<p>In the year of 2000 the European Commission adopted a communication</p><p>called EU Financial Reporting Strategy: the Way Forward. The communication intended to make all listed companies within the EU arrange their financial statements in accordance with</p><p>International Accounting Standards by 2005 at the latest. When the amendments of IFRS 3 was introduced in March 2004 it meant that companies from that moment on, when acquiring another company, have to allocate the part of the purchase price assignable to customer contracts and the related customer relationships as an intangible asset. IFRS 3 does not give any guidance whatsoever on how to</p><p>accomplish the above described allocation and estimate a true and fair value of customer contracts and relationships. Let alone any direction regarding the establishment of the remaining useful life of the customer relationships and contracts, which constitutes the</p><p>foundation of the fair valuation but also a true and fair view regarding amortizations. The purpose of this thesis is to examine how the establishments regarding remaining useful life of customer relationships and contracts have been done. Furthermore, the purpose of this thesis is to explain the decision process and motives that results in why management choose to apply the specific remaining useful life of customer relationships and contracts they do. This study has been carried out with a qualitative approach involving two listed group companies within three different industries, hence, six companies are involved in this thesis. Semi-structured telephone interviews have been made with the companies and the annual reports have been examined. In order to explain the actions behind the valuation and establishment process, the positive accounting theory has been used. None of the six companies taking part in this study have applied an outspoken method for the establishment of the remaining useful life of the customer relationships and contracts and only half of the companies have identified different customer groups. A relation can be identified between using an external consultant</p><p>and applying different remaining lives for different customer groups. All companies amortize the customer relationships and contracts on a straight-line basis. This can be explained by the positive accounting theory to some extent. All companies applied straight-line amortization even though some of them actually admit that a declining</p><p>balance would provide a fairer view. Furthermore, long amortization plans are used in some companies in order to decrease the amortization costs and hence increase the net income. Positive accounting has been applied in order to shift reported earnings.</p> / <p>Under år 2000 beslutade den Europeiska kommissionen om att anta ett</p><p>förslag som hette EU Financial Reporting Strategy: the Way Forward. Antagandet av förslaget innebar att alla noterade bolag inom EU skulle presentera sin redovisning och sina årsredovisningar i linje med bestämmelserna i IAS – International Accounting Standards senast år 2005. När lagändringarna i IFRS 3 introducerades i mars 2004 innebar det att noterade bolag vid företagsförvärv fortsättningsvis skulle allokera den del av köpeskillingen som är hänförlig till kundkontrakt och relaterade kundrelationer som immateriell tillgång i</p><p>balansräkningen. IFRS 3 ger ingen vägledning överhuvudtaget med avseende på hur bolagen ska genomföra den ovan beskrivna allokeringen och uppskatta ett rättvist värde på kundkontrakt och kundrelationer. Inte heller finns det någon anvisning angående fastställandet av livslängd på kundkontrakt och kundrelationer som i sin tur ligger till grund för en rättvis värdering och en rättvis avskrivningsplan.</p><p>Syftet med den här uppsatsen är att undersöka hur fastställandet av livslängden på kundrelationer och kundkontrakt har utförts. Syftet är även att förklara beslutsprocessen och de bakomliggande motiven till varför företagsledningen väljer att använda den livslängd på kundrelationer och kundkontrakt de faktiskt gör. Studien har genomförts med en kvalitativ ansats som har involverat två noterade</p><p>koncernbolag inom tre olika branscher, totalt har alltså sex bolag medverkat i uppsatsen. Semistrukturerade telefonintervjuer har gjorts med de involverade bolagen och även deras årsredovisningar har undersökts. För att kunna förklara handlandet angående värderingsprocessen och livslängdsprocessen har den positiva redovisningsteorin använts. Inget av de sex bolagen som medverkat i studien har använt sig av någon etablerad metod för att fastställa den återstående livslängden av kundrelationerna och kundkontrakten, och endast hälften av företagen har identifierat olika grupper av kunder. Ett samband har identifierats mellan att använda sig av en extern konsult vid fastställandet och att använda sig av olika återstående livslängder för olika kundgrupper. Alla sex företagen använder sig av linjär avskrivning på kundkontrakten och kundrelationerna. Detta kan till en viss gräns förklaras med positiv redovisningsteori. Alla företagen har använt sig av linjär avskrivning även om vissa av företagen till och med medger att</p><p>degressiv avskrivning skulle ge en mer rättvis bild. Dessutom har långa avskrivningstider använts i en del av företagen för att sänka avskrivningskostnaderna som i sin tur ökar resultatet. Positiv redovisningsteori har alltså använts för att flytta vinster till innevarande år.</p>

The research aimed to evaluate the sediment transportation and deposition and the sedimentation (silt, siltation) in the Coruripe- I Reservoir, analyzing the quantification of the sediment transportation by drag (drag, dragging), and in suspension. The lake has, nowadays, 373 ha of water surface, and was built in 2006 to demand water for irrigation. It is located in the Coruripe River Hydrographic Basin, with 1562 Km2 of area. According to the batimétricos (bathymetric) data, the depth of the reservoir varies from 0.8 to 12.3 m, from the montant to the dam. To quantificate the transportation of the sediments in suspension and bearing, samples were taken above the reservoir, and the bottom sediments samples were collected within the lake at the same time as the Topo-bathymetric survey, with a Ecman dredging machine. Samples of suspended sediments were analyzed through total evaporation and subsequent weighting, than quantified in proportion to the sample volume. The size of the bottom samples wasn t possible to determine due the composition homogeneity of the samples, containing only mud. It was verified that the depositions are predominantly made up of silt and clay. It was estimated that the assoread volume of the lake, in 3 year of existence, is about 59,12%, with mean rate of sediment accumulated around 512,549.43 ton.ano-1. The areas of greater sedimentation and eutrophication were in the direction from downstream to montant by sediments, derived from the river that provides the reservoir and from the laterals to the centre, due to sediment erosion brought from areas of the reservoir slopes, planted with cane sugar, in which are not maintained the tracks of ciliary preservation, which would act as a kind of filter by reducing this direct contribution. It is estimated that, if urgent decisions to contain the marginal sediments were taken, this reservoir utile life can rise to approximately 85 years, otherwise, if the current level of sedimentation (sedimentation) continues, the effective utile life will not exceed 3 years. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A pesquisa teve como objetivo avaliar o transporte no rio Coruripe e o empilhamento de sedimentos provindos de uma barragem que rompeu à montante do Reservatório Coruripe - I, mediante estudos da quantificação do transporte de sedimentos por arraste e em suspensão. O lago possui atualmente espelho d água de 373 ha, construído para demanda de água para irrigação em 2006. Situa-se na BH do Rio Coruripe, com área de 1.562 km². Pela batimetria, a profundidade do reservatório varia de 0,8 a 12,3 m, de montante à barragem. Para a quantificação dos sedimentos transportados em suspensão e rolamento foram coletadas amostras acima do reservatório e para os sedimentos de fundo foram coletados no interior do lago na mesma época do levantamento topo-batimétrico com amostrador draga tipo Ecman.As amostras de sedimentos em suspensão foram analisadas através da secagem total e posterior pesagem, as quais foram quantificadas proporcionalmente ao volume amostrado. Já com as amostras de fundo não foi possível determinar a granulometria por apresentarem homogeneidade na composição, contendo somente lodo. Estima-se que o volume inutilizado do lago em 3 anos de existência é de 59,12 %, com taxa média de sedimentos acumulados de aproximadamente 512.549,43 ton.ano-1. As áreas de maior assoreamento e eutrofização estão no sentido de jusante à montante por sedimentos oriundos de uma barragem rompida à montante e do rio que abastece o reservatório e das laterais para o centro, devido a sedimentos carreados pela erosão das áreas de encostas, as quais são cultivadas com cana-de-açúcar. Diante disso, não são mantidas as faixas de preservação ciliar, que atuariam como uma espécie de filtro, diminuindo essa contribuição direta. Estimou-se ainda que, se forem tomadas decisões urgentes para a contenção de sedimentos marginais, a vida útil deste reservatório pode se elevar para aproximadamente 85 anos. Caso contrário, se o atual nível de assoreamento continuar, a vida útil efetiva não ultrapassará 3 anos.

O objetivo principal deste trabalho é a análise e possível otimização de um projeto de válvulas de esfera. É apresentado um estudo para determinação do torque de acionamento de válvulas de esfera industriais, bem como um estudo de vida útil das válvulas. Os estudos foram realizados utilizando projeto de experimentos e permitiram a construção de modelos de previsão de torque e de previsão de vida útil. A previsão de torque é fundamental para possibilitar a otimização do projeto das válvulas, na fase de desenvolvimento do produto. O uso dos modelos permitiu a determinação do ajuste ótimo, levando em conta pressão, temperatura, esmagamento das sedes, torque de aperto na porca da haste e torque de acionamento desejado. Já os estudos de vida útil são importantes para informar à empresa o número de ciclos até o vazamento. Os resultados do estudo, realizado através de ensaios acelerados, permitiram a construção de modelos de confiabilidade associada ao número de ciclos de operação, permitindo assim a avaliação e possível melhoria do projeto das válvulas. / The main objective of this dissertation is the analysis and optimization of a ball valve project. A study for determining the operational torque of industrial ball valves as well as a life study of valves are presented. The studies were performed using design of experiments and allowed the construction of torque and life prevision models. The prevision of torque is fundamental to enable project optimization on the phase of product development. Results allowed the definition of an optimal setting regarding pressure, temperature, seats tightening, stem nut tightening torque and the desired operational torque. Further, the life studies are helpful to inform the company the number of cycles until leakage. Results, obtained through accelerated tests, allowed the construction of reliability models associated to the number of operational cycles, conducting to valve design evaluation and optimization.

O objetivo principal deste trabalho é a análise e possível otimização de um projeto de válvulas de esfera. É apresentado um estudo para determinação do torque de acionamento de válvulas de esfera industriais, bem como um estudo de vida útil das válvulas. Os estudos foram realizados utilizando projeto de experimentos e permitiram a construção de modelos de previsão de torque e de previsão de vida útil. A previsão de torque é fundamental para possibilitar a otimização do projeto das válvulas, na fase de desenvolvimento do produto. O uso dos modelos permitiu a determinação do ajuste ótimo, levando em conta pressão, temperatura, esmagamento das sedes, torque de aperto na porca da haste e torque de acionamento desejado. Já os estudos de vida útil são importantes para informar à empresa o número de ciclos até o vazamento. Os resultados do estudo, realizado através de ensaios acelerados, permitiram a construção de modelos de confiabilidade associada ao número de ciclos de operação, permitindo assim a avaliação e possível melhoria do projeto das válvulas. / The main objective of this dissertation is the analysis and optimization of a ball valve project. A study for determining the operational torque of industrial ball valves as well as a life study of valves are presented. The studies were performed using design of experiments and allowed the construction of torque and life prevision models. The prevision of torque is fundamental to enable project optimization on the phase of product development. Results allowed the definition of an optimal setting regarding pressure, temperature, seats tightening, stem nut tightening torque and the desired operational torque. Further, the life studies are helpful to inform the company the number of cycles until leakage. Results, obtained through accelerated tests, allowed the construction of reliability models associated to the number of operational cycles, conducting to valve design evaluation and optimization.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-06-26T22:26:10Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Caio Bezerra Souto Maior.pdf: 3924685 bytes, checksum: 6968386bf75059f45ee80306322d2a56 (MD5) / Made available in DSpace on 2018-06-26T22:26:10Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Caio Bezerra Souto Maior.pdf: 3924685 bytes, checksum: 6968386bf75059f45ee80306322d2a56 (MD5) Previous issue date: 2017-02-21 / CAPES / The useful life time of equipment is an important variable related to reliability and maintenance. The knowledge about the useful remaining life of operation system by means of a prognostic and health monitoring could lead to competitive advantage to the corporations. There are numbers of models trying to predict the reliability’s variable behavior, such as the remaining useful life, from different types of signal (e.g. vibration signal), however several could not be realistic due to the imposed simplifications. An alternative to those models are the learning methods, used when exist many observations about the variable. A well-known method is Support Vector Machine (SVM), with the advantage that is not necessary previous knowledge about neither the function’s behavior nor the relation between input and output. In order to achieve the best SVM’s parameters, a Particle Swarm Optimization (PSO) algorithm is coupled to enhance the solution. Empirical Mode Decomposition (EMD) and Wavelets rise as two preprocessing methods seeking to improve the input data analysis. In this paper, EMD and wavelets are used coupled with PSO+SVM to predict the rolling bearing Remaining Useful Life (RUL) from a vibration signal and compare with the prediction without any preprocessing technique. As conclusion, EMD models presented accurate predictions and outperformed the other models tested. / O tempo de vida útil de um equipamento é uma importante variável relacionada à confiabilidade e à manutenção, e o conhecimento sobre o tempo útil remanescente de um sistema em operação, por meio de um monitoramento do prognóstico de saúde, pode gerar vantagens competitivas para as corporações. Existem diversos modelos utilizados na tentativa de prever o comportamento de variáveis de confiabilidade, tal como a vida útil remanescente, a partir de diferentes tipos de sinais (e.g. sinal de vibração), porém alguns podem não ser realistas, devido às simplificações impostas. Uma alternativa a esses modelos são os métodos de aprendizado, utilizados quando se dispõe de diversas observações da variável. Um conhecido método de aprendizado supervisionado é o Support Vector Machine (SVM), que gera um mapeamento de funções de entrada-saída a partir de um conjunto de treinamento. Para encontrar os melhores parâmetros do SVM, o algoritmo de Particle Swarm Optimization (PSO) é acoplado para melhorar a solução. Empirical Mode Decomposition (EMD) e Wavelets são usados como métodos pré-processamento que buscam melhorar a qualidade dos dados de entrada para PSO+SVM. Neste trabalho, EMD e Wavelets foram usadas juntamente com PSO+SVM para estimar o tempo de vida útil remanescente de rolamentos a partir de sinais de vibração. Os resultados obtidos com e sem as técnicas de pré-processamento foram comparados. Ao final, é mostrado que modelos baseados em EMD apresentaram boa acurácia e superaram o desempenho dos outros modelos testados.

Turbines encounter blade failures due to fatigue and creep. It has been shown in the literature that the primary cause of steam turbine blade failures worldwide can be ascribed to fatigue in low pressure (LP) turbine blades. The failure and damage to these blades can lead to catastrophic consequences. Some utilities use empirical methods to determine the forces experienced by turbine blades but desire more accurate methods. The inaccurate prediction of high-cycle fatigue (HCF), thermal durability and stage performance is introduced when one does not consider blade row interaction. Blade row interactions can, however, be accounted for by means of computational fluid dynamics (CFD). Furthermore, modern high- fidelity CFD tools would be able to contribute greatly in predicting the forces experienced by turbine blades. Numerical tools such as CFD and nite element analysis (FEA) can greatly contribute to the estimation of the remaining useful life (RUL) of turbine blades. However, in this estimation process, there are various uncertainties and aspects that affect the estimated RUL. Understanding the sensitivity of the estimated RUL to these various uncertainties and aspects is of great importance if RUL is to be estimated as accurately as possible. In this dissertation, a sensitivity analysis is performed with the purpose of establishing the sensitivity of the estimated RUL of the last stage rotor of an LP steam turbine, to the number of harmonics used in a nonlinear harmonic (NLH) CFD simulation. The sensitivity of the estimated RUL is evaluated in the HCF regime, where the cyclic stresses occur below the yield strength of the turbine blade. A CFD model, FE model, and fatigue model were therefore developed in such a manner that would suffice, regarding the purpose of the sensitivity analysis. The CFD model is validated by comparing the predicted CFD power to that of actual generated power of a dual 100MW LP steam turbine. The sensitivity analysis is performed for 3 operation conditions, and for each operational condition the aerodynamic forces were computed using 1, 2, and 3 harmonics in an NLH simulation. The estimation process considers a weak coupling between the CFD model and FE model. NLH simulations are firstly performed to calculate the unsteady static surface pressure distributions on the last stage rotor. This is followed by the mapping thereof to the FE model, for which a transient structural analysis is performed. Finally, the RUL is estimated by performing a fatigue analysis on the stress history obtained from the transient structural analysis. Based on the results of the sensitivity analysis, the following recommendations were made, from a conservative point of view. Firstly, in general, if the RUL is to be estimated with reasonable accuracy, just using 1 harmonic in an NLH simulation will not be sufficient and 2 harmonics should be used. Secondly, if the RUL has to be estimated with high accuracy, 3 harmonics should be used. / Dissertation (MEng)--University of Pretoria, 2018. / National Research Foundation (NRF) / Mechanical and Aeronautical Engineering / MEng / Unrestricted

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With the advancement of sensor technology and data processing capacities, various types of high volume data are available for process monitoring and prognostics in manufacturing systems. In a broaching process, a multi-toothed broaching tool removes material from the workpiece by sequential engagement and disengagement of multiple cutting edges. The quality of the final part, including the geometric integrity and surface finish, is highly dependent upon the broaching tool condition. Though there has been a considerable amount of research on tool condition monitoring and prognostics for various machining processes, the broaching process is unique in the following aspects: 1) a broaching process involves multiple cutting edges, which jointly contribute to the final part quality; 2) the resharpening and any other process adjustments to the tool can only be performed with the whole broaching tool or at least a whole segment of the tool replaced. The overarching goal of this research is to explore how engineering knowledge can be used to improve process monitoring and prognostics for a complex manufacturing process like broaching. This dissertation addresses the needs for developing new monitoring and prognostics approaches based on various types of data. Specifically, the research effort focuses on 1) the use of in-situ force profile data for real-time process monitoring and fault diagnosis, 2) degradation characterization for broaching processes on an individual component level based on image processing; and 3) system-level degradation modeling and remaining useful life prediction for broaching processes based on multiple images. / Ph. D.