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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.
511

Friheten i flödet : En studie av nuflöde och frihet i Henri Bergsons filosofi

Roberntz, Tuija January 2020 (has links)
Ett av nyckelbegreppen i Henri Bergson filosofi är Nuflödet. Bergson använder nuflödet för att beskriva hur varat i tiden är konstituerat som rörligt. I denna uppsats undersöker jag vad som är frihetens plats i nuflödet genom att studera hur Bergsons tankar om de mänskliga villkoren, intuitionen, livet och evolutionen utvecklas i Tiden och den fria viljan - En studie i omedelbara medvetandefakta (1889), Intuition och intelligens – Introduktion till metafysiken (1903) samt Creative Evolution (1907). För att se intuitionens roll för friheten i Bergsons filosofi har jag gått i dialog med Gilles Deleuzes ”Intuition as a method” (Bergsonism, 1988) samt "Lecture Course on Chapter Three of Bergson's "Creative Evolution"(1960). Deleuze klargör vikten av Bergsons intuitiva metod för att nå frihet i nuflödet. För att göra en kritisk jämförelse vänder jag mig sedan till Daniela Vallega-Neus artikel "Disseminating Time: Durations, Configurations, and Chance." (2017). Denna jämförelse öppnar upp för en vidare förståelse av vad frihet inifrån nuflödet skulle kunna vara. Den möjliggör även en argumentation om dans som en alternativ metod för att uppnå frihet i nuflödet. / One of the key concepts of Henri Bergson’s philosophy is Duration. Bergson uses duration to describe how being in time is constituted as moving. In this thesis I am searching for what room there is for freedom within duration by studying how Bergson’s thoughts about human conditions, intuition, life and evolution evolve in Time and Free Will (1889), An Introduction to Metaphysics (1903) and Creative Evolution (1907). I do this in dialogue with Gilles Deleuze´s ”Intuition as a method” (Bergsonism, 1966) and “Lecture Course on Chapter Three of Bergson's "Creative Evolution"”(1960). Deleuze clarifies the importance of Bergson’s intuitive method to reach freedom in duration. To make a critical comparison I use the article "Disseminating Time: Durations, Configurations, and Chance." (2017) written by Daniela Vallega-Neu. This comparison opens up to a broader sense of how freedom within duration could be conceived. It also makes an argument for dancing as an alternative method in order to reach freedom in duration possible.
512

Role of Fasting in Caloric Restriction Improved Glucose Tolerance

Dillon, Makayla M. 23 June 2022 (has links)
No description available.
513

A Network Approach to Understanding Patterns of Coflowering in Diverse Communities

Arceo-Gómez, Gerardo, Kaczorowski, Rainee L., Ashman, Tia Lynn 01 September 2018 (has links)
Premise of research. The duration and intensity of flowering overlap among plants are the first determiners of the potential for pollinator-mediated plant-plant interactions. Yet, our ability to describe community-wide patterns of coflowering, and thus understand its impact on the structure of plant-pollinator communities, is limited. Methodology. We present a conceptual framework for how network theory can reveal structural properties that are ecologically relevant in diverse coflowering communities. Coflowering modules, in particular, may suggest that groups of species coflower more strongly (clustering) with each other than with other species (over-dispersion) in the community. Such a finding would indicate that competitive and facilitative interactions do not act alone but instead act simultaneously to mediate the assembly of coflowering communities. We illustrate our conceptual framework in four diverse coflowering communities in the serpentine seeps in northern California. Pivotal results. Our coflowering networks vary in size and degree but not in overall connectance, suggesting that both intrinsic community features (species richness) and ecological constraints (length of flowering season) play a role in mediating coflowering community structure (distribution of frequency and intensity of flowering overlap among plant species). We show, for the first time, that groups of species tend to coflower more strongly with each other than with other species in a community, supporting the idea that competition and facilitation are not mutually exclusive processes mediating coflowering community assembly. Our results show that the degree of modularity is not sensitive to the number of coflowering species within each community, suggesting that ecological factors may be more important in driving this pattern. Conclusions. Coflowering networks have the potential to advance our understanding of the causes and consequences of flowering overlap in diverse plant communities by revealing a more in-depth and novel characterization of coflowering community structure. Such characterization will allow for a better understanding of the importance of coflowering patterns in mediating the structure of plant-pollinator interactions.
514

Optimal sequential selection of a gambler assessed by the prophet

Laumann, Werner 09 March 2001 (has links)
In this thesis an optimal stopping problem related to the classical secretary problem is studied. The theory of optimal stopping represents a special branch of stochastic optimization. Here the socalled full information best choice problem with a known number of offers is generalized by maximizing the probability of selecting an r-candidate, where an offer is called r-candidate if it is not lower than the maximal offer reduced by function r. In the first part discrete time is investigated. For this optimal stopping problem to select an r-candidate an optimal stopping time is indicated, the suboptimal myopic stopping time is displayed and threshold rules are studied including asymptotic behaviour. The basis of this optimal stopping problem is displayed in a general setting where the payoff depends on the prophet´s choiceand on the maximal offer, i.e. the value of the prophet. As a further application the mean of the ratio of the gambler´s choice and prophet´s value is investigated. Then in the second part offers arrive in continuous time. Offers are presented according to random arrival times and the horizon terminating the period of choosing is taken to be fixed and random. Here stress is layed on the geometric and on the exponential distribution, i.e. the Poisson process. In the final part the optimal stopping problem of maximizing the duration of owning a sufficiently good offer is applied to the concept of an r-candidate. A distinction between an overall and a temporary r-candidate is made. The duration of owning an r-candidate is investigated for a finite number of offers with regard to recall. The duration problem with discounted epochs is resolved. Finally the duration of owning an r-candidate is considered regarding the Poisson process where the horizon is fixed and exponentially distributed.
515

A Hydrological Framework for Geo-referenced Steady-State Exposure Assessment in Surface Water on the Catchment Scale

Wissing, Jutta 30 September 2010 (has links)
The major benefit of geo-referenced exposure modelling tools is the provision of spatially distributed information on expected environmental concentrations. This allows for identifying local and regional concentration differences in the environment which facilitates the development of efficient mitigation strategies. Predicted substance concentrations in the environment are governed by emission rates and representation of the substances' transport and transformation processes on the one hand and by the description of the spatial environmental heterogeneity and temporal variability on the other hand. The shape of river basins and streamflow variability within them is a product of physiographic and climatic factors like e. g. topography, land use, precipitation, or evapotranspiration. These factors are very variable in space and time. This heterogeneity in river basins may have an impact on surface water concentrations of various substances. In this work a hydrological framework for geo-referenced exposure assessment in river networks has been developed which predominantly addresses spatial heterogeneity of river basins. The theoretical background for parameterising a river network for the application of GREAT-ER (Geo-referenced Regional Exposure Assessment Tool for European Rivers) is elaborated and implemented. Quantity of discharge, flow velocity of river water and depth of river bed have to be determined at any location in a river network for the representation of substance dilution, transport and degradation. Temporal variability is handled by a probabilistic approach which demands choice and parameterisation of probability distribution functions to describe the river network characteristics. It is substantiated that discharge and its variation can be described by a lognormal probability distribution. This distribution can be parameterised by spatially distributed information on effective precipitation and specific low flow discharge from the German Hydrological Atlas. Geoprocessing methods are applied to couple information from these maps and the river network. Evaluation of discharge probability distributions by means of gauging data demonstrates good agreement. River depth and flow velocity are estimated on the basis of spatially distributed river structure data and therefore account for actual river morphology more than former approaches do. A comparison with hitherto used flow velocity and depth estimation shows significant differences which trigger perceivable differences in surface water concentration estimates. Identification of the sensitivity of hydrological parameters in terms of chemical fate estimation attaches importance to spatial explicit consideration of river networks. The main benefit of the presented methods is comprehensive incorporation of geo-referenced river basin characteristics into the data basis for the GREAT-ER model because this provides the basis for successful prediction of surface water concentrations by GREAT-ER.
516

Bridging Grammar and Speech Acoustics: Effects of Morpheme Status on Duration and Center of Gravity

Ebert, Rebecca L. 27 May 2021 (has links)
No description available.
517

Ereignisbezogene Veränderungen der visuellen Fixationsdauer

Pannasch, Sebastian 09 October 2003 (has links)
Der Ansatz der Arbeit lässt sich auf zwei Gebiete aus der Blickbewegungsforschung zurückführen. Einerseits basieren die Studien auf Experimenten zum remote distractor effect, andererseits auf Untersuchungen beim Lesen bzw. der Wahrnehmung komplexer Szenen. Innerhalb beider Ansätze findet eine Analyse der Auswirkungen unterschiedlichen Reizmaterials (z.B. Texte oder Bilder) auf die Fixationsdauer statt. Aktuelle Erklärungsansätze werden im Bezug zu den gefundenen Ergebnissen dargestellt und kritisch bewertet. Anhand der Ergebnisse einer Voruntersuchung wird vorgeschlagen, die gefundenen Effekte im Rahmen der Orientierungsreaktion (OR) zu betrachten. In einer Serie von vier Untersuchungen wird dargelegt, dass die Dauer von Fixationen auch durch externe Ereignisse moduliert wird. In der ersten Untersuchung wurden die zeitlichen Aspekte des Distraktoreffekts untersucht. Dafür erschienen Distraktoren mit verschiedenen Latenzen nach Fixationsbeginn. Zusätzlich wurde untersucht, welche Auswirkungen unterschiedliche Distraktormodalitäten (visuell und akustisch) zeigen. Die Ergebnisse demonstrierten eine deutliche Verlängerung der jeweils vom Distraktor betroffenen Fixation für alle Latenzen. Für Distraktoren beider Modalitäten zeigte sich eine vergleichbare Verlängerung betroffener Fixationen. Bei der zweiten Untersuchung wurde für visuelle Distraktoren geprüft, inwieweit sich die vorgeschlagene Interpretation im Rahmen der OR bestätigen lässt. Dafür wurde der Effekt hinsichtlich einer Habituation untersucht. Für die Studie wurden Distraktoren mit zwei verschiedenen Latenzen auf umweltbezogenen vs. retinal fixierten Koordinaten präsentiert. Die Ergebnisse zeigten, dass eher Störungen auf gleichen retinalen Positionen eine Abnahme des Effektes zur Folge haben (also habituieren). Für Distraktoren auf konstanten Bildpositionen konnte keine systematische Abnahme des Distraktoreffektes gemessen werden. Für die dritte Untersuchung wurden Augenbewegungen und blickkontingente ereigniskorrelierte Potentiale (EKP?s) parallel aufgezeichnet. Bisher liegen keine Erkenntnisse vor, wie anhand von Parametern der Augenbewegungen Habituation nachweisbar ist, die Abnahme der N1-Komponente der EKP?s hingegen gilt als etablierter Nachweis einer Habituation. Die Ergebnisse zeigten, neben der Verlängerung der Fixationsdauer für visuelle und akustische Distraktoren, eine deutliche Auswirkung auf die N1-Komponente. Bei der Prüfung der Habituation über die betrachteten Bilder zeigte sich eine Verringerung des Effektes in der Fixationsdauer und der N1-Komponente. Auf Schwierigkeiten in Bezug auf den Nachweis einer ausgeprägten Habituation wurde an entsprechender Stelle hingewiesen. Die letzte Studie (N=1) testete, ob sich die Neuinterpretation des Effektes mit neurophysiologischen Erkenntnissen vereinbaren lässt. Bei dem Probanden wurde aufgrund eines Unfalls eine Schädigung des frontalen Augenfeldes (FEF) angenommen. Es wurden Distraktoren links, rechts, ober- und unterhalb des Fixationsorts dargeboten. Beim ersten Versuch, 12 Monate nach dem Unfall, zeigte sich für Distraktoren links des Fixationsortes keinerlei Verlängerung der betroffenen Fixationen. Beim zweiten Versuch, acht Monate später, zeigte sich der Distraktoreffekt auf allen Positionen. Dies lässt sich als Unterstützung der Annahme einer Schädigung der FEF interpretieren, da sich in verschiedenen Studien selbst bei operativer Entfernung der FEF eine deutliche Verringerung der entstandenen Defizite nach einigen Wochen zeigte. Mögliche Alternativen der dargestellten Interpretation wurden an entsprechender Stelle diskutiert. Diese Untersuchungen bestätigen, dass sich ereignisbezogene Verlängerungen der visuellen Fixationsdauer mit dem Rahmenkonzept der OR in Verbindung bringen lassen. Es gilt jedoch zu berücksichtigen, dass eine Reihe weiterer Einflussfaktoren an der Modulation des Effektes beteiligt sind, obwohl es sich offenbar um eine Reaktion subkortikalen Ursprungs handelt.
518

Assessing Visual Attention Methods in Video Games : A Comparative Study of Effectiveness and Colorblind Accessibility

Lindkvist, Joaquin January 2023 (has links)
Background. Visual attention in video games is a relatively underdeveloped field, especially so when it comes to colorblind accessibility. According to recent research, there is an increased social demand for options to alleviate problems colorblind individuals experience in video games. Finding simple and effective ways to achieve visual attention, which work well for both colorblind individuals and non-colorblind individuals simultaneously, would therefore be beneficial to the video game industry. Objectives. The objectives of this thesis were to analyze the effectiveness of three already utilized methods for achieving visual attention in video games and how their effectiveness differs when seen from a trichromatic or dichromatic perspective. The selected methods are animation, color, and outline. These are commonly used in video games, not only for the sake of attention but also for design in general. By testing each method individually and combined with color it is possible to analyze their effectiveness and how it differs when seen from different color perspectives. Methods. In order to gather the data required, an eye-tracking experiment with a sample size of 20 participants was conducted. The experiment showed scenes consisting of either a control background or game-inspired background. The scenes contained two objects which had color, animation, outline, animation combined with color, or outline combined with color applied to them. This experiment was performed on campus, so the primary group tested were students. The eye-tracker analyzed the participant's eye movements and together with areas of interest, it provided two different metrics: time to first fixation and total fixation duration. Results. The results of the experiment show that animation was the best-performing method for achieving visual attention in a video game regardless of which colorblind perspective it was seen from, both in terms of time to first fixation and total fixation duration. Out of red, green, blue, and yellow which were the colors tested, yellow was the best-performing color in terms of average time to first fixations and total fixation duration across all colorblind perspectives. However, green was the most consistent color from all perspectives. Conclusions. The eye-tracking method used for gathering the data provided good results. Out of animation, color, and outline, animation was substantially better at achieving visual attention compared to the other two methods. A noticeable difference in attention can also be found depending on what chromatic perspective the scenes were viewed from. This thesis serves as a way to raise awareness about visual attention in video games, and examples of how the results can be utilized are provided. The experiment could be used as inspiration for future work within the field, where a larger sample size and more methods for achieving visual attention could be tested.
519

Discrete-time crossing-point estimation for switching power converters

Smecher, Graeme. January 2008 (has links)
No description available.
520

Reliability Assessment of a Power Grid with Customer Operated Chp Systems Using Monte Carlo Simulation

Manohar, Lokesh Prakash 01 January 2009 (has links) (PDF)
This thesis presents a method for reliability assessment of a power grid with distributed generation providing support to the system. The distributed generation units considered for this assessment are Combined Heat and Power (CHP) units operated by individual customers at their site. CHP refers to the simultaneous generation of useful electric and thermal energy. CHP systems have received more attention recently due to their high overall efficiency combined with decrease in costs and increase in reliability. A composite system adequacy assessment, which includes the two main components of the power grid viz., Generation and Distribution, is done using Monte Carlo simulation. The State Duration Sampling approach is used to obtain the operating history of the generation and the distribution system components from which the reliability indices are calculated. The basic data and the topology used in the analysis are based on the Institution of Electrical and Electronics Engineers - Reliability Test System (IEEE-RTS) and distribution system for bus 2 of the IEEE-Reliability Busbar Test System (IEEE-RBTS). The reliability index Loss of Energy Expectation (LOEE) is used to assess the overall system reliability and the index Average Energy Not Supplied (AENS) is used to assess the individual customer reliability. CHP reliability information was obtained from actual data for systems operating in New England and New York. The significance of the results obtained is discussed.

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