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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.
21

A Cloud-Based Execution Environment for a Pandemic Simulator

Basile, Maurizio, Raciti, Massimiliano Gabriele January 2009 (has links)
<p>The aim of this thesis is to develop a flexible distributed platform designed toexecute a disease outbreaks simulator in a fast way over many types of platformsand operating systems. The architecture is realized using the Elastic ComputeCloud (EC2) supplied by Amazon and Condor as middleware among the varioustypes of OS. The second part of the report describes the realization of a webapplication that allows users to manage easily the various part of the architecture,to launch the simulations and to view some statistics of the relative results.</p>
22

Infraestructura para computación de alta disponibilidad y administración de recursos mediante Condor

Martínez, Paula 29 December 2014 (has links)
Los trabajos que requieren capacidad de cómputo intensiva necesitan de un administrador de carga de trabajo especializado, que brinde mecanismos de cola, políticas de planificación, esquema de prioridades, monitoreo y administración de recursos. Cuando los usuarios emiten sus trabajos, el administrador deberá decidir cuándo y dónde ejecutarlos, teniendo en cuenta sus requerimientos, realizar un monitoreo del progreso e informar al usuario cuando haya finalizado su ejecución. Al integrar capacidad de proceso, almacenamiento y acceso a recursos remotos, se podrán ejecutar aplicaciones que no pueden procesarse en una computadora única y así satisfacer demandas de cómputo complejas. En este trabajo se discute el uso de Condor como gestor de recursos disponibles en un entorno de Computación de Alta Disponibilidad ya que es un sistema que ofrece funcionalidades de HTC donde los usuarios no tienen que preocuparse, por ejemplo, dónde enviar sus trabajos para ejecución, ni de tener que enviar manualmente un gran número de ellos cuando así lo requieran.
23

Integration of hydrothermal processes on a forest-based biorefinery site

Häreskog, Linnea January 2018 (has links)
The pulp and paper industry (PPI) is a business that produce large amounts of residues annually. Besides bark, large quantities of sludge are produced from the various parts of the industrial process. The sludge that comes from the biological wastewater purification process is denoted biosludge and is known as a particularly problematic waste product. It is of interest to reduce the amount of sludge from the PPI or to find new ways of handling the produced sludge. The common way to treat the PPI sludge is by incineration in the site’s bark boiler. The material is however difficult to dewater and often does more harm than good in the boilers. Different technologies to try and dewater the sludge further have been investigated previously, one that has recently been noted is hydrothermal treatment. The technology described in this thesis work is called hydrothermal carbonization (HTC) which uses water as a reaction media to turn the sludge into a coal-like material called hydrochar. The hydrochar has a higher heating value than the initial sludge and is more hydrophobic which makes it easier to dewater. This Master’s thesis describes the process technologies of the HTC process and presents some of the recent work done within the area. The properties of different residues from the PPI are presented before the integration of an HTC process on the biorefinery site in Domsjö, Sweden is discussed using previously published articles. A survey concerning sludge from industries within a 500 km range of the Domsjö biorefinery site is made to investigate whether residual streams similar to the ones at the Domsjö site are available in the vicinity. The results show that an HTC process demands energy in the form of steam and/or electricity. A previously made pinch and total site analysis show that the most accessible steam at the Domsjö biorefinery site, that most appliances and process steps uses, is at 7 bars. There are also steam levels of 20 and 32 bar in the area, which is within the range an HTC plant requires. The HTC process water demands further treatment which puts an extra stress on the already existing water purification process. The Domsjö biorefinery site produces 6000 tonnes of biosludge per year. Several HTC companies produce units that normally treat 20000-50000 tonnes of sludge per year, which indicates that additional sludge could be added to reach full capacity. The survey shows that there are similar materials available in the surroundings. It is concluded that further investigations concerning the sludge materials must be made before real implementation consequences can be calculated.
24

Real Time Cross Platform Collaboration Between Virtual Reality & Mixed Reality

January 2017 (has links)
abstract: Virtual Reality (hereafter VR) and Mixed Reality (hereafter MR) have opened a new line of applications and possibilities. Amidst a vast network of potential applications, little research has been done to provide real time collaboration capability between users of VR and MR. The idea of this thesis study is to develop and test a real time collaboration system between VR and MR. The system works similar to a Google document where two or more users can see what others are doing i.e. writing, modifying, viewing, etc. Similarly, the system developed during this study will enable users in VR and MR to collaborate in real time. The study of developing a real-time cross-platform collaboration system between VR and MR takes into consideration a scenario in which multiple device users are connected to a multiplayer network where they are guided to perform various tasks concurrently. Usability testing was conducted to evaluate participant perceptions of the system. Users were required to assemble a chair in alternating turns; thereafter users were required to fill a survey and give an audio interview. Results collected from the participants showed positive feedback towards using VR and MR for collaboration. However, there are several limitations with the current generation of devices that hinder mass adoption. Devices with better performance factors will lead to wider adoption. / Dissertation/Thesis / Final Output / Keynote / Thesis Demo / Masters Thesis Computer Science 2017
25

Análise dos efeitos citotóxicos, genotóxicos e mutagênicos do inseticida malation, utilizando os sistemas teste de Allium cepa e células de mamíferos /

Bianchi, Jaqueline. January 2008 (has links)
Orientador: Maria Aparecida Marin Morales / Banca: Silvia Tamie Matsumoto / Banca: Mário sérgio Mantovani / Resumo: Os agrotóxicos, substâncias químicas muito utilizadas para combater pragas na agricultura e nas residências, além de contribuírem para o aumento da produtividade e, conseqüentemente, o crescimento economia, também são responsáveis pela contaminação ambiental, quando utilizados indiscriminadamente, e por muitos casos de intoxicações e doenças genéticas nos seres humanos. Dependendo de sua composição química, degradabilidade e persistência no ambiente, os agrotóxicos podem comprometer a cadeia alimentar e afetar o ecossistema como um todo. Dentre os agrotóxicos bastante utilizados em todo o mundo, está o organofosforado malation. Pelo seu amplo uso, torna-se preocupante os possíveis danos que este inseticida possa promover no meio ambiente e nos organismos a ele expostos, pois alguns trabalhos já mostram esta sua ação detrimental. Desta forma, este trabalho investigou o potencial de indução de danos no DNA, para diferentes concentrações de malation, por meio das técnicas de aberrações cromossômicas e teste do micronúcleo em A. cepa e micronúcleo e ensaio do cometa em células HTC (hepatoma tissue culture). Nos testes com células meristemáticas e F1 de A. cepa, expostas por 24 e 48 horas ao malation, foram verificadas freqüências significativamente elevadas de AC e MN. Após 24 horas de exposição, não houve aumento na quantidade de AC, mas sim de MN. A análise das células F1 de A. cepa, juntamente com o teste de AC, forneceu dados importantes sobre a fixação dos danos genéticos induzidos pelo malation. Nenhum resultado relevante de citotoxicidade foi verificado em A. cepa. Após passarem pelo teste de recuperação, somente as células expostas às menores concentrações testadas apresentaram diminuição nos índices de AC e MN. / Abstract: Pesticides, chemicals widely used to combat pest in agriculture and in homes, besides contribute to the increase productivity and the economy, are also responsible for environmental pollution and for many intoxications cases and genetic diseases in human beings. Depending on their chemical composition, degradability and degree of persistence in the environment, the pesticides can endanger the food chain and affect the entire ecosystem. Among the pesticides most used in the world is the organophosphate malathion. Due to its widespread use it has been worrying the possible damages that can promote this insecticide in the environment and in organisms exposed to it. This study investigated the induction potential of DNA damage with several malathion concentrations using chromosomic aberration (CA) techniques, micronucleus test (MN) in A. cepa and micronucleus and comet assay in hepatoma tissue culture (HTC). In A. cepa tests, meristematic and F1 cells exposed for 24 and 48 hours to malathion showed significative frequencies of CA and MN. After 24 hours of exposure, there was no increase in the CA amounts, but was observed an increase to frequency of MN. The F1 cells analysis, together with the CA tests, provided important data on the genetic damages fixation induced by malathion. No relevant results of citotoxicity were verified in A. cepa. After the recovery test, the cells exposed to the smaller tested concentrations of malathion showed reduction of AC and MN indices. In the HTC cells test, was verified by the comet assay, genotoxic effects for all the tested concentrations, after exposure for 24 hours to the insecticide, but by the micronucleus tests, no significative results were found. These data suggest that the DNA lesions were repaired and not elapsed in mutation. With the concomitant realization of different tests, the clastogenic action of malathion could be verified. / Mestre
26

A Cloud-Based Execution Environment for a Pandemic Simulator

Basile, Maurizio, Raciti, Massimiliano Gabriele January 2009 (has links)
The aim of this thesis is to develop a flexible distributed platform designed toexecute a disease outbreaks simulator in a fast way over many types of platformsand operating systems. The architecture is realized using the Elastic ComputeCloud (EC2) supplied by Amazon and Condor as middleware among the varioustypes of OS. The second part of the report describes the realization of a webapplication that allows users to manage easily the various part of the architecture,to launch the simulations and to view some statistics of the relative results.
27

AC losses in superconductors : a multi-scale approach for the design of high current cables / Pertes AC dans les supraconducteurs : une approche multi-échelle pour le dimensionnement de câbles fort courant

Escamez, Guillaume 21 October 2016 (has links)
Le travail de cette thèse porte sur l'étude des pertes AC dans les supraconducteurs pour des applications tels que les câbles ou les aimants. Les modélisations numériques rapportées sont de type éléments-finis et méthode intégrale. Toutes ces méthodes visent à résoudre à calculer les distributions de densité de courant et de champ magnétique en prenant en compte différents loi de comportement pour le supraconducteur. Deux conducteurs sont introduits dans ce mémoire. Tout d'abord, les supraconducteurs à haute température critiques sont étudiées avec l'introduction d'une nouvelle forme de conducteur (fils cylindriques) et sont envisagés pour des câbles fort courant de 3~kA. Dans un second temps, des simulations numériques 3-D sont réalisés sur un conducteur MgB2. Le chapitre suivant traite des contraintes de calculs des pertes dans le but de dimensionner l'ensemble des pertes d'un câble complet. Enfin, les modèles numériques développés précédemment sont utilisé sur un exemple concret : le démonstrateur 10~kA fait à l'aide du conducteur MgB2 dans le projet BEST-PATHS / The work reported in this PhD deals with AC losses in superconducting material for large scale applications such as cables or magnets. Numerical models involving FEM and integral methods have been developed to solve the time transient electromagnetic distributions of field and current density with the peculiarity of the superconducting constitutive E-J equation. Two main conductors have been investigated for two ranges of superconducting cables. First, REBCO superconductors working at 77 K are studied and a new architecture of conductor (round wires) for 3~kA cables. Secondly, for very high current cables, 3-D simulations on MgB2 wires are approach and solved using FEM modeling. The following chapter introduced new development used for the calculation of AC losses in DC cables. The thesis ends with the use of the developed numerical model on a practical example in the BEST-PATHS project: a 10 kA MgB2 demonstrator.
28

Serverklustring

Fendell, Robert, Nordström, Philemond January 2014 (has links)
Klustring innebär att flera servrar arbetar tillsammans och på så sätt klarar av en uppgift som en ensam server inte skulle klara. Klustring kan också användas för att säkra drift med hjälp av en eller ett flertal servrar som väntar i startgropen om den aktiva servern som tillhandahåller tjänsten går ner.   Detta examensarbete utfördes genom att först undersöka vilka kluster­lösningar som fanns tillgängliga. Därefter utfördes intervjuer med företag som använde sig av olika typer av klustring. Laborationer gjordes för vidare undersökning av några av de mjukvaror som de intervjuade företagen använde.   Det upptäcktes att variationen av lösningar hos de intervjuade företagen inte var så stor som förväntat innan arbetet påbörjades.   Efter genomförd litteraturstudien och intervjumaterialet, för att sedan ge rekommendationer på vilka lösningar som bör väljas av exempelföretag utifrån vilka krav och kriterier som finns hos dessa.
29

Production of polymers from a papermills wastewater using HTC substrate. : Investigating the viability of using wastewater sludge from Skoghalls’ papermill in combination with filtrate from HTC of sewage sludge to produce biological plastic producing polymers. / Tillverkning av polymerer från skogsindustriellt avloppsvatten med användning av HTC-substrat. : Undersökning av möjligheten att använda avloppsvattnet från Skoghalls pappersbruk samt filtrat från HTC av slam för att producera bioplast.

George, Regan January 2023 (has links)
Since their conception, plastics have been a dominant product due to the versatility of use, and readily available raw materials. However, the production and consumption of synthetic plastics have continued to increase over the years, leading to a significant rise in plastic waste and its associated environmental impacts, such as the detrimental effects plastic waste has on ecosystems, including the presence of toxic microplastics and risks to marine life, are becoming the focus of criticism. Moreover, the contribution of plastic production to global warming through the usage of petroleum as a raw material cannot be understated. Solutions are being sought after to reduce the impact of this plastic waste, with one such solution being the replacement of the raw materials involved in plastic production. If a biologically degradable plastic product can be produced, then even if the dangers associated with plastic waste cannot be removed, they can be reduced. One method is the production of plastics using polyhydroxyalkanoates (PHA) as a replacement as these are shown to have similar properties as synthetic plastics while being 100% degradable. PHA production has existed since the 1960’s, but the process has always been too expensive to be a viable alternative to the cheaper petroleum-based products. A reduction of the production costs is needed for PHA to be an economically viable alternative, and there are two areas that contain the highest costs; The usage of expensive monocultural bacteria, and specially crafted carbon sources used to feed these bacteria to stimulate PHA accumulation. By switching to a multi-cultural bacterium and using readily available organic carbon sources can the costs of production be brought down, allowing the prospective biological plastics a chance to compete in the plastic market.  This thesis focuses on the usage of a multi-cultural bacterium collected from the water purification plant of a papermill, and the filtrate from the hydrothermal carbonisation (HTC) of sludge as the organic carbon source as materials in the production of PHA. The aim of the thesis is to investigate how successful PHA accumulation can occur using these two readily available waste products, and if successful to analyse the characteristics of any biological plastic that could be produced. The trials were performed in a cylindrical tank; one benchmark trial using acetic acid as the carbon source to be used as a reference for successful PHA accumulation, and five trials investigating the PHA accumulation that occurred using the HTC filtrate as the carbon source. The trials were analysed by extraction, TGA, FT-IR, TOC, and SS. During the trials pH, temperature and concentration of diffused oxygen was monitored. The trials indicated that the accumulation of PHA was possible, with various results. The most successful accumulation was observed in trial I-1, where PHA reached 12.45%, only slightly lower than the benchmark trials accumulation of 13.6%. Trials I-2 and I-3 also showed potential for high PHA content according to FTIR analysis. However, trials F-1 and F-2 failed to accumulate any PHA, and the inhibiting factors behind this were not fully understood. Possible reasons included high ammonia levels, incompatible bacteria, or imbalanced nutrient ratios. Various extraction methods were attempted to isolate the polymers found within the biomass for use in plastic production. While one extraction method was successful and used to analyse the PHA content found in the biomass, the amount of polymer that was extracted via this method was too small for use in plastic production, and as such the characteristic investigation of the plastic was unable to be completed. Overall, the study identified successful PHA accumulation in some trials but faced challenges and uncertainties regarding inhibiting factors and extraction methods. Future improvements should focus on standardizing experimental conditions and optimizing extraction techniques for better results.
30

Evaluation of PC-Based Virtual Reality as a Tool to Analyze Pedestrian Behavior at Midblock Crossings

Mai, Kristina Lynn 01 June 2017 (has links) (PDF)
The aim of this research was to analyze if current generation PC-driven virtual reality simulations can be used to accurately mimic and therefore, observe behavior at a crosswalk. Toward that goal, the following research tasks were carried out: a) Designing a 3D virtual crosswalk and recruiting volunteers to wear the HTC Vive headset and to walk across the street, b) Setting up cameras near the midblock crosswalk on University Drive at California Polytechnic State University, San Luis Obispo to observe pedestrians, and c) Comparing pedestrian behavior data from both the virtual and real midblock crosswalk. The comparison was based on the following criteria: a) Pedestrian walking speed, b) Observation patterns prior to crossing the road, characterized by glancing left and right to detect cars, and c) Pedestrians’ decisions as to where to cross, defined by if they chose to walk directly on or outside of the midblock crosswalk. Walking speed and the number of pedestrians who looked left and right before crossing were significantly different in both the virtual and real environments. On the other hand, the proportion of people who chose to walk on the crosswalk was similar in both environments. This result indicates that there is a future potential in using virtual reality to analyze pedestrian behavior at roundabouts. Although this study showed that PC-driven virtual reality is not effective in replicating pedestrian walking speeds or pedestrian observation patterns at a midblock crosswalk, researchers may expect PC-driven virtual reality to have greater applications within the transportation discipline once the technology improves over the years. Potential improvements in technology that would help include being wireless, allowing users to walk in a non-confining space, and making the equipment more affordable, allowing the technology to become more mainstream.

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