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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

Microfluidic control systems in deep etch optical lithography

Pye, Nathan January 1999 (has links)
No description available.
32

Algal Preferences in the Masking Behaviour of the Spider Crab, Notomithrax ursus

Ertel, Catherine Monica January 2008 (has links)
The purpose of this study was to examine the masking preferences of the spider crab, Notomithrax ursus. The algal composition of the mask in the natural habitat at Kaikoura was examined to determine the general rules the crab follows when decorating itself. The effects of size and sex on the mask composition were examined, as well as determining how the composition of the mask varies by body part. The preference of the crabs was further examined through the use of choice and background change experiments in the laboratory. It was determined that the preference of certain types of algae for mask material is not entirely dependent on their relative abundance in the environment. Possible explanations for this behaviour are given.
33

Efficient Side-channel Resistant MPC-based Software Implementation of the AES

Fernandez Rubio, Abraham 27 April 2017 (has links)
Current cryptographic algorithms pose high standards of security yet they are susceptible to side-channel analysis (SCA). When it comes to implementation, the hardness of cryptography dangles on the weak link of side-channel information leakage. The widely adopted AES encryption algorithm, and others, can be easily broken when they are implemented without any resistance to SCA. This work applies state of the art techniques, namely Secret Sharing and Secure Multiparty Computation (SMC), on AES-128 encryption as a countermeasure to those attacks. This embedded C implementation explores multiple time-memory trade-offs for the design of its fundamental components, SMC and field arithmetic, to meet a variety of execution and storage demands. The performance and leakage assessment of this implementation for an ARM based micro-controller demonstrate the capabilities of masking schemes and prove their feasibility on embedded software.
34

Ljudets funktioner i filmen No Country for Old Men : En audiovisuell analys

Sundbye, Martin January 2019 (has links)
Sundbye, Martin (2019). Ljudets funktioner i filmen No Country for Old men – En audiovisuell analys. Examensuppsats inom Ljud- och musikproduktion, Högskolan Dalarna, Akademin för språk och medier, Falun. I denna uppsats undersöktes främst ljudet men också bilden ur en scen från filmen No Country for Old Men. Detta gjordes för att ta reda på hur scenen använder sina ljudresurser ur ett berättelsefunktionsperspektiv, samt att få en djupare förståelse för ljudets roll och vad ljudet bidrar med till berättelsen som bilden inte gör. Den valda scenen granskades med hjälp av en audiovisuell analysteknik kallad Masking, som myntades av den franske filmljudsforskaren Michel Chion. Resultatet visade att scenen använder sig av en mycket begränsad ljudpallet. Filmskaparna har gjort ett medvetet val att välja bort viktigt berättardimensioner som musik och dialog. Scenen förlitar sig istället på atmosfärsljud och ljudeffekter för att berätta historien. Ljudeffekter blir en central del i berättelsen och är direkt nödvändiga för att scenen ska kunna förstås till fullo. Ljuden ignorerar också det visuella tempot som delvis närvarar och strävar istället efter en mer naturlig ljudberättelse, där ljudet förblir oförvrängd. Alla ljud som hörs är även diegetiska vilket tillsammans med den begränsade ljudpaletten bidrar till en intim och realistisk upplevelse, trots scenens relativt surrealistiska händelseförlopp.
35

Mascaramento espacial: um processo criativo envolvendo a espacialidade corporal do ator / Spatial Masking: a creative process involving bodily spatiality of the actor

Silva, Ipojucan Pereira da 19 March 2015 (has links)
A pesquisa apresenta as etapas de um processo de criação no qual a espacialidade corporal do ator lhe serve de mascaramento. Utiliza uma série progressiva de laboratórios que investigam o trânsito entre espaço e performatividade, a partir de estruturas plástico-arquitetônicas empregadas como máscaras espaciais. Organiza os resultados em partituras cênicas, tratadas como mascaramentos responsáveis por uma qualidade psicofísica diferenciada. Aponta como principais resultados: a dinâmica do corpo como princípio que anima e ativa o espaço; a disponibilidade para atuar e ser atuado pelo ambiente; o emprego da espacialidade corporal na criação cênica. Conclui que a composição de partituras em perspectiva de mascaramento espacial pode servir de base à escritura cênica / The research presents the steps of a creation process in which the actor\'s body spatiality serves them as a masking. It uses a progressive series of laboratories investigating the transit between space and performativity, from plastic-architectural structures used as spatial masks. It organizes the results in scenic scores, treated as masking which are responsible for a distinct psychophysical quality. It indicates that the main results: the dynamics of the body as a principle that animates and activates the space; the ability to act and be acted by the environment; the use of body spatiality in the scenic creation. It concludes that the composition of scores in spatial masking perspective can be the basis for a scenic scripture
36

The Spatial Distribution of Geoprivacy Concerns in Florida: A County Level Analysis

House, Joshua W 08 April 2008 (has links)
Certain types of spatial data maintained and distributed by counties at taxpayer expense can be used with powerful mapping and analysis software, called Geographic Information Systems (GIS), to compromise an indvidual's locational privacy. The kind of privacy at threat here is referred to as geoprivacy, which is concerned with the rights to prevent disclosure of the location of one's home, workplace, or daily activities. While the availability of accessible and accurate geospatial data has increased geoprivacy concerns in recent years, this threat remains virtually unknown to the general public. Although previous research has explored various components of the geoprivacy debate, the fragmented and localized nature of this work does not adequately address the threat on a large scale or lend itself for use in multi-level policy discussions. This thesis fills the need for a comprehensive and systematic geoprivacy study by examining county data availability in the entire state of Florida. Ultimately, the success of geoprivacy violation attempts is determined by the availability and quality of the data being used. In order to evaluate this threat,a statewide inventory of the data necessary for a reverse geocoding operation, defined here as geoprivacy data elements, was created. A specific county (Bay County) with complete data availability was then selected and its geoprivacy data elements, specifically street, parcel, and address point layers were evaluated for their reverse geocoding and subsequent identity disclosure success. These findings were then compared with the results of the statewide inventory to determine the level of exposure that the state's residents are subjected to, based on their county's data offerings. The statewide data inventory indicated substantial variation in county availability, quality, and delivery methods of the desired geoprivacy data elements. The results of the reverse geocoding operation performed with Bay County's geoprivacy data elements revealed that both property parcels and address points in conjunction with ownership information have a high rate of identity disclosure success. Geocodable streets were found to have a low rate of identity disclosure success and their results were comparable to a non-county maintained street layer that was used for control purposes. Although the street layers had a low rate of identity disclosure success, they could be used to identify a narrow range of address possibilities and still pose a geoprivacy threat. Forty-two counties in which approximately 13 million people reside make parcel data with ownership information available for free or purchase. Given the high success rate of the parcel data to disclose individual identity, this research suggests that the majority of the state's residents are vulnerable to potential geoprivacy violations.
37

Développement et évaluation de médicaments à usage pédiatrique : masquage de goût du principe actif et fabrication de minigranules à désintégration rapide / Development and evaluation of medicines for paediatric use

Hoang Thi, Thanh Huong 25 November 2012 (has links)
Face au manque de médicaments spécifiquement conçus et mis au point pour répondre aux besoins thérapeutiques de la population pédiatrique, les autorités nationales et européennes se sont vues dans l’obligation d’établir un cadre réglementaire visant à encourager le développement de médicaments à usage pédiatrique. Un médicament destiné à l’enfant nécessite une présentation galénique spécifique et adaptée à son âge, pour permettre une administration simple et sûre. L’Académie nationale de Pharmacie a également travaillé sur le sujet et élaboré un rapport en juin 2005 avec certaines propositions notamment favoriser les formes orales solides dispersibles ou orodispersibles. Cependant, les formes orales solides posent le problème de l’acceptabilité et de l’évaluation de la palatabilité, condition requise qui représente un véritable défi. L’objectif de ce travail était (i) de développer des techniques de masquage du goût d’un principe actif modèle, l'acétaminophène, (ii) de mettre au point des méthodes d’évaluation du masquage de goût et de caractérisation des particules obtenues et, (iii) d'élaborer un procédé de fabrication d’une forme dispersible : des minigranules à désintégration rapide. Le caséinate de sodium et la lécithine, excipients potentiellement tolérables et sans danger pour un usage pédiatrique, ont été utilisés pour encapsuler le principe actif par atomisation-séchage. Le masquage de goût est évalué in vitro de façon indirecte par des études de libération du principe actif. Nous avons développé une méthode simple avec une pompe à seringues qui utilise de faibles volumes et débits de tampon et simule le flux salivaire. La méthode d’évaluation de masquage de goût développée donne des résultats en accord avec ceux d’autres méthodes existantes comme la langue électronique. La caractérisation des particules obtenues, notamment grâce à la spectroscopie par Rayons X qui permet d’obtenir une cartographie de la composition à la surface des particules enrobées, a montré une différence de composition en fonction du ratio caséinate de sodium/lécithine utilisé lors de l’atomisation. Cette différence a pu être mise en relation avec l'efficacité de masquage de goût. Une étude a ensuite été menée pour évaluer l'effet des paramètres du procédé et de la formulation sur l'efficacité de masquage de goût. Un plan factoriel complet a permis de déterminer les variables les plus importantes influant sur la quantité de principe actif libéré durant les premières minutes, soit la quantité de caséinate de sodium et de lécithine. L’optimisation par la méthode du simplex a permis d’obtenir une formulation optimisée pour laquelle la quantité libérée était 7 fois inférieure à celle du principe actif initial durant les deux premières minutes de l’essai de libération. Une autre approche visant à améliorer l'effet de masquage de goût incluait l'utilisation de caséinate de calcium à la place de caséinate de sodium. Le caséinate de calcium a été montré capable de retarder la libération du principe actif de façon plus importante lors de son association avec de la lécithine, ce qui améliore le masquage de goût. En effet, le masquage de goût est obtenu quand sur une courte période de temps (1 à 2 minutes), soit le principe actif n’est pas détecté, soit la quantité détectée est sous le seuil de perception du patient. Une forme galénique multiparticulaire à base de minigranules à désintégration rapide a ensuite été élaborée par extrusion-sphéronisation suivie d’une lyophilisation. Les minigranules présentent des qualités appropriées à savoir, une bonne sphéricité, une faible friabilité, la capacité d’incorporer une quantité élevée de principe actif et de plus, ces minigranules sont presque immédiatement désintégrés en présence d'eau lors de la mesure du temps de désagrégation avec l'analyseur de texture. Ce type de minigranules promet une forme galénique adaptée à la population pédiatrique grâce à la facilité d’administration et la flexibilité de dosage. / The development of paediatric formulations involves an urgent need but also presents many difficulties, e.g. the safety data of existing and new excipients in children stay restrictive; the development of palatable formulations for better compliance is requisite and challenging; the appropriateness of dosage form faces to dysphagia issue and flexibility of dosing for a large range of age. The aim of this work was (i) to develop a taste-masking formulation of a model drug (acetaminophen) on the one hand, and (ii) to elaborate a process for manufacture of fast disintegrating minigranules on the other hand. Sodium caseinate and lecithin, potentially tolerable and safe excipients for paediatric use, were utilized in order to encapsulate the drug through spray-drying. Taste-masking effect was demonstrated by in vitro drug release study and electronic tongue analysis. The characterization of spray-dried particles showed a difference in the surface composition according to the sodium caseinate/lecithin ratio, which related to the taste-masking efficiency. A study was subsequently undertaken to evaluate the effect of process and formulation parameters on the taste-masking efficiency. A full factorial design allowed screening for the most important variables that affect the released amount of drug during the early minutes, i.e. quantity of sodium caseinate and lecithin. An optimized formulation was successfully achieved by simplex design that released the drug 7-fold less than the unmasked drug during the first two minutes. Another approach to improve the taste-masking effect included the use of calcium caseinate rather than sodium caseinate. Calcium caseinate was showed to be more effective in delaying the drug release to a higher extent in association with lecithin. Indeed, the lower the released amount, the better the taste-masking. A multiparticulate dosage form of fast disintegration was developed through extrusion-spheronization followed by freeze-drying. The pellets exhibited suitable quality, e.g. good sphericity, low friability, ability of high drug loading, and moreover, almost immediately disintegrated in contact with water during measurement of disintegration by texture analyzer. This type of pellets promises age-appropriate dosage form for pediatric population thank to facility of administration and flexibility of dosing.
38

Olfactory discrimination in the rat

Sokolic, Ljiljana January 2009 (has links)
Doctor of Philosophy (PhD) / Abstract Olfactory tasks are used very often with laboratory animals in studies of the neurobiology of learning and memory. Rats and mice are extremely sensitive in their detection and discrimination of odours, learn olfactory tasks rapidly, and can display higher order cognitive functions in olfactory tasks. This cognitive capacity may rival the ability of primates to learn analogous tasks with visual cues and most likely reflects strong anatomical connections between the olfactory bulbs and higher brain regions such as the piriform cortex, orbitofrontal cortex and hippocampus. The current thesis explored olfactory discrimination learning and performance in rats and had two principal aims. The first part of the thesis was oriented around odour masking phenomena in rats: the ability of one odour in a mixture to suppress detection of a second odour in that mixture. A specialized behavioural paradigm was developed to allow the study of odour masking in the rat. The second part of the thesis was pharmacological and determined whether the acquisition, reversal and performance of olfactory discriminations, and analogous auditory discriminations, are affected by two commonly used classes of drugs (benzodiazepines and cannabinoids). Together, these studies attempt to gain a better understanding of the nature of olfactory discrimination learning in rats, by using both psychophysical and pharmacological approaches, and to develop behavioural paradigms which may be used in future psychophysical and pharmacological studies. Following an introduction and review of olfactory and auditory studies in rat (Chapter 1), odour masking phenomena were studied in Chapter 2. The aliphatic aldehydes butanal (C4) and heptanal (C7) were used in the study. Aldehydes were of interest as this class of odorants abound in nature and may be important for rodents’ species-specific communication. Thirsty rats were initially trained to discriminate C4 and C7 in the olfactometer, using a go/no-go olfactory discrimination task. This involved rats learning to nose poke in an odour port and to lick a tube for a water reward on presentation of the rewarded component S+, while withholding licking at the tube when the other, unrewarded, aldehyde (S-) was presented. Odour mixtures (C4C7 or C7C4) were then introduced into the task as an additional non-rewarded condition (mixture S-). The concentration of the non-rewarded aldehyde in the mixture was then systematically decreased, while the concentration of the rewarded aldehyde was kept constant. When the non-rewarded aldehyde reached a critical low level in the mixture, rats started to make responses to the non-rewarded mixture (false alarms) showing that the S+ odour was suppressing the S- odour in the mixture, so the mixture was being responded to in the same manner as the S+ odour presented alone. Results also showed asymmetric suppression in the mixture condition, such that butanal suppressed detection of heptanal at a much lower concentration than vice versa. A second experiment demonstrated that when both butanal and heptanal were present in a binary mixture at the same concentration (10-6 volume %), rats responded to the mixture as if only butanal was present. Our findings are in agreement with human studies showing component interactions in binary mixtures of aldehydes. The molecular feature of carbon chain length appears to be a critical factor in determining the outcome of interactions between aldehydes at peripheral olfactory receptors, with smaller chain aldehydes better able to compete for receptor occupancy. Subsequent chapters explored the effects of two classes of commonly used drugs - benzodiazepines and cannabinoids - on olfactory and auditory discrimination in rats. Animal models such as the radial arm maze, Morris water maze and object recognition test are routinely used to test adverse and facilitatory effects of drugs on cognition in rodents. However, comparatively few pharmacological studies employ olfactory or auditory go/no-go paradigms. Thus, an important part of the present thesis was to assess the viability of using such paradigms in detecting pharmacological effects, and to identify whether such effects may be modality specific (i.e. whether a drug has a greater effect on olfactory or auditory tasks). In Chapter 3, the effects of benzodiazepines on olfactory discrimination tasks were explored. Rats were injected with the benzodiazepine drugs midazolam or diazepam and tested on discrimination tasks involving either the auditory and olfactory modality. Results showed that midazolam (0.5–2 mg/kg sc) did not affect the performance of a well-learned two-odour olfactory discrimination task, and moderately facilitated the performance of a go/no-go auditory discrimination task. On the contrary, midazolam (1 mg/kg) impaired the acquisition of a novel go/no-go olfactory discrimination task, as well as the reversal of a previously well-learned olfactory discrimination. However, midazolam did not affect the acquisition or reversal of an equivalent auditory discrimination task. The olfactory bulb and the piriform cortex are intimately involved in associative learning and behavioural aspects of olfactory performance, and have high concentrations of benzodiazepine receptors. These may therefore be possible neural substrates for the disruptive effects of benzodiazepines on olfactory learning. Findings from Chapter 4 indicated that the prototypical cannabinoid agonist delta-9-tetrahydrocanabinol (Δ9 THC) (0.3, 1 and 3 mg/kg) impairs auditory discrimination performance, but had no effect on equivalent olfactory discriminations. This is in marked contrast to the effects of benzodiazepines. Residual effects were observed, such that auditory discrimination performance was still impaired on the day following Δ9 THC administration. Delta-9-tetrahydrocanabinol effects were prevented by co-administration of the cannabinoid antagonist rimonabant (3 mg/kg). In addition, the anandamide hydrolysis inhibitor URB597 (0.1 and 0.3 mg/kg), which boosts levels of endogenous cannabinoids in the synapse, also impaired auditory discrimination performance, and this effect was also reversed by rimonabant. This study also assessed the effects of Δ9 THC (0.3, 1 and 3 mg/kg) and URB597 (0.1 and 0.3 mg/kg) on acquisition and reversal of novel olfactory discriminations. Results showed that Δ9 THC impairs olfactory reversal learning without affecting acquisition of the original discrimination. It is argued that this reversal deficit may be part of a wider capacity for cannabinoids to impair cognitive flexibility. The final Chapter (General Discussion) discusses the relevance and implications of the combined findings. The results add significantly to our current understanding of perceptual, learning and memory processes involving the olfactory modality in rats. With respect to olfactory perception, this thesis introduced a new behavioural paradigm, which can be used to assess component suppression in mixtures, and may be of use in future psychophysical studies involving rodents or other species. With respect to learning and memory, the thesis provides novel information on the disruptive effects of benzodiazepines and cannabinoids on olfactory and auditory tasks. It is concluded that go/no-go olfactory and auditory discrimination tasks in rats can provide a useful platform for assessing the disruptive and modality-specific effects of drugs on learning, performance and cognitive flexibility. Future studies might expand the range of drugs tested on these paradigms and might consider chronic as well as acute drug effects.
39

Auditory masking of wind turbine noise with ambient sounds

Kedhammar, Anders January 2010 (has links)
<p>The expansion of wind energy production creates an increase in wind turbine (WT) noise. The purpose of this paper is to examine if a possible reduction of WT noise might be achieved by adding natural ambient sounds, so called auditory masking. A loudness experiment was conducted to explore this possibility, using four ambient sounds of trees, birds and water as maskers. Sixteen listeners assessed the loudness of WT noise heard alone or in the presence of 40 dB masking sounds, using the method of magnitude estimation. Partial masking of WT noise was found in the presence of all ambient sounds. The masking effect corresponded to a dB-reduction of the WT noise from a few dB for signal-to-noise ratios (S/N) close to 0 dB up to around 10 dB at -15 dB S/N. These results indicate that addition of ambient sounds may be a useful method for masking unwanted noise from wind turbines.</p>
40

Wind Turbine Noise and Natural Sounds : Masking, Propagation and Modeling

Bolin, Karl January 2009 (has links)
Wind turbines are an environmentally friendly and sustainable power source. Unfortunately, the noise impact can cause deteriorated living conditions for nearby residents. The audibility of wind turbine sound is influenced by ambient sound. This thesis deals with some aspects of noise from wind turbines. Ambient sounds influence the audibility of wind turbine noise. Models for assessing two commonly occurring natural ambient sounds namely vegetation sound and sound from breaking waves are presented in paper A and B. A sound propagation algorithm has been compared to long range measurementsof sound propagation in paper C. Psycho-acoustic tests evaluating the threshold and partial loudness of wind turbine noise when mixed with natural ambient sounds have been performed. These are accounted for in paper D. The main scientific contributions are the following.Paper A: A semi-empiric prediction model for vegetation sound is proposed. This model uses up-to-date simulations of wind profiles and turbulent wind fields to estimate sound from vegetation. The fluctuations due to turbulence are satisfactory estimated by the model. Predictions of vegetation sound also show good agreement to measured spectra. Paper B: A set of measurements of air-borne sound from breaking waves are reported. From these measurements a prediction method of sound from breaking waves is proposed. Third octave spectra from breaking waves are shown to depend on breaker type. Satisfactory agreement between predictions and measurements has been achieved. Paper C: Long range sound propagation over a sea surface was investigated. Measurements of sound transmission were coordinated with local meteorological measurements. A sound propagation algorithm has been compared to the measured sound transmission. Satisfactory agreement between measurements and predictions were achieved when turbulence were taken into consideration in the computations. Paper D: The paper investigates the interaction between wind turbine noise and natural ambient noise. Two loudness models overestimate the masking from two psychoacoustic tests. The wind turbine noise is completely concealed when the ambient sound level (A-weighed) is around 10 dB higher than the wind turbine noise level. Wind turbine noise and ambient noise were presented simultaneously at the same A-weighed sound level. The subjects then perceived the loudness of the wind turbine noise as 5 dB lower than if heard alone. Keywords: Wind turbine noise, masking, ambient noise, long range sound propagation / QC 20100705

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