15,900 research outputs found

    Aggregation in activity-based costing and the short run activity cost function

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    This paper first identifies the conditions that support the construction of an aggregate output, i.e. the conditions under which a single measure of output can be used to accurately determine cost object incremental costs within a cost pool. This is a significant issue which has not been fully explored in the management accounting literature. Two conditions are jointly necessary and sufficient. The first one is the linear homogeneity property associated with each cost object production function. This condition ensures that costs are linear with output, which is essential if the cost reported by an activity-based costing (ABC) system is also to be a relevant cost for decision?making. The second is that all (cost object) cost driver rates for a given cost pool are equal. This condition guarantees that the cost function at a given activity depends on only one cost driver. The short run structure of ABC is also introduced. It is shown that the fundamental ABC property of linearly between costs and output does not generally hold in the short run, even assuming that technologies are linearly homogeneous. Only under very particular conditions, such as when inputs are combined in completely fixed proportions, are short run costs linear with output.activity-based costing; aggregate output; cost driver; multi-output technologies; short run activity cost function

    How to control market power of activity centres? A theoretical model showing the advantages of implementing competition within organizations

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    One important issue in firms’ governance is how to create incentives so that activity centres can become more efficient. In this paper, we first introduce an agency contract where the salary of the manager of an activity centre that produces an intermediate product is dependent of its performance. Secondly, we add competition within the organization. This latter point is new in the literature. We then develop a "static analysis" comparing a firm that has only one activity centre producing an intermediate product with another firm that has two activity centres producing the same intermediate product, in a context where the technology manifests increasing returns to scale. We conclude that the introduction of internal competition makes the firm globally more efficient, even though it cannot fully explore the existence of increasing returns to scale.Activity centres, internal market power, firm efficiency

    ComplicaçÔes relacionadas ao implante cirĂșrgico de 146 cateteres de diĂĄlise peritoneal do tipo swan neck missouri

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    Trabalho de ConclusĂŁo de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Dapartamento de ClĂ­nica CirĂșrgica

    A cidade e o rio: origem e evolução da frente ribeirinha de Lisboa

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    Em Lisboa, ao longo dos sĂ©culos, o homem foi conquistando as ĂĄguas do Tejo. Hoje, apĂłs os diversos aterros, a frente ribeirinha da cidade Ă© uma consolidada faixa de terreno, rematada por muros que, contra a «ondulação» do Tejo, definem uma expandida ĂĄrea que acolhe uma intensa actividade portuĂĄria. Foi nesta faixa junto do rio que se desenrolou parte importante da histĂłria de Lisboa, desde as ocupaçÔes romana e muçulmana, e tambĂ©m muito particularmente aquando do perĂ­odo dos Descobrimentos, da reconstrução pombalina pĂłs-terramoto e do surto industrial do sĂ©culo XIX. Alguns destes momentos histĂłricos encontram-se reflectidos nas inĂșmeras plantas, cartas e mapas disponĂ­veis neste estudo, desde a Planta da Cidade de Lisboa : 1650, de JoĂŁo Nunes Tinoco, atĂ© ao Plano de Melhoramentos do Porto de Lisboa, de 1946. É com base nessas plantas, mas tambĂ©m em cartas manuscritas, relatos de Ă©poca, gravuras e fotografias antigas – documentos em grande parte inĂ©ditos –, que este trabalho de investigação propĂ”e cartografar este territĂłrio, realizando desenhos originais que possibilitam um novo olhar sobre o seu processo de crescimento e consolidação. Assim, este estudo concilia todos estes elementos, constituindo uma anĂĄlise completa que se debruça sobre a evolução da frente ribeirinha de Lisboa e que permite descobrir inĂșmeros aspectos atĂ© aqui desconhecidos, ajudando a responder Ă  pergunta que hoje se coloca: perante o cenĂĄrio que o porto actual atravessa, como melhor poderĂĄ Lisboa recuperar a relação com o rio?; THE CITY AND THE RIVER: ORIGIN AND EVOLUTION OF LISBON'S RIVERFRONT ABSTRACT: In Lisbon, over the centuries, man was conquering the waters of the Tagus. Today, after the various landfills, the city's riverfront is a consolidated strip of land, finished by walls that, against the "ripple" of the Tagus, define an expanded area that hosts an intense port activity. It was in this band along the river that unfolded important part of the history of Lisbon, from the Roman and Muslim occupations, and also very particularly during the period of the Discoveries, the post-earthquake reconstruction, and the industrial boom of the nineteenth century. Some of these historical moments are reflected in many plans, charts and maps available in this study, since the plan designated Planta da Cidade de Lisboa : 1650, made by JoĂŁo Nunes Tinoco, to the plan called Plano de Melhoramentos do Porto de Lisboa, drawn in the year of 1946. Based on these plans, but also in handwritten letters, time reports, antique prints and photographs – documents that are mostly unpublished – this research work proposes map this territory, performing original drawings that provide a new look at their growth process and consolidation. Thereby, this study combines all these elements, providing a complete analysis which focuses on the evolution of the Lisbon riverfront and that allows you to discover many aspects unknown until now, helping to answer the question that now arises: according to the present scenario that the harbour is going through, how can Lisbon recover the relationship with the river

    Decoder design and decoding models for joint source-network coding

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    Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Universidade do Porto. Faculdade de Engenharia. 201

    A BI-LEVEL SCHEME FOR ASSESSING THE IMPACT OF AIR TRANSPORTATION ON LOCAL DEVELOPMENT

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    An approach to assess the impact of the creation or expansion of an air transport infrastructure over regional development is proposed in this paper. Effective long term planning of this costly investment requires performing an overall analysis of socio-economic consequences through long term forecasting, scenario generation and risk analysis. One of main aspects of this task is related with the estimation of future demand over the modified transportation network which attends the considered region. The proposed approach makes use of two complementary models: One model is devoted to demand forecasting taking into account the modified accessibility of the multimodal transportation network, the other one defines the global transport supply according to a profit maximization behavior for the involved transport system. The demand forecasting process is based on an entropy maximization approach with flexible origin-destination levels to determine the intensity and the distribution of new origin-destination vectors. A two level solution technique considering vehicle flows at the first level and the payload/passengers flows at the second level is introduced. The proposed solution scheme is composed of an iterative process between the current solution for demand forecasting and the supply optimization problem: the entropy maximizing distribution problem provides the origin-destination matrix given a cost/capacity structure, while the supply optimization problem provides this cost/capacity structure resulting from the accessibility level, given the updated origin-destination vectors. The proposed approach is illustrated in the case of a fast developing rural agro-industrial area in central Brazil, where the consequences of the installation of a medium size airport are assessed.

    Blueprint: descrição da complexidade da regulação metabólica através da reconstrução de modelos metabólicos e regulatórios integrados

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    Tese de doutoramento em Biomedical EngineeringUm modelo metabĂłlico consegue prever o fenĂłtipo de um organismo. No entanto, estes modelos podem obter previsĂ”es incorretas, pois alguns processos metabĂłlicos sĂŁo controlados por mecanismos reguladores. Assim, vĂĄrias metodologias foram desenvolvidas para melhorar os modelos metabĂłlicos atravĂ©s da integração de redes regulatĂłrias. Todavia, a reconstrução de modelos regulatĂłrios e metabĂłlicos Ă  escala genĂłmica para diversos organismos apresenta diversos desafios. Neste trabalho, propĂ”e-se o desenvolvimento de diversas ferramentas para a reconstrução e anĂĄlise de modelos metabĂłlicos e regulatĂłrios Ă  escala genĂłmica. Em primeiro lugar, descreve-se o Biological networks constraint-based In Silico Optimization (BioISO), uma nova ferramenta para auxiliar a curação manual de modelos metabĂłlicos. O BioISO usa um algoritmo de relação recursiva para orientar as previsĂ”es de fenĂłtipo. Assim, esta ferramenta pode reduzir o nĂșmero de artefatos em modelos metabĂłlicos, diminuindo a possibilidade de obter erros durante a fase de curação. Na segunda parte deste trabalho, desenvolveu-se um repositĂłrio de redes regulatĂłrias para procariontes que permite suportar a sua integração em modelos metabĂłlicos. O Prokaryotic Transcriptional Regulatory Network Database (ProTReND) inclui diversas ferramentas para extrair e processar informação regulatĂłria de recursos externos. Esta ferramenta contĂ©m um sistema de integração de dados que converte dados dispersos de regulação em redes regulatĂłrias integradas. AlĂ©m disso, o ProTReND dispĂ”e de uma aplicação que permite o acesso total aos dados regulatĂłrios. Finalmente, desenvolveu-se uma ferramenta computacional no MEWpy para simular e analisar modelos regulatĂłrios e metabĂłlicos. Esta ferramenta permite ler um modelo metabĂłlico e/ou rede regulatĂłria, em diversos formatos. Esta estrutura consegue construir um modelo regulatĂłrio e metabĂłlico integrado usando as interaçÔes regulatĂłrias e as ligaçÔes entre genes e proteĂ­nas codificadas no modelo metabĂłlico e na rede regulatĂłria. AlĂ©m disso, esta estrutura suporta vĂĄrios mĂ©todos de previsĂŁo de fenĂłtipo implementados especificamente para a anĂĄlise de modelos regulatĂłrios-metabĂłlicos.Genome-Scale Metabolic (GEM) models can predict the phenotypic behavior of organisms. However, these models can lead to incorrect predictions, as certain metabolic processes are controlled by regulatory mechanisms. Accordingly, many methodologies have been developed to extend the reconstruction and analysis of GEM models via the integration of Transcriptional Regulatory Network (TRN)s. Nevertheless, the perspective of reconstructing integrated genome-scale regulatory and metabolic models for diverse prokaryotes is still an open challenge. In this work, we propose several tools to assist the reconstruction and analysis of regulatory and metabolic models. We start by describing BioISO, a novel tool to assist the manual curation of GEM models. BioISO uses a recursive relation-like algorithm and Flux Balance Analysis (FBA) to evaluate and guide debugging of in silico phenotype predictions. Hence, this tool can reduce the number of artifacts in GEM models, decreasing the burdens of model refinement and curation. A state-of-the-art repository of TRNs for prokaryotes was implemented to support the reconstruction and integration of TRNs into GEM models. The ProTReND repository comprehends several tools to extract and process regulatory information available in several resources. More importantly, this repository contains a data integration system to unify the regulatory data into standardized TRNs at the genome scale. In addition, ProTReND contains a web application with full access to the regulatory data. Finally, we have developed a new modeling framework to define, simulate and analyze GEnome-scale Regulatory and Metabolic (GERM) models in MEWpy. The GERM model framework can read a GEM model, as well as a TRN from different file formats. This framework assembles a GERM model using the regulatory interactions and Genes-Proteins-Reactions (GPR) rules encoded into the GEM model and TRN. In addition, this modeling framework supports several methods of phenotype prediction designed for regulatory-metabolic models.I would like to thank Fundação para a CiĂȘncia e Tecnologia for the Ph.D. studentship I was awarded with (SFRH/BD/139198/2018)
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