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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Bountiful mind : memory, cognition and knowledge acquisition in Plato's Meno

Beaugrand, Selina January 2016 (has links)
The Meno has traditionally been viewed as "one of Plato's earliest and most noteworthy forays into epistemology." In this dialogue, and in the course of a discussion between Socrates and his young interlocutor, Meno, about the nature of virtue and whether it can be taught, “Meno raises an epistemological question unprecedented in the Socratic dialogues.” This question - or rather, dilemma - has come to be known in the philosophical literature as Meno’s Paradox of Inquiry, due its apparently containing an easy-to-detect equivocation of the word ‘know’. Immediately after the paradox, and in an apparent response to it, Socrates recounts a myth: a story told by priests and priestesses about the pre-natal existence and immortality of the soul. From this this myth, Socrates concocts the infamous theory of recollection – a theory according to which the soul has acquired knowledge of everything before it was born, while in a disincarnate state. According to the traditional reading of Meno’s paradox, this theory constitutes Plato’s response to it. The traditional reading has come under fire in recent years by advocates of the epistemological reading (ERM), who argue that the theory of recollection is not Plato’s intended response to the paradox. Instead, they suggest, Plato’s distinction between true belief and knowledge – which appears towards the end of the dialogue – is sufficient for solving the paradox; and as such, it ought to be read as Plato’s response to it. In this thesis, I argue against ERM’s claim that a mere epistemological distinction is all it takes to solve the paradox. To do so, I explore the metaphysics of change in Plato’s ontology. From this, I appeal to our everyday notion of ‘memory’ in order to show that Meno’s paradox, in fact, contains a hidden-premise, which when laid bare, reveals two distinct challenges contained within the argument: a superficial one, and a deeper one. I argue that although it appears at first blush as though the former could easily be dismissed as an equivocation, to which the epistemological distinction between belief and knowledge could provide an answer, the latter cannot. This is because the deeper challenge threatens the very preconditions of knowledge itself – that is to say, it renders cognition impossible – and, as such, it cancels out any effort to provide an epistemological response to the superficial challenge. Hence, unless the deeper-level challenge is satisfactorily disarmed, both challenges remain unanswered. I argue that although the major motivation for the theory of recollection in the Meno is indeed to provide an answer to scepticism about knowledge, nevertheless, it ought to be understood, first, as a theory of cognition – i.e. as a theory about the preconditions and atomic building blocks of knowledge – and not a theory of knowledge per se. This answer comes in the form of a radical theory of the mind and cognition – one that stands in stark opposition to our common-sense views about the mind: a view from which, Plato believed, the paradox arises. Drawing on recent debates between Nativists and Empiricists in the Cognitive Sciences, I argue that it was a great achievement of Plato’s to grasp that our common-sense view about the mind, and its concomitant process of learning, language acquisition and knowledge acquisition, might in fact be at the very root of scepticism about our ability to engage in meaningful philosophical practice, and our ability to acquire objective knowledge – especially, objective moral knowledge. The Meno’s paradox, then – so I contend - is not a puzzle whose solution rests upon merely pointing to an epistemological distinction between true belief and knowledge, as advocates of ERM have suggested. Rather, it is a puzzle about cognition. More precisely, it is a puzzle that targets the rudimentary cognitive stages of initial cognition and truth-recognition - one whose solution entails offering an account of the mind that would make these elementary cognitive processes possible. Accordingly, Plato’s theory of recollection in the Meno ought to be read as an attempt to map the structure of the mind, and as such, to provide an account of cognition. In doing so, he intended to put forward a view about the preconditions of knowledge – the sort of preconditions without which language acquisition and knowledge acquisition would simply not be possible. With this theory, Plato has the beginnings of an argument against the kind of relativism and scepticism prevalent at his time. As such, a correct interpretation of the so-called paradox of inquiry (and Plato’s proposed solution to it via the theory of recollection) should approach it as a puzzle about mind and cognition – and not solely as an epistemological one, as it has previously been treated.
122

Appealing to intuitions

Langkau, Julia January 2013 (has links)
This thesis is concerned with the ontology, epistemology, and methodology of intuitions in philosophy. It consists of an introduction, Chapter 1, and three main parts. In the first part, Chapter 2, I defend an account of intuitions as appearance states according to which intuitions cannot be reduced to beliefs or belief-like states. I argue that an account of intuitions as appearance states can explain some crucial phenomena with respect to intuitions better than popular accounts in the current debate over the ontology of intuitions. The second part, Chapters 3 to 5, is a reply to Timothy Williamson's (2004, 2007) view on the epistemology and methodology of intuitions. The practice of appealing to the fact that we have an intuition as evidence from thought experiments has recently been criticised by experimental philosophers. Williamson argues that since thought experiments reliably lead to knowledge of the content of our intuition, we can avoid this criticism and the resulting sceptical threat by appealing to the content of the intuition. I agree that thought experiments usually lead to knowledge of the content of our intuition. However, I show that appealing to the fact that we have an intuition is a common and useful practice. I defend the view that for methodological reasons, we ought to appeal to the fact that we have an intuition as initial evidence from thought experiments. The third part, Chapter 6, is devoted to a paradigm method involving intuitions: the method of reflective equilibrium. Some philosophers have recently claimed that it is trivial and could even accommodate scepticism about the reliability of intuitions. I argue that reflective equilibrium is not compatible with such scepticism. While it is compatible with the view I defend in the second part of the thesis, more specific methodological claims have to be made.
123

Maximising expected value under axiological uncertainty : an axiomatic approach

Riedener, Stefan January 2015 (has links)
The topic of this thesis is axiological uncertainty - the question of how you should evaluate your options if you are uncertain about which axiology is true. As an answer, I defend Expected Value Maximisation (EVM), the view that one option is better than another if and only if it has the greater expected value across axiologies. More precisely, I explore the axiomatic foundations of this view. I employ results from state-dependent utility theory, extend them in various ways and interpret them accordingly, and thus provide axiomatisations of EVM as a theory of axiological uncertainty. Chapter 1 defends the importance of the problem of axiological uncertainty. Chapter 2 introduces the most basic theorem of this thesis, the Expected Value Theorem. This theorem says that EVM is true if the betterness relation under axiological uncertainty satisfies the von Neumann-Morgenstern axioms and a Pareto condition. I argue that, given certain simplifications and modulo the problem of intertheoretic comparisons, this theorem presents a powerful means to formulate and defend EVM. Chapter 3 then examines the problem of intertheoretic comparisons. I argue that intertheoretic comparisons are generally possible, but that some plausible axiologies may not be comparable in a precise way. The Expected Value Theorem presupposes that all axiologies are comparable in a precise way. So this motivates extending the Expected Value Theorem to make it cover less than fully comparable axiologies. Chapter 4 then examines the concept of a probability distribution over axiologies. In the Expected Value Theorem, this concept figures as a primitive. I argue that we need an account of what it means, and outline and defend an explication for it. Chapter 5 starts to bring together the upshots from the previous three chapters. It extends the Expected Value Theorem by allowing for less than fully comparable axiologies and by dropping the presupposition of probabilities as given primitives. Chapter 6 provides formal appendices.
124

Belief, rationality, and truth

Ziska, Jens Dam January 2015 (has links)
Modern philosophy is often said to privilege rationality over received wisdom, but to some extent this is an ideal which we pursue under a measure of uncertainty. It is not always obvious what rationality requires. Nor is it clear how rationality is to be traded against other ideals. This dissertation seeks to clarify both questions as they pertain to the rationality of belief. The choice of topic is apposite, since many argue that the case of belief illustrates that what is rational and what there is most reason to do is one and the same thing. In particular, so-called evidentialists often argue that to believe what the evidence indicates is both to believe rationally and to believe what one has most reason to believe, since (i) rationality consists in responding to reasons, and (ii) only evidence that p can be a reason to believe that p. My first objective is to challenge this thesis. I do so by arguing that the class of reasons that rationalise a belief does not coincide with the class of reasons there are to have the belief all things considered. To equate the two classes would be to conflate the psychological issue of how we respond to reasons with the ontological issue of what reasons there are. My case against evidentialism does not depend on pragmatism being true, however. Even if Pascal was wrong to claim that the expected benefit of believing can be a reason to believe, it does not follow that evidentialism is true. Some non-pragmatic form of anti-evidentialism may still be true. The latter half of the dissertation explores this possibility in greater detail. There I argue that there is at least one class of beliefs which is not subject to common evidentiary strictures. When we use practical reasoning to form intentions about what to do in the future, we typically also form beliefs about what we will do. Yet, those beliefs are not based on evidence about what we will do, I argue. Typically, we do not predict what we do based on what we intend to do. Nor should we. When it is up to us whether we will perform an action, our intentions do to not carry enough weight as evidence that we must use them to predict what we will do. In the last part of the dissertation, I use this point to elucidate how we acquire self-knowledge and how belief relates to truth.
125

Achieving the standard for the analytical scope and sensitivity of forensic toxicology urine testing in drug facilitated crime investigations via laminar flow tandem mass spectrometry

McManus, Kelsey Lynn 23 November 2021 (has links)
Drug-facilitated sexual assaults are a public health and safety concern. Liquid chromatography paired with tandem mass spectrometry is theoretically capable of detecting the scope of drugs commonly encountered in these types of cases. An analytical method was developed for the quantitative analysis of 40 drugs designated by Academy Standards Board 121 “Standard for the Analytical Scope and Sensitivity for Forensic Toxicological Testing of Urine in Drug Facilitated Crime” (ASB 121). The targeted analytes spanned a range of drug classes including antidepressants, antihistamines, barbiturates, benzodiazepines, cannabinoids, stimulants, and opioids. The final method utilized supported liquid extraction, followed by liquid chromatography tandem mass spectrometry with electrospray ionization in simultaneous positive and negative mode. Multiple reaction monitoring allowed quantification of analytes along with stable isotope internal standards. Validation parameters assessed included linearity, bias, precision, limit of detection, lower limit of quantitation, interference, and ion suppression or enhancement. The utilized sample preparation method was able to extract 36 of the 40 target analytes and the developed analytical method was able to detect and quantify all analytes to the sensitivities required by ASB 121.
126

Multiple Binding Sites for [<sup>125</sup>I]RTI-121 and Other Cocaine Analogs in Rat Frontal Cerebral Cortex

Boja, J. W., Carroll, F. I., Vaughan, R. A., Kopajtic, T., Kuhar, M. J. 01 September 1998 (has links)
In an effort to identify novel binding sites for cocaine and its analogs, we carried out binding studies with the high-affinity and selective ligand [125I]RTI-121 in rat frontal cortical tissue. Very low densities of binding sites were found. Saturation analysis revealed that the binding was to both high- and low-affinity sites. Pharmacological competition studies were carried out with inhibitors of the dopamine, norepinephrine, and serotonin transporters. The various transporter inhibitors inhibited the. binding of 15 pM [125I]RTI-121 in a biphasic fashion following a two-site binding model. The resultant data were complex and did not suggest a simple association with any single transporter. Correlational analysis supported the following hypothesis: [125I] RTI-121 binds to known transporters and not to novel sites; these include dopamine, norepinephrine, and serotonin transporters. Immunoprecipitation of transporters photoaffinity labeled with [125]RTI-82 and subsequent analysis of SDS-page gels revealed the presence of authentic dopamine transporters in these samples; displacement of the photoaffinity label occurred with a typical dopamine transporter pharmacology. These data are compatible with the binding properties of RTI- 121 and the presence of several known transporters in the tissue studied.
127

Comportement mécanique du bois d'érable à sucre en conditions d'humidité relative constantes et variables

Segovia Abanto, Franz 18 April 2018 (has links)
Le comportement mécanique du bois dépend fortement de la température, de la teneur en humidité, de la géométrie de la pièce, ainsi que de l’historique de sorption. Il est alors indispensable de caractériser le comportement du bois sous l’action mixte de la température, de l’humidité relative et d’une charge mécanique pour en prédire le comportement durant l’utilisation et pour mieux maîtriser les procédés de transformation et également obtenir un matériau pouvant répondre à des besoins bien spécifiques. L’objectif de cette étude a été de déterminer le comportement viscoélastique et mécanosorptif du bois d’érable à sucre (Acer saccharum Marsh.), en utilisant des essais de fluage-recouvrance sous conditions d’humidité relative constantes et variables. Les essais de fluage-recouvrance ont été réalisés sur des échantillons de bois d’érable à sucre (Acer saccharum Marsh.), de 110 mm de longueur (R), 25 mm de largeur (T) et 7 mm d’épaisseur (L). Des essais ont été réalisés dans un environnement contrôlé à 30°C ± 0,5°C de température et à 37%, 67% et 83% ± 2% d’humidité relative pour les essais en conditions constantes et entre 37% et 83% d’humidité relative pour les essais en conditions variables. Les essais ont été réalisés sous différents niveaux de charge appliquée. Ils ont permis de mesurer simultanément la déformation superficielle en utilisant des jauges électriques et la flèche maximale en utilisant des capteurs de déplacement. Les résultats ont montré l’impact des niveaux de charge et de la teneur en humidité d’équilibre sur le fluage du bois. Les résultats ont aussi confirmé le comportement linéaire viscoélastique du fluage du bois et la présence de l’effet mécanosorptif pendant les changements d’humidité relative. Les résultats obtenus peuvent aider à mieux comprendre le comportement des planchers de bois d’érable à sucre pendant leur utilisation.
128

Revêtements nanocomposites UV-Aqueux pour le bois à usage intérieur

Sow, Caroline 16 April 2018 (has links)
L’objectif principal de cette recherche consistait à étudier l’influence de nanoparticules d’alumine et de silice sur les propriétés de revêtements nanocomposites UV-aqueux de type vernis pour les produits du bois. Les propriétés mécaniques (résistance à l’abrasion, dureté, résistance aux égratignures, résistance à l’impact et adhésion), optiques (brillance et couleur) et thermiques (stabilité thermique et température de transition vitreuse) ont été analysées et comparées à celles du vernis de référence ne contenant pas de nanoparticules. L’ajout de nanoparticules d’alumine et de silice a permis d’améliorer non seulement la résistance aux égratignures mais également l’adhésion des vernis nanocomposites. Cependant, la présence d’agrégats de nanoparticules, comme l’a démontré l’imagerie par microscopie électronique en transmission (MET), a entraîné une diminution des propriétés de résistance à l’abrasion, de dureté et de résistance à l’impact. Comme on pouvait s’y attendre, la présence des agrégats de nanoparticules, qui augmentent la rugosité de surface des vernis nanocomposites, a réduit la brillance des vernis bien que les propriétés de couleur n’aient pas changées en termes de clarté et de jaunissement. L’étude de la méthode de dispersions aux ultrasons a permis de mettre en évidence l’efficacité de cette technique de dispersion. En effet, la dispersion des nanoparticules d’alumine et de silice dans la matrice polyuréthanne-acrylate (PUA) au moyen des ultrasons a permis de réduire non seulement la taille des agrégats mais également leur quantité. De plus, l’amélioration de la dispersion des nanoparticules a permis d’améliorer les propriétés de dureté et de résistance à l’impact des vernis nanocomposites comparativement aux vernis à base de nanoparticules dispersées au mélangeur à haute vitesse. Les ultrasons ne présentent pas que des avantages puisque l’analyse des propriétés thermiques a démontré que cette méthode de dispersion pouvait altérer la résine PUA. L’étude de la cinétique de cuisson au moyen de la photocalorimétrie différentielle à balayage (photo-DSC) a permis de mettre en évidence deux avantages remarquables des revêtements UV-aqueux : la cuisson UV est très rapide, en 18s la réaction est complète et contrairement aux revêtements UV 100% solides, la photopolymérisation est insensible à la présence d’oxygène dans l’air malgré la formation de radicaux libres au cours de la réaction. L’analyse des courbes exothermes, obtenues par photo-DSC, a démontré que la présence des nanoparticules diminuait l’efficacité de la photopolymérisation des vernis nanocomposites. Enfin, il a été démontré que le profil cinétique des vernis nanocomposites UV-aqueux étudiés pouvait être décrit à l’aide d’un modèle autocatalytique. L’étude du comportement des nanoparticules de silice a permis de souligner l’importance de la modification de surface. En effet, le greffage de groupements méthacryloxypropyltriméthoxysilane (MEMO) à la surface des nanoparticules de silice a permis non seulement de réduire la taille et la quantité des agrégats de nanosilice mais également d’augmenter le nombre de fonctions acrylates réactifs pouvant participer à la réaction de polymérisation radicalaire. En conséquence, la dispersion des nanoparticules de silice était meilleure que celle des nanoparticules d’alumine et les vernis à base de nanosilice présentaient globalement de meilleures propriétés que les vernis à base de nanoalumine. / This research aimed to study the effect of alumina and silica nanoparticles on the properties of varnishes type UV-waterborne nanocomposite coatings for wood products. Mechanical (abrasion resistance, hardness, scratch resistance, impact resistance and adhesion), optical (gloss and color) and thermal (thermal stability and glass transition temperature) properties were analyzed and compared to those of the neat varnish containing no nanoparticles. Not only was the scratch resistance improved following the addition of nanoparticles but also the adhesion of nanocomposite varnishes. However, the presence of nanoparticle aggregates as suggested by transmission electron microscopy (TEM) led to a decrease of the abrasion resistance, the hardness and the impact resistance. As expected, the gloss of varnishes was reduced because of the presence of aggregates which increase the surface roughness of nanocomposite varnishes, although color properties remained unchanged in terms of lighting and yellowing. Ultrasonication was shown to be an efficient dispersion method. Not only did the size of aggregates decrease following the dispersion of nanoalumina and nanosilica in polyurethane-acrylate (PUA) by means of ultrasounds but also their number. Moreover, the improvement of nanoparticle dispersion led to improve the hardness and the impact resistance of nanocomposite varnishes in comparison to varnishes based on nanoparticles dispersed with high speed mixer. Also, ultrasonication presents some disadvantage as thermal properties have demonstrated that ultrasounds could affect PUA resin. Curing kinetic study by means of photodifferential scanning calorimetry (photo-DSC) demonstrated two interesting advantages of UV-waterborne coatings: UV-curing is very fast as the reaction is achieved after 18s and contrary to high solid content UV-coatings, photopolymerization is insensitive to oxygen in spite of free-radical formation during the reaction. The decrease of exothermic curves, obtained from photo-DSC, revealed that the addition of nanoparticles reduced the photopolymerization efficiency of nanocomposite varnishes. Finally, it has been demonstrated that the kinetic profile of nanocomposite varnishes could be described using an autocatalytic model. The importance of surface modification was demonstrated with the study of nanosilica behavior. Not only did the amount and the size of nanosilica aggregates decrease following grafting methacryloxypropyltrimethoxysilane (MEMO) groups on the surface of silica nanoparticles but also the number of reactive acrylates functions which can take part in the free-radical polymerization. As a result, the dispersion of silica nanoparticles was better than the one of alumina nanoparticles and nanocomposite varnishes containing nanosilica presented better properties in comparison to nanocomposite varnishes containing nanoalumina dispersed with high speed mixer.
129

Détermination de la ligne des hautes eaux dans le cadre de l'application de la Politique de protection des rives, du littoral et des plaines inondables : le cas des petits cours d'eau non instrumentés

Messier, Frédéric 13 April 2018 (has links)
Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2006-2007 / Par souci environnemental, la Politique de protection des rives, du littoral et des plaines inondables fixe des contraintes aux propriétés riveraines québécoises. Ces contraintes sont applicables à l'intérieur de bandes de protection de largeur prédéterminée. La ligne des hautes eaux en constitue le point d'ancrage. Il s'agit d'une limite environnementale, indépendante des limites de propriété, possédant une double nature entre lesquelles il existe une corrélation. Une nature botanique basée sur les traces laissées par le passage récurrent des eaux. Une nature hydrologique-hydraulique basée sur les statistiques et la modélisation des écoulements. Pour les cours d'eau drainant de grands bassins versants, les mesures historiques de débits ou de hauteurs d'eau et les études hydrologiques-hydrauliques préexistantes fournissent une cote, directement applicable par les intervenants oeuvrant en aménagement du territoire qui ne sont ni expert en botanique, ni en hydrologie-hydraulique. Par contre, pour les petits cours d'eau non instrumentés, il n'existe aucune méthode à la fois simple, expéditive et réellement accessible pour remplir une telle tâche. En effet, lorsqu'elle est utilisée par un non-expert, la méthode botanique simplifiée proposée par le ministère du Développement durable de l'Environnement et des Parcs (MDDEP) mène à l'identification de plusieurs lignes correspondant chacune à un état significatif d'écoulement. L'incertitude sur la localisation des contraintes s'en trouve grandement affectée. Pour discriminer parmi ces lignes multiples, une relation hydrologique adaptée aux petits cours d'eau de la plaine du Saint-Laurent est établie. Cette dernière est combinée à des équations hydrauliques existantes et à des observations d'indicateurs botaniques, morphologiques et physiques au sein d'une toute nouvelle approche mixte s'appuyant sur la double nature de la limite recherchée. Afin d'évaluer les possibilités de celle-ci, elle est appliquée à neuf sites pour lesquels la cote d'élévation de la ligne des hautes eaux est préalablement connue. Les sciences géomatiques permettent d'y exploiter la complémentarité de la botanique et de l'hydrologie-hydraulique. Elles fournissent un cadre de comparaison unique : la mesure d'élévation. Elles permettent également de recueillir de façon cohérente, de stocker et d'exploiter des observations géoréféfencées de nature pourtant différentes. Au moyen de levés d'arpentage, les indicateurs-terrain et les paramètres liés à l'écoulement sont mesurés aux neuf sites. Les observations sont stockées à l'intérieur d'un fichier de coordonnées unique, puis exploitées à l'aide de logiciels DAO et COGO traditionnels afin d'examiner la corrélation existant entre les traces laissées par le cours d'eau et les modélisations hydrologiques-hydrauliques. En somme, l'addition de manipulations hydrologiques et hydrauliques permettent de réduire considérablement le nombre de lignes potentielles à considérer. D'autre part, l'étude valide ou infirme quelques relations proposées par le frère Marie-Victorin et le MDDEP quant à la position altimétrique de la limite environnementale par rapport à des indices physiques précis (par exemple les marques laissées par les glaces sur le tronc des arbres). L'utilisation de ces relations, de concert avec l'approche mixte, permet une réduction supplémentaire du domaine d'incertitude.
130

Variation morpho-physiologique des plants d'épinette blanche de différentes sources génétiques et implications pour la migration assistée

Villeneuve, Isabelle 23 April 2018 (has links)
Les semences forestières génétiquement améliorées pourraient ne plus être adaptées aux sites où elles sont destinées à cause des changements climatiques. La migration assistée figure parmi les stratégies d'adaptation proposées pour maintenir la productivité forestière et diminuer la vulnérabilité des écosystèmes. Les réponses morpho-physiologiques des plants d’épinette blanche (Picea glauca (Moench) Voss) issus de huit vergers à graines ont été évaluées en pépinière et sur trois sites de plantation. La modélisation des courbes de croissance a montré que la hauteur des vergers méridionaux et de deuxième génération est significativement supérieure à celle des autres vergers. Un modèle à régression multiple a montré que la hauteur finale des plants était significativement corrélée aux conditions climatiques d’origine des vergers. Le verger et le site de plantation ont affecté significativement la croissance en hauteur des plants. Les résultats de la présente étude et ceux obtenus à long terme contribueront à raffiner les règles opérationnelles de transfert des semences propres à la migration assistée. / Due to climate change, genetically improved trees may no longer be adapted to the sites where they are intended to be planted. Assisted migration is a potential adaptation strategy for maintaining forest productivity and reducing vulnerability in the face of a changing climate. Morpho-physiological responses of white spruce (Picea glauca (Moench) Voss) seedlings from eight seed orchards were evaluated in a nursery and at three planting sites. The modeling of growth curves showed that the height of both the southern orchards and second generation orchards was significantly higher than the other orchards. A multiple regression model showed that the final height of the plants was significantly correlated with climatic conditions of the orchards. The orchard and the planting site significantly affected height growth of seedlings. The results of this study and those obtained over the longer term should help to refine the operational rules of seed transfer for assisted migration.

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