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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.
91

The conformational analysis of small, flexible molecules using NMR of liquid crytalline solutions

Foord, Elizabeth Kate January 1996 (has links)
No description available.
92

Construction of hyperkähler metrics for complex adjoint orbits

Santa Cruz, Sergio d'Amorim January 1995 (has links)
No description available.
93

An investigation of the regular indirect boundary element method

Rahman, Abdul Ghaffar Abdul January 1985 (has links)
No description available.
94

Potentiell etablering av strandvegetation längs torrfåror : En pilotstudie av en modelleringsmodell för miljöanpassade flöden

Andersson, Jens January 2015 (has links)
Running water is an ecosystem that has high biodiversity despite its relatively small presence on the planet in terms of area. Water is also one of the most affected ecosystems, where hydropower is one of the actors with great impact and widespread use. Hydropower production often change the flow regime in rivers and damages, among other things, the littoral zone which is dependent on a natural flow regime. Without the natural flow regime's disturbance, the natural flora of the littoral zone is either displaced by upland vegetation, or it the zone becomes barren. One way to mitigate the negative effects of hydropower on the ecosystem are realesing water with a natural-like temporal variation in the original reaches. Reaches are often completely dry when water is redirected in to pass the turbines in the hydropower station. Previously there have been no attempts in Sweden to model the riparian potential below the dams using a theoretical environmental flow regime. This paper shows a way to inventory the potential for vegetation establishment of the riparian zone by field inventory of suitable substrate for riparian vegetation. For the inventoried locations, models of environmental flow at four levels of discharge (5, 10, 15 and 20% of the mean annual discharge) are used to predict the potetial extent of riparian vegetation. The modeling is done in ArcGIS using the "Riparian Topoghraphy Tool." The modelling show how much of the potential of water that inundates the riparian zone at varying levels of the hydropower production loss. / Rinnande vatten är ett ekosystem som har hög biodiversitet trots sin arealmässigt relativt ringa förekomst på vår jord. Vattendrag är också ett av de mest påverkade ekosytemen, där vattenkraften är en av aktörerna med stor inverkan och stor utbredning. Produktionen av vattenkraft ändrar ofta flödesregimen i vattendrag vilket slår hårt mot bland annat strandzonen, vars organismsamhällen är beroende av en naturlig flödesregim. Utan den naturliga flödesregimens störningar blir den naturliga floran i strandzonen undanträngd av annan vegetation, eller så blir strandzonen kal av för kraftiga störningar. Fåror torrläggs ofta helt då vatten leds till turbinerna i kraftverket. Ett sätt att mildra de negativa effekter vattenkraften har på ekosystemet är att tappa vatten i de ursprungliga fårorna med en tidsmässig variation liknande naturliga vattendrag. Tidigare har det inte gjorts några försök i Sverige att modellera strandzonens potential nedom dammar att hysa vegetation med hjälp av en teoretiskt miljöanpassad flödesregim. Den här rapporten visar på ett sätt att inventera potentialen för utveckling av strandzonen genom att i fält inventera lämpligt substrat för strandvegetation. För de inventerade lokalerna modelleras sedan ett miljöanpassat flöde baserad på fyra nivåer med ökande andel av årsmedelflödet (5, 10, 15 och 20 %). Modelleringarna sker i ArcGIS med hjälp av verktyget ”Riparian Topoghraphy Tool”. Modelleringarna visar hur mycket av potentialen som hamnar inom strandzonen vid olika nivåer av produktionsbortfall. / Ekologisk potential i naturfåror
95

Trapping ultracold atoms in time-averaged adiabatic potentials

Gildemeister, Marcus January 2010 (has links)
This thesis describes the trapping and manipulation of ultracold atoms in time-averaged adiabatic potentials (TAAP). The time-averaged adiabatic potential, proposed in [Phys. Rev. Lett. 99, 083001 (2007)], uses resonant radio frequency (rf) radiation to couple the different magnetic substates of a hyperfine level manifold. The resultant dressed states are time-averaged and produce smooth and versatile trapping geometries. More specifically, we apply rf-radiation (MHz) to a quadrupole magnetic field, which results in an ellipsoidal trapping potential for rubidium-87 atoms in the F=1 manifold. This geometry is time-averaged with the help of oscillating (kHz) Helmholtz fields. We develop a convenient loading scheme for the TAAP which uses a standard TOP trap and suffers negligible atom losses and heating. Subsequently we characterize the TAAP trap itself and observe low heating rates and sufficient lifetimes (>3s). Furthermore it is possible to use a second, weaker rf-field to evaporatively cool the atoms to quantum degeneracy [Phys. Rev. A. 81, 031402 (2010)]. This opens up a route for further experiments in this potential: we show how atoms can be trapped in a double well potential and a ring trap geometry. Additionally a process to instigate rotation in these potentials by rotating the polarization of the rf-radiation is developed and implemented. This allows us to impart angular momentum onto the atomic cloud and spin it into a ring.
96

Characterising action potential in virtual game worlds applied with the mind module

Eladhari, Mirjam Palosaari January 2009 (has links)
Because games set in persistent virtual game worlds (VGWs) have massive numbers of players, these games need methods of characterisation for playable characters (PCs) that differ from the methods used in traditional narrative media. VGWs have a number of particularly interesting qualities. Firstly, VGWs are places where players interact with and create elements carrying narrative potential. Secondly, players add goals, motives and driving forces to the narrative potential of a VGW, which sometimes originates from the ordinary world. Thirdly, the protagonists of the world are real people, and when acting in the world their characterisation is not carried out by an author, but expressed by players characterising their PCs. How they can express themselves in ways that characterise them depend on what they can do, and how they can do it, and this characterising action potential (CAP) is defined by the game design of particular VGWs. In this thesis, two main questions are explored. Firstly, how can CAP be designed to support players in expressing consistent  characters in VGWs? Secondly, how can VGWs support role-play in their rule-systems? By using iterative design, I explore the design space of CAP by building a semiautonomous agent structure, the Mind Module (MM) and apply it in five experimental prototypes where the design of CAP and other game features is derived from the MM. The term semiautonomy is used because the agent structure is designed to be used by a PC, and is thus partly controlled by the system and partly by the player. The MM models a PC's personality as a collection of traits, maintains dynamic emotional state as a function of interactions with objects in the environment, and summarises a PC's current emotional state in terms of `mood'.   The MM consists of a spreading-activation network of affect nodes that are interconnected by weighted relationships.  There are four types of affect node: personality trait nodes, emotion nodes, mood nodes, and sentiment nodes. The values of the nodes defining the personality traits of characters govern an individual PC's state of mind through these weighted relationships, resulting in values characterising for a PC's personality. The sentiment nodes constitute emotionally valenced connections between entities. For example, a PC can `feel' anger toward another PC. This thesis also describes a guided paper-prototype play-test of  the VGW prototype World of Minds, in which the game mechanics build upon the MM's model of personality and emotion. In a case study of AI-based game design, lessons learned from the test are presented. The participants in the test were able to form and communicate mental models of the MM and game mechanics, validating the design and giving valuable feedback for further development. Despite the constrained scenarios presented to test players, they discovered interesting, alternative strategies, indicating that for game design the `mental physics' of the MM may open up new  possibilities.The results of the play-test influenced the further development of the MM as it was used in the digital VGW prototype the Pataphysic Institute. In the Pataphysic Institute the CAP of PCs is largely governed by their mood. Depending on which mood  PCs are in they can cast different `spells', which affect values such as mental energy, resistance and emotion in their targets. The mood also governs which `affective actions' they can perform toward other PCs and what affective actions they are receptive to. By performing affective actions on each other PCs can affect each others' emotions, which - if they are strong - may result in sentiments toward each other. PCs' personalities govern the individual fluctuations of mood and emotions, and define which types of spell PCs can cast. Formalised social relationships such as friendships affect CAP, giving players more energy, resistance, and other benefits. PCs' states of mind are reflected in the VGW in the form of physical manifestations that emerge if an emotion is very strong. These manifestations are entities which cast different spells on PCs in close proximity, depending on the emotions that the manifestations represent. PCs can also partake in authoring manifestations that become part of the world and the game-play in it. In the Pataphysic Institute potential story structures are governed by the relations the sentiment nodes constitute between entities.Because games set in persistent virtual game worlds (VGWs) have massive numbers of players, these games need methods of characterisation for playable characters (PCs) that differ from the methods used in traditional narrative media. VGWs have a number of particularly interesting qualities. Firstly, VGWs are places where players interact with and create elements carrying narrative potential. Secondly, players add goals, motives and driving forces to the narrative potential of a VGW, which sometimes originates from the ordinary world. Thirdly, the protagonists of the world are real people, and when acting in the world their characterisation is not carried out by an author, but expressed by players characterising their PCs. How they can express themselves in ways that characterise them depend on what they can do, and how they can do it, and this characterising action potential (CAP) is defined by the game design of particular VGWs. In this thesis, two main questions are explored. Firstly, how can CAP be designed to support players in expressing consistent  characters in VGWs? Secondly, how can VGWs support role-play in their rule-systems? By using iterative design, I explore the design space of CAP by building a semiautonomous agent structure, the Mind Module (MM) and apply it in five experimental prototypes where the design of CAP and other game features is derived from the MM. The term \textit{semiautonomy} is used because the agent structure is designed to be used by a PC, and is thus partly controlled by the system and partly by the player. The MM models a PC's personality as a collection of traits, maintains dynamic emotional state as a function of interactions with objects in the environment, and summarises a PC's current emotional state in terms of `mood'.   The MM consists of a spreading-activation network of affect nodes that are interconnected by weighted relationships.  There are four types of affect node: personality trait nodes, emotion nodes, mood nodes, and sentiment nodes. The values of the nodes defining the personality traits of characters govern an individual PC's state of mind through these weighted relationships, resulting in values characterising for a PC's personality. The sentiment nodes constitute emotionally valenced connections between entities. For example, a PC can `feel' anger toward another PC. This thesis also describes a guided paper-prototype play-test of  the VGW prototype World of Minds, in which the game mechanics build upon the MM's model of personality and emotion. In a case study of AI-based game design, lessons learned from the test are presented. The participants in the test were able to form and communicate mental models of the MM and game mechanics, validating the design and giving valuable feedback for further development. Despite the constrained scenarios presented to test players, they discovered interesting, alternative strategies, indicating that for game design the `mental physics' of the MM may open up new  possibilities.The results of the play-test influenced the further development of the MM as it was used in the digital VGW prototype the Pataphysic Institute. In the Pataphysic Institute the CAP of PCs is largely governed by their mood. Depending on which mood  PCs are in they can cast different `spells', which affect values such as mental energy, resistance and emotion in their targets. The mood also governs which `affective actions' they can perform toward other PCs and what affective actions they are receptive to. By performing affective actions on each other PCs can affect each others' emotions, which - if they are strong - may result in sentiments toward each other. PCs' personalities govern the individual fluctuations of mood and emotions, and define which types of spell PCs can cast. Formalised social relationships such as friendships affect CAP, giving players more energy, resistance, and other benefits. PCs' states of mind are reflected in the VGW in the form of physical manifestations that emerge if an emotion is very strong. These manifestations are entities which cast different spells on PCs in close proximity, depending on the emotions that the manifestations represent. PCs can also partake in authoring manifestations that become part of the world and the game-play in it. In the Pataphysic Institute potential story structures are governed by the relations the sentiment nodes constitute between entities.
97

Městský cestovní ruch v regionálním centru na příkladu města Plzně / Urban tourism in a regional centre Plzeň as a case study

Koutenková, Zuzana January 2012 (has links)
URBAN TOURISM IN A REGIONAL CENTRE PLZEŇ AS A CASE STUDY Abstract The main themes of this thesis are urban tourism in important regional centre Plzeň, its present situation, tourism potential and future development. The aim of this assignment is to survey tourism in Plzeň. The preamble is devoted to general problems of tourism, methods for processing and evaluation of bibliography. The content of the next chapters describes assumptions and subsequently forms of tourism and their possible future potential. During a field research questionnaire survey with accommodation operators was made, which is evaluated in several parts of this work. The final section contains an evaluation of the issue. Keywords: urban tourism, Pilsen, potential of development
98

The extent to which actual development of proportional reasoning creates conditions for potential development in Vygotsky's ZPD.

Brenner, Elisabeth Ann 03 September 2009 (has links)
This study has examined how the attainment of theoretical frameworks may create the conditions for and support subsequent learning of related material. In this regard, it has investigated a particular conception of Vygotsky‟s proposal that learning only occurs in the zone of proximal development, which he defined as the gap between what can be performed independently and what can be achieved with assistance. Specifically, it used a multi-pronged, mixed method research approach to probe the relationship between the actual level of development, as reflected by an ability to do proportional reasoning, and potential development, which was measured as the ability to perform certain strategic procedural operations in the molecular biosciences which were underpinned by proportionality. This four phase study which was carried out on a class of 106 second year students registered for Basic Molecular Biosciences II in the School of Molecular and Cell Biology, at the University of the Witwatersrand, Johannesburg, South Africa, initially measured proportional reasoning ability by posing a generative question requiring proportional reasoning to the class during a lecture and established that only 49% of the students who participated were able to answer the question. It could be shown statistically that these students were more adept at answering a contextual question based on proportion than those who had answered the generative question incorrectly, which suggested that actual development created the conditions for future learning. A paper and pencil test developed from Fleener (1993) which claimed to measure the hierarchical development of proportional reasoning ability was administered to the class and was used to select two groups for comparative purposes. The first group (group one) was comprised of the 23 students who scored 50 % or less, and the control group (group two) consisted of the 15 students who scored 100 %. Using these two groups, it was shown that the control group performed better than group one on specific questions underpinned by proportion which had been included in pre-laboratory tests and in summative assessments. Moreover, the control group‟s general performance in the course, as assessed by their marks in the examination at the end of the first semester, was substantially better than that of group one (67 % as opposed to a 51% average mark). These results were supported by findings where conceptual development of proportion had been judged from student‟s informal written accounts of the concept. Drawing on biological evidence, it was concluded that the actual level produces the structures necessary for further development. The second phase of the study utilized two focus groups constituted from students who iv had been randomly selected from the two groups compared in phase one of the research. Facilitated guided informal discussions probed which of factors like play and leisure activities, early childhood enrichment, schooling, mathematical ability and practices, instruction in proportional reasoning, and parental involvement, might have augmented the development of proportional reasoning ability. In phase three, the factors which emerged from the discussions were interrogated in a specially designed questionnaire which was administered to a sub-set of students who were concurrently registered for Basic Molecular Biosciences II and Biochemistry and Cell Biology II. Statistical analysis of the questionnaire which occurred in phase four of the research led to the conclusion that enrichment in early childhood, and having learnt proportion at school were the two factors that contributed most to attainment of the actual level of development which would enable subsequent learning of more elaborate procedural knowledge constructs based on the concept of proportion. These results supported the view that mediation results in internalisation of the embedded knowledge which can be drawn on for further learning in that domain. Therefore, in the final analysis of the research, it was concluded that actual levels of development create conditions for potential development as conceived by Vygotsky‟s zone of proximal development.
99

Do the electrophysiological correlates of recognition memory change with time?

Roberts, Jenna January 2013 (has links)
The aim of this PhD thesis was to explore the way in which recognition memory changes over time. Of particular interest was how forgetting and systems level consolidation processes alter the qualitative nature of recognition judgments and the impact this has on event related potentials (ERPs) recorded during recognition. An emerging body of fMRI and animal work has started to suggest that changes to the neural basis of memory can be observed after intervals in the order of days and weeks. Although much research has examined the ERP correlates of recent recognition, there has been little attempt to compare this to remote recognition. This gap in the literature is investigated in the present PhD thesis over five ERP and two behavioural experiments. The first set of experiments investigated recognition success i.e. the subjective awareness that a stimulus has been encountered before. Previous work has associated familiarity-based recognition with an early midfrontal ERP effect whereas recollection-based recognition has been linked to a later onsetting parietal ERP effect. These effects were compared for recently studied stimuli and stimuli studied 1 week earlier. Results revealed an attenuation of the late parietal effect. This quantitative difference suggests that the neural networks underlying the ERPs for recent and remote recollection remain the same after a 1 week delay but may be less active after a period of forgetting. Behavioural work linked this to a drop in strength and episodic detail for remote recollection. Examining the midfrontal effect over time produced a more complex pattern of results. The effect was not reliable in Experiment 1 for remote familiarity judgments. In follow up experiments, however, midfrontal effects were reliable for week old memories but were not modulated by either delay or memory strength manipulations. These findings do not permit strong conclusions regarding the way familiarity memory and midfrontal ERPs vary over time, other than to say that the midfrontal effect is not a short lived correlate of recognition memory. A second set of experiments investigated how the length of the delay between study and test impacts on retrieval orientation and retrieval effort. Retrieval orientation refers to the way in which participants strategically alter how a memory cue is processed based on current task demands. Results showed ERP differences when remote memories were cued compared to when recent memories were cued. However, these differences were eliminated when recent and remote memory was matched for performance. This finding indicated that effort required at retrieval rather than memory age per se influenced differential cue processing. A follow up experiment supported this claim but found that participants may utilise delay information during recognition in a very general sense. In this experiment, ERPs indicated different cue processing when participants knew the age of the memories they were trying to retrieve compared to when they did not. Taken together, the results suggest that memory age does not influence the ERP correlates of recognition in a direct manner. More important are the indirect changes occurring over time, such as reduced memory strength, reduced episodic detail, slower reaction times and increased effort at retrieval. These variables, and possibly a range of others, should be controlled as far as possible in studies aiming to explore neural changes driven by systems consolidation. Prospective studies, where the learning phase can be controlled makes this aim feasible, as some of the experiments in this thesis have shown. Future work might benefit from focusing more on variations at encoding, rather than large differences in the length of the retention interval, as has been the traditional approach to this issue.
100

Hodnocení potenciálu a předpokladů pro cestovní ruch regionu Blanský les - Netolicko / Evaluation of Potential and Prerequisites of Tourism for Blansky les Netolicko Region

Vačkář, Petr January 2009 (has links)
Working analytically evaluates the potential of tourism and assumptions for the region's tourism Blanský les - Netolicko. Based on theoretical knowledge of the potential, assumptions, their own evaluation and investigation, I tried to design appropriate activities based on the assumptions and the potential for tourism. Conclusions arising from work can function as a basis for management decisions MAS Blanský les - Netolicko.

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