91 |
Untersuchungen zur Bestimmung der Übergreifungslängen textiler Bewehrungen aus Carbon in Textilbeton (TRC)Lorenz, Enrico, Ortlepp, Regine 01 December 2011 (has links) (PDF)
Für das Funktionieren von Verstärkungsschichten aus Textilbeton ist eine sichere Kraftübertragung zwischen den einzelnen Verbundbaustoffen sicherzustellen. Aufgrund der sehr hohen Garnzugfestigkeiten sind besonders bei Verwendung textiler Bewehrungen aus Carbon sehr effektive Verstärkungen herstellbar. In Textilbetonbauteilen sind hierbei im Regelfall Übergreifungsstöße der textilen Bewehrungslagen nicht zu vermeiden. Der vorliegende Beitrag befasst sich daher mit der experimentellen und analytischen Bestimmung der Übergreifungslängen textiler Bewehrungsstrukturen innerhalb von Textilbetonverstärkungsschichten. / A safe introduction and transmission of the acting forces is crucial for the functioning of composite materials. Because of the very high yarn tensile strengths of textile reinforcements made of carbon, the manufacturing of very effective TRC strengthening layers is possible. In TRC members, overlap joints within the textile layers usually cannot be avoided. This contribution deals with the experimental and analytical determination of the lap lengths of textile fabrics within a textile reinforced concrete strengthening layer.
|
92 |
Self-other overlap and its relationship to perspective taking: Underlying mechanisms and implicationsMyers, Michael William, 1979- 09 1900 (has links)
xv, 103 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / While research has extensively documented the inter- and intra-personal consequences of perspective taking, less is known about the mechanisms that underlie this process. Recent research has explored self-other overlap as a mediator of perspective taking on various pro-social outcomes, such as helping and decreased stereotyping. Results have been mixed, perhaps due to the use of different methodologies and scales that actually measure different facets of self-other overlap. This dissertation investigates the structure of self-other overlap and examines how perspective taking may affect only certain facets of self-other overlap, as well as the direction in which this overlap occurs. To test the conceptual equivalence of different overlap measures, in Study 1, participants completed several previously used measures of overlap for two targets: their best friend and an acquaintance. Factor analyses revealed two distinct factors of self-other overlap-- perceived closeness and attribute overlap --although small variations emerged depending on target. These two factors had unique associations with several relationship quality and individual difference measures. Study 2 extended these results by manipulating perspective taking with a stranger. Results replicated the same factor structure from Study 1, and found that perspective taking had different effects on the two factors. Study 3 examined whether or not perspective taking affected the direction of self-other overlap by changing one's attitudes and beliefs to become more like the other person. Results supported a model in which perceived closeness predicted belief change toward the target person, even after accounting for other related consequences of perspective taking such as empathy and positive attitudes. Together, these results suggest that self-other overlap is a multi-dimensional construct associated with different psychological responses. These results are discussed in connection with the relationship between self-other overlap and perspective taking and how this may lead to "self-expansion." / Committee in charge: Sara Hodges, Chairperson, Psychology;
Sanjay Srivastava, Member, Psychology;
Marjorie Taylor, Member, Psychology;
John Lysaker, Outside Member, Philosophy
|
93 |
Preferência alimentar por insetos aquáticos em espécies de peixes de riacho tropical /Pinto, Tamara Leite Ferreira. January 2009 (has links)
Orientador: Virgínia Sanches Uieda / Banca: Marcos Gomes Nogueira / Banca: Alaíde Gessner / Resumo: A composição da fauna de um riacho pode variar tanto em função de alterações sazonais em sua estrutura, como em função da presença ou ausência da mata ciliar, acarretando alterações na oferta de nichos e modificando a composição de espécies. Uma questão que tem sido pouco considerada em estudos de partilha de recursos no Brasil, sao mudanças no hábito alimentar, em função da disponibilidade de alimento e mudanças na escolha do alimento, em função de sua qualidade. Assim, a determinação da existência ou não de uma preferência alimentar pela ictiofauna de riachos permitiria uma análise das relarções tróficas entre os membros da comunidade, levando em conta os recursos disponíveis no ambiente e a seletividade alimentar das espécies. No presente trabalho, as comunidades de macroinvertebrados aquáticos e de peixes de um riacho de 3ª ordem situado no município de Itatinga (SP) foram estudadas com objetivo de verificar possíveis mudanças na estrutura destas comunidades e na seletividade alimentar dos peixes, em função de variações sazonais (estação seca-Junho/2006 e chuvosa-Dezembro/2006) e espaciais (presença ou ausência de mata ciliar). A partir de uma análise quantitativa da fauna bentônica em corredeiras e da dieta da ictiofauna, a preferência alimentar foi avaliada através da aplicação de índices de eletividade. Para a comunidade de macroinvertebrados bentônicos foi observado um predomínio do filo Arthropoda, com destaque para a classe Insecta. Uma variação espacial e temporal foi verificada para os grandes grupos de macroinvertebrados bentônicos amostrados, com maiores valores de abundância, riqueza e elevada dominância de Insecta registrados para área aberta, durante a estação seca, e maiores valores de diversidade durante a estação chuvosa, nas duas áreas. A estrutura trófica da ictiofauna também variou espacial e sazonalmente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this research was to describe the spatial and seasonal variations in the trophic structure of a stream fish community. The fishes were sampled on June 2006 (dry season) and December 2006 (rainy season), at an area shaded by a well-preserved riparian gallery forest (closed area) and at other area with herbaceous vegetation at the margin (open area). Macrophytes were abundant in the open area, covering the river bank and the bed. The diet analysis of the fish species sampled in the two areas showed a predominance of insectivores, mainly during the rainy season. Although aquatic insects were eaten by many species, leading to a high diet overlap between many pairs of species, differences related to the type (order/family) of insect consumed reduced this overlap. A more complex trophic structure was found in the open area during the rainy season, probably because of the great number of fish species and the high food resources availability. In the open area, the macrophytes were used as substrate by a diversified fauna. They also form an important barrier that traps the organic matter imported to the system from the upstream forested area. Seasonal and spatial variations of the fish diets emphasize the adaptability, greatflexibility and plasticity of their feeding habits and can be related to changes in the environmental complexity / Mestre
|
94 |
Ecologia trÃfica de quatro espÃcies de peixes de um rio no semiÃrido, Pentecoste - Cearà / Trophic ecology four species of fish a river in the semiarid, Pentecost - CearaUbirajara Lima Fernandes 21 June 2011 (has links)
A maioria dos rios do semiÃrido apresentam regimes irregulares e intermitentes, com um sà perÃodo anual de escoamento na chegada das precipitaÃÃes pluviomÃtricas que caracterizam o perÃodo chuvoso. Nesses rios, as perturbaÃÃes hidrolÃgicas naturais exercem forte influÃncia na organizaÃÃo do sistema, sendo as interaÃÃes alimentares complexas e modificadas pela sazonalidade e pela produtividade do sistema. A dieta de peixes pode variar de acordo com a disponibilidade de recursos alimentares de origem autÃctone ou alÃctone, bem como em resposta à variaÃÃo sazonal. A hipÃtese do presente estudo à de que em um rio do semiÃrido as espÃcies de peixes herbÃvoras/ onÃvoras apresentam partilha de recursos trÃficos. O objetivo foi determinar a partilha de recursos trÃficos a partir da dieta de quatro espÃcies de peixes no rio Curu. As coletas foram realizadas em um trecho do rio Curu (Pentecoste, CearÃ), no perÃodo chuvoso de 2010. Foi analisado o conteÃdo estomacal de 197 indivÃduos das seguintes espÃcies: Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1), pelo mÃtodo volumÃtrico e frequÃncia
de ocorrÃncia, para o cÃlculo do Ãndice alimentar (IAi). Com os dados morfomÃtricos foi obtido o Quociente Intestinal (QI). A amplitude de nicho foi estimada atravÃs do Ãndice de Levins e a sobreposiÃÃo trÃfica atravÃs do Ãndice de Pianka. PadrÃes de sobreposiÃÃo de nicho trÃfico foram calculados e estatisticamente testados contra um modelo nulo, atravÃs dos algoritmos de randomizaÃÃo RA3 e RA4. A dieta de A. bimaculatus foi constituÃda por 13 itens, e a de A. fasciatus constituÃda por 15, com preferÃncia alimentar pela alga filamentosa Spirogyra em ambas as espÃcies, sendo a importÃncia alimentar de 89,34% para A. bimaculatus e 96,86% A. fasciatus. A dieta de P. vivipara foi constituÃda por 60 itens, com maior importÃncia para as algas diatomÃceas (28,82%), clorofÃceas (23,17%) e cianofÃceas (5,2%), tendo as clorofÃceas Spirogyra e Closterium, maior importÃncia alimentar com 12,89% e 8,85%, respectivamente e fragmentos de insetos aquÃticos com 39,18%. A dieta de H. jaguribensis esteve constituÃda por 42 itens alimentares, com maior importÃncia para Spirogyra com 23,42%, e Compsopogon com 19%. O grupo diatomÃcea apresentou maior nÃmero de itens na dieta com 21 tÃxons e 16,38% de IAi, seguido pelo item alimentar detrito
com 27,72% de importÃncia. De acordo com o quociente intestinal A. bimaculatus e A. fasciatus apresentam intestino caracterÃstico de carnÃvoro/onÃvoro e P. vivipara de herbÃvoro. A anÃlise de variÃncia (ANOVA) para os valores mÃdios do quociente intestinal dos peixes analisados foi significativa com F= 3,50, df = 2, p< 0,05. A largura de nicho foi maior em P. vivipara com 1.32, seguido por A. bimaculatus com 0,78 e A. fasciatus com 0,426. Maior sobreposiÃÃo de nicho ocorreu entre as espÃcies de Astyanax com o valor de 0,98. A anÃlise dos modelos nulos realizados pelos itens totais e os itens agrupados indicou que os valores observados foram sempre maiores do que os esperados para a matriz RA3 e RA4. A variÃncia mÃdia observada tambÃm foi maior do que a simulada. De acordo com a dieta das quatro espÃcies analisadas, destacam a importÃncia de itens de origem autÃctone, principalmente as algas. Os modelos nulos indicam que as espÃcies de peixes herbÃvoras/onÃvoras apresentam partilha de recursos trÃficos, ou seja, a competiÃÃo nÃo à o agente estruturador dessa
comunidade. / The semiarid rivers present two patterns: the intermittent and the irregular one, with a single flowing off period per year, during the rainy season. In these rivers, the natural hydrological disturb acts as an important factor driving the organization of the system, in which feeding interactions are complex and modified by seasonality and system productiveness. Fishes often feed on autochthonous or allochthonous resources, with their diets varying according to the with seasonal variation of food availability. The hypothesis of this the present study is that in the semiarid river herbivorous/onivorous fish species present trophic resources partitioning. The major aim of this study the present investigation is was to determine the trophic resources partitioning for four species of fishes at in the Curu River. Field work collections were carried out throughout the rainy season, at the Curu River, in Pentecoste city town, in Cearà state. The stomach content of 197 individuals of the species Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1) was analyzed through the volumetric method in order to obtain for the frequency of each feeding item, so that the Index of Alimentary Importance (IAi) could have been measured. The morphometric data were used to obtain the intestinal quotient (IQ), the niche breadth estimated for the Levinsâ index and the trophic overlap for the Piankaâs index. Patterns of trophic niche overlap were calculated and statistically tested against a null model using the randomization algorithms RA3 and RA4. A. bimaculatus and A. fasciatus fed on 13 and 15 items, respectively. Both species presented feeding preferences for the filamentous algae Spirogyra sp., encompassing 89.34% and 96.86% of their diets, respectively. Poecilia viviparaâs diet comprised 60 items, mainly made up of algae (Bacillariophyta - 28.82%, Chlorophyta - 23.17% and Cyanophyta â 5.2%). Amongst the âgreen algaeâ, Spirogyra sp. (12.89%) and the Closterium sp. (8.85%) were the chief principal items eaten. Aquatic insects (39.18%) made up the second most important item. A total of 42 items compounded the diet of H. jaguribensis, which detritus (27,72%), the algae Spyrogira sp. (23.42%) and Compsopogon sp. (19%) were the foremost most important items. The diatom group comprised the most abundant item, with 21 taxa and 16.38% of IAi. According to the intestinal quotient, A. bimaculatus e A. fasciatus showed a typical carnivorous/omnivorous intestine, whereas P. vivipara showed a herbivorous one. The analysis of variance shows that the intestinal quotient varied among species (F = 3.50; d.f = 2; p < 0.05). The niche breadth was greater for P. vivipara (1.32), followed by A. bimaculatus (0.78) and A. fasciatus (0.426). The higher niche overlap occurred within the Astyanax species (0.98). The null model analysis carried out for the total and clustered grouped items indicated that the observed values were always higher than the expected ones for the RA3 and RA4 matrices. In addition, the mean observed variance was higher than the simulated one. The four studied fish species fed mainly on autochthonous items, chiefly on algae. The null models demonstrated that there is a resource partitioning amongst these herbivorous/omnivorous fish species, where competition seems not to be the structuring agent.
|
95 |
Problem med trådlösa nätverkPettersson, Jack, Jansson, Frida January 2014 (has links)
Målet med detta arbete har varit att besvara frågan; ”Varför uppstår det så mycket problem med trådlösa nätverk?”. Detta har gjorts genom att studera relevant litteratur för att sedan kunna utföra två egna studier: en enkätundersökning och tre experiment. Teorin har framförallt hämtats ur kurser och material från Cisco. Undersökningen har hjälpt till att fastställa den generella datoranvändarens kunskaper om trådlösa nätverk. Respondenternas kunskapsnivå visade bland annat på skillnader i hur de använde sin utrustning; de med lägre kunskap om nätverk gick sällan eller aldrig in i sin routers webbgränssnitt. Det vanligaste problemet som uppgavs i undersökningen var en långsam trådlös hastighet; att uppleva svårigheter vid konfigurationen av en ny trådlös router visade sig däremot vara det mest ovanliga. Experimenten genomfördes med hjälp av två accesspunkter och två klientdatorer. De visade bland annat hur kanalöverlappning i trådlösa nätverk leder till minskad hastighet, och betonade även vikten av att välja rätt kanal. Avslutningsvis kunde vi konstatera att varken konsumenten eller teknikindustrin ensidigt kan beskyllas för problemen inom trådlösa nätverk. Båda två har enskilda saker att jobba på. Konsumenterna bör i allt högre grad ta reda på mer om den utrustning de använderför att undvika att ställa till problem, inte bara för sig själv men också för andra. Industrin skulle kunna underlätta genom att dra ner utvecklandet av nya standarder – och inte enbart fokusera på ökad genomströmningshastighet. / The goal with this research has been to answer the question; ”Why are there so many problems linked to wireless networks?”. This has been done by studying the relevant literature to then be able to conduct two self-written studies: one survey and three laboratory experiments. The theory has been taken primarily out of courses and material from Cisco. The survey has helped to determine the knowledge of the general computer-user in regards to wireless networks. The respondents level of knowledge showed, among other things, differences in the way they used their devices; those with less network-knowledge rarely, or never, accessed their routers web-interface. The most common problem that was selected in the survey was a slow wireless speed; experiencing difficulties when configuring a new wireless router proved to be the most unusual one. The experiments were completed through the use of two access points and two computer clients. They demonstrated, among other things, how channel overlap in wireless networks leads to a reduced data-rate, and also stressed the importance of choosing the right channel. Lastly, the work revealed that neither the consumer nor the industry can be solely blamed for the problems that appear in wireless networks. Both of them have separate things towork towards. The consumers should, to a higher extent, find out more about the equipment they use to avoid causing problems, not only for themselves but also for others. The industry could help by slowing down the development of new standards – and to not only focus on achieving higher throughput-rates.
|
96 |
Brain activity associated with episodic memory : similarities and differences between encoding and retrievalPersson, Jonas January 2002 (has links)
Understanding the mnemonic functions of the brain has been extensively facilitated by the development of functional neuroimaging techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The present thesis aims at investigating the neural mechanisms underlying memory for personally experienced events (episodic memory), using PET. In paper I, similarities between encoding and retrieval of enacted (motor) information were explored. We observed increased retrieval activation in right premotor areas in the brain when sentences encoded by motor enactment and sentences encoded by maintenance rehearsal were contrasted. In paper II, overlap between encoding and retrieval was explicitly tested for three types of event information: spatial, item, and temporal. Using conjunction analyses, we found that encoding and retrieval of spatial information was associated with increased brain activity in bilateral inferior parietal regions. Encoding and retrieval of item information were related to increased activation in right inferior temporal cortex, and encoding and retrieval of temporal information were associated with increased activation in left inferior temporal and left inferior frontal cortex. In paper III, brain activity associated with retrieval success was examined. Conditions included three levels of retrieval success (high, medium, and low level), for two types of information (pictures and sentences). The results showed a pattern of activation that distinguished between brain regions involved in processing of sentences vs. processing of pictures. A second pattern that distinguished between brain regions involved in encoding vs. retrieval processes, irrespectively of material (sentences and pictures) and retrieval success, was also found. The manipulation of retrieval success was associated with systematic changes in the correlation between material specific regions and other areas of the brain. In study IV, changes in activation related to successful retrieval of pictures were investigated. More specifically, we expected to find decreases in infero-temporal (IT) regions of the brain that were associated with successful recognition memory. As expected, we found a region in left IT cortex that showed decreased activation related to memory for event information. This decrease in activation could be dissociated from responses related to novelty detection, and perceptual priming. The results from study I and II are discussed in relation to findings and theories regarding similarities between encoding and retrieval processes, and reactivation of modality-specific brain areas important for memory storage. The results from studies III and IV are discussed in relation to differences between encoding and retrieval processes, e.g. asymmetric frontal activation and sub-processes of episodic memory, such as retrieval mode, retrieval success, and novelty detection. Taken together, the studies show that different episodic memory processes are correlated with distinct brain areas, hence supporting the view that remembering is based on multiple component processes. / digitalisering@umu.se
|
97 |
Le burnout est-il une forme de dépression ? Approches psychométrique et expérimentale / Is burnout a form of depression ? Psychometric and experimental approachesBianchi, Renzo 13 November 2014 (has links)
La singularité nosologique du burnout vis-à-vis de la dépression n’est pas établie à ce jour. L’objectif de cette thèse de doctorat était d’examiner si burnout et dépression font référence à une même réalité pathologique ou constituent des phénomènes distincts. Nos travaux ont articulé approches dimensionnelles et catégorielles, et études transversales et longitudinales. Empiriquement, ces travaux ont révélé que burnout et dépression sont associés à des symptômes similaires, fluctuent à travers le temps de manière concomitante, et prédisent les mêmes altérations du traitement attentionnel de l’information émotionnelle – tel qu’indexé par l’enregistrement des mouvements oculaires des participants. En parallèle, notre analyse des fondements théoriques de la distinction burnout-dépression a montré que cette dernière est fragile et requiert une clarification. En effet, l’idée selon laquelle le burnout serait « spécifique du contexte de travail » tandis que la dépression serait « indépendante du contexte » n’est pas nosologiquement discriminante en soi. Saisis dans leur ensemble, ces résultats suggèrent que burnout et dépression pourraient couvrir une même réalité pathologique et renvoyer à une même catégorie nosologique, questionnant ainsi la vision actuellement dominante du chevauchement burnout-dépression / To date, the nosological singularity of burnout with respect to depression remains controversial. The aim of this doctoral dissertation was to examine whether burnout and depression refer to a single pathological realm or constitute distinct phenomena. Both dimensional and categorical approaches were adopted, and both cross-sectional and longitudinal designs were used. At an empirical level, our work revealed that burnout and depression are associated with similar symptoms, fluctuate concomitantly over time, and predict the same alterations in the attentional processing of emotional information—as indexed by eye movement recording of participants’ gaze. At a theoretical level, our analyses showed that the grounds of the burnout-depression distinction are fragile and require clarification. Indeed, the idea that burnout is “work-specific” whereas depression is “context-free” is not nosologically discriminating per se. Overall, these results suggest that burnout and depression may cover a single pathological realm and belong to a single nosological category, thus questioning the currently-dominant view of the burnout-depression overlap
|
98 |
The victim-offender as the epitome of the nonideal victimBerrend, Ashanti January 2020 (has links)
The victim-offender overlap has been extensively studied and documented overthe last decades. Various studies have identified young men as the most commonvictims of violent assault, yet the public, the media, but also criminologicalresearch have actively favored the discourse on the ideal victim. Consequently,not much is known about how victim-offenders experience and perceivevictimization.The present systematic literature review aims to analyze how violent victimizationis experienced and narrated by male victim-offenders in the context of hegemonicmasculinity. Secondly, it aims to analyze in how far the public’s attitudes ofvictim blaming and victim concern are affected by a belief in a just world.Collectively, these findings aim to create a better understanding of criminal men’svictim identities.The public’s empathy and concern are reserved to the innocent and vulnerablevictim; criminal men are perceived as culpable and deserving of victimization.The latter use violence as an instrument of dominance and subordination, in linewith hegemonic masculinity beliefs, and reject the victim identity (antithesis ofmasculinity), forming a new category of the nonideal victim.
|
99 |
Full-Duplex Communications in Large-Scale Cellular NetworksAlammouri, Ahmad 04 1900 (has links)
In-band full-duplex (FD) communications have been optimistically promoted to improve the spectrum utilization and efficiency. However, the penetration of FD communications to the cellular networks domain is challenging due to the imposed uplink/downlink interference. This thesis presents a tractable framework, based on stochastic geometry, to study FD communications in multi-tier cellular networks. Particularly, we assess the FD communications effect on the network performance and quantify the associated gains. The study proves the vulnerability of the uplink to the downlink interference and shows that the improved FD rate gains harvested in the downlink
(up to 97%) comes at the expense of a significant degradation in the uplink rate (up to 94%). Therefore, we propose a novel fine-grained duplexing scheme, denoted as α-duplex scheme, which allows a partial overlap between the uplink and the downlink frequency bands. We derive the required conditions to harvest rate gains from the α-duplex scheme and show its superiority to both the FD and half-duplex (HD) schemes. In particular, we show that the α-duplex scheme provides a simultaneous improvement of 28% for the downlink rate and 56% for the uplink rate. We also show that the amount of the overlap can be optimized based on the network design objective.
Moreover, backward compatibility is an essential ingredient for the success of new technologies. In the context of in-band FD communication, FD base stations (BSs) should support HD users' equipment (UEs) without sacrificing the foreseen FD gains. The results show that FD-UEs are not necessarily required to harvest rate gains from FD-BSs. In particular, the results show that adding FD-UEs to FD-BSs offers a maximum of 5% rate gain over FD-BSs and HD-UEs case, which is a marginal gain compared to the burden required to implement FD transceivers at the UEs' side. To this end, we shed light on practical scenarios where HD-UEs operation with FD-BSs outperforms the operation when both the BSs and UEs are FD and we find a closed
form expression for the critical value of the self-interference cancellation power required for the FD UEs to outperform HD UEs.
|
100 |
Jämförelse mellan 60 % och 80 % övertäckning vid matchning av flygbilder : För framställning av ytmodellRudolfsson, Anton January 2017 (has links)
No description available.
|
Page generated in 0.0736 seconds