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Dissertations / Theses on the topic 'Machines'
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Tebbifakhr, Amirhossein. "Machine Translation For Machines." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/320504.
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Traditionally, Machine Translation (MT) systems are developed by targeting fluency (i.e. output grammaticality) and adequacy (i.e. semantic equivalence with the source text) criteria that reflect the needs of human end-users. However, recent advancements in Natural Language Processing (NLP) and the introduction of NLP tools in commercial services have opened new opportunities for MT. A particularly relevant one is related to the application of NLP technologies in low-resource language settings, for which the paucity of training data reduces the possibility to train reliable services. In this specific condition, MT can come into play by enabling the so-called “translation-based” workarounds. The idea is simple: first, input texts in the low-resource language are translated into a resource-rich target language; then, the machine-translated text is processed by well-trained NLP tools in the target language; finally, the output of these downstream components is projected back to the source language. This results in a new scenario, in which the end-user of MT technology is no longer a human but another machine. We hypothesize that current MT training approaches are not the optimal ones for this setting, in which the objective is to maximize the performance of a downstream tool fed with machine-translated text rather than human comprehension. Under this hypothesis, this thesis introduces a new research paradigm, which we named “MT for machines”, addressing a number of questions that raise from this novel view of the MT problem. Are there different quality criteria for humans and machines? What makes a good translation from the machine standpoint? What are the trade-offs between the two notions of quality? How to pursue machine-oriented objectives? How to serve different downstream components with a single MT system? How to exploit knowledge transfer to operate in different language settings with a single MT system? Elaborating on these questions, this thesis: i) introduces a novel and challenging MT paradigm, ii) proposes an effective method based on Reinforcement Learning analysing its possible variants, iii) extends the proposed method to multitask and multilingual settings so as to serve different downstream applications and languages with a single MT system, iv) studies the trade-off between machine-oriented and human-oriented criteria, and v) discusses the successful application of the approach in two real-world scenarios.
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Dinakar, Karthik. "Lensing Machines : representing perspective in machine learning." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112523.
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Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.<br>Cataloged from PDF version of thesis. Due to the condition of the original material with text runs off the edges of the pages, the reproduction may have unavoidable flaws.<br>Includes bibliographical references (pages 167-172).<br>Generative models are venerated as full probabilistic models that randomly generate observable data given a set of latent variables that cannot be directly observed. They can be used to simulate values for variables in the model, allowing analysis by synthesis or model criticism, towards an iterative cycle of model specification, estimation, and critique. However, many datasets represent a combination of several viewpoints - different ways of looking at the same data that leads to various generalizations. For example, a corpus that has data generated by multiple people may be mixtures of several perspectives and can be viewed with different opinions by others. It isn't always possible to represent the viewpoints by clean separation, in advance, of examples representing each perspective and train a separate model for each point of view. In this thesis, we introduce lensing, a mixed-initiative technique to (i) extract lenses or mappings between machine-learned representations and perspectives of human experts, and (2) generate lensed models that afford multiple perspectives of the same dataset. We explore lensing of latent variable model in their configuration, parameter and evidential spaces. We apply lensing to three health applications, namely imbuing the perspectives of experts into latent variable models that analyze adolescent distress and crisis counseling.<br>by Karthik Dinakar.<br>Ph. D.
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Le, Flohic Julien. "Vers une commande basée modèle des machines complexes : application aux machines-outils et machines d'essais mécaniques." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22551/document.
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De nos jours, les exigences de productivité et de maîtrise des coûts ont incité les industriels à développer de nouvelles machines, et avec elles, de nouveaux enjeux sont apparus : souplesse de la structure, vibration, effets dynamiques non-négligeables, etc. Pourtant, leur mise en œuvre est toujours issue de méthodes employées pour les machines conventionnelles. Ces travaux s’intéressent donc à la définition de stratégies globales englobant la prise en compte de la structure utilisée et de la tâche à réaliser, appliquée à deux contextes d’illustration. Dans le contexte de l’usinage, nous proposons un réglage des machines basé sur le modèle comportemental de la structure qui ne nécessite que peu de modifications manuelles et permettant un gain de temps pour la mise en œuvre. Une nouvelle loi de commande en couple calculé est également proposé, elle permet de réduire les phénomènes vibratoires lors de phases dynamiquement exigeantes. Dans le contexte des essais mécaniques, l’objectif est de montrer la faisabilité de l’utilisation de machines parallèles à 6 degrés de liberté dans le cadre d’essais dont la gestion des conditions aux limites est critique. Nous proposons une instrumentation et un schéma de commande qui permettent de respecter les consignes avec une erreur maximale de l’ordre de 0.40μm, même dans le cas d’éprouvettes très rigide (en béton par exemple)<br>Nowadays, the requirements in productivity and costs mastering have forced the industrial manufacturers to develop new kind of mechanisms. Thus, the complexity of the machine-tools structures and machining processes has increased and new challenges have emerged : flexible structure, vibration, non-negligible dynamic effects, etc ... However, their implementation still comes from methods used for conventional machines. These works are thus about defining overall strategies including consideration of the kind of structure used and the task to realise. Two illustrative contexts are used. In the context of machining, we propose a generic tuning method based on kinematic and dynamic model of machine-tools structure that requires only a few manual modifications, in order to save time for implementation. A new computed torque control law is proposed, it reduces vibration phenomena in dynamical demanding phases. In the context of the mechanical tests, the objective is to demonstrate the feasibility of using parallel machines with 6 degrees of freedom in the context of mechanical tests, whereas the boundary conditions are perfectly controlled. We propose an instrumentation and control scheme that is able to perform mechanical tests with a maximum error of about 0.40 mu m, even in the case of very rigid specimen (concrete for example)
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Bromberg, Paul. "Clockworks, hot pots, heat machines, and chemical machines : the contrivance aspect of the machine metaphor." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30405.
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From a general discussion concerning the shortcomings of the received view of scientific theories and scientific explanation I conclude that metaphorical thinking, until quite recently restricted to literary analysis, may play a significant role not only in the way theories are conceived, but also in the way that meaning is ascribed to the concepts used in science. The analysis of the literal realm of 'machine' considers three aspects that could appear in the metaphorical assimilation of organisms to machines: the contrivance aspect, which is the 'hardware'; the fact that machines exhibit purpose; finally, the integrated aspect of the machine (its harmony). The study is devoted only to the first aspect.
I offer a narrative of pivotal ideas about the workings of the biological individual, from the clockworks of the early mechanicists to modern biochemistry, not just as a succession of discoveries but also as alleged accomplishments of the 'machine metaphor' revealing its scope.
Some recognized milestones in the history of ideas about the inner workings of organisms are surveyed: the proposals of the early mechanicists during the Scientific Revolution, Lavoisier's view of respiration as combustion, Liebig's description of the human body as a chemical machine and the suggestion that the chemical accomplishments in living beings are the result of myriads of fermentation-like processes. I devote special attention to the problem of the direct conversion of chemical energy into mechanical energy using the evolution of ideas about muscular contraction as the main example.
During the period 1900-1930 the study of colloidal behavior was considered to be the right path for unraveling most of the mysteries of vital processes. I carefully describe this work particularly the proposed models for muscular contraction and enzymatic action. The dismissal of this colloidal approach after the acceptance of the existence of those particular kinds of macromolecules that exist in living organisms marks the entrance of our modern approach. One of the remarkable features of the modern approach is the incessant elaboration of the idea of 'molecular machine'. I conclude with a discussion of the problem how literally can this metaphor be taken?<br>Graduate and Postdoctoral Studies<br>Graduate
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Lanarolle, W. D. Gamini. "Machine setting automation for circular weft-knitting machines." Thesis, University of Manchester, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488354.
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Kent, W. F. "Machine learning for parameter identification of electric induction machines." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399178.
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This thesis is concerned with the application of simulated evolution (SE) to the steady-state parameter identification problem of a simulated and real 3-phase induction machine, over the no-load direct-on-line start period. In the case of the simulated 3-phase induction machine, the Kron's two-axis dynamic mathematical model was used to generate the real and simulated system responses where the induction machine parameters remain constant over the entire range of slip. The model was used in the actual value as well as the per-unit system, and the parameters were estimated using both the genetic algorithm (GA) and the evolutionary programming (EP) from the machine's dynamic response to a direct-on-line start. Two measurement vectors represented the dynamic responses and all the parameter identification processes were subject to five different levels of measurement noise. For the case of the real 3-phase induction machine, the real system responses were generated by the real 3-phase induction machine whilst the simulated system responses were generated by the Kron's model. However, the real induction machine's parameters are not constant over the range of slip, because of the nonlinearities caused by the skin effect and saturation. Therefore, the parameter identification of a real3-phase induction machine, using EP from the machine's dynamic response to a direct-on-line start, was not possible by applying the same methodology used for estimating the parameters of the simulated, constant parameters, 3-phase induction machine.
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Sokola, Matija. "Vector control of induction machines using improved machine models." Thesis, Liverpool John Moores University, 1998. http://researchonline.ljmu.ac.uk/4899/.
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Park, Yongwon Baskiyar Sanjeev. "Dynamic task scheduling onto heterogeneous machines using Support Vector Machine." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Computer_Science_and_Software_Engineering/Thesis/Park_Yong_50.pdf.
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Thorén, Daniel. "Radar based tank level measurement using machine learning : Agricultural machines." Thesis, Linköpings universitet, Programvara och system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176259.
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Agriculture is becoming more dependent on computerized solutions to make thefarmer’s job easier. The big step that many companies are working towards is fullyautonomous vehicles that work the fields. To that end, the equipment fitted to saidvehicles must also adapt and become autonomous. Making this equipment autonomoustakes many incremental steps, one of which is developing an accurate and reliable tanklevel measurement system. In this thesis, a system for tank level measurement in a seedplanting machine is evaluated. Traditional systems use load cells to measure the weightof the tank however, these types of systems are expensive to build and cumbersome torepair. They also add a lot of weight to the equipment which increases the fuel consump-tion of the tractor. Thus, this thesis investigates the use of radar sensors together witha number of Machine Learning algorithms. Fourteen radar sensors are fitted to a tankat different positions, data is collected, and a preprocessing method is developed. Then,the data is used to test the following Machine Learning algorithms: Bagged RegressionTrees (BG), Random Forest Regression (RF), Boosted Regression Trees (BRT), LinearRegression (LR), Linear Support Vector Machine (L-SVM), Multi-Layer Perceptron Re-gressor (MLPR). The model with the best 5-fold crossvalidation scores was Random For-est, closely followed by Boosted Regression Trees. A robustness test, using 5 previouslyunseen scenarios, revealed that the Boosted Regression Trees model was the most robust.The radar position analysis showed that 6 sensors together with the MLPR model gavethe best RMSE scores.In conclusion, the models performed well on this type of system which shows thatthey might be a competitive alternative to load cell based systems.
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Romano, Donato. "Machine Learning algorithms for predictive diagnostics applied to automatic machines." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22319/.
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In questo lavoro di tesi è stato analizzato l'avvento dell'industria 4.0 all'interno dell' industria nel settore packaging. In particolare, è stata discussa l'importanza della diagnostica predittiva e sono stati analizzati e testati diversi approcci per la determinazione di modelli descrittivi del problema a partire dai dati. Inoltre, sono state applicate le principali tecniche di Machine Learning in modo da classificare i dati analizzati nelle varie classi di appartenenza.
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Schneider, C. "Using unsupervised machine learning for fault identification in virtual machines." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7327.
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Self-healing systems promise operating cost reductions in large-scale computing environments through the automated detection of, and recovery from, faults. However, at present there appears to be little known empirical evidence comparing the different approaches, or demonstrations that such implementations reduce costs. This thesis compares previous and current self-healing approaches before demonstrating a new, unsupervised approach that combines artificial neural networks with performance tests to perform fault identification in an automated fashion, i.e. the correct and accurate determination of which computer features are associated with a given performance test failure. Several key contributions are made in the course of this research including an analysis of the different types of self-healing approaches based on their contextual use, a baseline for future comparisons between self-healing frameworks that use artificial neural networks, and a successful, automated fault identification in cloud infrastructure, and more specifically virtual machines. This approach uses three established machine learning techniques: Naïve Bayes, Baum-Welch, and Contrastive Divergence Learning. The latter demonstrates minimisation of human-interaction beyond previous implementations by producing a list in decreasing order of likelihood of potential root causes (i.e. fault hypotheses) which brings the state of the art one step closer toward fully self-healing systems. This thesis also examines the impact of that different types of faults have on their respective identification. This helps to understand the validity of the data being presented, and how the field is progressing, whilst examining the differences in impact to identification between emulated thread crashes and errant user changes – a contribution believed to be unique to this research. Lastly, future research avenues and conclusions in automated fault identification are described along with lessons learned throughout this endeavor. This includes the progression of artificial neural networks, how learning algorithms are being developed and understood, and possibilities for automatically generating feature locality data.
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Sow, Souleymane. "Simulateur vibratoire de machines tournantes à base de machine-learning." Electronic Thesis or Diss., Reims, 2024. http://www.theses.fr/2024REIMS038.
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Placée dans le cadre de la maintenance 4.0, cette thèse vise à développer un simulateur vibratoire pour un banc d’essais de roulements à gorges profondes, afin d’améliorer la précision des diagnostics basés sur des algorithmes de machine learning. Le travail se concentre d’abord sur l’intégration de la flexibilité des paliers dans un modèle numérique existant, créant ainsi un jumeau numérique plus représentatif des conditions réelles d’exploitation. La méthodologie s’articule autour de la conception d’un modèle numérique hybride, combinant un modèle méso (éléments discrets) et un modèle macro (éléments finis). Ces deux sous-modèles communiquent pour décrire la dynamique du système et simuler différents modes de fonctionnement. Les données générées par le simulateur sont ensuite exploitées pour mettre à jour le modèle et entraîner des algorithmes de classification (MSVM, KNN, arbres de décision), obtenant un taux de classification de 94 %. Ce résultat montre une amélioration de 10 % par rapport aux méthodes précédentes, confirmant l’efficacité de l’approche. Dans le but de mesurer l’apport qualitatif et quantitatif des données dans un diagnostic par classification, les données issues de ce modèle numérique mis à jour sont utilisées dans différentes stratégies d’hybridation de données avec les celles mesurées sur le système<br>Framed within maintenance 4.0, this thesis aims to develop a vibratory simulator for a deep-groove ball bearing test bench to improve the accuracy of diagnostics based on machine learning algorithms. The work initially focuses on integrating the flexibility of the bearing supports into an existing numerical model, thereby creating a digital twin that more accurately reflects real operating conditions. The methodology is centred around the design of a hybrid numerical model, combining a meso-model (discrete elements) and a macro-model (finite elements). These two sub-models interact to describe the system's dynamics and simulate different operating modes. The data generated by the simulator is then used to update the model and train classification algorithms (MSVM, KNN, decision trees), achieving a classification accuracy of 94%. This result demonstrates a 10% improvement compared to previous methods, confirming the approach’s effectiveness. To assess the qualitative and quantitative contributions of the data in a classification-based diagnostic, the data from the updated numerical model is used in various data hybridization strategies with those measured from the physical system
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KöÅ, er Hür 1976. "Development of magnetic induction machines for micro turbo machinery." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8119.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.<br>Includes bibliographical references.<br>This thesis presents the nonlinear analysis, design, fabrication, and testing of an axial-gap magnetic induction micro machine, which is a two-phase planar motor in which the rotor is suspended above the stator via mechanical springs, or tethers. The micro motor is fabricated from thick layers of electroplated NiFe and copper, by our collaborators at Georgia Institute of Technology. The rotor and the stator cores are 4 mm in diameter each, and the entire motor is about 2 mm thick. During fabrication, SU-8 epoxy is used as a structural mold material for the electroplated cores. The tethers are designed to be compliant in the azimuthal direction, while preventing axial deflections and maintaining a constant air gap. This enables accurate measurements of deflections within the rotor plane via a computer microvision system. The small scale of the magnetic induction micro machine, in conjunction with the good thermal contact between its electroplated stator layers, ensures an isothermal device which can be cooled very effectively. Current densities over 109 A/m2 simultaneously through each phase is repeatedly achieved during experiments; this density is over two orders of magnitude larger than what can be achieved in conventional macro-scale machines. More than 5 Nm of torque is obtained for an air gap of about 5 zm, making this micro motor the highest torque density micro-scale magnetic machine to date. About 0.3 buNm for the large air gap of 70 m is also achieved in systematic tests that reveal the influence of strong eddy-currents and associated nonlinear saturation within the micro motor.<br>(cont.) Eddy-current effects are modeled using a finite-difference vector potential formulation. Its results demonstrate the presence of flux crowding on the stator surface, which leads to heavy saturation. To capture saturation effects, a fully nonlinear finite-difference time-domain simulation is developed to solve Maxwell's Equations within the computational space of the micro machine. To mitigate the inherent stiffness in the partial differential equations, the speed of light is artificially reduced by five orders of magnitude, taking special care that assumptions of magnetoquasistatic behavior are still met. The results from this model are in very good agreement with experimental data from the tethered magnetic induction micro motor.<br>by Hür KöÅer.<br>Ph.D.
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Griffith, Saul Thomas 1974. "Growing machines." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28780.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004.<br>Includes bibliographical references.<br>construction is developed in three dimensions. It is similarly shown that right-angled tetrahedrons, when folded from an edge-connected string, can generate any three dimensional structure where the primitive pixel (or voxel) is a rhombic hexahedron. This construction also suggests a concept of 3D completeness for assembly, somewhat analogous to the concept of Turing completeness in computation. In combination, these pieces of work suggest that a manufacturing system based on four tiles, with seven states per tile, is capable of self-replication of arbitrary 3D structure by copying, then folding, bit strings of those tiles where the desired structure is encoded in the tile sequence.<br>Biological systems are replete with examples of high complexity structures that have "self assembled," or more accurately, programmatically assembled from many smaller, simpler components. By comparison, the fabrication systems engineered by humans are typically top down, or subtractive, processes where systems of limited complexity are carved from bulk materials. Self-assembly to date has resembled crystallization more than it has the programmatic assembly of complex or useful structures--these systems are information limited. This thesis explores the programming of self-assembling systems by the introduction of small amounts of state to the sub-units of the assembly. A six-state, kinematic, conformational latching component is presented that is capable of self-replicating bit strings of two shape differentiated versions of the same component where the two variants represent the 0 and 1 bits. Individual units do not assemble until a string is introduced to the assembly environment to be copied. Electro-mechanical state machine emulators were constructed. Operating on an air table, the units demonstrated logic limited aggregation, or error-preventing assembly, as well as autonomous self-replication of bit strings. A new construction was developed that demonstrates that any two dimensional shape composed of square pixels can be deterministically folded from a linear string of vertex-connected square tiles. This non-intersecting series of folds implies a 'resolution' limit of four tiles per pixel. It is shown that four types of tiles, patterned magnetically, is sufficient to construct any shape given sequential folding. The construction was implemented to fold the letters 'M I T' from sequences of the 4 tile types. An analogous<br>Saul Thomas Griffith.<br>Ph.D.
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Jones, Leslie Braziel Raines Brian Edward. "Adding machines." Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5311.
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Awad, Edmond. "Moral machines : perception of moral judgment made by machines." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112532.
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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 79-85).<br>While technological development of vehicular autonomy has been progressing rapidly, a parallel discussion has emerged with regard to the moral implications of a future wherein people hand over to autonomous machines the controls to a mode of transportation. These discussions have entered a new phase with the U.S. Department of Transportation (DoT) releasing a 15-point policy that requires manufacturers to explain how their AVs will handle "ethical considerations". However, there is a huge gap in our understanding of the ethical perception of Al, as there have been few large-scale empirical studies on human moral perception of outcomes to autonomous vehicle moral dilemmas. Additionally, public engagement is a very important piece of the puzzle, especially given the emotional salience of traffic accidents. With that in mind, I co-developed the "Moral Machine" (http://moralmachine.mit.edu). Moral Machine is a platform for gathering a human perspective on moral decisions made by machine intelligence, such as AVs. The web site went viral, and got covered in various media outlets. This web site has also been a valuable data collection tool, allowing us to collect the largest dataset on Al ethics ever collected in history (with 30 million decisions by over 3 million visitors, so far). This thesis will introduce the Moral Machine platform as a data-gathering platform. Moreover, insights about the human perception of the different routes to full automation will be covered in the thesis, with the data collected through other online platforms.<br>by Edmond Awad.<br>S.M.
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Papakyriakopoulos, Orestis [Verfasser], Simon [Akademischer Betreuer] Hegelich, Jürgen [Gutachter] Pfeffer, and Simon [Gutachter] Hegelich. "Political Machines: Machine learning for understanding the politics of social machines / Orestis Papakyriakopoulos ; Gutachter: Jürgen Pfeffer, Simon Hegelich ; Betreuer: Simon Hegelich." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/121302627X/34.
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GOUVEA, RODRIGO MOSCONI DE. "SERVICES, PROCESSES AND MACHINES: A METHODOLOGIES STUDY FOR MACHINE REASSIGNMENT PROBLEM." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34639@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>PROGRAMA DE EXCELENCIA ACADEMICA<br>A organização lógica de data centers recai principalmente na questão estratégica de distribuir os serviços nos equipamentos de forma que os custos operacionais sejam os menores possíveis. Além desses custos, devem ser considerados outros aspectos que envolvem a interdependência de seus serviços internos e a distribuição entre suas localidades, visando assim melhorar a qualidade de seu produto aos seus clientes. Este trabalho explora o problema de atribuição de processos a máquinas do desafio ROADEF de 2012 pelos métodos de programação inteira e geração de colunas. Apresenta estratégias para lidar com as dificuldades numéricas encontradas. Na geração de colunas, analisa técnicas para acelerar a convergência, por meio de resolver
o mestre restrito após cada variável, geração prévia de colunas e estabilização das variávies duais. Ao final do trabalho, são comparados os resultados obtidos com os melhores resultados oficiais.<br>A data center logic organization lies mainly by the strategic decision on how distribute services between machines, so the operational costs should be the smallest as possible. Beside those costs, must also consider the interdependence of their own services, the distribution between their localities, to improve the quality of their product to their customers. This work explores the challenge ROADEF 2012 machine assignment problem by the means of integer programming and column generation. Shows strategies to address numeric issues. At column generation, it analyzes techniques to speed up the convergence, by solving after each variable adiction, a previous generation of columns and stabilization of duals variables. At the end of the work, it compares the results obtained are compared with the best official results.
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Karlbom, Hannes. "Hybrid Machine Translation : Choosing the best translation with Support Vector Machines." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-304257.
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In the field of machine translation there are various systems available which have different strengths and weaknesses. This thesis investigates the combination of two systems, a rule based one and a statistical one, to see if such a hybrid system can provide higher quality translations. The classification approach was taken, where a support vector machine is used to choose which sentences from each of the two systems result in the best translation. To label the sentences from the collected data a new method of simulated annealing was applied and compared to previously tried heuristics. The results show that a hybrid system has an increased average BLEU score of 6.10% or 1.86 points over the single best system, and that using the labels created through simulated annealing, over heuristic rules, gives a significant improvement in classifier performance.
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Preux, Philippe. "Mad : une machine virtuelle vectorielle : conséquences sur l'architecture des machines vectorielles." Lille 1, 1991. http://www.theses.fr/1991LIL10030.
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Cette thèse s'insère dans un projet de recherches visant l'informatique vectorielle, tant du point de vue programmation que du point de vue architecture des machines. Les aspects programmation du projet étudient une alternative à l'approche classique utilisant un langage scalaire associé à un vectoriseur. Nous nous intéressons à la définition d'outils autorisant l'expression d'algorithmes vectoriels de manière explicite, de manière indépendante de toute cible matérielle particulière. Cette approche résout les problèmes de portabilité d'une manière simple, les programmes ne faisant aucune référence à l'architecture sous-jacente. Pour que les programmes puissent être compilés d'une manière optimale, le langage donne la possibilité au programmeur d'exprimer la connaissance dont il dispose sur son algorithme, ainsi que sur les données traitées. Ces informations n'ont plus à être extraites des sources par un outil d'analyse (vectoriseur dans l'approche classique). La compilation repose sur l'utilisation d'une couche virtuelle (machine abstraite MAD et son langage Devil). Celle-ci est décrite dans ce document. A côté de ces aspects langages, nous nous intéressons aux aspects matériels des machines vectorielles. La définition dans notre langage de vecteurs originaux (autres que de simples tableaux) nous a mené à étudier la prise en compte des vecteurs au niveau matériel. Aussi, nous avons défini une mémoire contenant des vecteurs en tant que tels et y autorisant l'accès. Les définitions de cette mémoire et d'un processeur associé sont données. Enfin, en marge de ces travaux, face aux problèmes dus aux conflits d'accès aux données dans la mémoire des supercalculateurs, nous introduisons un modèle d'exécution des opérations vectorielles pipelinées dénommé traitement vectoriel désordonné (tvd). Dans ce modèle un conflit mémoire ne bloque pas nécessairement le port mémoire, et donc les pipelines qui y sont chaînés. Nous montrons l’intérêt de ce modèle selon le taux de conflits. Par ailleurs, nous montrons que ce modèle est implantable assez facilement sur un processeur de type Cray
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Razet, Benoit. "Machines d'Eilenberg Effectives." Phd thesis, Université Paris-Diderot - Paris VII, 2009. http://tel.archives-ouvertes.fr/tel-00463049.
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La théorie des automates est apparue pour résoudre des problèmes aussi bien pratiques que théoriques, et ceci dès le début de l'informatique. Désormais, les automates font partie des notions fondamentales de l'informatique, et se retrouvent dans la plupart des logiciels. En 1974, Samuel Eilenberg proposa un modèle de calcul qui unifie la plupart des automates (transducteurs, automates à pile et machines de Turing) et qui a une propriété de modularité intéressante au vu d'applications reposant sur différentes couches d'automates ; comme cela peut être le cas en linguistique computationnelle. Nous proposons d'étudier les techniques permettant d'avoir des machines d'Eilenberg effectives. Cette étude commence par la modélisation de relations calculables à base de flux, puis continue avec l'étude de la simulation des machines d'Eilenberg définies avec ces relations. Le simulateur est un programme fonctionnel énumérant progressivement les solutions, en explorant un espace de recherche selon différentes stratégies. Nous introduisons, en particulier, la notion de machine d'Eilenberg finie pour laquelle nous fournissons une preuve formelle de correction de la simulation. Les relations sont une première composante des machines d'Eilenberg, la deuxième composante étant son contrôle, qui est défini par un automate fini. Dans ce contexte, on peut utiliser une expression régulière comme syntaxe pour décrire la composante de contrôle d'une machine d'Eilenberg. Récemment, un ensemble de travaux exploitant la notion de dérivées de Brzozowski, a été la source d'algorithmes efficaces de synthèse d'automates non-déterministes à partir d'expressions régulières. Nous faisons l'état de l'art de ces algorithmes, tout en donnant une implémentation efficace en OCaml permettant de les comparer les uns aux autres.
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Sokolova, Marina L. "Decision list machines." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/6380.
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We learn decision lists over a space of features that are constructed from the data. A practical machine which we call the Decision List Machine comes as a result. We construct the Decision List Machine which uses generalized balls as data-dependent features. We compare practical performance on some data sets with the performance of some other learning algorithms such as the Set Covering Machine and the Support Vector Machine. This performance is evaluated for both symmetric and asymmetric loss coefficients. We also provide a theoretical assessment of the performance of the DAM by computing upper bounds of the generalization error.
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Nowostawski, Mariusz, and n/a. "Evolvable virtual machines." University of Otago. Department of Information Science, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081204.145510.
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The Evolvable Virtual Machine abstract architecture (EVMA) is a computational architecture for dynamic hierarchically organised virtual machines. The concrete EVM instantiation (EVMI) builds on traditional stack-based models of computation and extends them by notions of hierarchy and reflection on the virtual machine level. The EVM Universe is composed of a number of autonomous and asynchronously communicating EVM machines. The main contribution of this work lies in the new model of computation and in the architecture itself: a novel, compact, flexible and expressive representation of distributed concurrent computation. The EVMA provides a way of expressing and modelling auto-catalytic networks composed of a hierarchical hypercycle of autopoietic subsystems characterised by self-adaptable structural tendencies and self-organised criticality. EVMA provides capabilities for: a) self-learning of dynamical patterns through continuous observation of computable environments, b) self-compacting and generalisation of existing program structures, c) emergence of efficient and robust communication code through appropriate machine assembly on both ends of communication channel. EVMA is in one sense a multi-dimensional generalisation of stack machine with the purpose of modelling concurrent asynchronous processing. EVMA approach can be also seen as a meta-evolutionary theory of evolution. The EVMA is designed to model systems that mimic living autonomous and adaptable computational processes. The EVMI prototype has been designed and developed to conduct experimental studies on complex evolving systems. The generality of our approach not only provides the means to experiment with complex hierarchical, computational and evolutionary systems, but it provides a useful model to evaluate, share and discuss the complex hierarchical systems in general. The EVMA provides a novel methodology and language to pursue research, to understand and to talk about evolution of complexity in living systems. In this thesis, we present the simple single-cell EVMI framework, discuss the multi-cell EVM Universe architecture, present experimental results, and propose further extensions, experimental studies, and possible hardware implementations of the EVMI.
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Harris, T. L. "Extensible virtual machines." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603746.
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Virtual machines (VMs) have enjoyed a resurgence as a way of allowing the same application program to be used across a range of computer systems. This flexibility comes from the abstraction that the VM provides over the native interface of a particular computer. However, this also means that the application is prevented from taking the features of particular physical machines into account in its implementation. This dissertation addresses the question of why, where and how it is useful, possible and practicable to provide an application with access to lower-level interfaces. It argues that many aspects of VM implementation can be devolved safely to untrusted applications and demonstrates this through a prototype which allows control over run-time compilation, object placement within the heap and thread scheduling. The proposed architecture separates these application-specific policy implementations from the application itself. This allows one application to be used with different policies on different systems and also allows naïve or premature optimizations to be removed.
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Fredriksson, Olle. "Distributing abstract machines." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6196/.
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Today's distributed programs are often written using either explicit message passing or Remote Procedure Calls (RPCs) that are not natively integrated in the language. It is difficult to establish the correctness of programs written this way compared to programs written for a single computer. We propose a generalisation of RPCs that are natively integrated in a functional programming language meaning that they have support for higher-order calls across node boundaries. Our focus is on how such languages can be compiled correctly and efficiently. We present four different solutions. Two of them are based on interaction semantics --- the Geometry of Interaction and game semantics --- and two are extensions of conventional abstract machines --- the Krivine machine and the SECD machine. To target as general distributed systems as possible our solutions support RPCs without sending code. We prove the correctness of the abstract machines with respect to their single-node execution, and show their viability for use for compilation by implementing prototype compilers based on them. The conventionally based machines are shown to enable efficient programs. Our intention is that these abstract machines can form the foundation for future programming languages that use the idea of higher-order RPCs.
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Karkinsky, Damien A. "Mobile B machines." Thesis, University of Surrey, 2007. http://epubs.surrey.ac.uk/844588/.
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Specifications and implementations of systems need to be concerned with the interactions that can occur within a system and model the data structures appropriately. We are interested in combinations of formal methods which consider the state and dynamic requirements of a system. We recognise that many such combinations already exist, including, CSP || B and Circus, but we are concerned with a state description, being accessed and updated by control components with dynamically reconfigurable interconnections. Our work is motivated by what we see in Peer-to-Peer networks and Object-Oriented systems where instantiation and dynamically reconfigurable interconnection are essential paradigms. For example, in a Peer-to-Peer network nodes can act as both server and client in exchanging data to complete a certain task. Nodes are also independent and can leave or join the network at any time. In Object-Oriented systems, an object instance can be created with a unique reference. This reference can be used by other objects to communicate with the object. Our aim is to provide a formal framework which supports this kind of interaction so that the integrity of each active object or node is preserved, and so that we can reason about the overall behaviour of the system. The approach we consider in this thesis is a combination of the pi-calculus and the B-Method. In order to be able to reason about specifications based on both these notations we need common semantics. We define an approach which enables the interpretation of a B machine as a pi-calculus labelled transition system. This allows the integration of machines into parallel combination with pi-agents. As a result, this work extends B machines with instantiation and pi-calculus dynamic reconfiguration capabilities. We use a behavioural type-system with variant types to maintain low level server/client style consistencies between instances of machines and pi-process agents. (For example, all agents call operations that relate to some machine in the specification.) Using the type system, we identify a class of pi-agents whose behaviour with respect to the machine instances allows a weakest pre-condition style proof to be carried out on the agents. We use this property to define an approach for detecting agents that might cause a machine instance to diverge.
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Razet, Benoît. "Machines d'Eilenberg effectives." Paris 7, 2009. http://www.theses.fr/2009PA077195.
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La théorie des automates est apparue pour résoudre des problèmes aussi bien pratiques que théoriques, et ceci dès le début de l'informatique. Désormais, les automates font partie des notions fondamentales de l'informatique, et se retrouvent dans la plupart des logiciels. En 1974, Samuel Eilenberg proposa un modèle de calcul qui unifie la plupart des automates (transducteurs, automates à pile et machines de Turing) et qui a une propriété de modularité intéressante au vu d'applications reposant sur différentes couches d'automates ; comme cela peut être le cas en linguistique computationnelle. Nous proposons de rendre effectif ce modèle en étudiant des techniques de simulation. Le simulateur est défini par un programme fonctionnel énumérant progressivement les solutions en explorant un espace de recherche selon différentes stratégies. Nous introduisons la notion de machines d'Eilenberg finies pour lesquelles nous fournissons une preuve formelle de correction de la simulation. La composante de contrôle d'une machine d'Eilenberg est un automate fini non-déterministe; dans ce contexte, on peut utiliser une expression régulière comme syntaxe pour décrire cet automate. Récemment, un ensemble de travaux approfondissant la notion de dérivées de Brzozowski, a été la source d'algorithmes efficaces de synthèse d'automates non-déterministes à partir d'expressions régulières. Ces algorithmes sont de nature algébrique et nous en faisons un état de l'art, tout en donnant une implémentation en OCaml permettant de les comparer les uns aux autres dans un cadre commun<br>Automata theory bas been developed to overcome both theoretical and practical problems. Nowadays, automata are considered as basic knowledge by all computer scientists, and they are used in most softwares. In 1974, Samuel Eilenberg gave a new machine model unifying the most common automata such as transducers, pushdown automata, and even Turing machines. Eilenberg machines also have an interesting modularity property that is useful for applications modeled using different levels of automata; as may appear in computational linguistics. We propose an effective design of Eilenberg machines and study simulation techniques. Our Simulator is defined by a functional program that progressively enumerates solutions, exploring a research space according to various of strategies. We introduce the notion of finite Eilenberg machines, and formally prove the correction of the underlying simulation engine. The control component of an Eilenberg machine is defïned by a non-deterministic automaton; in this context, regular expressions may be used as syntax describing the automaton. In recent years, the concept of Brzozowski's derivatives has led to many novel and efficient algorithms that compile regular expressions into non-deterministic automata. We review these state of the art algorithms, give an efficient OCaml implémentation, and compare their efficiency in a common framework
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Andersen, Kristina. "Making Magic Machines." Doctoral thesis, KTH, Medieteknik och interaktionsdesign, MID, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214017.
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How can we design experiences that explore ideas and notions of the unknown? The aim of the work outlined here is to create short, intense, workshop-like experiences that generate strong commitments, and expose underlying personal desires as drivers for new ideas. I would like to propose a material practice, which uses open-ended making to engage in the imagination of new things. Informed by a concern or a longing, this exploration employs familiar yet mundane materials - such as candy and cardboard - through which several planes collide: the possible, the unknown, the feared and the desired. The process is aimed at allowing a broad range of knowledge to materialise - through ways that are less normative, and less constrained by commercial and technological concerns, and to emerge instead as far-fetched ideas that offer a kind of knowledge, which belongs to no one. The format has evolved over time, from relatively elaborate workshops for technology prototyping, towards the point where they are now focussed on the making of work that is about technology, rather than of technology.<br>Hur kan vi iscensätta upplevelser som tillåter oss att utforska och skapa idéer för det som vi ännu inte vet något om? Genom att engagera deltagare i korta, intensiva, workshop-liknande upplevelser har jag lyckats få dem att öppna sig, uttrycka personliga drivkrafter och önskemål, vilket i sin tur gör det möjligt för dem att skapa helt nya designkoncept. Mitt bidrag är en ny materiell praktik där skapande-processen görs öppen och därmed låter deltagarna fantisera fram helt nya möjliga saker. Praktiken är grundad i deltagarnas djupt kända personliga drivkrafter och önskemål, men vi ber dem uttrycka dem i prosaiska fysiska material - såsom godis eller kartong - där motsatsförhållandet mellan dessa båda leder till att olika synsätt kan komma till ytan och ställas mot varandra: det möjliga, det okända, det fruktade och det önskade. Praktiken öppnar för att ge ett brett spektrum av kunskap fysisk form - och då vi gör det på ett icke-normativt sätt, där vi undviker att begränsas av kommersiella eller tekniska förutsättningar, skapar vi en grund för att få fram idéer bortom de självklara - idéer som egentligen inte tillhör någon av oss och samtidigt alla. Formatet har utvecklats över en lång tidsrymd, från workshops där vi skapade prototyper i tekniska material, till den form de har idag som fokuserar på att uttrycka idéer om teknik snarare än i teknik.<br><p>QC 20170911</p>
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Vier, Riley Todd. "Machines of curation." Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6322.
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Machines of Curation is an attempt to confront the ever-growing landscape of technology I observe and live inside of daily. This work is specifically concerned with my interest in how we interact with and alter our surrounding environments through technology. The constant tether we have to our devices is becoming more reminiscent of a parasite and host, rather than of a device and user. It informs how we are to look at things, speak with those we love, pay for things, and receive news; just to name a few. I seek to co-opt these methods to urge the viewer to ask their own questions and make their own decisions on how they feel technology is shaping them in ways they may be unaware of. Graphic design holds a unique vernacular to our digital universe as one of the primary mediums that helps organize and create it. The overall goal of this work is that a consistent irony can be established through the work that helps the viewer experiencing it question their views of technology.
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ERDMAN, Paolo Andrea. "Quantum Thermal Machines." Doctoral thesis, Scuola Normale Superiore, 2020. http://hdl.handle.net/11384/95512.
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Fernandez, sanchez Alejandro. "Étude de machines électriques non conventionnelles pour des alternateurs industriels." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC084/document.
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Cette thèse s’intéresse à l’analyse de structures de machines électriques non conventionnelles destinées à la production d’électricité par des groupes électrogènes. Les topologies recherchées doivent utiliser moins de matières actives et/ou simplifier la procédure de fabrication par rapport aux machines actuelles.Une des structures est dédiée au système d’excitation de la machine. Elle possède un stator à griffes avec un bobinage toroïdal. Son dimensionnement est réalisé à l’aide d’un modèle de calcul par éléments finis en 3D, qui a été validé expérimentalement. Cette structure permet d’obtenir une réduction significative de la quantité de cuivre dans le bobinage.Les deux autres structures traitées concernent l’alternateur principal. Une machine synchro-réluctante à barrières deflux et à rotor bobiné a été proposée. L’objectif est d’augmenter la densité de couple grâce au couple de saillance. Elle est dimensionnée et comparée avec la structure conventionnelle. Ce cas met en évidence les limitations des structures proches de la structure actuelle.La dernière structure est une nouvelle topologie de machine électrique. Elle combine les caractéristiques des machines à flux axial et des machines à griffes, permettant de simplifier le système d’excitation. Une approche de modélisation originale a été développée pour l’analyse de cette topologie 3D en vue de son dimensionnement par optimisation. Le système d’excitation a un rôle important dans les performances de cette machine.Cette thèse constate aussi que l’évolution future des matériaux magnétiques pourrait tirer meilleur profit des structures non-conventionnelles avec des trajets de flux tridimensionnels<br>The PhD project aims to analyse nonconventional structures of electric machines for electric power generation with diesel gensets. The researched topologies should use less active materials and/or simplify the manufacturing process compared to today’s machines.One of the structures is intended for the excitation system of the electric machine. It is composed of a claw-pole stator and a toroidal winding. It is designed using a 3D Finite Element model, previously validated by a prototype. This structure allows a significant reduction of the quantity of copper of the field winding.The other two structures under study are proposed for the main generator. A synchronous-reluctance machine with flux-barriers and a field winding in the rotor is analysed. The objective is to increase the torque density by increasing the reluctance torque. The designed machine is compared to the conventional structure. This case shows the limitations of structures similar to the current structure.The last structure is a new topology of electric machine. It combines the characteristics of claw-pole machines andaxial-flux machines. An original modelling approach is developed to analyse this 3D structure for its design based on an optimization algorithm. The study shows that the excitation system has a key role in its performances.This work also notes that the future evolution of magnetic materials should benefit the use of non-conventional structures with 3D flux paths
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Aigbomian, Anthony Omonzejele. "Traction machines for automotive applications : efficiency maps for permanent magnet machines." Thesis, University of Nottingham, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.739378.
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This research work proposes a fast computing tool for performance evaluation of electrical machines. It focuses on Interior Permanent Magnet (IPM) machines, where a combination of Finite-Element (FE) method and mathematical approximations are used to predict iron losses and eddy current losses in the magnets in addition to torque-speed characteristics. These losses are then used to generate the efficiency map of the machine following a set criterion. The adopted tool is based on FE and computes the complete machines' characteristic semi-analytically without any further FE computation. For the initial analysis and model verification a 16-pole 24-slot Interior Permanent Magnet (IPM) is adopted. The results obtained, compared to completely FE-based solution show that the proposed tool predicts the electromagnetic losses effectively within less computation time. Finally, Experimental work done on an existing IPM traction machine is described and the obtained results are confronted to the predicted ones.
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O'Hara, Daniel Finbarr John. "Machine fictions : a genealogy of machines in twentieth-century prose and art." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432166.
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Westerberg, Simon. "Semi-Automating Forestry Machines : Motion Planning, System Integration, and Human-Machine Interaction." Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-89067.
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The process of forest harvesting is highly mechanized in most industrialized countries, with felling and processing of trees performed by technologically advanced forestry machines. However, the maneuvering of the vehicles through the forest as well as the control of the on-board hydraulic boom crane is currently performed through continuous manual operation. This complicates the introduction of further incremental productivity improvements to the machines, as the operator becomes a bottleneck in the process. A suggested solution strategy is to enhance the production capacity by increasing the level of automation. At the same time, the working environment for the operator can be improved by a reduced workload, provided that the human-machine interaction is adapted to the new automated functionality. The objectives of this thesis are 1) to describe and analyze the current logging process and to locate areas of improvements that can be implemented in current machines, and 2) to investigate future methods and concepts that possibly require changes in work methods as well as in the machine design and technology. The thesis describes the development and integration of several algorithmic methods and the implementation of corresponding software solutions, adapted to the forestry machine context. Following data recording and analysis of the current work tasks of machine operators, trajectory planning and execution for a specific category of forwarder crane motions has been identified as an important first step for short term automation. Using the method of path-constrained trajectory planning, automated crane motions were demonstrated to potentially provide a substantial improvement from motions performed by experienced human operators. An extension of this method was developed to automate some selected motions even for existing sensorless machines. Evaluation suggests that this method is feasible for a reasonable deviation of initial conditions. Another important aspect of partial automation is the human-machine interaction. For this specific application a simple and intuitive interaction method for accessing automated crane motions was suggested, based on head tracking of the operator. A preliminary interaction model derived from user experiments yielded promising results for forming the basis of a target selection method, particularly when combined with some traded control strategy. Further, a modular software platform was implemented, integrating several important components into a framework for designing and testing future interaction concepts. Specifically, this system was used to investigate concepts of teleoperation and virtual environment feedback. Results from user tests show that visual information provided by a virtual environment can be advantageous compared to traditional video feedback with regards to both objective and subjective evaluation criteria.
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Brus, Alexander. "Validation of energy efficiency requirements for machine tools and industrial washing machines." Thesis, KTH, Energiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256062.
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Production equipment accounts for a large portion of the energy use from industry. But so far there has been no standardized way of requiring energy efficiency when purchasing a new machine. Scania is therefore implementing energy efficiency requirements in their purchasing process for production equipment. As a part of this, there needs to be a way of validating that the requirements have been fulfilled. This study aims to find how requirements on energy efficiency in production equipment can be validated in a user friendly and time efficient way. Firstly, the energy efficiency requirements set by Scania and by regulations are mapped. Then these requirements are clearly defined to enable a validation. Two component-level measurements of one machine tool and one industrial washing machine are analyzed. And then a cost analysis is conducted to determine the timespan that can be said to be time efficient for a validation procedure. The results from this are used to develop a validation method and an interactive protocol to make the validation more user friendly. This method is then tested through a simulated validation. The method proposed consists of two parts, an inspection and a measurement. The inspection is purely visual and validates the requirements on efficiency class for electrical motors and pumps, as well as requirements of specific equipment. The measurement is performed by running the machine through four different machine states in eight steps and validates requirements on when energy is used, and how much is used. The proposed method validates all energy efficiency requirements set by Scania for machine tools and industrial washing machines. It can be performed in a timespan that is far shorter than what is cost efficient. The proposed method can validate requirements on the energy use from any electrical components, compressed air use, and visually confirm that required equipment is present and some of its properties based on labelling. It will also be able to validate any new requirements on the energy use of electrical components, meaning it can easily be applied to other types of production equipment.<br>Produktionsutrustning står för en stor andel av energianvändningen inom industrin. Men än så länge finns det inget standardiserat sätt att kravställa energieffektivitet vid inköp av nya maskiner. Scania har därför börjat implementera krav på energieffektivitet i deras inköpsprocess för produktionsutrustning. Som en del av detta behövs ett sätt att validera att de ställda kraven också uppfylls. Denna studie undersöker hur krav på energieffektivitet kan valideras på ett användarvänligt och tidseffektivt sätt. Först kartläggs de energieffektivitetskrav som ställs av Scania och lagstiftning. Dessa krav definieras sedan så tydligt som möjligt för att möjliggöra en validering. Två mätningar av energianvändning på komponentnivå på en bearbetningsmaskin och en industriell tvättmaskin analyseras. Sedan utförs en kostnadsanalys för att avgöra ett tidsspann som kan sägas vara tidseffektivt för en valideringsprocess. Resultaten från detta används sedan för att utveckla en valideringsmetod och ett interaktivt protokoll. Denna metoden testas sedan genom en simulerad validering. Den föreslagna metoden består av två delar, en inspektion och en mätning. Inspektionen är endast visuell och validerar kraven på effektivitetsklass på motorer och pumpar, samt krav på specifik utrustning. Mätningen utförs genom att köra maskinen genom fyra olika maskinlägen i åtta steg och validerar krav på när energi används, och hur mycket som används. Den föreslagna metoden validerar alla krav på energieffektivitet som Scania ställer på bearbetningsmaskiner och industriella tvättmaskiner. Den kan utföras under ett tidsspann som är mycket kortare än gränsen för vad som är kostnadseffektivt. Den föreslagna metoden kan validera krav på energianvändning från elektriska komponenter, tryckluftsanvändning, och visuellt bekräfta att kravställd utrustning är på plats och vissa egenskaper baserat på märkningen. Metoden kommer också att kunna validera alla nya krav på energianvändning från elektriska komponenter, vilket innebär att den enkelt kan appliceras på andra typer av produktionsutrustning.
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Farhan, Uday Hameed. "An integrated system to design machine layouts for modular special purpose machines." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2018. https://ro.ecu.edu.au/theses/2081.
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This thesis introduces the development of an integrated system for the design of layouts for special purpose machines (SPMs). SPMs are capable of performing several machining operations (such as drilling, milling, and tapping) at the same time. They consist of elements that can be arranged in different layouts. Whilst this is a unique feature that makes SPMs modular, a high level of knowledge and experience is required to rearrange the SPM elements in different configurations, and also to select appropriate SPM elements when product demand changes and new layouts are required. In this research, an integrated system for SPM layout design was developed by considering the following components: an expert system tool, an assembly modelling approach for SPM layouts, an artificial intelligence tool, and a CAD design environment. SolidWorks was used as the 3D CAD environment. VisiRule was used as the expert system tool to make decisions about the selection of SPM elements. An assembly modelling approach was developed with an SPM database using a linked list structure and assembly relationships graph. A case-based reasoning (CBR) approach was developed and applied to automate the selection of SPM layouts. These components were integrated using application programing interface (API) features and Visual Basic programming language. The outcome of the application of the novel approach that was developed in this thesis is reducing the steps for the assembly process of the SPM elements and reducing the time for designing SPM layouts. As a result, only one step is required to assemble any two SPM elements and the time for the selection process of SPM layouts is reduced by approximately 75% compared to the traditional processes. The integrated system developed in this thesis will help engineers in design and manufacturing fields to design SPM layouts in a more time-effective manner.
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SOAVE, Elia. "Diagnostics and prognostics of rotating machines through cyclostationary methods and machine learning." Doctoral thesis, Università degli studi di Ferrara, 2022. http://hdl.handle.net/11392/2490999.
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In the last decades, the vibration analysis has been exploited for monitoring many mechanical systems for industrial applications. Although several works demonstrated how the vibration based diagnostics may reach satisfactory results, the nowadays industrial scenario is deeply changing, driven by the fundamental need of time and cost reduction. In this direction, the academic research has to focus on the improvement of the computational efficiency for the signal processing techniques applied in the mechanical diagnostics field. In the same way, the industrial word requires an increasing attention to the predictive maintenance for estimating the system failure avoiding unnecessary machine downtimes for maintenance operations. In this contest, in the recent years the research activity has been moved to the development of prognostic models for the prediction of the remaining useful life. However, it is important to keep in mind how the two fields are strictly connected, being the diagnostics the base on which build the effectiveness of each prognostic model. On these grounds, this thesis has been focused on these two different but linked areas for the detection and prediction of possible failures inside rotating machines in the industrial framework.
The first part of the thesis focuses on the development of a blind deconvolution indicator based on the cyclostationary theory for the fault identification in rotating machines. The novel criterion aims to decrease the computational cost of the blind deconvolution through the exploitation of the Fourier-Bessel series expansion due to its modulated nature more comparable with the fault related vibration pattern. The proposed indicator is extensively compared to the other cyclostationary one based on the classic Fourier transform, taking into account both synthesized and real vibration signals. The comparison proves the improvement given by the proposed criterion in terms of number of operations required by the blind deconvolution algorithm as well as its diagnostic capability also for noisy measured signals. The originality of this part regards the combination of cyclostationarity and Fourier-Bessel transform that leads to the definition of a novel blind deconvolution criterion that keeps the diagnostic effectiveness of cyclostationarity reducing the computational cost in order to meet the industrial requirements.
The second part regards the definition of a novel prognostic model from the family of the hidden Markov models constructed on a generalized Gaussian distribution. The target of the proposed method is a better fitting quality of the data distribution in the last damaging phase. In fact, the fault appearance and evolution reflects on a modification of the observation distribution within the states and consequently a generalized density function allows the changes on the distribution form through the values of some model parameters. The proposed method is compared in terms of fitting quality and state sequence prediction to the classic Gaussian based hidden Markov model through the analysis of several run to failure tests performed on rolling element bearings and more complex systems. The novelty of this part regards the definition of a new iterative algorithm for the estimation of the generalized Gaussian model parameters starting from the observations on the physical system for both monovariate and multivariate distributions. Furthermore, the strictly connection between diagnostics and prognostics is demonstrated through the analysis of a not monotonically increasing damaging process proving how the selection of a suitable indicator enables the correct health state estimation.<br>Negli ultimi decenni, l’analisi vibrazionale è stata sfruttata per il monitoraggio di molti sistemi meccanici per applicazioni industriali. Nonostante molte pubblicazioni abbiano dimostrato come la diagnostica vibrazionale possa raggiungere risultati soddisfacenti, lo scenario industriale odierno è in profondo cambiamento, guidato dalla necessità di ridurre tempi e costi produttivi. In questa direzione, la ricerca deve concentrarsi sul miglioramento dell’efficienza computazionale delle tecniche di analisi del segnale applicate a fini diagnostici. Allo stesso modo, il mondo industriale richiede una sempre maggior attenzione per la manutenzione predittiva, al fine di stimare l’effettivo danneggiamento del sistema evitando così inutili fermi macchina per operazioni manutentive. In tale ambito, negli ultimi anni l’attività di ricerca si sta spostando verso lo sviluppo di modelli prognostici finalizzati alla stima della vita utile residua dei componenti. Tuttavia, è importante ricordare come i due ambiti siano strettamente connessi, essendo la diagnostica la base su cui fondare l’efficacia di ciascun modello prognostico. Su questa base, questa tesi è stata incentrata su queste due diverse, ma tra loro connesse, aree al fine di identificare e predire possibile cause di cedimento su macchine rotanti per applicazioni industriali.
La prima parte della tesi è concentrata sullo sviluppo di un nuovo indicatore di blind deconvolution per l’identificazione di difetti su organi rotanti sulla base della teoria ciclostazionaria. Il criterio presentato vuole andare a ridurre il costo computazionale richiesto dalla blind deconvolution tramite l’utilizzo della serie di Fourier-Bessel grazie alla sua natura modulata, maggiormente affine alla tipica firma vibratoria del difetto. L’indicatore proposto viene accuratamente confrontato con il suo analogo basato sulla classica serie di Fourier considerando sia segnali simulati che segnali di vibrazione reali. Il confronto vuole dimostrare il miglioramento fornito dal nuovo criterio in termini sia di minor numero di operazioni richieste dall’algoritmo che di efficacia diagnostica anche in condizioni di segnale molto rumoroso. Il contributo innovativo di questa parte riguarda la combinazione di ciclostazionarietà e serie di Furier-Bessel che porta alla definizione di un nuovo criterio di blind deconvolution in grado di mantenere l’efficacia diagnostica della ciclostazionarietà ma con un minor tempo computazionale per venire incontro alle richieste del mondo industriale. La second parte riguarda la definizione di un nuovo modello prognostico, appartenente alla famiglia degli hidden Markov models, costruito partendo da una distribuzione Gaussiana generalizzata. L’obbiettivo del metodo proposto è una miglior riproduzione
della reale distribuzione dei dati, in particolar modo negli ultimi stadi del danneggiamento. Infatti, la comparsa e l’evoluzione del difetto comporta una modifica della distribuzione delle osservazioni fra i diversi stati. Di conseguenza, una densità di probabilità generalizzata permette la modificazione della forma della distribuzione tramite diversi valori dei parametri del modello. Il metodo proposto viene confrontato con il classico hidden Markov model di base Gaussiana in termini di qualità di riproduzione della distribuzione e predizione della sequenza di stati tramite l’analisi di alcuni test di rottura su cuscinetti volventi e sistemi complessi. L’innovatività di questa parte è data dalla definizione di un algoritmo iterativo per la stima dei parametri del modello nell’ipotesi di distribuzione Gaussiana generalizzata, sia nel caso monovariato che multivariato, partendo dalle osservazioni sul sistema fisico in esame.
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Monaco, Beatrice. "Machinic modernism: the Deleuzian literary machines of Woolf, Lawrence and Joyce." Thesis, Birkbeck (University of London), 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491002.
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Roderus, Jens, Simon Larson, and Eric Pihl. "Hadoop scalability evaluation for machine learning algorithms on physical machines : Parallel machine learning on computing clusters." Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-20102.
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The amount of available data has allowed the field of machine learning to flourish. But with growing data set sizes comes an increase in algorithm execution times. Cluster computing frameworks provide tools for distributing data and processing power on several computer nodes and allows for algorithms to run in feasible time frames when data sets are large. Different cluster computing frameworks come with different trade-offs. In this thesis, the scalability of the execution time of machine learning algorithms running on the Hadoop cluster computing framework is investigated. A recent version of Hadoop and algorithms relevant in industry machine learning, namely K-means, latent Dirichlet allocation and naive Bayes are used in the experiments. This paper provides valuable information to anyone choosing between different cluster computing frameworks. The results show everything from moderate scalability to no scalability at all. These results indicate that Hadoop as a framework may have serious restrictions in how well tasks are actually parallelized. Possible scalability improvements could be achieved by modifying the machine learning library algorithms or by Hadoop parameter tuning.
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Herman, Paul Andrew. "Improvement of surface finish quality in peripheral milling VIA precision compensation for cutter runout." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/16696.
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Davis, Tyler A. "Flexible machine tool control for direct, in-process dimensional part inspection /." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd478.pdf.
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Melo, Brandao De Raissa. "Surveillance de l’apparition de fissures sur des composants structuraux de machines." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI073.
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Le principe de la maintenance conditionnelle consiste à évaluer en permanence l’intégrité des machines industrielles, à partir des mesures et de traitements du signal appropriés, afin d’intervenir uniquement au moment le plus opportun. Dans ce contexte, l’objectif de cette thèse est de développer une technique de détection, aussi précoce que possible, de l’amorce de dégradation lente d’une structure vibrante, telle que les fissures de fatigue, pour éviter toute défaillance inattendue des machines. Notre approche se base sur les données mesurées à l’aide de deux moyens expérimentaux mis en œuvre au laboratoire. L’étude a démarré avec une poutre encastrée-libre sollicitée en flexion et s’est poursuivie sur un banc d’essais plus représentatif de la problématique industrielle. Dans les deux cas, l'endommagement de la structure a été naturel et progressif, depuis un état réputé sain jusqu’à l’apparition de la fissure. Le comportement dynamique a été suivi à l’aide d’accéléromètres. Ainsi, afin d’identifier des indicateurs sensibles au phénomène d’endommagement, plusieurs pistes ont été envisagées. Nous avons examiné les indicateurs scalaires descriptifs des signaux mesurés, qui sont les moments statistiques, fréquences moyennes et médianes. Ces indicateurs sont utilisés avec succès pour la détection de défaut sur les éléments de machines tournantes, mais ils se sont montrés peu sensibles pour détecter des défaillances structurales. Les fréquences propres identifiées automatiquement à partir des signaux temporels acquis sous chargements opérationnels ont également été étudiées. Ensuite, nous nous sommes orientés vers une approche plus globale pour surveiller les changements spectraux causés par l’apparition d’un défaut sur une structure. En se basant sur les matrices spectrales, fonctions et matrices de transmissibilité, des indicateurs multi-capteurs ont été développés et testés pour les deux cas d’étude. Une Analyse en Composantes Principales a permis d’identifier, entre les indicateurs analysés, ceux qui sont les plus pertinents pour la surveillance de l’intégrité des structures<br>The principle of the conditional maintenance consists in continuously evaluating the health state of industrial machines, from measurements and appropriate signal processing, in order to carry out maintenance operations only at the most convenient time. In this context, the objective of this PhD thesis is to implement a technique for detecting as soon as possible slow damage initiation in vibrating structures, such as the fatigue cracks, to avoid the unexpected failure of machines. We have conducted empirical investigations with two experimental setups built in the laboratory. The study started with a cantilever beam subjected to dynamic bending loads, and continued on a test-bench more representative of the industrial problem. In both cases, the structure was naturally and progressively damaged, from a state considered to be healthy, until the crack occurs. Its dynamical behavior was monitored using accelerometers. Therefore, in order to identify damage-sensitive features, many leads were investigated. We have examined the features describing the measured signals waveform, which are statistical moments, mean frequencies and median frequencies. They are successfully used for fault detection on rotating machinery, but they did not demonstrate enough sensitiveness to detect structural damage. The natural frequencies automatically identified from the measured time signals under operational loads have also been studied. Thus, we oriented our work towards a more global approach to monitor the spectral changes caused by the appearance of damage on a structure. Based on the spectral matrices and transmissibility quantities, multi-sensor indicators were developed and tested for the two cases of study. A Principal Component Analysis allowed us to identify, between the surveyed features, the ones most relevant for monitoring the integrity of structures
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Mahfoud, Jarir. "Recherches en Dynamique pour un Développement d'Eco Machines Tournantes Réactives - Smart Machines." Habilitation à diriger des recherches, INSA de Lyon, 2009. http://tel.archives-ouvertes.fr/tel-00545388.
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Les machines tournantes sont présentes dans bien de domaines de nos industries et de nos sociétés et jouent un rôle primordial dans le transport et l'énergie. Le contexte actuel d'épuisement de ressources fossiles et la demande continuellement en augmentation d'énergie, font du domaine de la production de l'énergie (qu'elle soit électrique, thermique, éolienne, hydraulique ou nucléaire) un secteur qui concentre une part importante de l'innovation et de l'investissement des institutions et des industriels. Les tendances actuelles concernent l'augmentation du rendement et de la fiabilité, la diminution des dimensions, des coûts d'exploitation et des impacts environnementaux. Les machines doivent donc opérer dans des conditions respectant les normes de sécurité, de sûreté, de confort et d'environnement. La maîtrise et l'optimisation de ces conditions ont constitué le fil conducteur des recherches menées. L'ensemble de cette recherche concerne le suivi du comportement, l'équilibrage et le contrôle actif des machines tournantes. Trois thèmes qui ont un point commun la définition et l'identification d'un modèle de la machine ensuite, connaissant les réponses identifier les perturbations et les forces extérieures. Ces recherches constituent la base vers le développement de machines avec une capacité de réagir, sans interventions extérieures, en présence d'une défaillance ou lors de passage des zones de vitesses critiques ou des zones d'instabilités, de modifier ses caractéristiques afin d'avoir toujours un comportement respectant les normes de sécurité, de sûreté, de confort et d'environnement. La base vers un développement d'une Eco machine tournante réactive: une Smart machine tournante. Les premières recherches traitent du suivi de comportement et du diagnostic des boites de transmission de puissance par engrenages. L'objectif est la mise en place d'une approche de maintenance préventive de machines tournantes en présence de défauts combinés d'engrenages et de roulements. L'approche scientifique est à la fois numérique et expérimentale. Dans les deux approches, les défauts critiques étudiés ont été choisis suite à une étude AMDEC (Analyse de Modes de Défaillance, de leurs Effets et leurs Criticités). Les approches pour réduire les nuisances et d'assurer la sécurité de fonctionnement se déclinent, selon les possibilités et les moyens d'intervention, en deux solutions; équilibrage et contrôle actif. En équilibrage les recherches permettront d'une part le développement de méthodes basées sur des modèles identifiés expérimentalement prenant en compte des non linéarités dues à la très grande flexibilité des structures étudiées ou à la dépendance de certaines caractéristiques aux fréquences; elles permettront d'autre part l'optimisation de la répartition des masses de correction à la fois en position et en valeur en considérant des perturbations stochastiques des mesures. Le thème contrôle actif des machines tournantes porte sur le développement et la mise en place de stratégies de contrôle permettant la modification du comportement dynamique des rotors en flexion, en régime transitoire, par l'utilisation d'actionneurs. Le contrôleur peut être dans le domaine physique ou modal avec une commande floue ou neuro-floue. Concernant la technologie d'actionneurs, des travaux ont déjà été réalisés en utilisant des actionneurs piézoélectriques. Le contrôle est efficace et robuste, le seul inconvénient concerne la liaison entre l'actionneur et la machine. Nos recherches actuelles portent sur la conception et le dimensionnement d'actionneurs électromagnétiques qui présentent l'avantage d'être sans contact et offrent la possibilité de contrôler à la fois l'arbre du rotor et un de ces composants (paliers hydrodynamiques). Les activités et thèmes de recherches sont présentés en trois chapitres sans prendre en compte l'aspect chronologique. Chaque chapitre présente la recherche déjà réalisée, celle en cours puis future. Un chapitre est consacré au projet de recherche concernant les études initiées dans un souci d'appliquer et d'adapter les acquis dans des contextes particuliers de complexité des nouvelles machines ou tout simplement la volonté de considérer les besoins environnementaux et le développement d'Eco- Machines Tournantes.
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Amara, Yacine. "Modélisation pour le dimensionnement des machines électriques. Application à des machines spéciales." Habilitation à diriger des recherches, Université du Havre, 2012. http://tel.archives-ouvertes.fr/tel-00831948.
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Après mes travaux de thèse effectués au Laboratoire l'Electricité, Signaux, et Robotique, (LESiR) de l'Ecole Normale Supérieure de Cachan, devenu depuis Laboratoire des Systèmes et Applications des Technologies de l'Information et de l'Energie (SATIE), j'ai eu la chance de travailler au sein de différentes équipes de recherche en génie électrique, tout d'abord, en Grande Bretagne, à l'"Electrical Machines and Drives Group" de l'Université de Sheffield, puis à Belfort au Laboratoire d'Electronique, Electrotechnique et Systèmes (L2ES), et enfin au Havre, au sein du Groupe de Recherche en Electrotechnique et Automatique du Havre (GREAH). Ce document me permet de présenter ces travaux afin de solliciter une Habilitation à Diriger des Recherches. Ce mémoire comporte trois parties. Une première partie où sont regroupés mon CV, une présentation de mes activités d'enseignement, d'administration, d'encadrement et de recherche et enfin une énumération des publications auxquelles j'ai participé. Dans la seconde partie, qui constitue le cœur de ce mémoire, une présentation plus approfondie de mes thématiques de recherche sera abordée. Ces thématiques sont regroupées en deux catégories : l'une plus fondamentale, du point de vue des sciences de l'ingénieur, concerne la modélisation des machines électriques, et la seconde plus applicative concerne les machines synchrones à double excitation. Alors que lors de mes travaux de thèse, qui concernaient les machines synchrones à double excitation, j'ai été plus utilisateur que développeur de méthodes de modélisation, je me suis de plus en plus orienté vers le développement de modèles au cours de mon séjour à l'Université de Sheffield et maintenant au GREAH. Les modèles développés sont bien adaptés pour le dimensionnement optimal des machines électriques. Ils sont de deux natures : * modèles analytiques ; * modèles semi-numériques. Les modèles analytiques sont basés sur la résolution formelle des équations de Maxwell dans les régions à perméabilité uniforme. Par modèles semi-numériques on entend les modèles basés sur les réseaux de permeances. La thématique des machines synchrones à double excitation, bien que n'étant pas une problématique fondamentale à proprement dit, permet d'apporter des réponses à des problématiques qui ne le sont pas moins : "défluxage" des machines à aimants permanents, optimisation énergétique, et enfin augmentation du coût des aimants permanents. Cette thématique est essentiellement menée en collaboration avec des collègues de l'équipe Systèmes d'Énergies pour les Transports et l'Environnement (SETE) du SATIE. Enfin, dans la troisième partie un bilan global des activités de recherche est dressé. Ce bilan permettra de revenir sur les points que je considère essentiels de ces activités, et de dégager quelques perspectives aux court, moyen, et long termes.
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Tait, Jack. "Programmable analogue drawing machines : Machines and timers designed to make art works." Thesis, Manchester Metropolitan University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534242.
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Jain, Brijnesh Johannes. "Structural neural learning machines." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=98007911X.
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Nanchen, Stanislas. "Verifying abstract state machines /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17489.
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Zhang, Gefei. "Aspect-Oriented State Machines." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-128399.
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Hillbrecht, Ricardo. "A Virtual-Machines-MIB." reponame:Repositório Institucional da UFPR, 2013. http://hdl.handle.net/1884/29370.
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Resumo: Este trabalho apresenta a Virtual-Machines-MIB, uma MIB para a gerˆencia de m´aquinas virtuais baseada no Simple Network Management Protocol (SNMP). A Virtual-Machines- MIB define uma interface padronizada para a gerˆencia de m´aquinas virtuais, permitindo que a mesma ferramenta possa gerenciar, atrav´es do protocolo SNMP, diferentes monitores de m´aquinas virtuais, como KVM, Xen e VMWare. Diferente da maior parte das MIB's existentes, a Virtual-Machines-MIB permite ao gerente n˜ao apenas monitorar aspectos da m´aquina f´?sica e das VM's, mas tamb´em executar a?c˜oes de controle, como criar, excluir, reiniciar, ligar, desligar e congelar VM's. Tamb´em ´e poss´?vel alterar o nome, a quantidade de mem´oria RAM e de CPU's das VM's, al´em de alterar as unidades de armazenamento das mesmas. Resultados pr´aticos s˜ao apresentados utilizando ferramentas de gerˆencia SNMP comuns para gerenciar diferentes monitores de m´aquinas virtuais. Para isso, foram criados agentes SNMP que oferecem suporte `a Virtual-Machines-MIB e instalados em m´aquinas com o KVM e o Xen. Os agentes foram criados com base no agente SNMP de dom´?nio p´ublico NET-SNMP, que foi estendido para que passe a oferecer suporte `a Virtual-Machines-MIB utilizando as fun?c˜oes da libvirt.
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Jin, Bo. "Evolutionary Granular Kernel Machines." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/cs_diss/15.
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Kernel machines such as Support Vector Machines (SVMs) have been widely used in various data mining applications with good generalization properties. Performance of SVMs for solving nonlinear problems is highly affected by kernel functions. The complexity of SVMs training is mainly related to the size of a training dataset. How to design a powerful kernel, how to speed up SVMs training and how to train SVMs with millions of examples are still challenging problems in the SVMs research. For these important problems, powerful and flexible kernel trees called Evolutionary Granular Kernel Trees (EGKTs) are designed to incorporate prior domain knowledge. Granular Kernel Tree Structure Evolving System (GKTSES) is developed to evolve the structures of Granular Kernel Trees (GKTs) without prior knowledge. A voting scheme is also proposed to reduce the prediction deviation of GKTSES. To speed up EGKTs optimization, a master-slave parallel model is implemented. To help SVMs challenge large-scale data mining, a Minimum Enclosing Ball (MEB) based data reduction method is presented, and a new MEB-SVM algorithm is designed. All these kernel methods are designed based on Granular Computing (GrC). In general, Evolutionary Granular Kernel Machines (EGKMs) are investigated to optimize kernels effectively, speed up training greatly and mine huge amounts of data efficiently.