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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.
1

What Are They Learning: a Study of Errors Produced During Behavior Acquisition Utilizing Two Prompting Procedures with a Cat

Beasley, Robin Lynn 08 1900 (has links)
Prompting methods are common amongst animal trainers, both novice and experts. However, there is little empirical evidence to demonstrate the strengths or weaknesses of common prompting procedures. The current study assessed the strengths and weaknesses during behavior acquisition of two prompting methods, luring and targeting. Luring placed an edible directly in front of the animal which guided the animal through the desired behavior. Targeting, however used a target, an arbitrary object the animal has been trained to touch, guide behavior. A cat was trained, using each method, to walk around a flower. Walking around the right flower pot was trained using luring and walking around the left flower pot was trained using targeting. After both behaviors were acquired, a delay cue method was designed to transfer stimulus control. Later a combination of a delay cue and prompt fading was used. During acquisition the luring method acquired the behavior of walking around a pot more quickly with consistently fewer errors. During stimulus transfer the cat began independently initiating the behavior earlier with the target trained behavior and produced more correct behaviors after the verbal cue. Luring appeared to produce the faster behavior, but after stimulus transfer it could be concluded that the cat did not learn the desired behavior, but rather following the lure. Both methods could be beneficial in different circumstance, however, given the desired behavior was to walk around a flower pot on cue, targeting would be considered best practice.
2

Die Fabrikation der nordischen Bronzeluren

Bose, Fritz 30 March 2020 (has links)
No description available.
3

Estimativa do conjunto atrator e da área de atração para o problema de Lure estendido utilizando LMI / An estimate of attractor set and its associated attraction area of the extended Lure problem using LMI

Martins, André Christóvão Pio 23 March 2005 (has links)
A análise de estabilidade de sistemas não-lineares surge em vários campos da engenharia. Geralmente, esta análise consiste na determinação de conjuntos atratores estáveis e suas respectivas áreas de atração. Os métodos baseados no método de Lyapunov fornecem estimativas destes conjuntos. Entretanto, estes métodos envolvem uma busca não sistemática por funções auxiliares chamadas funções de Lyapunov. Este trabalho apresenta um procedimento sistemático, baseado no método de Lyapunov, para estimar conjuntos atratores e as respectivas áreas de atração para uma classe de sistemas não-lineares, aqui chamado de problema de Lure estendido. Este problema consiste de sistemas não-lineares que podem ser escritos na forma do problema de Lure, cuja função não-linear pode violar a condição de setor em torno da origem. O procedimento desenvolvido é baseado na extensão do princípio de invariância de LaSalle e usa as funções de Lyapunov genéricas do problema de Lure para estimar o conjunto atrator e sua respectiva área de atração. Os parâmetros das funções de Lyapunov são obtidos resolvendo um problema de otimização que pode ser colocado na forma de desigualdades matriciais lineares (LMIs). / The stability analysis of nonlinear systems is present in several engineering fields. Usually, the concern is the determination of stable attractor sets and their associated attraction areas. Methods based on the Lyapunov method provide estimates of these sets. However, these methods involve a nonsystematic search for auxiliary functions called Lyapunov functions. This work presents a systematic procedure, based on Lyapunov method, to estimate attractor sets and their associated attraction areas of a class of nonlinear systems, called in this work extended Lure problem. The extended Lure problem consists of nonlinear systems like those of Lure problem where the nonlinear functions can violate the sector conditions around the origin. The developed procedure is based on the extension of invariance LaSalle principle and uses the general Lyapunov functions of Lure problem to estimate the attractor set and their associated attraction area. The parameters of the Lyapunov functions are obtained solving an optimization problem write like a linear matrix inequality (LMI).
4

Estimativa do conjunto atrator e da área de atração para o problema de Lure estendido utilizando LMI / An estimate of attractor set and its associated attraction area of the extended Lure problem using LMI

André Christóvão Pio Martins 23 March 2005 (has links)
A análise de estabilidade de sistemas não-lineares surge em vários campos da engenharia. Geralmente, esta análise consiste na determinação de conjuntos atratores estáveis e suas respectivas áreas de atração. Os métodos baseados no método de Lyapunov fornecem estimativas destes conjuntos. Entretanto, estes métodos envolvem uma busca não sistemática por funções auxiliares chamadas funções de Lyapunov. Este trabalho apresenta um procedimento sistemático, baseado no método de Lyapunov, para estimar conjuntos atratores e as respectivas áreas de atração para uma classe de sistemas não-lineares, aqui chamado de problema de Lure estendido. Este problema consiste de sistemas não-lineares que podem ser escritos na forma do problema de Lure, cuja função não-linear pode violar a condição de setor em torno da origem. O procedimento desenvolvido é baseado na extensão do princípio de invariância de LaSalle e usa as funções de Lyapunov genéricas do problema de Lure para estimar o conjunto atrator e sua respectiva área de atração. Os parâmetros das funções de Lyapunov são obtidos resolvendo um problema de otimização que pode ser colocado na forma de desigualdades matriciais lineares (LMIs). / The stability analysis of nonlinear systems is present in several engineering fields. Usually, the concern is the determination of stable attractor sets and their associated attraction areas. Methods based on the Lyapunov method provide estimates of these sets. However, these methods involve a nonsystematic search for auxiliary functions called Lyapunov functions. This work presents a systematic procedure, based on Lyapunov method, to estimate attractor sets and their associated attraction areas of a class of nonlinear systems, called in this work extended Lure problem. The extended Lure problem consists of nonlinear systems like those of Lure problem where the nonlinear functions can violate the sector conditions around the origin. The developed procedure is based on the extension of invariance LaSalle principle and uses the general Lyapunov functions of Lure problem to estimate the attractor set and their associated attraction area. The parameters of the Lyapunov functions are obtained solving an optimization problem write like a linear matrix inequality (LMI).
5

Figures, gestes et cibles du Sportsman : la chasse dans les textes de Jim Harrison et Thomas McGuane / Hunting in the texts of Jim Harrison and Thomas McGuane : the sportsman's figures, gestures and games

Rolland, Céline 10 June 2016 (has links)
La chasse occupe une place significative dans les textes des auteurs américains Jim Harrison et Thomas McGuane. Elle apparaît soit comme un thème central, traité directement et pour lui-même, soit comme un thème secondaire ou encore comme une métaphore ou un motif sous-jacent qui permet de mieux comprendre les enjeux du texte, ses implications morales et esthétiques. Dans le corpus, la chasse correspond à une stratégie d'écriture fondée sur le leurre, lorsqu'elle recouvre ou qu'elle révèle un sens second. Le motif du double a partie liée dans le corpus avec la complexité du chasseur, un personnage qui dramatise des visées contradictoires : il est partagé entre le respect de la proie et le désir de la posséder. Le sportsman se confronte aux limites de son champ d'action qu'il détermine pour les respecter, alors que par contraste, certaines figures sont présentées comme des contre-modèles qui transgressent les bornes. Cependant, la transgression apporte dans certains cas un bénéfice au personnage et au groupe auquel il se réfère. Le chasseur revêt alors une fonction paradoxale : il incarne celui qui révèle que les bornes doivent être déplacées et dont la chasse "noire" redéfinit les limites de fait. Il fait figure de modèle paradoxal, dans le récit mais aussi d 'un point de vue métatextuel Chez Harrison et McGuane, les textes sur la chasse invitent à considérer l'écrivain comme un "chasseur noir" qui braconne sur les terres d'autres auteurs et d'autres systèmes de représentation mais dont la transgression est finalement valorisée : le souci de justesse qu'il incarne nécessite un travail d'accommodement à un monde changeant et donc le renouvellement des bornes et des formes. L'idéal sportif de la relâche du gibier reflète l'entreprise de l'écrivain : le souci de la distance à garder face à l'animal et celui de redéfinir les cadres formels se manifestent à travers une esthétique de la déprise qui remet le sens du texte en mouvement. / In the writings of the American authors Jim Harrison and Thomas McGuane, hunting is a central theme. Even when it is not the main topic of the text, hunting is significant. It may be one of the main themes, tackled directly for itself or it can be an ancillary tl1eme used as a metaphor or as an implicit motif in the structure. Hunting is also a writing strategy, reproducing the mimetic seduction of the lure, hiding or revealing a second meaning. The motif of the double is indeed central; it has to do with the logics of make-believe but also with the complex character of the hunter who enacts contradictory tendencies: torn between his respect for the prey and his desire to grasp and kill it, he also embodies an ambivalent attitude toward the Law. The sportsman faces the limits of his scope; he defines them so as to respect tl1em. By contrast other character-types are presented as foils to the sportsman. Their transgression may however become beneficient to the group he belongs to. In such cases, ehe hunter has a paradoxical function: he reveals that the landmarks must be displaced and his "black hunt" effectively replaces them. He embodies a paradoxical model in the story and for tl1e writer. Harrison's and McGuane's texts thus suggest to look at the writer as "black hunter" who trespasses into other writers' territories, also violating the limits conventionally separating several systems of representation. This transgression proves fruitful and as such is valorized. The hunter and the writer try to adjust and accommodate to a changing world; this quest implies new frames. The sportsman's ideal of catch-and-release reflects tl1e writer's aesthetics of release: both try to put the game back in movement.
6

Evaluation of Video Modeling for Teaching Abduction Prevention Skills to Children Diagnosed With Autism and Aspergers Disorder

Godish, Danielle 23 March 2010 (has links)
Abduction prevention skills are crucial for any child to have. Unfortunately there has been a lack of research on teaching children with autism and aspergers these skills. Video modeling has been shown to be an effective method to teach children with autism various skills. Video modeling has also been shown to be cost efficient and easily implemented across various people and settings. The purpose of the present study was to assess the effectiveness of the video modeling technique for teaching children with autism and aspergers abduction prevention skills. The second purpose of the present study was to investigate the effectiveness of BST and IST for teaching children with autism and aspergers abduction prevention skills if video modeling was not effective. The results showed that the utilization of video modeling was effective in teaching all four participants abduction prevention skills.
7

Northern long-eared bat day roost ecology and novel bat sampling techniques in the mid-Atlantic

Freeze, Samuel Richard 19 September 2024 (has links)
White-nose syndrome (WNS), caused by the introduced fungal pathogen, Pseudogymnoascus destructans, has caused precipitous declines in bat populations including the now endangered northern long-eared bat (Myotis septentrionalis; NLEB). Remnant populations of NLEB have been found outside their traditional range in areas of the urbanized Piedmont and also the Coastal Plain of the mid-Atlantic region of the United States, where little is known about their summertime day-roost habitat needs. More broadly for the species, little research has examined the day-roost habitat use of both male and females. This information is vital to inform management and policy for the conservation of this endangered species. In this dissertation, I captured NLEB at three properties in eastern Virginia and Washington D.C. Captures at Marine Corps Base Quantico (MCBQ) and Prince William Forest Park (PRWI) in Virginia were male-biased and Rock Creek Park (ROCR) captures in D.C. were female-biased. I found that overall NLEB are associated with mature, deciduous forest. Males used red maples (Acer rubrum) in later decay stages and lower crown classes at MCBQ/PRWI. Females used taller oaks (Quercus) at ROCR. Differences between the two study areas may be an artifact of MCBQ/PRWI being an early mature forest whereas much of ROCR is approaching late mature to old-growth gap-phase conditions. Building off the fact that many WNS affected bat species are now substantially more difficult to detect on the landscape, I explored novel methods to help increase detection of bats during acoustic surveys. This included developing and testing an experimental ultraviolet (UV) light lure that attracted insects and thereby attracted bats. The lure increased overall bat feeding buzz calls and had a species-specific response, primarily attracting eastern red bats (Lasiurus borealis). The lure elicited an interesting negative response from NLEB within the illuminated area, but an increase above control conditions beyond the illuminated area. Overall, the UV lure shows promise for increasing detection of bats and warrants further research, however caution should be exercised as some bats showed a negative response. I also investigated the effects of environmental clutter on the reception of ultrasonic bat echolocation signals to help researchers better understand how different clutter types and configurations affect and potentially bias acoustic survey results. This is especially important when surveying for clutter-adapted bats, such as NLEB which are traditionally biased against in acoustic surveys due to their habitat associations and low detection probability. I found that the recording angle of the bat in relation to the microphone overshadowed most other effects. On-axis recording created the best quality recording and the signal rapidly degraded as the angle increased. Therefore, placement of microphones to where bats are expected to be flying is critical. Many small clutter objects, analogous to a young forest with a high stocking rate substantially degraded echolocation signals. Fewer, large objects, analogous to a mature forest with large trees and little understory actually generated echoes that were identifiable to species that would be beneficial to improving detection probability and occupancy estimates, but might generate bias by overcalculating activity estimates. / Doctor of Philosophy / A disease called white-nose syndrome (WNS), caused by the fungal pathogen, Pseudogymnoascus destructans, was introduced into the U.S. around 2006 and has decimated bat populations across much of the U.S. and Canada. Bats are responsible for providing important pest insect control services to the agriculture and forestry industries as well as helping to control disease carrying insects. Once particular species, the northern long-eared bat (Myotis septentrionalis; NLEB) has seen some of the heaviest declines. Once a common bat in forests across the eastern and mid-western portions of North America, the NLEB is now considered an endangered species. Recently, populations of this bat have been found in areas where they were previously not known to exist and they represent potentially important remnant populations with high conservation value. In order to protect these NLEB, scientists must understand their forest habitat needs for roosting during the day and rearing young. Most past studies have focused on female NLEB, so information on male roost use is also needed. I captured NLEB at Marine Corps Base Quantico (MCBQ) and Prince William Forest Park (PRWI) in Virginia as well as at Rock Creek Park (ROCR) in Washington, D.C. and tracked NLEB to their day-roosts to characterize their habitat needs at multiple scales ranging from the day-roost itself, the surrounding forest area, and the greater landscape around the bat roosting areas. I found that NLEB prefer to roost in older deciduous hardwood forests. Male NLEB used red maples (Acer rubrum) that were shorter and more decayed than surrounding trees at MCBQ/PRWI. Females used taller oak trees (Quercus) at ROCR. Differences observed in the analysis between the two study areas may be an artifact of MCBQ/PRWI being a younger forest whereas much of ROCR is approaching conditions of a very old forest. Building off the fact that many WNS affected bat species are now substantially more difficult to find out on the landscape, I explored new research methods to help increase detection of bats during acoustic surveys. Scientists often use acoustic recording devices to record ultrasonic (above human hearing) echolocation calls that bats use for navigation and hunting at night. Those calls can be identified as specific types of bats for use in environmental studies using automated computer programs. The problem however, is that bats must fly close to the microphone in order to record a clear sound file that can be identified by the software. I built and tested a device that uses ultraviolet (UV) "blacklights" to attract insects that bats eat and thereby attract bats to an array of recording devices. The lure device worked, but for individual species of bats rather than all bats. Of particular interest is that NLEB were repelled within the area illuminated by the UV light lure, but increased outside the illuminated area. Overall, a UV light lure shows promise for increasing detection of bats, but caution is recommended because some bats seemed to avoid the light. I also investigated how clutter around these recording devices, such as trees and branches, affects the quality of recorded sound files under controlled conditions. I found that the angle of the recording device microphone to the sound source (a bat) mattered the most. Many smaller objects between a bat and the microphone, such as many small trees in a young forest, resulted in the worse recordings. Fewer large objects, such as large, old trees, resulted in echoes of the bat calls being recorded and actually helped the software identify the calls to a specific type of bat. However, this also warrants caution, as those echoes could introduce bias into counts of nightly bat activity.
8

Nonlinear and Hybrid Feedbacks with Continuous-Time Linear Systems / Rétroactions non linéaires et hybrides avec systèmes linéaires à temps continu

Cocetti, Matteo 21 May 2019 (has links)
Dans cette thèse, nous étudions la rétroaction de systèmes linéaires invariants dans le temps reliés entre eux par trois blocs non linéaires spécifiques : un opérateur de lecture/arrêt, un mécanisme de réinitialisation de commutation et une zone morte adaptative. Cette configuration ressemble au problème de Lure étudié dans le cadre de stabilité absolue, mais les types de non-linéarités considérés ici ne satisfont pas (en général) une condition sectorielle. Ces blocs non linéaires donnent lieu à toute une série de phénomènes intéressants, tels que des ensembles compacts d’équilibres, des ensembles hybrides oméga-limites et des contraintes d’état. Tout au long de la thèse, nous utilisons le formalisme des systèmes hybrides pour décrire ces phénomènes et analyser ces boucles. Nous obtenons des conditions de stabilité très précises qui peuvent être formulées sous forme d’inégalités matricielles linéaires, donc vérifiables avec des solveurs numériques efficaces. Enfin, nous appliquons les résultats théoriques à deux applications automobiles. / In this thesis we study linear time-invariant systems feedback interconnected with three specific nonlinear blocks; a play/stop operator, a switching-reset mechanism, and an adaptive dead-zone. This setup resembles the Lure problem studied in the absolute stability framework, but the types of nonlinearities considered here do not satisfy (in general) a sector condition. These nonlinear blocks give rise to a whole range of interesting phenomena, such as compact sets of equilibria, hybrid omega-limit sets, and state constraints. Throughout the thesis, we use the hybrid systems formalism to describe these phenomena and to analyze these loops. We obtain sharp stability conditions that can be formulated as linear matrix inequalities, thus verifiable with numerically efficient solvers. Finally, we apply the theoretical findings to two automotive applications.
9

Paléopentes, glissements synsédimentaires et reconstitution de bassin dans le domaine vocontien (valanginien-hauterivien de la zone subalpine-méridionale des Alpes occidentales françaises)

Tangri, Anjani 08 November 1980 (has links) (PDF)
Ce travail est consacré à l'étude des caractères sédimentologiques de la série du Crétacé inférieur de la zone subalpine méridionale, dans le domaine voconcien, en vue de la reconstitution paléogéographique du bassin à cette époque.
10

A model system using insects to vector Fusarium tumidum for biological control of gorse (Ulex europaeus)

Yamoah, Emmanuel January 2007 (has links)
The overall objective of this study was to test the hypothesis that insects can vector F. tumidum conidia to infect gorse plants with the aim of developing an alternative approach to mycoherbicide delivery to control weeds. Four potential insect species (Apion ulicis, Cydia ulicetana, Epiphyas postvittana and Sericothrips staphylinus) were assessed for their ability to vector F. tumidum conidia. To achieve this, the external microflora (bacteria and fungi) and the size and location of fungal spores on the cuticle of these insect species were determined. In addition, the ability of the insects to pick up and deposit F. tumidum conidia on agar was studied. Based on the results from these experiments, E. postvittana was selected for more detailed experiments to determine transmission of F. tumidum to infect potted gorse plants. The factors promoting pathogenicity of F. tumidum against gorse and the pathogen loading required to infect and kill the weed were also determined. The external microflora of the four insect species were recovered by washing and plating techniques and identified by morphology and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and sequencing of internally transcribed spacer (ITS) and 16S rDNA. A culture-independent technique (direct PCR) was also used to assess fungal diversity by direct amplification of ITS sequences from the washings of the insects. All insect species carried Alternaria, Cladosporium, Nectria, Penicillium, Phoma, Pseudozyma spp. and entomopathogens. Ninety four per cent of the 178 cloned amplicons had ITS sequences similarity to Nectria mauritiicola. E. postvittana carried the largest fungal spores (mean surface area of 125.9 ìm2) and the most fungal CFU/insect. About 70% of the fungi isolated from the insects were also present on the host plant (gorse) and the understorey grass. The mean size of fungal spores recovered from the insect species correlated strongly with their body length (R² = 85%). Methylobacterium aquaticum and Pseudomonas lutea were common on all four insect species. Pseudomonas fluorescens was the most abundant bacterial species. In the pathogenicity trials, the effectiveness of F. tumidum in reducing root and shoot biomass of 16 and 8 wk old gorse plants was significantly increased with wounding of the plants. Older plants (32 wk old) which were wounded and inoculated were significantly shorter, more infected and developed more tip dieback (80%) than plants which were not wounded (32%). This indicates that damage caused by phytophagous insect species present on gorse through feeding and oviposition may enhance infection by F. tumidum. Wounding may release nutrients (e.g. Mg and Zn) essential for conidia germination and germ tube elongation and also provide easier access for germ tube penetration. Conidial germination and germ tube length were increased by 50 and 877%, respectively when incubated in 0.2% of gorse extract solution for 24 h compared with incubation in water. Inoculum suspensions amended with 0.2% of gorse extract caused more infection and significantly reduced biomass production of 24 wk old gorse plants than suspensions without gorse extract. A minimum number of about 900 viable conidia/infection site of F. tumidum were required to infect gorse leaves. However, incorporation of amendments (which can injure the leaf cuticle) or provision of nutrients (i.e. gorse extract or glucose) in the formulation might decrease the number of conidia required for lesion formation. Scanning electron micrographs showed that germ tube penetration of gorse tissue was limited to open stomata which partly explain the large number of conidia required for infection. The flowers and leaves were more susceptible to F. tumidum infection than the spines, stems and pods. An experiment to determine the number of infection sites required to cause plant mortality showed that the entire plant needs to be inoculated in order for the pathogen to kill 10 wk old plants as F. tumidum is a non systemic pathogen. The number of infection sites correlated strongly with disease severity (R² = 99.3%). At least 50% of the plant was required to be inoculated to cause a significant reduction in shoot dry weight. F. tumidum, applied as soil inoculant using inoculated wheat grains in three separate experiments, significantly suppressed gorse seedling emergence and biomass production. In experiments to determine the loading capacity of the insect species, E. postvittana, the largest insect species studied, carried significantly more (68) and deposited significantly more (29) F. tumidum conidia than the other species. Each E. postvittana, loaded with 5,000 conidia of F. tumidum, transmitted approximately 310 conidia onto gorse plants but this did not cause any infection or affect plant growth as determined by shoot fresh weight and shoot height. E. postvittana on its own did not cause any significant damage to gorse and did not enhance F. tumidum infection. It also failed to spread the pathogen from infected plants to the healthy ones. There was no evidence of synergism between the two agents and damage caused by the combination of both E. postvittana and F. tumidum was equivalent to that caused by F. tumidum alone. This study has shown that E. postvittana has the greatest capacity to vector F. tumidum since it naturally carried the largest and the most fungal spores (429 CFU/insect). Moreover, it naturally carried Fusarium spp. such as F. lateritium, F. tricinctum and Gibberella pulicaris (anamorph Fusarium sambucinum) and was capable of carrying and depositing most F. tumidum conidia on agar. Coupled with the availability of pheromone for attracting the male insects, E. postvittana may be a suitable insect vector for delivering F. tumidum conidia on gorse using this novel biocontrol strategy. Although it is a polyphagous insect, and may visit non-target plants, F. tumidum is a very specific pathogen of gorse, broom and a few closely related plant species. Hence, using this insect species to vector F. tumidum in a biological control programme, should not pose a significant threat to plants of economic importance. However, successful control of gorse using this "lure-load-infect" concept would depend, to a large extent on the virulence of the pathogen as insects, due to the large size of F. tumidum macroconidia, can carry only a small number of it.

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