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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.
31

Etude expérimentale de la microstructure et des propriétés électriques et optiques de couches minces et de nanofils d'oxydes métalliques (d­­­­­­-Bi­2O3 et ZnO) synthétisés par voie électrochimique / Experimental study on the microstructure and the physical properties of the metallic oxide thin films and nanowires (delta-Bi­2O3 and ZnO) synthesized by electrodeposition

Laurent, Kévin 08 July 2008 (has links)
L’intérêt porté sur la miniaturisation des systèmes par la communauté scientifique est grand, que ce soit pour des raisons de mobilité, d’économie d’énergie ou d’innovation technologique. L’objectif de cette thèse est de déterminer les caractéristiques physiques et structurales des couches minces et des nanofils d’oxydes métalliques synthétisés par la méthode électrochimique. La première partie de cette thèse est consacrée à l’oxyde de bismuth en phase delta. Les couches minces élaborés par électrochimie sont de très bonne qualité cristalline, et seul la phase delta- Bi2O3 est présente. Le caractère nano structuré des couches minces est mis en évidence par les expériences de microscopie électronique en transmission (MET) et participe à la stabilisation de cette phase à température ambiante. Les mesures de conductivité réalisées par spectroscopie d’impédance complexe montrent un comportement différent selon la nature du substrat utilisé. Nous observons une excellente conductivité électrique des dépôts réalisés sur les substrats en argent doré (4·10-3 S·cm-1), alors que les dépôts obtenus sur l’inox montre un comportement très résistif (10-7 S·cm-1). La seconde partie de cette étude concerne l’oxyde de zinc. Les conditions d’élaboration par électrochimie influence les propriétés structurales et physiques des couches minces obtenues. Les différents traitements thermiques réalisés sur les couches minces de ZnO ont permis d’améliorer la qualité optique des couches et de modifier la structure du ZnO par incorporation d’azote lors de recuit dans l’ammoniaque. La dernière partie est consacrée à la synthèse et à la caractérisation de nanofils de ZnO élaborés par la méthode « template ». Cette méthode nous a permis de confiner la croissance par électrochimie dans des pores de différents diamètres. Les observations réalisés par MET et MET en Haute Résolution montrent que les nanofils obtenus sont monocristallins et de bonne qualité. Les propriétés d’émission observées en PL sont très proches des propriétés d’émission des couches minces / The growing interest towards micro and nano devices has improved in the recent years. This interest arises from the need of mobility devices, energy savings or technologic innovation. The aim of the present work is to determine structural and physical properties of electrodeposited metallic oxide thin film and nanowires. The first part of this work will treat the case of bismuth oxide in delta phase. Electrodeposition method is used to stabilized the delta phase at room temperature, structure studies revealed a good cristallinity of the films and the high purity of the deposit. The stability of delta-Bi2O3 at room temperature is probably due to the nanostructuration of the deposit which had been observed in TEM experiments. The electrical behaviour of the film different from the substrate used to perform electrodeposition. We observed an excellent electrical conductivity (4·10-3 S·cm-1) from samples deposited on gilded silver, while low conductivity of the film is observed when deposit on stainless steel (10-7 S·cm-1). The second part of this work deal with zinc oxide thin film electrodeposited from aqueous solution. The experimental conditions used to perform electrodeposition have been found to influence structural and physical properties of the electrodeposited ZnO. Thermal treatment applied to electrodeposited ZnO improve the crystal quality and annealing under NH3 atmosphere at 400°C induced the formation of Zn:N bonds in the deposit. The last part of this report is related to the fabrication of ZnO nanowires using template method. This method has allowed us to restrict the growth of the ZnO into Nanopores. Observations made using TEM and HR-TEM, shows that electrodeposited nanowires are of a good crystal quality and monocrystalline. PL experiments have revealed that the emission is very close to the emission observed for the ZnO thin film
32

"Det är pojkar överallt!" : En studie om genus och maktpositioner i barnens fria lek

Nilsson, Karin, Svensson, Malin January 2012 (has links)
Syftet med vår studie var att undersöka hur barn på förskolan upplever maktpositioner och roller i den fria leken med fokus på genus. Vi ville se om de rådande föreställningar som finns kring hur pojkar respektive flickor förväntas vara stämmer, då pojkar framställs som att ta mycket plats medan flickor kliver åt sidan. Genom både intervjuer och observationer har vi jämfört barnens uppfattningar med det vi såg i olika leksituationer. Studien utfördes på två förskolor under sammanlagt fem tillfällen. Resultaten visar att pojkarna oftast tog på sig roller som stora och starka medan flickorna intog mer lugnare roller. Genom intervjuerna framkom det att flickorna upplever att alla får bestämma när de leker. Pojkarna däremot ansåg att de hade en ledare i sina lekar. Trots detta var det flickorna som hade makten och bestämde över lekarna på förskolan, det fanns också alltid en tydlig ledare i lekarna. Ledaren var alltid en flicka i lekar där både pojkar och flickor deltog.
33

Snabbhet och precision hos det visuella korttidsminnet för randmönster och ovaler

Berbyuk, Tanya, Gjerss, Gabriel January 2010 (has links)
Den här uppsatsen handlar om korttidsminnet (arbetsminnet) och dess kapacitet att lagra och processa information. Ett perceptionsexperiment som utfördes ger en inblick i hur korttidsminnet fungerar i praktiken och innefattar randmönster och ovaler som stimuli. Responstid och precision mäts och jämförs med avseende på betingelser som position och orientering. Uppsatsens hypotes är att samma respektive olika position på stimuli har betydelse för både snabbhet och precision. Resultatet bekräftade denna hypotes. Det visade sig också att även orientering på våra stimuli har en signifikant effekt på precision. Dock finns det ingen signifikant skillnad i snabbhet eller precision med avseende på om det är ovaler eller spatial frekvens.
34

The Impact of Strategic Position on E-Broker's CRM Applications

Li, Shin-Chin 07 February 2001 (has links)
With the change of market focus from product-orientation to customer-orientation, more and more companies realize the importance of customer relationship management (CRM). Internet and emerging information technology have further made CRM easier than before to implement. In the meantime, most stockbrokers start operating electronic transactions through the Internet. Electronic stockbrokers can change traditional business operation models from focusing exclusively on few significant customers to taking care of every individual valuable customer with the latest technology developed. The purpose of this thesis is to study the relevance between CRM strategic positions and associated CRM applications based on two cases: a nationwide e-stockbroker and a regional e-stockbroker. Their strategic positions toward the CRM trend are investigated by making use of the value compass proposed by Wayland and Cole. Their CRM applications are then measured by performance indices introduced by Körner et al. Several hypotheses are proposed under careful analysis on these two cases. It shows that e-brokers¡¦ strategic positions toward CRM have impact on their CRM applications. In details, different positions on customer portfolio management will result in different levels of communication contents, added value for the customer, customer profiling, and privacy policy. Positions on value proposition design will shape the value added by relevant information and customer profiling. Confidence levels, however, may be affected by factors other than strategic positions on the value compass. Finally, the implementation of CRM will also cause changes of business organization and business culture.
35

The Study of Fitness of the New Venture's Positioning and Marketing Strategy- a Case of Springhill Hotel

Tung, Hung-Chang 03 September 2008 (has links)
Abstract During the process of marketing strategy planning and positioning in a new venture, the formation process of top management team plays an important role where it¡¦s interesting for research. However, it¡¦s the answer a new venture is eager to know that the marketing strategy and position can meet requirements of market ornot. But, it¡¦s pity the research about fitness of marketing strategy and position is very few. The Spring Hill Resort will be scheduled to be open this November, it¡¦s an issue how it creates a whole new blue ocean with past experiences of building industry. Besides, I would like to know the demands of targeted customers through queationnaires which hopefully provide more objective suggestions as references for future operation and marketing activities. The method of literatures analysis was explored to collect the meeting minutes, marketing plans, and business plans. In accordance with thrughoutly understand the whole pictures of marketing plans and positioning, the research hyposis are set up. Then The three segmentations which separately are engineers of Lu-Zu Science Park & Tainan Science Park, and consumers of Royal Resort in Jiao-Sea and Spring Resort in Jin Mountain. The 150 copies were collected by either email or direct delivery, but only 75 copies meets requirement in the thesis. The primary data were put into Minitab, and subsequently T test or ANOVA were applied to test fitness, which can be concluded as the followings. We concluded that the targeted customers significantly support the positioning and marketing strategy(p-value are all less than£\=0.05). To be analyzed with ANOVA, the groups of both 600-800 thousand dollars & above in personal annual income are indifferent in between, but below the group of below 600 thousand dollar relatively supports the above viewpoint. The entertainment expenses are minority to the low income, thus they would not like to pre-pay big deal money, but oppositely the high imcome would relatively like to do in it. Likewize, the low incomes do not support the positioning of health as strongly as the high income. But for strategy alliances with other companies, the same attractiveness does not differ from the three. Under the consideration of transportation, the accessible of destination is not so important to the targets (P=0.049<£\=0.05), due to 96% people drives to travel domestically. And this result can be applied to service of shuttle bus; they think it¡¦s not necessarily as well. In aspects of spring quality, the expectation of the targets is the same and means a lot (P=0.00<£\=0.05), and this can be taken as a prerequisite. Finally, we can find opinions of customers diversified relatively (see table 4-18), but it¡¦s a little weired that quality of room space is not so emphasized than other aspects and this can be futher discussed. Key words: marketing strategy and position, spring resort,
36

The relative difficulty of three position discriminations for persons with severe to profound developmental disabilities

Sloan, Jennifer L. 04 January 2011 (has links)
The Assessment of Basic Learning Abilities (ABLA) test, developed by Kerr, Meyerson, and Flora (1977) assesses the ease or difficulty with which individuals with developmental disabilities are able to learn a simple imitation and five two-choice discrimination tasks. During ABLA Level 2, referred to as a position discrimination task, the client is presented with a yellow can always on the left and a smaller red box always on the right. The client is required to place an irregularly shaped piece of foam into the container on the left (the yellow can) for a correct response. With this task a client can learn to make a correct response based on position, colour, shape, or size cues, or some combination of these. The current study evaluated the relative difficulty of ABLA Level 2 and two additional types of position discriminations. The first type of task was similar to ABLA Level 2, except that it used identical containers, and thus contained both relative and absolute position cues (the REAB task), but not shape, colour, or size cues. The second type of task was similar to ABLA Level 2; however, it incorporated identical containers that varied in their absolute positions, which required a relative position discrimination to arrive at the correct response (the RE task). In Experiment 1, I used an alternating-treatments design with replication within and across three participants who passed ABLA Level 2 but failed all higher levels, to examine how many trials were required to master tasks analogous to ABLA Level 2, versus REAB tasks, versus RE tasks. In Experiment 2, I used a within-subject design with replication across three participants to further clarify the relative difficulty of the three position discrimination tasks, and to determine whether correct container location (i.e. left versus right) can influence the difficulty of learning the tasks. The results demonstrated that there was no consistent difference in difficulty between the three types of tasks, and the difficulties experienced by P1 and P2 can be accounted for entirely by an interaction between the right-left location of the correct response and handedness.
37

The relative difficulty of three position discriminations for persons with severe to profound developmental disabilities

Sloan, Jennifer L. 04 January 2011 (has links)
The Assessment of Basic Learning Abilities (ABLA) test, developed by Kerr, Meyerson, and Flora (1977) assesses the ease or difficulty with which individuals with developmental disabilities are able to learn a simple imitation and five two-choice discrimination tasks. During ABLA Level 2, referred to as a position discrimination task, the client is presented with a yellow can always on the left and a smaller red box always on the right. The client is required to place an irregularly shaped piece of foam into the container on the left (the yellow can) for a correct response. With this task a client can learn to make a correct response based on position, colour, shape, or size cues, or some combination of these. The current study evaluated the relative difficulty of ABLA Level 2 and two additional types of position discriminations. The first type of task was similar to ABLA Level 2, except that it used identical containers, and thus contained both relative and absolute position cues (the REAB task), but not shape, colour, or size cues. The second type of task was similar to ABLA Level 2; however, it incorporated identical containers that varied in their absolute positions, which required a relative position discrimination to arrive at the correct response (the RE task). In Experiment 1, I used an alternating-treatments design with replication within and across three participants who passed ABLA Level 2 but failed all higher levels, to examine how many trials were required to master tasks analogous to ABLA Level 2, versus REAB tasks, versus RE tasks. In Experiment 2, I used a within-subject design with replication across three participants to further clarify the relative difficulty of the three position discrimination tasks, and to determine whether correct container location (i.e. left versus right) can influence the difficulty of learning the tasks. The results demonstrated that there was no consistent difference in difficulty between the three types of tasks, and the difficulties experienced by P1 and P2 can be accounted for entirely by an interaction between the right-left location of the correct response and handedness.
38

The molecular basis of gene expression variability in transgenic tobacco plants

Laverty, Edward January 1996 (has links)
An extensive investigation into and charactaisation of factors influencing transgene expression following introduction of the transgoie into tobacco via Agrobacterium- mediated transformation was carried out. Characterisation of material supplied at the outset of this project revealed that this material was unacceptable for further analysis. It was thus deemed necessary to obtain large populations of transgenic tobacco heterogenous for levels of transgene expression. Characterisation of these populations (CaMV-lecA and ssRubisco-lecA plants) showed that all plants fell into one of four segregation classes based on segregation of the kanamycin-resistance selectable marker. Results showed that the majority of regenerants contained multiple nptII-containing inserts, while the presence of one or two such inserts was also found, albeit at a much lower frequency. Segregation analysis based on detection of the lecA transgene agreed, in the majority of cases, with these results. However, in a few cases it was found that data obtained from both segregation analyses did not agree, with the presence of a single lecA-containing transgene being detected in plants shown to contain two copies of the nptII-contaning transgene. This result indicates the occurrence of T-DNA rearrangement either within the tobacco genome or during T-DNA transfer and integration. Southern blot analyses allowed a detailed characterisation of T-DNA structure, copy number and number of integration sites to be undertaken. Results from these analyses revealed a higher frequency of T-DNA rearrangement within plants containing multiple inserts. However, such rearrangements did not correlate with a significant reduction in levels of transgene expression since all detected rearrangements were found to occur at or towards the left hand border of the T-DNA, that border distant to the lecA transgene. Plants containing more than one T-DNA were also frequently found to contain these T-DNAs arranged as an inverted repeat at a single locus although no significant relationship between copy number and the presence of such structures was found. Correlating transgene expression levels, as determined by radioimmunoassay-based quantitation of lectin protein in tissues of transgenic plants, with T-DNA copy number, organisation and structure revealed no significant relationship. It is thus feasible to conclude that the major contributory factor influencing levels of transgene expression is the location of T-DNA integration within the plant genome. Subsequent work concerned with investigating the nature of those integration site-specific factors i.e. 'position effect' indicated a possible role for methylation-induced modulation of gene expression. Results presented in this thesis provide an insight into the fate of transgenes following introduction into the plant genome and clearly demonstrate the importance of further exploring the molecular mechanisms underlying transgene expression variability.
39

Relations entre les indicateurs socio-économiques, les événements de vie et les comportements alimentaires d’adultes français / Associations Between Socioeconomic Indicators, Life Events and Dietary Behaviours in French Adults

Si hassen, Wendy 18 October 2017 (has links)
Aujourd’hui, de fortes inégalités sociales de santé persistent entre les individus les plus favorisés socio-économiquement et ceux vivants dans des situations moins favorables, et l’alimentation y contribue fortement. Bien que les disparités sociales de nutrition soient bien documentées, notamment en ce qui concerne le niveau d’études, les connaissances relatives à l’influence indépendante des différents indicateurs socio-économiques sur l’alimentation et notamment ses dimensions comportementales sont insuffisantes. Par ailleurs, les mécanismes sous-jacents des disparités en nutrition sont encore mal compris. Parmi les déterminants individuels, nous manquons de connaissances sur l’influence du parcours de vie des individus sur leurs comportements alimentaires. Dans ce contexte, les objectifs de cette thèse étaient d’analyser les associations entre les facteurs socio-économiques et les comportements alimentaires, abordés sous différentes dimensions : apports en nutriments, prise des repas principaux, et pratiques de snacking (i.e. prises alimentaires différentes des repas principaux). Il s’agissait également d’évaluer l’influence d’événements de vie professionnels sur les comportements alimentaires. Les résultats montrent que les individus ayant la position socio-économique (PSE) la plus favorisée ont des apports plus élevés en nutriments recommandés (fibre, vitamine C, B9, magnésium, etc.). Le niveau d’éducation semble être un déterminant majeur des apports nutritionnels et modifie les associations entre revenus et apports en nutriments. Bien que les individus de PSE moins favorisée soient moins susceptibles d’avoir des prises de snacking, la qualité nutritionnelle de ces prises est moindre. Par ailleurs, le passage à la retraite est associé à des apports alimentaires moins favorables à la santé (qualité globale, lipides, sodium, acides gras saturés…), en particulier chez les hommes ayant les plus bas revenus avant la retraite (diminution de l’apport en produits laitiers et augmentation de l’apport en lipides). L’ensemble de ces résultats soulignent l’importance des déterminants socio-économiques ainsi que des événements de vie professionnels sur les comportements alimentaires et la nécessité de mieux adapter les politiques nutritionnelles de santé en fonction des sous-groupes de la population et des périodes et événements de la vie. / Strong health inequalities remain between socio-economically advantaged individuals and those of lower socioeconomic position. Diet appears to be an important modifiable factor, which contributes to health inequalities. Although social disparities in nutrition have been well documented, the independent influences of the different socioeconomic indicators on diet – in particular its behavioural dimensions – have not been deeply investigated. In addition, the pathways underlying these disparities are still poorly understood. Among individual determinants, there is a lack of knowledge regarding effects of life course on dietary behaviours.The objective of this Ph.D. thesis was to investigate the associations between socioeconomic factors and dietary behaviours, expressed in terms of nutrient intakes and snacking practices. The influence of occupational life events on dietary behaviours was also assessed.The results showed that individuals with high socioeconomic position (PSE) had higher intakes of recommended nutrients (fibre, vitamin C, folate, magnesium, etc.). Education appears to be a major determinant of dietary intakes and modifies the associations between income and dietary intakes. Although individuals with low socioeconomic position are less likely to snack, the nutritional quality of their snacks is lower. Moreover, retirement was associated with unhealthier dietary intakes (overall diet quality, lipids, sodium, saturated fatty acids,...), particularly in men with the lowest income before retirement (decrease in intake of dairy products and increase in intake of lipids).The results underline the importance of socioeconomic determinants and life events on dietary behaviours. The identification of life periods and events leading to changes in dietary behaviours enables on one hand to improve knowledge regarding pathways underlying socioeconomic inequalities in health related to nutrient and food intake, and on the other hand to determine target populations for interventions. Adapting nutritional public interventions among social subgroups of the population and throughout the entire life is key to improve dietary behaviours.
40

A Study of Constancy of Sociometric Position in Two Different Populations

Yates, James Rodney 08 1900 (has links)
The purpose of this study will be to ascertain the extent social acceptance, or social status of an individual in one population, measured sociometrically, tends to remain constant for that individual in another population.

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