. The combined coatings were characterised and machining performance was evaluated. Coating characteristics were examined using SEM, AFM and Raman spectroscopy. Cutting trials designed to simulate the expected tool life were conducted. Micro and nano-crystalline diamond coatings, with and without an additional DLC layer were trialled along with a single layer DLC coating. Commercially available uncoated and TiN coating inserts of identical geometry were also trialled as a reference. The results showed that the addition of the DLC layer effectively reduced the roughness of the diamond, however, this did not translate into reduced adhesion of the aluminium to the cutting tip. It has been shown that for this particular machining scenario, a smoother coating effectively increased friction and adhesion of the workpiece material. The investigation has highlighted that due to the complex dynamics of material transfer effects in sliding, it cannot be assumed that a smoother surface layer will lead to improved tribological performance.

The World Wide Web contains a vast amount of information. This feature makes it a very useful part of our everyday activities but the information contained within is made up of an exponentially increasing repository of semantically unstructured data. The semantic web movement involves the evolution of the existing World Wide web in order to enable computers make meaning of and understand the data they process and consequently increase their processing capabilities. Over the past decade a number of new projects implementing the semantic web technology have been developed albeit still in their infancy. These projects are based on semantic data models and one such is the Wikidata project. The Wikidata project is targeted at providing a more semantic platform for editing and sharing data throughout the Wikipedia and Wikimedia communities. This project studies how the Wikidata project facilitates such a semantic platform for the Wikimedia communities and includes the development of an application utilizing the semantic capabilities of Wikidata. The objective of the project is to develop an application capable of retrieving and presenting statistical data and also be able to make missing or invalid data on Wikidata detectable. The result is an application currently aimed at researchers and students who require a convenient tool for statistical data collection and data mining projects. Usability and performance tests of the application are also conducted with the results presented in the report. Keywords: Semantic web, World Wide Web, Semantic data model, Wikidata, data mining.

The ray formalism is critical to understanding light propagation, yet current pedagogy relies on inadequate 2D representations. We present a system in which real light rays are visualized through an optical system by using a collimated laser bundle of light and a fog chamber. Implementation for remote and immersive access is enabled by leveraging a commercially available 3D viewer and gesture-based remote controlling of the tool via bi-directional communication over the Internet.

Master of Agribusiness / Department of Agricultural Economics / Jeffery R. Williams / For the past couple years, farm income has declined due to lower prices for corn, soybeans, and wheat. This decline has caused agricultural producers to keep equipment longer, which has affected equipment sales at John Deere. When times are good, producers buy new and trade used equipment, but when a producer’s profit is lower than previous years, they tend to save their money for input costs for the next growing season. The decline in farm income has had a negative effect on agriculture sales, but dealers can maintain their market share goals and still be profitable if they adjust their focus to other areas of their business, including sales of parts and equipment service. The goal of this study is to create an analysis tool that field managers can use to help dealers see the potential sales, profit, and pay for performance that they are missing because they are not up to suggested guidelines for sales of parts and equipment service. The tool includes several metrics from an existing report called the Categorization Report. These metrics are Dealer Performance Market Share, Aftermarket Performance Factor, Service Market Performance Factor, and Net Operating Return on Sales. The tool calculates the differences between the dealer metrics and John Deere metrics. Further, this tool is used to compare an individual dealer to other dealer averages and determine what a high performance, fully optimized dealer looks like and how much more a dealership could be selling in sales, parts and service to be a sustainable business in today’s economy. The tool is used to examine three scenarios to demonstrate its flexibility. These scenarios include a top-ten dealer, a large-scale above-average dealer, and a merger of three dealerships. The spreadsheet tool will display a two-page summary that shows how a dealership compares with other dealers that are similar in size and how they compare to the top-ten elite dealers in their category. The summary will also include market share maps to show which dealer-specific geographical areas need improvement to earn more sales in the future.

The aim of this research was to explore empirically how firms create and implement strategic decisions (SD’s). The research was inspired by the need to understand further organizational process underpinning SD’s phenomenon and potentially contribute to the overall performance of firms. Previous research on SD’s has been focusing on the formal strategic planning approaches, which have been criticized for their highly prescriptive views of SD’s, separating creation from implementation, and focusing on the content and discrete elements rather than the holistic process. Despite all these studies, our understanding of the actual nature of the SD phenomenon from creation to implementation remains incomplete. Motivated by the need to look empirically and holistically at this very complex social phenomenon, this research problematizes the above aspects of SD’s literature and positions this research within a wider social and descriptive process based approach. The research employed qualitative and Analytic Induction (AI) methodologies, and addressed the above need in three projects. The objective of each project has evolved and lead to the emergence of the final findings, which suggest a possible answer to the overall research aim. The Scoping Study proposed a theoretical framework of successful SD’s implementation factors. Project 1 went further and investigated these factors empirically. Project 2 developed empirically the process of how people actually create and implement SD’s. In Project 3, this process was analysed through the theoretical lens of the sensemaking perspective and was applied by practitioners through an empirically tested diagnostic tool. This research has made a step towards a better understanding of SD’s in practice and contributed to the academic knowledge by proposing a different, yet viable descriptive process, which can improve the overall quality of the SD’s, and potentially lead to better performance.

In the early 1950s the study on how to determine true ore-grade distributions in the mining sector, sparked the development of a series of statistical tools that specifically allows for spatial and subsequently spatial-temporal dependence. These statistics are commonly referred to as geostatistics, and has since been incorporated in several fields of study characterized by this dependence. Basic descriptive statistics and mapping tools for geostatistics are defined and illustrated by means of a simulated dataset. The moments are modelled according to predefined conditions and model structures to describe the spatial and spatial-temporal variance in the data. These variograms and covariance structures are subsequently utilized in the least square procedure, namely kriging. At present, kriging is most commonly used in geostatistics for the interpolation and simulation of spatial or spatial-temporal data. The univariate and multivariate spatial and spatial-temporal kriging techniques are tested on the simulated dataset, to demonstrate how interpolation weights are determined according to the lag distances and underlying variance structure. The strength, weaknesses and inherent complexities of the methodologies are highlighted. / Dissertation (MSc)--University of Pretoria, 2010. / Statistics / unrestricted