996 resultados para Structural-Parametrical Optimization
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Optimization is a very important field for getting the best possible value for the optimization function. Continuous optimization is optimization over real intervals. There are many global and local search techniques. Global search techniques try to get the global optima of the optimization problem. However, local search techniques are used more since they try to find a local minimal solution within an area of the search space. In Continuous Constraint Satisfaction Problems (CCSP)s, constraints are viewed as relations between variables, and the computations are supported by interval analysis. The continuous constraint programming framework provides branch-and-prune algorithms for covering sets of solutions for the constraints with sets of interval boxes which are the Cartesian product of intervals. These algorithms begin with an initial crude cover of the feasible space (the Cartesian product of the initial variable domains) which is recursively refined by interleaving pruning and branching steps until a stopping criterion is satisfied. In this work, we try to find a convenient way to use the advantages in CCSP branchand- prune with local search of global optimization applied locally over each pruned branch of the CCSP. We apply local search techniques of continuous optimization over the pruned boxes outputted by the CCSP techniques. We mainly use steepest descent technique with different characteristics such as penalty calculation and step length. We implement two main different local search algorithms. We use “Procure”, which is a constraint reasoning and global optimization framework, to implement our techniques, then we produce and introduce our results over a set of benchmarks.
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Dissertação para obtenção do Grau de Mestre em Bioquímica
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Breast cancer is the most common cancer among women, being a major public health problem. Worldwide, X-ray mammography is the current gold-standard for medical imaging of breast cancer. However, it has associated some well-known limitations. The false-negative rates, up to 66% in symptomatic women, and the false-positive rates, up to 60%, are a continued source of concern and debate. These drawbacks prompt the development of other imaging techniques for breast cancer detection, in which Digital Breast Tomosynthesis (DBT) is included. DBT is a 3D radiographic technique that reduces the obscuring effect of tissue overlap and appears to address both issues of false-negative and false-positive rates. The 3D images in DBT are only achieved through image reconstruction methods. These methods play an important role in a clinical setting since there is a need to implement a reconstruction process that is both accurate and fast. This dissertation deals with the optimization of iterative algorithms, with parallel computing through an implementation on Graphics Processing Units (GPUs) to make the 3D reconstruction faster using Compute Unified Device Architecture (CUDA). Iterative algorithms have shown to produce the highest quality DBT images, but since they are computationally intensive, their clinical use is currently rejected. These algorithms have the potential to reduce patient dose in DBT scans. A method of integrating CUDA in Interactive Data Language (IDL) is proposed in order to accelerate the DBT image reconstructions. This method has never been attempted before for DBT. In this work the system matrix calculation, the most computationally expensive part of iterative algorithms, is accelerated. A speedup of 1.6 is achieved proving the fact that GPUs can accelerate the IDL implementation.
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Fundação para a Ciência e Tecnologia - EXPL/BBB-BEP/0274/2012
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Theawareness that fossil fuels exist in limited quantities has stimulated research into energy production from renewable sources. Future energy sources! should! be! plentiful! with! negligible! impact! on! the! environment.! Hydrogen!has!the!potential!to!satisfy!these!requirements.!Nevertheless,!current! methods! of! H2! production! rely! on! nonOrenewable! resources.! Biological! H2! production! from! sunlight! or! biomass! is! an! appealing! alternative! to! current! production!methods.!!(...)
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This work aims to identify and rank a set of Lean and Green practices and supply chain performance measures on which managers should focus to achieve competitiveness and improve the performance of automotive supply chains. The identification of the contextual relationships among the suggested practices and measures, was performed through literature review. Their ranking was done by interviews with professionals from the automotive industry and academics with wide knowledge on the subject. The methodology of interpretive structural modelling (ISM) is a useful methodology to identify inter relationships among Lean and Green practices and supply chain performance measures and to support the evaluation of automotive supply chain performance. Using the ISM methodology, the variables under study were clustered according to their driving power and dependence power. The ISM methodology was proposed to be used in this work. The model intends to provide a better understanding of the variables that have more influence (driving variables), the others and those which are most influenced (dependent variables) by others. The information provided by this model is strategic for managers who can use it to identify which variables they should focus on in order to have competitive supply chains.
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If an opening to the argument of this dissertation is of imperative necessity, one might tentatively begin with Herbert Quain, born in Roscommon, Ireland, author of the novels The God of the Labyrinth (1933) and April March (1936), the short-story collection Statements (1939), and the play The Secret Mirror (undated). To a certain extent, this idiosyncratic Irish author, who hailed from the ancient province of Connacht, may be regarded as a forerunner of the type of novels which will be considered in this dissertation. Quain was, after all, the unconscious creator of one of the first structurally disintegrated novels in the history of western literature, April March. His first novel, The God of the Labyrinth, also exhibits elements which are characteristic of structurally disintegrated fiction, for it provides the reader with two possible solutions to a mysterious crime. As a matter of fact, one might suggest that Quain’s debut novel offers the reader the possibility to ignore the solution to the crime and carry on living his or her readerly life, turning a blind eye to the novel itself. It may hence be argued that Quain’s first novel is in fact a compound of three different novels. It is self-evident that the structure of Quain’s oeuvre is of an experimental nature, combining geometrical precision with authorial innovation, and one finds in it a higher consideration for formal defiance than for the text itself. In other words, the means of expression are the concern of the author and not, interestingly, the textual content. April March, for example, is a novel which regresses back into itself, its first chapter focussing on an evening which is preceded by three possible evenings which, in turn, are each preceded by three other, dissimilar, possible evenings. It is a novel of backward-movement, and it is due to this process of branching regression that April March contains within itself at least nine possible novels. Structure, therefore, paradoxically controls the text, for it allows the text to expand or contract under its formal limitations. In other words, the formal aspects of the novel, usually associated with the restrictive device of a superior design, contribute to a liberation of the novel’s discourse. It is paradoxical only in the sense that the idea of structure necessarily entails the fixation of a narrative skeleton that determines how plot and discourse interact, something which Quain flouts for the purposes of innovation. In this sense, April March’s convoluted structure allows for multiple readings and interpretations of the same text, consciously germinating narratives within itself, producing different texts from a single, unique source. Thus, text and means of expression are bonded by a structural design that, rather than limiting, liberates the text of the novel.
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The objective of this work project is to analyse and discuss the importance of the “Cost to Serve” as a differentiation key factor, by accessing cost to serve customers of a Portuguese subsidiary of a multinational company, which is operating in the sector of fast moving consumer goods (FMCG) – Unilever – Jerónimo Martins (UJM). I will also suggest and quantify key proposals to decrease costs and increase customers’ value. Hence, the scope of this work project is focused on logistics and distribution processes of the company supply chain.
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RESUMO: Enthesitis is the hallmark of spondyloarthritis (SpA), and is observed in all subtypes. Wide information on SpA abnormalities, including synovitis, tendinitis and enthesitis, can be efficiently perceived by Doppler ultrasound. Furthermore, several studies on imaging of enthesis showed that imaging techniques are better than clinical examination to detect enthesis alterations; and vascularized enthesitis detected by Doppler ultrasound appears to be a valuable diagnostic tool to confirm SpA diagnosis. However, data published until now concerning entheseal elementary alterations that characterize SpA enthesitis (enthesis inflammatory activity) or enthesopathy (permanent structural changes) reflect rather the authors’ empiric opinion than a methodological validation process. In this sense it seems crucial to identify elementary entheseal lesions associated with activity or damage, in order to improve monitoring and treatment response in SpA patients. The development of better assessment tools is today a challenge and a need in SpA. The first study of this thesis focused on the analysis of the reliability of inter-lector and inter-ultrasonography equipment of Madrid sonography enthesitis index (MASEI). Fundamental data for the remaining unrolling project validity. In the second and third studies we concerned about two entheseal elemental lesions: erosions and bursa. In literature erosions represent a permanent structural damage, being useful for monitoring joint injury, disease activity and therapeutic response in many rheumatic diseases; and to date, this concept has been mostly applied in rheumatoid arthritis (RA). Unquestionably, erosion is a tissue-related damage and a structural change. However, the hypothesis that we decided to test was if erosions represent a permanent structural change that can only grow and worsen over time, as occurs in RA, or a transitory alteration. A longitudinal study of early SpA patients was undertaken, and the Achilles enthesis was used as a model. Our results strongly suggested that previously detected erosions could disappear during the course of the disease, being consistent with the dynamic behavior of erosion over time. Based on these striking results it seems reasonable to suggest that the new-bone formation process in SpA could be associated with the resolution of cortical entheseal erosion over time. These results could also be in agreement with the apparent failure of anti-tumor necrosis factor (TNF) therapies to control bone proliferation in SpA; and with the relation of TNF-α, Dickkopf-related protein 1 (Dkk-1) and the regulatory molecule of the Wnt signaling pathway in the bone proliferation in SpA. In the same model, we then proceeded to study the enthesis bursa. Interestingly, the Outcome Measures in Rheumatology Clinical Trials (OMERACT) enthesopathy definition does not include bursa as an elementary entheseal lesion. Nonetheless, bursa was included in 46% of the enthesis studies in a recently systematic literature review, being in agreement with the concept of “synovio-entheseal complex” that includes the link between enthesitis and osteitis in SpA. It has been clarified in recent data that there is not only a close functional integration of the enthesis with the neighboring bone, but also a connection between enthesitis and synovitis. Therefore, we tried to assess the prevalence and relevance of the bursa-synovial lesion in SpA. Our findings showed a significant increase of Achilles bursa presence and thickness in SpA patients compared to controls (healthy/mechanical controls and RA controls). These results raise awareness to the need to improve the enthesopathy ultrasonographic definition. In the final work of this thesis, we have explored new perspectives, not previously reported, about construct validity of enthesis ultrasound as a possible activity outcome in SpA. We performed a longitudinal Achilles enthesis ultrasound study in patients with early SpA. Achilles ultrasound examinations were performed at baseline, six- and twelve-month time periods and compared with clinical outcome measures collected at basal visit. Our results showed that basal erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are higher in patients with Doppler signal in enthesis, and even that higher basal ESR, CRP and Ankylosing Spondylitis Disease Activity Score (ASDAS) predicted a higher Doppler signal (an ultrasound alteration accepted as representative of inflammation) six months later. Patients with very high disease activity assessed by ASDAS (>3.5) at baseline had significantly higher Achilles total ultrasound score verified at the same time; and ASDAS <1.3 predicted no Doppler signal at six and twelve months. This seems to represent a connection between classical biomarkers and clinical outcomes associated with SpA activity and Doppler signal, not only at the same time, but also for the following months. Remarkably, patients with inactive disease (ASDAS < 1.3) at baseline had no Doppler signal at six and twelve months. These findings reinforce the potential use of ultrasound related techniques for disease progression assessment and prognosis purposes. Intriguingly, Ankylosing Spondylitis Disease Activity Index (BASDAI) didn’t show significant differences between different cut-offs concerning ultrasound lesions or Doppler signal, while verified with ASDAS. These results seem to indicate that ASDAS reflects better than BASDAI what happens in the enthesis. The work herein discussed clearly shows the potential utility of ultrasound in enthesis assessment in SpA patients, and can be important for the development of ultrasound activity and structural damage scores for diagnosis and monitoring purposes. Therefore, local promotion of this technique constitutes a medical intervention that is worth being tested in SpA patients for diagnosis, monitoring and prognosis purposes.
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This work project focuses on developing new approaches which enhance Portuguese exports towards a defined German industry sector within the information technology and electronics fields. Firstly and foremost, information was collected and a set of expert and top managers’ interviews were performed in order to acknowledge the demand of the German market while identifying compatible Portuguese supply capabilities. Among the main findings, Industry 4.0 presents itself as a valuable opportunity in the German market for Portuguese medium sized companies in the embedded systems area of expertise for machinery and equipment companies. In order to achieve the purpose of the work project, an embedded systems platform targeting machinery and equipment companies was suggested as well as it was developed several recommendations on how to implement it. An alternative approach for this platform was also considered within the German market namely the eHealth sector having the purpose of enhancing the current healthcare service provision.
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The present paper is a personal reflection on a work project carried out to promote exports from Portugal to Germany in the IT area, under consideration of the deliverables required by the clients CCILA and Anetie. The project outcome approaches the fact that the majority of the Portuguese market players has disadvantages in size and does rarely coordinate activities among each other, which hinders them to export successfully on a broad scale. To bring together Portuguese delivery potential and German market demand, expert interviews were conducted. Based on the findings, a concept was developed to overcome the domestic collaboration issues in order to strengthen the national exports in the identified sector - embedded systems implementation services for machinery and equipment companies.
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Product fundamentals are essential in explaining heterogeneity in the product space. The scope for adapting and transferring capabilities into the production of different goods determines the speed and intensity of the structural transformation process and entails dissimilar development opportunities for nations. Future specialization patterns become then partly determined by the current network of products’ relatedness. Building on previous literature, this paper explicitly compares methodological concepts of product connectivity to conclude in favor of the density measure we propose combined with the Revealed Relatedness Index (RRI) approach presented by Freitas and Salvado (2011). Overall, RRI specifications displayed more consistent behavior when different time horizons are equated.
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This work project regards a challenge presented by a Portuguese organization on the retail sector, SONAEMC, which is a case study of how and why fruit shrinkage occurs in the fruit supply chain within their convenience stores. A qualitative research methodology enabled to infer in which stages throughout the chain shrinkage’s causes occur and, to conclude that internal rules for procedures and processes are not always followed and whose compliance would be enough to reduce fruit shrinkage. The key conclusion is that if fruit stock loss is reduced by as much as 15% the category’s profitability could increase about 8%.
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Tese de Doutoramento em Psicologia na área de especialização de Psicologia das Organizações apresentada ao ISPA - Instituto Universitário
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The goal of this thesis is the investigation and optimization of the synthesis of potential fragrances. This work is projected as collaboration between the University of Applied Sciences in Merseburg and the company Miltitz Aromatics GmbH in Bitterfeld‐Wolfen (Germany). Flavoured compounds can be synthesized in different ways and by various methods. In this work, methods like the phase transfer catalysis and the Cope‐rearrangement were investigated and applied, for getting a high yield and quantity of the desired substances and without any by‐products or side reactions. This involved the study of syntheses with different process parameters such as temperature, solvent, pressure and reaction time. The main focus was on Cope‐rearrangement, which is a common method in the synthesis of new potential fragrance compounds. The substances synthesized in this work have a hepta‐1,5‐diene‐structure and that is why they can easily undergo this [3,3]‐sigma tropic rearrangement. The lead compound of all research was 2,5‐dimethyl‐2‐vinyl‐4‐hexenenitrile (Neronil). Neronil is synthesized by an alkylation of 2‐methyl‐3‐butenenitrile with prenylchloride under basic conditions in a phase‐transfer system. In this work the yield of isolated Neronil is improved from about 35% to 46% by according to the execution conditions of the reaction. Additionally the amount of side product was decreased. This synthesized hexenenitrile involved not only the aforementioned 1,5‐diene‐structure, but also a cyano group, that makes this structure a suitable base for the synthesis of new potential fragrance compounds. It was observed that Neronil can be transferred into 2,5‐dimethyl‐2‐vinyl‐4‐hexenoic acid by a hydrolysis under basic conditions. After five hours the acid can be obtained with a yield of 96%. The following esterification is realized with isobutanol to produce 2,5‐dimethyl‐2‐vinyl‐4‐hexenoic acid isobutyl ester with quantitative conversion. It was observed that the Neronil and the corresponding ester can be converted into the corresponding Cope‐product, with a conversion of 30 % and 80%. Implementing the Cope‐rearrangement, the acid was heated and an unexpected decarboxylated product is formed. To achieve the best verification of reaction development and structure, scrupulous analyses were done using GC‐MS, 1H‐NMR and 13C‐ NMR.