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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.
101

Quantitative imaging of multi-component turbulent jets

Ash, Arash 26 April 2012 (has links)
The Gaseous state of hydrogen at ambient temperature, combined with the fact that hydrogen is highly flammable, results in the requirement of more robust, high pressure storage systems that can meet modern safety standards. To develop these new safety standards and to properly predict the phenomena of hydrogen dispersion, a better understanding of the resulting flow structures and flammable regions from controlled and uncontrolled releases of hydrogen gas must be achieved. In this study the subsonic release of hydrogen was emulated using helium as a substitute working fluid. A sharp-edged orifice round turbulent jet is used to emulate releases in which leak geometry is circular. Effects of buoyancy, crossflow and adjacent surfaces were studied over a wide range of Froude numbers. The velocity fields of turbulent jets were characterized using particle image velocimetry (PIV). The mean and fluctuation velocity components were well quantified to show the effect of buoyancy due to the density difference between helium and the surrounding air. In the range of Froude numbers investigated, increasing effects of buoyancy were seen to be proportional to the reduction of the Fr number. The obtained results will serve as control reference values for further concentration measurement study and for computational fluid dynamics (CFD) validation. / Graduate
102

A replay driven model of spatial sequence learning in the hippocampus-prefrontal cortex network using reservoir computing / Un modèle de rejeu de séquences spatiales dans un réseau Hippocampe-Cortex préfrontal utilisant le reservoir computing

Cazin, Nicolas 12 July 2018 (has links)
Alors que le rat apprend à chercher de multiples sources de nourriture ou d'eau, des processus d'apprentissage de séquences spatiales et de rejeu ont lieu dans l'hippocampe et le cortex préfrontal.Des études récentes (De Jong et al. 2011; Carr, Jadhav, and Frank 2011) mettent en évidence que la navigation spatiale dans l'hippocampe de rat implique le rejeu de l'activation de cellules de lieu durant les étant de sommeil et d'éveil en générant des petites sous séquences contigues d'activation de cellules de lieu cohérentes entre elles. Ces fragments sont observés en particulier lors d'évènements sharp wave ripple (SPWR).Les phénomènes de rejeu lors du sommeil dans le contexte de la consolidation de la mémoire à long terme ont beaucoup attiré l'attention. Ici nous nous focalisons sur le rôle du rejeu pendant l'état d'éveil.Nous formulons l'hypothèse que ces fragments peuvent être utilisés par le cortex préfrontal pour réaliser une tâche d'apprentissage spatial comprenant plusieurs buts.Nous proposons de développer un modèle intégré d'hippocampe et de cortex préfrontal capable de générer des séquences d'activation de cellules de lieu.Le travail collaboratif proposé prolonge les travaux existants sur un modèle de cognition spatiale pour des tâches orientés but plus simples (Barrera and Weitzenfeld 2008; Barrera et al. 2015) avec un nouveau modèle basé sur le rejeu pour la formation de mémoire dans l'hippocampe et l'apprentissage et génération de séquences spatiales par le cortex préfrontal.En contraste avec les travaux existants d'apprentissage de séquence qui repose sur des règles d'apprentissage sophistiquées, nous proposons d'utiliser un paradigme calculatoire appelé calcul par réservoir (Dominey 1995) dans lequel des groupes importants de neurones artificiels dont la connectivité est fixe traitent dynamiquement l'information au travers de réverbérations. Ce modèle calculatoire par réservoir consolide les fragments de séquence d'activations de cellule de lieu en une plus grande séquence qui pourra être rappelée elle-même par des fragments de séquence.Le travail proposé est supposé contribuer à une nouvelle compréhension du rôle du phénomène de rejeu dans l'acquisition de la mémoire dans une tâche complexe liée à l'apprentissage de séquence.Cette compréhension opérationnelle sera mise à profit et testée dans l'architecture cognitive incarnée d'un robot mobile selon l'approche animat (Wilson 1991) [etc...] / As rats learn to search for multiple sources of food or water in a complex environment, processes of spatial sequence learning and recall in the hippocampus (HC) and prefrontal cortex (PFC) are taking place. Recent studies (De Jong et al. 2011; Carr, Jadhav, and Frank 2011) show that spatial navigation in the rat hippocampus involves the replay of place-cell firing during awake and sleep states generating small contiguous subsequences of spatially related place-cell activations that we will call "snippets". These "snippets" occur primarily during sharp-wave-ripple (SPWR) events. Much attention has been paid to replay during sleep in the context of long-term memory consolidation. Here we focus on the role of replay during the awake state, as the animal is learning across multiple trials.We hypothesize that these "snippets" can be used by the PFC to achieve multi-goal spatial sequence learning.We propose to develop an integrated model of HC and PFC that is able to form place-cell activation sequences based on snippet replay. The proposed collaborative research will extend existing spatial cognition model for simpler goal-oriented tasks (Barrera and Weitzenfeld 2008; Barrera et al. 2015) with a new replay-driven model for memory formation in the hippocampus and spatial sequence learning and recall in PFC.In contrast to existing work on sequence learning that relies heavily on sophisticated learning algorithms and synaptic modification rules, we propose to use an alternative computational framework known as reservoir computing (Dominey 1995) in which large pools of prewired neural elements process information dynamically through reverberations. This reservoir computational model will consolidate snippets into larger place-cell activation sequences that may be later recalled by subsets of the original sequences.The proposed work is expected to generate a new understanding of the role of replay in memory acquisition in complex tasks such as sequence learning. That operational understanding will be leveraged and tested on a an embodied-cognitive real-time framework of a robot, related to the animat paradigm (Wilson 1991) [etc...]
103

Sjöstridskrafter i fredsfrämjande operationer : En teoriprövande studie av Geoffrey Tills teori i Operation Sharp Guard och UNIFIL MTF448

Jönsson, Anna January 2018 (has links)
This research paper examines the advantages of deployment of naval forces in peace support operations. The study has been undertaken because the research on this subject is fairly limited. The research tends to be normative and traditional strategists are often focusing on the effect of naval force in terms of war. None of the writers on the subject dispute the use of naval force moreover, they tend to highlight the advantages of a naval force.   The purpose is to analyse the usefulness of a naval force in peace support operations. This has been achieved by testing Till´s theory of the inherently advantage of a naval force in a study of two cases, Operation Sharp Guard in the Adriatic Sea during the conflict in former Yugoslavia and the Swedish contribution to UNIFIL MTF448 in Lebanon. These two cases were selected in order to ascertain to what extent Till´s theory can explain the effect of naval force. Results of this analyse demonstrate the existence of sound arguments for the use of naval force in peace support operations and the empirics of the two cases are valid evidence for that. Naval force can sometimes even work as an enabler for ground troops and air force. The analysis shows furthermore that flexibility and strategic mobility was the two most distinguishing features of a naval force in both cases.
104

COMPARAÇÃO ENTRE DOIS SISTEMAS HIDRÁULICOS DE MEDIÇÃO DE AGUA DE IRRIGAÇÃO DE ARROZ / COMPARISON BETWEEN TWO HIDRAULICS SYSTEMS OF MEASUREMENT OF RICE IRRIGATION WATER

Luz, Glauco de Oliveira da 24 February 2011 (has links)
The irrigated farm crops are the main users of water. With this, in places where there is a water shortage to attend all sorts of use, this kind of activity is characterized like as a potentially conflicting, once that to produce one hectare of rice, are necessary thousands cubic meters of water. To work out this conflict, many actions are been developed, as giving rights and tax to use water. Although, to the effectiveness of that actions, is necessary an effective inspection over all of the producers and users, monitoring each volume used. Being a inspection this kind unsustainable to the manager, is necessary the study of methodologies to determine water flow and volumes of irrigation, which shall be easily understood and applied, to be used by the producers themselves. Were tested, comparatively, two sorts of hydraulics systems, sharp crested Weirs and Velocimetric Hydrometers, measurers of water flow and volumes respectively, for monitoring the volumes of irrigation of two parcels of irrigated rice in the harvest 2009/2010, located in Cachoeira do Sul city, in Capané locality. In each parcel, one with Direct tillage and area of 0,66 ha and another one with Conventional tillage and area of 0,80 ha, the monitoring of water occurred simultaneously by using the Weirs and Hydrometers installed in sequence and confined, in other words, the monitored water was the same in both systems. Was used Pluviometer to monitoring the total volume of rain fall, in order that, with the irrigation volume was calculated the total volume necessary to that rice parcels. The results of the comparative monitoring between Weirs of Thin Wall and Velocimetric Hydrometers showed a small difference in the final results, been the difference of 1,15% bigger by the Hydrometer in relation to Weir in the parcel with Direct tillage and 6,75% smaller by Hydrometer in relation to Weir in Conventional tillage. However, Were verified daily variations between the Weirs and Hydrometers that reached 82% in the Direct tillage and 39% in the Conventional tillage. The total volume monitored to each parcel was 8565,15 m³/ha in the parcel with Direct tillage and 9987,25 m³/ha in the conventional tillage, both considering the results of Weirs. With the results found and the characteristics of operation and maintenance of the analyzed systems, is checked the availability of using sharp crested Weirs for monitoring water quantity in rice crops, although by the comparatively study oh both systems, is not recommended to use hydrometers in these ways. / As lavouras de arroz irrigado são as principais usuárias de água durante o seu ciclo produtivo. Com isto, em locais onde existe escassez de água para atender a diversos usos este tipo de empreendimento se caracteriza como um potencial conflitante, uma vez que para produção de um hectare de arroz são necessários milhares de metros cúbicos de água. Para resolver estes conflitos, muitos instrumentos estão sendo desenvolvidos, como a outorga e a cobrança pelo uso da água. No entanto, para a efetividade destes instrumentos, é necessária uma fiscalização extensiva sobre todos os produtores e usuários, monitorando os respectivos volumes utilizados. Sendo uma fiscalização deste tipo insustentável para o órgão gestor se faz necessário o estudo de metodologias de determinação de vazões e volumes de irrigação que sejam de fácil entendimento e aplicação, para que possam ser utilizadas e monitoradas pelos próprios produtores rurais (automonitoramento). Foram testados comparativamente dois tipos de sistemas hidráulicos, Vertedores de parede delgada e Hidrômetros Velocimétricos, medidores de vazões e volumes respectivamente, para monitoramento dos volumes de irrigação de duas parcelas de arroz irrigado na safra de 2009/2010, localizados na cidade de Cachoeira do Sul, na localidade de Capané. Em cada uma das parcelas, uma com sistema de plantio Direto e área de 0,66 ha e outra com plantio Convencional com área de 0,80 ha, o monitoramento da água ocorreu de forma simultânea através da utilização de vertedores e hidrômetros instalados em série e confinados, ou seja, a água monitorada por um era a mesma que a monitorada pelo outro. Foi utilizado Pluviômetro no monitoramento do volume total de precipitações, para que juntamente com o volume de irrigação fosse determinado o volume total necessário ao cultivo do arroz naquelas parcelas. O resultado do monitoramento comparativo entre Vertedores e Hidrômetros apresentou pequena variação no resultado final, sendo a diferença de 1,15% monitorada a mais pelo Hidrômetro em relação ao vertedor na parcela com plantio Direto e 6,75% a menos pelo Hidrômetro que o Vertedor na parcela com plantio Convencional. No entanto, foram verificadas variações diárias entre os Vertedores e os Hidrômetros que alcançaram 82% no plantio direto e 39% no plantio convencional. O volume total monitorado para cada parcela foi de 8565,15 m³/ha na parcela com plantio Direto e 9987,25 m³/ha no plantio Convencional, ambos considerando os resultados obtidos com os vertedores. Com os resultados obtidos e as características de operação e manutenção dos sistemas analisados, verifica-se a viabilidade da utilização de Vertedores de parede delgada para o automonitoramento de água em lavouras orizicolas, no entanto, através do estudo comparativo dos dois sistemas, não se recomenda a utilização de Hidrômetros Velocimétricos neste meio.
105

Code Switching on Flashback : A Study of Code Switching on an Internet Based Discussion Forum

Aronsson, Johanna January 2014 (has links)
This essay is a study of how English is used in a Swedish discussion forum called Flashback. The mixing of two languages when speaking or writing is called Code switching. Code switching often occurs in bilingual societies. In Sweden it is possible to say that English is a second language due to the daily encounter with the language through education, but also through different media. The daily encounter with English and the number of English loan words in Swedish might be a reason why code switching exists in Sweden. The material that was analyzed in this essay was collected from Flashback and analyzed with a method based on Sharp’s (2001) study of spoken language. The aim of this study was to see how often and in what way the users on Flashback code switched between Swedish and English. The results showed that even though English was used in the discussion, Swedish was the main language. Most of the code switches that were found in the material occurred in mixed units, in other words English was mixed with Swedish.
106

A C Navigational System

Hammerquist, James D. (James Daniel) 05 1900 (has links)
The C Navigational System (CNS) is a proposed programming environment for the C programming language. The introduction covers the major influences of programming environments and the components of a programming environment. The system is designed to support the design, coding and maintenance phases of software development. CNS provides multiple views to both the source and documentation for a programming project. User-defined and system-defined links allow the source and documentation to be hierarchically searched. CNS also creates a history list and function interface for each function in a module. The final chapter compares CNS and several other programming environments (Microscope, Rn, Cedar, PECAN, and Marvel).
107

Pacifismo e não-violência : pensamento político e humanitário em Gene Sharp /

Vieira, André Luiz Valim. January 2020 (has links)
Orientador: Rafael Salatini de Almeida / Resumo: O presente projeto procura estudar e debater o tema relacionado à antinomia permanente entre, de um lado, a paz e pacifismo, e, de outro, a guerra e a violência. Assim, partir da doutrina da não-violência em face do conflito político permeado pelos Estados contra seus cidadãos, mesmo perante organizações ditas democráticas, procuraremos compreender os temas da paz e da não violência e sua conformação nos escritos de Gene Sharp. Assim, levantando-se a discussão acerca de um direito humano de resistência não-violenta, tomando por referência a doutrina da desobediência civil e culminando em um direito humano de todos os povos de revolução, todavia, realizável por meios pacíficos. As práticas filosóficas da não-violência, propostas por Gandhi e outros pacifistas, se transformam em teoria política de resistência e em ação coletiva de confrontação e de lutas. Porém, enquanto toda revolução pressupõe violência e uso da força, a prática da não-violência como referencial de um agir político, na esfera nacional e internacional, se mostra como grande potencial de adesões e de conquistas, obtendo cada vez mais o apoio social. Somente se entendendo os estudos políticos e humanitários relacionados à paz e ao pacifismo, conseguiremos mensurar o alcance das teorias e doutrinas de não-violência. Estes se mostram fundamentais para a discussão e análise dos métodos de luta e revolução não-violentos propostos por Gene Sharp. O estudo e a proposta tomam por ponto de convergência desses institutos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This project seeks to study and debate the theme related to the permanent antinomy between peace and pacifism, and on the other hand war and violence. Thus, from the doctrine of nonviolence in the face of political conflict permeated by states against their citizens, even before so-called democratic organizations, we will seek to understand the themes of peace and nonviolence and their conformation to the writings of Gene Sharp. Thus, raising the discussion about a human right of nonviolent resistance by reference to the doctrine of civil disobedience and culminating in a human right of all peoples of revolution, yet achievable by peaceful means. The philosophical practices of nonviolence proposed by Gandhi and other pacifists become political theory of resistance and collective action of confrontation and struggle. However, while every revolution presupposes violence and the use of force, the practice of nonviolence as a reference for political action and at the national and international levels is shown to be a great potential for adhesions and achievements, increasingly obtaining social support. Only by understanding the political and humanitarian studies related to peace and pacifism can we measure the extent of nonviolence theories and doctrines. These are fundamental for the discussion and analysis of the methods of nonviolent struggle and revolution proposed by Gene Sharp. The study and proposal take as a point of convergence of these institutes of pacifism and nonviol... (Complete abstract click electronic access below) / Astratto: Questo progetto mira a studiare e discutere il tema relativo all'antinomia permanente tra pace e pacifismo, e d'altra parte guerra e violenza. Quindi, dalla dottrina della nonviolenza di fronte al conflitto politico permeato dagli stati contro i loro cittadini, anche prima delle cosiddette organizzazioni democratiche, cercheremo di comprendere i temi della pace e della nonviolenza e della loro conformazione agli scritti di Gene Sharp. Quindi, sollevando la discussione su un diritto umano di resistenza non violenta facendo riferimento alla dottrina della disobbedienza civile e culminando in un diritto umano di tutti i popoli della rivoluzione, eppure raggiungibile con mezzi pacifici. Le pratiche filosofiche di nonviolenza proposte da Gandhi e altri pacifisti diventano teoria politica di resistenza e azione collettiva di confronto e lotta. Tuttavia, mentre ogni rivoluzione presuppone la violenza e l'uso della forza, la pratica della nonviolenza come riferimento per l'azione politica e a livello nazionale e internazionale ha dimostrato di essere un grande potenziale per adesioni e risultati, ottenendo sempre più supporto sociale. Solo comprendendo gli studi politici e umanitari relativi alla pace e al pacifismo possiamo misurare l'estensione delle teorie e delle dottrine della non violenza. Questi sono fondamentali per la discussione e l'analisi dei metodi di lotta e violenza nonviolenta proposti da Gene Sharp. Lo studio e la proposta prendono come punto di convergenza questi is / Doutor
108

Simulating Human Movement Patterns in an Area : A Part of the Crowdmapper Project

Svanberg, Rasmus, Svensson, Hampus January 2021 (has links)
In 2019, the Covid-19 pandemic struck the world, creating a need for social distancing to stop the spreading of the virus. This report will discuss and cover how a simulation was implemented in the game engine Unity that simulates human movement-patterns, which in turn will help with spreading people out in public areas. To be able to do this accurately, research was made about which behaviours can be of importance to get as realistic a representation of human movements as possible. The performed research showed that some contributing factors to get a realistic result includes how many destinations (e.g. in a Supermarket, a destination would be a shelf with wares) a human usually visits during a shopping trip to a supermarket. This is something that was quickly realized and could be used and implemented in the simulation, as it directly affects how long each human stays in the store, which in the long run makes crowds, and places where they form, more realistic. When the simulation was finished, a Google Forms was created, which were spread in numerous different groups on Facebook and Reddit, in which a total of 60 participants were registered. This quantitative research gave a good understanding of how the project had turned out and what could be improved. The results were very promising, and more or less what was hoped for. There is still room for further improvements, which are all mentioned in the chapter “Further Research” of this report. One example that is mentioned here is whether or not collisions between our simulated humans matter enough to make a difference to the end result. It is argued that it does not, but this is something one should perform further studies on.
109

Operationssjuksköterskors upplevelser av att handha vassa instrument : En kvalitativ intervjustudie / Theatre nurses’ experiences of handling sharp instruments : A qualitative interview study

Beckenham, Nadia, Frost, Jenny January 2020 (has links)
Introduktion Operationssjuksköterskor handhar dagligen vassa instrument och har ett nära samarbete med operatören. Det finns risk för stick- och skärskador, varför flera utarbetade preventiva metoder finns att tillgå. Instrumenteringen av vassa instrument ska vara effektiv och säker. Handhavandet kräver kunskap och ställer krav på operationssjuksköterskan. Syfte Syftet med studien var att beskriva operationssjuksköterskors upplevelser av det intraoperativa handhavandet av vassa instrument. Metod Kvalitativ metod med induktiv ansats och individuella semistrukturerade intervjuer. Data analyserades genom manifest och latent innehållsanalys. Resultat Sju underkategorier, tre huvudkategorier samt ett övergripande tema framkom. Operationssjuksköterskorna var trygga i sin roll och arbetade med lugnt och fokuserat förhållningssätt utifrån personligt utformade arbetssätt för att bevara kontrollen. Säkert handhavande hos operatören upplevdes respektfullt och operationssjuksköterskorna anpassade sig och sade ifrån när riskfyllt handhavande observerades. Vid stick- och skärskada var professionellt handlande med bevarad aseptik angeläget. En viss rädsla för blodburen smitta fanns, men de såg samtidigt stick- och skärskador som en del av vardagen i deras arbetsmiljö. Slutsats Operationssjuksköterskorna var trygga i handhavandet av vassa instrument vilket gav dem förmåga till att anpassa sig. Konsekvent användande av personligt utformade arbetssätt upplevdes säkert och bidrog till kontroll. Stick- och skärskadepreventiva metoder användes i synnerhet vid känd blodburen smitta då rädsla förelåg att drabbas av smitta. / Introduction Theatre nurses manages sharp instruments and works closely with the surgeon. There is a risk of sharps injury and several developed preventative methods are avaliable. Instrumentation of sharp instruments must be effective and safe. The management requires knowledge and puts demands on the theatre nurse. Aim To describe the theatre nurses’ experiences of the intraoperative management of sharp instruments. Method Qualitative method with an inductive approach and individual semi-structured interviews. Data was analyzed with manifest and latent content analysis. Results Seven subcategories, three main categories and one covering theme. Theatre nurses were confident in their role and worked with a calm and focused approach with own personal designed work routines to maintain control. Safe management by the surgeon led to feelings of respect towards the theatre nurses and they adapted and reprimanded the surgeon when hazardous management was observed. In case of sharps injury, professional managing with remained asepsis was important. There was some level of fear towards bloodborne pathogen, but at the same time they saw sharp injuries as a common occurrence in their work environment. Conclusion Theatre nurses were confident in the management of sharp instruments which gave them the ability to adapt. Consistent use of personal designed work routines was percieved as safe and contributed to control. Preventative methods against sharps injury were especially used in care of patients with known bloodbourne pathogene as there was a fear of being infected.
110

Correlation between saw blade width and kerf width

Menschel, Melissa 16 July 2020 (has links)
Previous studies of saw marks have primarily focused on morphological characteristics and their utility in identifying saws suspected to have been utilized in cases of criminal dismemberment. The present study examined the extent to which metric analysis may be used to correlate saw blades measurements of kerf width. A sample of 56 partially defleshed white-tailed deer (Odocoileus virginianus) limbs were utilized as a proxy for human remains. The partial limbs were cut using a variety of commercially available saws, including 11 manual-powered saws and 5 mechanical-powered saws. A total of 500 false start kerfs (FSKs) were measured using digital calipers. Two experiments were performed, with the first test examining the kerf widths of false starts produced on specimens that were restrained using clamps, while the second test analyzed the kerf widths of false starts produced on minimally restrained specimens. Statistical analysis using Hierarchical Linear Modeling indicated a positive relationship between saw blade width (mm) and minimum kerf width (MKW), with the model estimating that MKWs would increase by 1.61 mm for every millimeter increase in blade width. Results from the models indicated that blade width (p<0.001) and the difference between mechanical- and manual-powered saws (p=0.029) were considered statistically significant. A comparison of MKWs produced using manual-powered saws on unrestrained and restrained bones suggests that restraint condition (p=0.009) is statistically significant. In comparisons of MKWs to blade widths, the average ratio for used saws was 2.7% greater than the average ratio for new saws. The mode of the ratios was approximately 1.4, supporting the general rule that MKW does not exceed 1.5 times saw blade width.

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