992 resultados para Well-founded semantics
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Las indagaciones en la pregunta por lo que hay permiten distinguir a grandes rasgos entre dos enfoques: uno, el de los pensadores que entendieron que el tema a investigar era la naturaleza y estructura del mundo, y otro, el de aquellos quienes, al sostener que describir el mundo no es simplemente copiarlo, atendieron a lo que se llamó esquema conceptual: esto es, al marco conceptual cuya forma toman las descripciones del mundo. La situación se puede plantear como un dilema, ninguno de cuyos cuernos permite alentar esperanzas de avances bien fundados. O bien se pretende describir el mundo, tal como es, sin contemplar el hecho de que esa descripción incluye elecciones conceptuales propias de un sujeto, o bien se centra la investigación en los rasgos de el/los esquema/s conceptual/es imprescindibles para construir una descripción del mundo, imposibilitando, con ello, el acceso a la realidad tal como ésta es. En el siglo XX se cuenta con recursos de sistemas de lógica considerablemente más desarrollados y abarcadores (en sus posibilidades de aplicación) que los anteriores. Tales recursos brindan nuevas posibilidades de abordaje de la pregunta por lo que hay, no sólo por los ámbitos que se clarifican mediante ellos, sino también por el sustento que ofrecen para la reflexión filosófica los resultados obtenidos. Los avances producidos en el ámbito de la lógica en algo más de un siglo tuvieron variadas repercusiones en el enfoque y el tratamiento de distintas cuestiones filosóficas. Así, se ha echado mano a conceptos y recursos de lógica al considerar preguntas acerca de la estructura del mundo. Para la determinación de los componentes de la realidad se ha recurrido a la lógica, desde diversas posiciones filosóficas. Por ejemplo, se ha entendido que la lógica subyacente a la teoría científica brinda en algún sentido elementos para determinar la ontología (o para descartar la posibilidad de hacerlo, o para establecer qué función cumple la noción de ontología en la teoría científica). También, desde una óptica más amplia, se ha intentado mostrar que el uso del lenguaje tiene consecuencias respecto de la ontología. Hilary Putnam ha sugerido la posibilidad de ser al mismo tiempo un realista y un relativista conceptual. Involucra consideraciones como las mencionadas, respecto de lógica y ontología. Su objetivo es el intento de hacer justicia a la realidad y al misterio de nuestro mundo de sentido común. Tomo esta tesis como una propuesta de trabajo. Me interesa pensar en cómo ofrecer algunos elementos de juicio para evaluar sus alcances. Para ello, examino la sugerencia de Putnam mediante un ejemplo construido con ese objetivo. Entiendo que se requerirán, al menos, dos esquemas conceptuales diferentes: al que surgiría de la lógica de orden 1, tal como la desarrolla Quine, y al que podría obtenerse a partir de la teoría de objetos no existentes de Castañeda. Se contará así con elementos de juicio más precisos que los habituales para evaluar las consecuencias que se seguirían para la ontología en caso de sostener ambos esquemas conceptuales, en consonancia con la propuesta de Putnam que se ha tomado como objetivo general del proyecto
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The province of Salta is located the Northwest of Argentina in the border with Bolivia, Chile and Paraguay. Its Capital is the city of Salta that concentrates half of the inhabitants of the province and has grown to 600000 hab., from a small active Spanish town well founded in 1583. The city is crossed by the Arenales River descending from close mountains at North, source of water and end of sewers. But with actual growing it has become a focus of infection and of remarkable unhealthiness. It is necessary to undertake a plan for the recovery of the river, directed to the attainment of the well-being and to improve the life?s quality of the Community. The fundamental idea of the plan is to obtain an ordering of the river basin and an integral management of the channel and its surroundings, including the cleaning out. The improvement of the water?s quality, the healthiness of the surroundings and the improvement of the environment, must go hand by hand with the development of sport activities, of relaxation, tourism, establishment of breeding grounds, kitchen gardens, micro enterprises with clean production and other actions that contribute to their benefit by the society, that being a basic factor for their care and sustainable use. The present pollution is organic, chemical, industrial, domestic, due to the disposition of sweepings and sewer effluents that affects not only the flora and small fauna, destroying the biodiversity, but also to the health of people living in their margins. Within the plan it will be necessary to consider, besides hydric and environmental cleaning and the prevention of floods, the planning of the extraction of aggregates, the infrastructure and consolidation of margins works and the arrangement of all the river basin. It will be necessary to consider the public intervention at state, provincial and local level, and the private intervention. In the model it has been necessary to include the sub-model corresponding to the election of the entity to be the optimal instrument to reach the proposed objectives, giving an answer to the social, environmental and economic requirements. For that the authors have used multi-criteria decision methods to qualify and select alternatives, and for the programming of their implementation. In the model the authors have contemplated the short, average and long term actions. They conform a Paretooptimal alternative which secures the ordering, integral and suitable management of the basin of the Arenales River, focusing on its passage by the city of Salta.
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This chapter presents methodological guidelines that allow engineers to reuse generic ontologies. This kind of ontologies represents notions generic across many fields, (is part of, temporal interval, etc.). The guidelines helps the developer (a) to identify the type of generic ontology to be reused, (b) to find out the axioms and definitions that should be reused and (c) to adapt and integrate the generic ontology selected in the domain ontology to be developed. For each task of the methodology, a set of heuristics with examples are presented. We hope that after reading this chapter, you would have acquired some basic ideas on how to take advantage of the great deal of well-founded explicit knowledge that formalizes generic notions such as time concepts and the part of relation.
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Currently, there is a great deal of well-founded explicit knowledge formalizing general notions, such as time concepts and the part_of relation. Yet, it is often the case that instead of reusing ontologies that implement such notions (the so-called general ontologies), engineers create procedural programs that implicitly implement this knowledge. They do not save time and code by reusing explicit knowledge, and devote effort to solve problems that other people have already adequately solved. Consequently, we have developed a methodology that helps engineers to: (a) identify the type of general ontology to be reused; (b) find out which axioms and definitions should be reused; (c) make a decision, using formal concept analysis, on what general ontology is going to be reused; and (d) adapt and integrate the selected general ontology in the domain ontology to be developed. To illustrate our approach we have employed use-cases. For each use case, we provide a set of heuristics with examples. Each of these heuristics has been tested in either OWL or Prolog. Our methodology has been applied to develop a pharmaceutical product ontology. Additionally, we have carried out a controlled experiment with graduated students doing a MCs in Artificial Intelligence. This experiment has yielded some interesting findings concerning what kind of features the future extensions of the methodology should have.
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After the extensive research on the capabilities of the Boundary Integral Equation Method produced during the past years the versatility of its applications has been well founded. Maybe the years to come will see the in-depth analysis of several conflictive points, for example, adaptive integration, solution of the system of equations, etc. This line is clear in academic research. In this paper we comment on the incidence of the manner of imposing the boundary conditions in 3-D coupled problems. Here the effects are particularly magnified: in the first place by the simple model used (constant elements) and secondly by the process of solution, i.e. first a potential problem is solved and then the results are used as data for an elasticity problem. The errors add to both processes and small disturbances, unimportant in separated problems, can produce serious errors in the final results. The specific problem we have chosen is especially interesting. Although more general cases (i.e. transient)can be treated, here the domain integrals can be converted into boundary ones and the influence of the manner in which boundary conditions are applied will reflect the whole importance of the problem.
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El proyecto de una tienda concentra un poco de todo aquello que interesa al arquitecto: conforma una suerte de encrucijada en la que se dan cita, junto a cuestiones disciplinares que la hacen muy atractiva y ponen a prueba su habilidad como proyectista, la necesidad de aunar recursos compositivos procedentes de otros terrenos periféricos a la arquitectura para dar una respuesta adecuada a los requerimientos específicos de imagen y persuasión que la actividad comercial comporta. Las difíciles condiciones de partida, habitualmente configuraciones espaciales no excesivamente favorables, donde las preexistencias y los contornos coartan y encierran un espacio al que hay que dotar de un nuevo orden; el tamaño reducido y las posibilidades de control total de la obra que de éste se derivan; el corto plazo de tiempo y la rapidez de respuesta que la estrategia comercial impone; su posición estratégica, en relación directa con la calle, y la mayor evidencia que, por tanto, se le asigna a la fachada y al escaparate como ‘primeros anuncios’ de la actividad; la integración y el comentario recíproco entre arquitectura y objeto que tiene lugar en su seno…, son algunas de las razones que explican este interés y justifican que la tienda −ese espacio acotado tan apto para el invento y la innovación−, constituya un banco de pruebas donde poder ensayar nuevos conceptos de la arquitectura al reunir espacial y temporalmente los condicionantes ideales requeridos para la experimentación y la comprobación de hallazgos. Aunque escasas, existen en la arquitectura contemporánea tiendas que han logrado ocupar por méritos propios un lugar destacado dentro de la obra de sus autores. Entre las merecedoras de ese reconocimiento habría que citar la ‘mítica’ sastrería Kniže proyectada por Adolf Loos a comienzos del siglo XX en Viena, el Negozio Vitrum que Giuseppe Terragni diseñara en Como en los años treinta, o la sucursal londinense de las líneas aéreas de Iraq construida en los sesenta por Alison y Peter Smithson. La elección, lejos de ser gratuita, obedece a razones fundadas. Dentro de las circunstancias temporales en las que se gestaron −las tres fueron proyectadas y construidas a lo largo del pasado siglo en un arco que abarca algo más de cincuenta años (1907-1961)−, los ejemplos seleccionados aúnan toda una serie de ‘coincidencias’ entre las que no resulta difícil establecer ciertos paralelismos: las tres marcan la talla de unos creadores que fueron capaces de dedicar la misma intensidad creativa a estos temas ‘menores’, corroborando que el carácter de la arquitectura también puede hacerse grande en lo pequeño; las tres, debido al momento de madurez en el que se abordó su diseño, reflejan su condición de laboratorio experimental al servicio de los intereses proyectuales que en ese momento ocupaban la mente de los arquitectos; las tres corroboran hipótesis ya apuntadas en arquitecturas anteriores, prueban líneas de trabajo no materializadas por falta de oportunidad y testan de manera menos comprometida soluciones que luego se trasladarán a obras con mayor vocación de permanencia; obras −y esto es algo especialmente sorprendente− con las que mantuvieron una estrecha relación en el espacio y en el tiempo, convirtiéndose incluso en plataformas de experimentación paralelas: baste en este sentido con apuntar la cercanía física −a ‘metros’ de distancia− y temporal −realizadas en los mismos años− entre la sastrería Kniže (1907- 1913;1928) y la Casa en la Michaelerplatz (1910-11); la tienda Vitrum (1930) y la Casa del Fascio (1929; 1932-36) o las oficinas de venta de las Iraqi Airways (1960-61) y la sede del The Economist (1959-64). Esta potencialidad que la tienda encierra para erigirse en laboratorio de experimentación y ensayo de la arquitectura, constituye la clave de la investigación que la tesis propone. ABSTRACT A little of everything that interests the architect is concentrated in the designing of a shop: it forms a kind of crossroads bringing together, apart from certain disciplinary questions rendering it particularly attractive and testing one’s ability as a designer, the need to coordinate compositional resources from fields peripheral to architecture in order to devise an adequate response to the specific requirements of image and persuasion that are part and parcel of business activity. The difficult start-up conditions, the generally not overly favourable spatial configurations ‒where the pre-existing conditions and shape of the site encroach on and enclose a space which has to be given a new order‒, the reduced size and possibilities afforded in terms of controlling the work, the short time frame and the rapid response imposed by the business tactics and its strategic position and direct frontal relationship with the street, make the shopfront and the display window are the ‘first advertisements” of the activity, or the integration and the reciprocal commentary between architecture and what takes place within: these are but some of the reasons explaining this interest and justifying the claim that the shop –a dimensional space so well suited to invention and innovation− constitutes a test-bed for trying out new concepts of architecture, combining in space and time the ideal conditions for experiment and the examination of its findings. Albeit not numerous, there are shops in contemporary architecture which have managed on their own merit to obtain a special place among the works of their authors. Among those earning such recognition, one should mention the ‘mythical’ Kniže tailoring establishment designed by Adolf Loos at the beginning of the 20th century in Vienna, the Negozio Vitrum designed by Giuseppe Terragni in Como in the thirties, or the London offices of Iraqi Airways built in the sixties by Alison and Peter Smithson. This selection, far from gratuitous, is based on well-founded reasons. Within the circumstances of the time-frame in which they were developed −the three were designed and built during the 20th century in a period that spans just over fifty years (1907-1961)− the chosen examples bring together a whole series of ‘coincidences’ where it is not difficult to draw certain parallels: the three bear witness to the stature of creators who were capable of devoting the same creative intensity to these ‘minor’ themes, thus corroborating the fact that the nature of the architecture can also be great in less important works; the three, thanks to the moment of maturity in which their design was carried out, reflect their condition as an experimental laboratory at the service of the particular designing interests which at the time occupied the minds of these architects; the three confirm hypotheses already displayed in previous architectures, they test lines of work which had not materialised through lack of opportunity, and in a less comprised manner check solutions that were later transferred to works with a greater vocation for permanence; works −and this is something especially surprising – with which they maintained a close relationship in time and space, even becoming parallel experimental platforms: in this sense, we need only to mention the physical proximity –just metres away− and proximity in time –built within the same years− between the Kniže shop (1907-1913; 1928) and the House of Michaelerplatz (1910-11); the Vitrum shop (1930) and the Casa del Fascio (1929;1932-36); and the Iraqi Airways sales offices (1960-61) and the headquarters of The Economist (1959-64). The potential of the shop to set itself up as an experimental laboratory and architectural rehearsal constitutes the main focus of the research put forward by this thesis.
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This paper refers to a crucial issue for higher education institutions. In Mexico, particularly, the collective work of academic bodies is an unresolved issue despite the efforts made in this regard. In this context, a well-founded systematic discussion is essential to understand the potential of these academic bodies on faculty strengthening and their subsequent impact on the quality of education. This paper presents the results of a research project conducted by FIME with the purpose of identifying the characteristics of its academic bodies as well as their current and potential condition. (1) Translator’s Note: FIME refers to the Facultad de Ingeniería Mecánica y Eléctrica (College of Mechanical and Electrical Engineering).
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Relatório da Prática Profissional Supervisionada Mestrado em Educação Pré-Escolar
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Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1.º e 2.º Ciclos do Ensino Básico
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RESUMO:A depressão clínica é uma patologia do humor, dimensional e de natureza crónica, evoluindo por episódios heterogéneos remitentes e recorrentes, de gravidade variável, correspondendo a categorias nosológicas porventura artificiais mas clinicamente úteis, de elevada prevalência e responsável por morbilidade importante e custos sociais crescentes, calculando-se que em 2020 os episódios de depressão major constituirão, em todo o mundo, a segunda causa de anos de vida com saúde perdidos. Como desejável, na maioria dos países os cuidados de saúde primários são a porta de entrada para o acesso à recepção de cuidados de saúde. Cerca de 50% de todas as pessoas sofrendo de depressão acedem aos cuidados de saúde primários mas apenas uma pequena proporção é correctamente diagnosticada e tratada pelos médicos prestadores de cuidados primários apesar dos tratamentos disponíveis serem muito efectivos e de fácil aplicabilidade. A existência de dificuldades e barreiras a vários níveis – doença, doentes, médicos, organizações de saúde, cultura e sociedade – contribuem para esta generalizada ineficiência de que resulta uma manutenção do peso da depressão que não tem sido possível reduzir através das estratégias tradicionais de organização de serviços. A equipa comunitária de saúde mental e a psiquiatria de ligação são duas estratégias de intervenção com desenvolvimento conceptual e organizacional respectivamente na Psiquiatria Social e na Psicossomática. A primeira tem demonstrado sucesso na abordagem clínica das doenças mentais graves na comunidade e a segunda na abordagem das patologias não psicóticas no hospital geral. Todavia, a efectividade destas estratégias não se tem revelado transferível para o tratamento das perturbações depressivas e outras patologias mentais comuns nos cuidados de saúde primários. Novos modelos de ligação e de trabalho em equipa multidisciplinar têm sido demonstrados como mais eficazes e custo-efectivos na redução do peso da depressão, ao nível da prestação dos cuidados de saúde primários, quando são atinentes com os seguintes princípios estratégicos e organizacionais: detecção sistemática e abordagem da depressão segundo o modelo médico, gestão integrada de doença crónica incluindo a continuidade de cuidados mediante colaboração e partilha de responsabilidades intersectorial, e a aposta na melhoria contínua da qualidade. Em Portugal, não existem dados fiáveis sobre a frequência da depressão, seu reconhecimento e a adequação do tratamento ao nível dos cuidados de saúde primários nem se encontra validada uma metodologia de diagnóstico simples e fiável passível de implementação generalizada. Foi realizado um estudo descritivo transversal com os objectivos de estabelecer a prevalência pontual de depressão entre os utentes dos cuidados de saúde primários e as taxas de reconhecimento e tratamento pelos médicos de família e testar metodologias de despiste, com base num questionário de preenchimento rápido – o WHO-5 – associado a uma breve entrevista estruturada – o IED. Foram seleccionados aleatoriamente 31 médicos de família e avaliados 544 utentes consecutivos, dos 16 aos 90 anos, em quatro regiões de saúde e oito centros de saúde dotados com 219 clínicos gerais. Os doentes foram entrevistados por psiquiatras, utilizando um método padronizado, o SCAN, para diagnóstico de perturbação depressiva segundo os critérios da 10ª edição da Classificação Internacional de Doenças. Apurou-se que 24.8% dos utentes apresentava depressão. No melhor dos cenários, menos de metade destes doentes, 43%, foi correctamente identificada como deprimida pelo seu médico de família e menos de 13% dos doentes com depressão estavam bem medicados com antidepressivo em dose adequada. A aplicação seriada dos dois instrumentos não revelou dificuldades tendo permitido a identificação de pelo menos 8 em cada 10 doentes deprimidos e a exclusão de 9 em cada 10 doentes não deprimidos. Confirma-se a elevada prevalência da patologia depressiva ao nível dos cuidados primários em Portugal e a necessidade de melhorar a capacidade diagnóstica e terapêutica dos médicos de família. A intervenção de despiste, que foi validada, parece adequada para ser aplicada de modo sistemático em Centros de Saúde que disponham de recursos técnicos e organizacionais para o tratamento efectivo dos doentes com depressão. A obtenção da linha de base de indicadores de prevalência, reconhecimento e tratamento das perturbações depressivas nos cuidados de saúde primários, bem como a validação de instrumentos de uso clínico, viabiliza a capacitação do sistema para a produção de uma campanha nacional de educação de grande amplitude como a proposta no Plano Nacional de Saúde 2004-2010.------- ABSTRACT: Clinical depression is a dimensional and chronic affective disorder, evolving through remitting and recurring heterogeneous episodes with variable severity corresponding to clinically useful artificial diagnostic categories, highly prevalent and producing vast morbidity and growing social costs, being estimated that in 2020 unipolar major depression will be the second cause of healthy life years lost all over the world. In most countries, primary care are the entry point for access to health care. About 50% of all individuals suffering from depression within the community reach primary health care but a smaller proportion is correctly diagnosed and treated by primary care physicians though available treatments are effective and easily manageable. Barriers at various levels – pertaining to the illness itself, to patients, doctors, health care organizations, culture and society – contribute to the inefficiency of depression management and pervasiveness of depression burden, which has not been possible to reduce through classical service strategies. Community mental health teams and consultation-liaison psychiatry, two conceptual and organizational intervention strategies originating respectively within social psychiatry and psychosomatics, have succeeded in treating severe mental illness in community and managing non-psychotic disorders in the general hospital. However, these strategies effectiveness has not been replicated and transferable for the primary health care setting treatment of depressive disorders and other common mental pathology. New modified liaison and multidisciplinary team work models have been shown as more efficacious and cost-effective reducing depression burden at the primary care level namely when in agreement with principles such as: systematic detection of depression and approach accordingly to the medical model, chronic llness comprehensive management including continuity of care through collaboration and shared responsibilities between primary and specialized care, and continuous quality improvement. There are no well-founded data available in Portugal for depression prevalence, recognition and treatment adequacy in the primary care setting neither is validated a simple, teachable and implementable recognition and diagnostic methodology for primary care. With these objectives in mind, a cross-sectional descriptive study was performed involving 544 consecutive patients, aged 16-90 years, recruited from the ambulatory of 31 family doctors randomized within the 219 physicians working in eight health centres from four health regions. Screening strategies were tested based on the WHO-5 questionnaire in association with a short structured interview based on ICD-10 criteria. Depression ICD-10 diagnosis was reached according to the gold standard SCAN interview performed by trained psychiatrists. Any depressive disorder ICD-10 diagnosis was present in 24.8% of patients. Through the use of favourable recognition criteria, 43% of the patients were correctly identified as depressed by their family doctor and about 13% of the depressed patients were prescribed antidepressants at an adequate dosage. The serial administration of both instruments – WHO-5 and short structured interview – was feasible, allowing the detection of eight in ten positive cases and the exclusion of nine in ten non-cases. In Portugal, at the primary care level, high depressive disorder prevalence is confirmed as well as the need to improve depression diagnostic and treatment competencies of family doctors. A two-stage screening strategy has been validated and seems adequate for systematic use in health centres where technical and organizational resources for the effective management of depression are made available. These results can be viewed as primary care depressive disorders baseline indicators of prevalence, detection and treatment and, along with clinical useful instruments, the health system is more capacitated for the establishment of a national level large education campaign on depression such as proposed in the National Health Plan 2004-2010.
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Aquest treball presenta com s'ha de dur a terme un procés d'estimació que permeti obtenir estimacions de qualitat i analitza els principals mètodes d'estimació de programari. Es tracta de mètodes que persegueixen l'obtenció de mesures objectives i fonamentades sobre el mesurament de programari i l'estimació de temps i costos d'un projecte.
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In this book, I apply a philosophical approach to study the precautionary principle in environmental (and health) risk decision-making. The principle says that unacceptable environmental and health risks should be anticipated, and they ought to be forestalled before the damage comes to fruition even if scientific understanding of the risks is inadequate. The study consists of introductory chapters, summary and seven original publications which aim at explicating the principle, critically analysing the debate on the principle, and constructing a basis for the well-founded use of the principle. Papers I-V present the main thesis of this research. In the two last papers, the discussion is widened to new directions. The starting question is how well the currently embraced precautionary principle stands up to critical philosophical scrutiny. The approach employed is analytical: mainly conceptual, argumentative and ethical. The study draws upon Anglo-American style philosophy on the one hand, and upon sources of law as well as concrete cases and decision-making practices at the European Union level and in its member countries on the other. The framework is environmental (and health) risk governance, including the related law and policy. The main thesis of this study is that the debate on the precautionary principle needs to be shifted from the question of whether the principle (or its weak or strong interpretation) is well-grounded in general to questions about the theoretical plausibility and ethical and socio-political justifiability of specific understandings of the principle. The real picture of the precautionary principle is more complex than that found (i.e. presumed) in much of the current academic, political and public debate surrounding it. While certain presumptions and interpretations of the principle are found to be sound, others are theoretically flawed or include serious practical problems. The analysis discloses conceptual and ethical presumptions and elementary understandings of the precautionary principle, critically assesses current practices invoked in the name of the precautionary principle and public participation, and seeks to build bridges between precaution, engagement and philosophical ethics. Hence, it is intended to provide a sound basis upon which subsequent academic scrutiny can build.
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Tämän työn tavoitteena oli tehdä perusteltu esitys kahden suunnitellun sähköaseman toiminnan aloittamisen ajankohdasta sekä rakentamisen kestosta lupamenettelyineen. Työssä oli pyrkimys perustella asemien maantieteellinen sijainti, toteutustapa, rakenne sekä sähköasemien syöttöön tarvittavien 110 kV johtojen alustava rakenne ja reitti. Työssä on tarkasteltu uuden sähköaseman verkosto- ja kustannusvaikutuksia, sähköasemarakenteita ja niiden valintaa, sähköasemainvestointihankkeen vaiheita ja rakennuttamisprosessin läpivientiin tarvittavaa aikaa. Verkoston nykytilaa, käyttövarmuutta ja selviytymistä kuormituksen kasvusta on tarkasteltu sähköasemien toiminnan aloittamisen ajankohtien määrittämiseksi. Työn keskeisin painopiste oli sähköasemien rakentamisajankohdan määrittäminen. Sähköasemien toiminnan aloittamisen ajankohdan määrääväksi tekijäksi muodostuivat sähköasemien korvaustilanteet. Nykytilassa Valkealan haja-asutusalueen sähkönjakelua ei voida taata yksittäisen sähköaseman korvaustilanteessa, minkä takia sähköasemahankkeen valmistelu on aloitettava välittömästi. Kouvolan ydinkeskustan alueen maakaapeliverkon tehonsiirtokyky ja päämuuntajien reservitehokapasiteetti korvaustilanteissa riittävät vielä 5-10 vuotta riippuen suuresti alueen kuormituksen kasvusta.
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Learning of preference relations has recently received significant attention in machine learning community. It is closely related to the classification and regression analysis and can be reduced to these tasks. However, preference learning involves prediction of ordering of the data points rather than prediction of a single numerical value as in case of regression or a class label as in case of classification. Therefore, studying preference relations within a separate framework facilitates not only better theoretical understanding of the problem, but also motivates development of the efficient algorithms for the task. Preference learning has many applications in domains such as information retrieval, bioinformatics, natural language processing, etc. For example, algorithms that learn to rank are frequently used in search engines for ordering documents retrieved by the query. Preference learning methods have been also applied to collaborative filtering problems for predicting individual customer choices from the vast amount of user generated feedback. In this thesis we propose several algorithms for learning preference relations. These algorithms stem from well founded and robust class of regularized least-squares methods and have many attractive computational properties. In order to improve the performance of our methods, we introduce several non-linear kernel functions. Thus, contribution of this thesis is twofold: kernel functions for structured data that are used to take advantage of various non-vectorial data representations and the preference learning algorithms that are suitable for different tasks, namely efficient learning of preference relations, learning with large amount of training data, and semi-supervised preference learning. Proposed kernel-based algorithms and kernels are applied to the parse ranking task in natural language processing, document ranking in information retrieval, and remote homology detection in bioinformatics domain. Training of kernel-based ranking algorithms can be infeasible when the size of the training set is large. This problem is addressed by proposing a preference learning algorithm whose computation complexity scales linearly with the number of training data points. We also introduce sparse approximation of the algorithm that can be efficiently trained with large amount of data. For situations when small amount of labeled data but a large amount of unlabeled data is available, we propose a co-regularized preference learning algorithm. To conclude, the methods presented in this thesis address not only the problem of the efficient training of the algorithms but also fast regularization parameter selection, multiple output prediction, and cross-validation. Furthermore, proposed algorithms lead to notably better performance in many preference learning tasks considered.
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Machine learning provides tools for automated construction of predictive models in data intensive areas of engineering and science. The family of regularized kernel methods have in the recent years become one of the mainstream approaches to machine learning, due to a number of advantages the methods share. The approach provides theoretically well-founded solutions to the problems of under- and overfitting, allows learning from structured data, and has been empirically demonstrated to yield high predictive performance on a wide range of application domains. Historically, the problems of classification and regression have gained the majority of attention in the field. In this thesis we focus on another type of learning problem, that of learning to rank. In learning to rank, the aim is from a set of past observations to learn a ranking function that can order new objects according to how well they match some underlying criterion of goodness. As an important special case of the setting, we can recover the bipartite ranking problem, corresponding to maximizing the area under the ROC curve (AUC) in binary classification. Ranking applications appear in a large variety of settings, examples encountered in this thesis include document retrieval in web search, recommender systems, information extraction and automated parsing of natural language. We consider the pairwise approach to learning to rank, where ranking models are learned by minimizing the expected probability of ranking any two randomly drawn test examples incorrectly. The development of computationally efficient kernel methods, based on this approach, has in the past proven to be challenging. Moreover, it is not clear what techniques for estimating the predictive performance of learned models are the most reliable in the ranking setting, and how the techniques can be implemented efficiently. The contributions of this thesis are as follows. First, we develop RankRLS, a computationally efficient kernel method for learning to rank, that is based on minimizing a regularized pairwise least-squares loss. In addition to training methods, we introduce a variety of algorithms for tasks such as model selection, multi-output learning, and cross-validation, based on computational shortcuts from matrix algebra. Second, we improve the fastest known training method for the linear version of the RankSVM algorithm, which is one of the most well established methods for learning to rank. Third, we study the combination of the empirical kernel map and reduced set approximation, which allows the large-scale training of kernel machines using linear solvers, and propose computationally efficient solutions to cross-validation when using the approach. Next, we explore the problem of reliable cross-validation when using AUC as a performance criterion, through an extensive simulation study. We demonstrate that the proposed leave-pair-out cross-validation approach leads to more reliable performance estimation than commonly used alternative approaches. Finally, we present a case study on applying machine learning to information extraction from biomedical literature, which combines several of the approaches considered in the thesis. The thesis is divided into two parts. Part I provides the background for the research work and summarizes the most central results, Part II consists of the five original research articles that are the main contribution of this thesis.