1,594 research outputs found

    A quasi-prose, quasi-spoken word about the mullings of a first gen girl

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    There are many types of first generation students. I happen to be of the immigrant sort, with parents that have degrees that mean very little on this soil. The kingdom of the lingua franca mentioned‚ÄĒthe land of English‚ÄĒwas very difficult to navigate without first conquering the language, but even afterwards there are some immovable disadvantages. You\u27ll find rich Peruvian references in this piece‚ÄĒManco C√°pac, the founder of one of the longest lasting Inca dynasties, referred to himself as ‚Äúthe son of the sun‚ÄĚ; since the sun was a god, Inti, this gave him and succeeding rulers much political power. Pachamama is the Quechua word for Mother Earth, who was a goddess, mother of Inti. The description of the Conquistadores is eerily reminiscent of The Four Horsemen of the Apocalypse mentioned in the last book of the New Testament, respectively symbolizing Conquest, War, Famine, and Death. Cruelly fitting, seeing as they often used Christianity itself as an excuse for bringing those four very plagues upon the indigenous people

    Nadie: A Modern Rapunzel Story

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    The play explores the emerging identity of ‚ÄúUndocuqueer‚ÄĚ‚ÄĒthe intersection of undocumented immigrants and LGBTQ people-- as we follow Nadia\u27s upward journey to being the first in her family to attend a US university. Like many young kids in her situation, Nadia is a classic ni de aqui ni de alla, straddling two vastly different social classes, two nationalistic allegiances, two cultures and is eventually caught between the two women she cares about the most

    Aging in Place Perceptions Between Seniors Living in Independent Living Senior Communities and Seniors Living in Residential Homes

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    The purpose of this study was to examine the perceptions of aging in place between seniors living in residential homes in the community and seniors residing in independent living senior communities. A cross-sectional, quantitative research design and simple random sampling (SRS) strategy was used for this study. Results: 458 responded to a researcher developed likert scale survey. The sample was generally Caucasian/White (n=408, 89.1%), evenly divided between males (n=227, 49.6%) and females (n=224, 48.9%), and between the age of 65 to 74 (n=259, 56.6%). A significant difference was found between those living alone in a residential home and those living in an independent living senior apartment for relying on family (p=.020) to promote aging in place rather than accessing community resources. A significant difference was found between those living with other(s) in a residential home and those living in an independent living senior apartment for relying on family (p=.002) and relying on social network (p=.068) to promote aging in place rather than accessing community resources. There was no correlation found between living arrangement and any of the push factors, utilization of supportive services components, or perceptions rank statements. Conclusion: Although no significant relationships were found between living arrangement and the push factors, utilization of supportive services components, and the rank statements, there were differences found in the populations\u27 surveyed based on living arrangement. Further research is needed to truly understand the link between living arrangement, access and utilization of supportive services, and how families, social networks, and community resources interplay to shape seniors\u27 perceptions of aging in place

    Charge carrier dynamics and interfaces in perovskite solar cells

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    Tesi en cotutela: Universitat Polit√®cnica de Catalunya i Karlsruher Institut f√ľr TechnologieOrganometal halide perovskites for solar cells are hybrid semiconductors that recently have caught the attention of the scientific community due to its excellent performance and attractive optical properties. Since then, they have been used in solar cells, LEDs, and lasers, although the mechanisms by which such good performances are obtained are not known completely. This dissertation presents a study of the optical characteristics of perovskites for thin-film solar cells. Due to their small thickness, the morphology of the layer is sensitive to manufacturing parameters. In this way, the manufacturing process is optimized, trying to improve its characteristics. Among the challenges perovskites pose for implementation, the lack of stability during operation is one of the most relevant. Therefore, in this dissertation, the reasons for stability losses are also studied. For this purpose, interlayers are used, which introduce changes in the interface of the perovskite with the electron extraction layer, and with the initial purpose of reducing the hysteresis in the current-voltage curve. In addition to reducing it, they stabilize the power extracted from the solar cell under illumination. The effects of degradation on the characteristics of solar cells allow the identification of their origins and propose a solution to avoid or delay damage to the perovskite layer. With this in mind, it is established that the problem of stability does not only lie within the perovskite layer but also in the contact between the layers and in the charge transport within the perovskite solar cell. Careful control of these interfaces, then, facilitates the achievement of stable performances and long lifetimes of the perovskite solar cells.Las perovskitas organomet√°licas de haluros para celdas solares son un tipo de semiconductor h√≠brido que recientemente ha atrapado la atenci√≥n de la comunidad cient√≠fica debido a su excelente desempe√Īo y atractivas propiedades √≥pticas. Desde entonces, han sido utilizadas en celdas solares, LEDs y lasers, a pesar de que los mecanismos por los cuales se obtienen tan buenos desempe√Īos no son completamente conocidos. Con esta disertaci√≥n se presenta un estudio sobre las caracter√≠sticas √≥pticas de la perovskitas para su utilizaci√≥n en celdas solares de pel√≠culas delgadas. Debido a su delgado grosor, la morfolog√≠a de la capa es sensible a los par√°metros de fabricaci√≥n. De manera que se optimiza el proceso de fabricaci√≥n tratando de mejorar sus caracter√≠sticas. Entre los retos que presentan las perosvkitas para su implementaci√≥n, la falta de estabilidad durante su funcionamiento es uno de los m√°s relevantes. Entonces en este dissertationo se estudian tambi√©n las razones por las que se presenta p√©rdidas de estabilidad. Para esto se utilizan entrecapas, que introducen cambios en la interfaz de la perovksite con la capa extractora de electrones, y con el prop√≥sito inicial de reducir la hist√©resis en la curva de corriente-voltaje. Adem√°s de reducirlo, estabilizan la potencia extra√≠da de la celda solar bajo iluminaci√≥n. Los efectos de la degradaci√≥n en las caracter√≠sticas de las celdas solares nos permiten identificar sus or√≠genes y presentar propuestas para evitar o retardar los da√Īos a la capa de perovskita. Teniendo esto en cuenta, podemos establecer que el problema de la estabilidad no radica s√≥lo dentro de la perovskita, pero tambi√©n en el contacto entre las capas y en el transporte de carga dentro de la celda solar de perovskita. El control cuidadoso de estas interfaces, entonces, permite la obtenci√≥n de un rendimiento estable y una vida larga del dispositivo.Organometallhalogenid-Perowskite sind hybride Halbleiter, die in j√ľngster Zeit aufgrund ihrer hervorragenden Halbleitereingeschaften und attraktiven optischen Eigenschaften die Aufmerksamkeit der Wissenschaft auf sich gezogen haben. Seitdem wurde die exzellente Eignung dieser Materialklasse f√ľr verschiedenste opto-elektrische Anwendungen wie z.B. Solarzellen, LEDs und Lasern unter Beweis gestellt. Die physikalischen Mechanismen, die die Grundlage f√ľr diese einzigartigen, qualitativ Hochwertigen Eigenschaften bilden, sind jedoch noch weitgehend unbekannt. Dieses Manuskript stellt eine Studie √ľber die optischen Eigenschaften von Perowskitfilmen f√ľr den Einsatz in D√ľnnschichtsolarzellen dar, die mit dem Spin-Coating-Verfahren hergestellt wurden. Aufgrund des geringen Dicken der Perowskitschichten ist deren Morphologie empfindlich gegen√ľber kleinen Variationen der Fertigungsparameter. Deshalb muss der Herstellungsprozess durch Feinjustierung dieser Parameter optimiert werden, um hocheffiziente Solarzellen herzustellen. Eine der gr√∂√üten Herausforderungen f√ľr die Kommerzialisierung der Perowskitphotovoltaik ist neben der Herstellung durch die mangelnde Stabilit√§t des Wirkungsgerades w√§hrend des Betriebs gegeben. Daher werden in der vorliegenden Arbeit zus√§tzlich die Gr√ľnde f√ľr diese Stabilit√§tsverluste untersucht. Zu diesem Zweck werden zus√§tzliche Nanoschichten zwischen der Perowskit- und der Elektronenextraktionsschicht appliziert, die nicht nur eine Reduzierung der Hysterese in der Strom-Spannungskurve bewirken, sondern die Leistung der Solarzelle unter Sonneneinstrahlung stabilisieren. Der Vergleich der Stabilit√§t von Solarzellen mit und ohne zus√§tzlichen Zwischenschichten erm√∂glicht R√ľckschl√ľsse auf die Ursache der Degradationsmechanismen. Ein Hauptresultat dieser Stabilit√§ts- bzw. Degradationsstudie ist die Tatsache, dass ein Gro√üteil des beobachteten Effizienzverlustes nicht durch die Perowskitdegradation innerhalb des Filmes, sondern vielmehr durch die Instabilit√§t der Grenzfl√§chen des Perowskits mit den Extraktionsschichten zustande kommt. Die Grenzfl√§chendegradation erzeugt eine Barriere f√ľr den Ladungstransport durch die Erh√∂hung der lokalen ‚ÄěTrap-Dichte‚Äú. Basierend auf dieser Erkenntnis er√∂ffnet die sorgf√§ltige Modifikation der Grenzfl√§chen innerhalb der Solarzelle vielf√§ltige M√∂glichkeiten, um eine stabile Betriebsleistung der Solarzelle √ľber l√§ngere Zeiten durch Vermeidung bzw. Verz√∂gerung der Degradation zu erzielenPostprint (published version

    Serverless Computing Strategies on Cloud Platforms

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    [ES] Con el desarrollo de la Computaci√≥n en la Nube, la entrega de recursos virtualizados a trav√©s de Internet ha crecido enormemente en los √ļltimos a√Īos. Las Funciones como servicio (FaaS), uno de los modelos de servicio m√°s nuevos dentro de la Computaci√≥n en la Nube, permite el desarrollo e implementaci√≥n de aplicaciones basadas en eventos que cubren servicios administrados en Nubes p√ļblicas y locales. Los proveedores p√ļblicos de Computaci√≥n en la Nube adoptan el modelo FaaS dentro de su cat√°logo para proporcionar computaci√≥n basada en eventos altamente escalable para las aplicaciones. Por un lado, los desarrolladores especializados en esta tecnolog√≠a se centran en crear marcos de c√≥digo abierto serverless para evitar el bloqueo con los proveedores de la Nube p√ļblica. A pesar del desarrollo logrado por la inform√°tica serverless, actualmente hay campos relacionados con el procesamiento de datos y la optimizaci√≥n del rendimiento en la ejecuci√≥n en los que no se ha explorado todo el potencial. En esta tesis doctoral se definen tres estrategias de computaci√≥n serverless que permiten evidenciar los beneficios de esta tecnolog√≠a para el procesamiento de datos. Las estrategias implementadas permiten el an√°lisis de datos con la integraci√≥n de dispositivos de aceleraci√≥n para la ejecuci√≥n eficiente de aplicaciones cient√≠ficas en plataformas cloud p√ļblicas y locales. En primer lugar, se desarroll√≥ la plataforma CloudTrail-Tracker. CloudTrail-Tracker es una plataforma serverless de c√≥digo abierto basada en eventos para el procesamiento de datos que puede escalar autom√°ticamente hacia arriba y hacia abajo, con la capacidad de escalar a cero para minimizar los costos operativos. Seguidamente, se plantea la integraci√≥n de GPUs en una plataforma serverless local impulsada por eventos para el procesamiento de datos escalables. La plataforma admite la ejecuci√≥n de aplicaciones como funciones severless en respuesta a la carga de un archivo en un sistema de almacenamiento de ficheros, lo que permite la ejecuci√≥n en paralelo de las aplicaciones seg√ļn los recursos disponibles. Este procesamiento es administrado por un cluster Kubernetes el√°stico que crece y decrece autom√°ticamente seg√ļn las necesidades de procesamiento. Ciertos enfoques basados en tecnolog√≠as de virtualizaci√≥n de GPU como rCUDA y NVIDIA-Docker se eval√ļan para acelerar el tiempo de ejecuci√≥n de las funciones. Finalmente, se implementa otra soluci√≥n basada en el modelo serverless para ejecutar la fase de inferencia de modelos de aprendizaje autom√°tico previamente entrenados, en la plataforma de Amazon Web Services y en una plataforma privada con el framework OSCAR. El sistema crece el√°sticamente de acuerdo con la demanda y presenta una escalado a cero para minimizar los costes. Por otra parte, el front-end proporciona al usuario una experiencia simplificada en la obtenci√≥n de la predicci√≥n de modelos de aprendizaje autom√°tico. Para demostrar las funcionalidades y ventajas de las soluciones propuestas durante esta tesis se recogen varios casos de estudio que abarcan diferentes campos del conocimiento como la anal√≠tica de aprendizaje y la Inteligencia Artificial. Esto demuestra que la gama de aplicaciones donde la computaci√≥n serverless puede aportar grandes beneficios es muy amplia. Los resultados obtenidos avalan el uso del modelo serverless en la simplificaci√≥n del dise√Īo de arquitecturas para el uso intensivo de datos en aplicaciones complejas.[CA] Amb el desenvolupament de la Computaci√≥ en el N√ļvol, el lliurament de recursos virtualitzats a trav√©s d'Internet ha crescut granment en els √ļltims anys. Les Funcions com a Servei (FaaS), un dels models de servei m√©s nous dins de la Computaci√≥ en el N√ļvol, permet el desenvolupament i implementaci√≥ d'aplicacions basades en esdeveniments que cobreixen serveis administrats en N√ļvols p√ļblics i locals. Els prove√Įdors de computaci√≥ en el N√ļvol p√ļblic adopten el model FaaS dins del seu cat√†leg per a proporcionar a les aplicacions computaci√≥ altament escalable basada en esdeveniments. D'una banda, els desenvolupadors especialitzats en aquesta tecnologia se centren en crear marcs de codi obert serverless per a evitar el bloqueig amb els prove√Įdors del N√ļvol p√ļblic. Malgrat el desenvolupament alcan√ßat per la inform√†tica serverless, actualment hi ha camps relacionats amb el processament de dades i l'optimitzaci√≥ del rendiment d'execuci√≥ en els quals no s'ha explorat tot el potencial. En aquesta tesi doctoral es defineixen tres estrat√®gies inform√†tiques serverless que permeten demostrar els beneficis d'aquesta tecnologia per al processament de dades. Les estrat√®gies implementades permeten l'an√†lisi de dades amb a integraci√≥ de dispositius accelerats per a l'execuci√≥ eficient d'aplicacion scient√≠fiques en plataformes de N√ļvol p√ļbliques i locals. En primer lloc, es va desenvolupar la plataforma CloudTrail-Tracker. CloudTrail-Tracker √©s una plataforma de codi obert basada en esdeveniments per al processament de dades serverless que pot escalar autom√°ticament cap amunt i cap avall, amb la capacitat d'escalar a zero per a minimitzar els costos operatius. A continuaci√≥ es planteja la integraci√≥ de GPUs en una plataforma serverless local impulsada per esdeveniments per al processament de dades escalables. La plataforma admet l'execuci√≥ d'aplicacions com funcions severless en resposta a la c√†rrega d'un arxiu en un sistema d'emmagatzemaments de fitxers, la qual cosa permet l'execuci√≥ en paral¬∑lel de les aplicacions segon sels recursos disponibles. Este processament √©s administrat per un cluster Kubernetes el√†stic que creix i decreix autom√†ticament segons les necessitats de processament. Certs enfocaments basats en tecnologies de virtualitzaci√≥ de GPU com rCUDA i NVIDIA-Docker s'avaluen per a accelerar el temps d'execuci√≥ de les funcions. Finalment s'implementa una altra soluci√≥ basada en el model serverless per a executar la fase d'infer√®ncia de models d'aprenentatge autom√†tic pr√®viament entrenats en la plataforma de Amazon Web Services i en una plataforma privada amb el framework OSCAR. El sistema creix el√†sticament d'acord amb la demanda i presenta una escalada a zero per a minimitzar els costos. D'altra banda el front-end proporciona a l'usuari una experi√®ncia simplificada en l'obtenci√≥ de la predicci√≥ de models d'aprenentatge autom√†tic. Per a demostrar les funcionalitats i avantatges de les solucions proposades durant esta tesi s'arrepleguen diversos casos d'estudi que comprenen diferents camps del coneixement com l'anal√≠tica d'aprenentatge i la Intel¬∑lig√®ncia Artificial. Aix√≤ demostra que la gamma d'aplicacions on la computaci√≥ serverless pot aportar grans beneficis √©s molt √†mplia. Els resultats obtinguts avalen l'√ļs del model serverless en la simplificaci√≥ del disseny d'arquitectures per a l'√ļs intensiu de dades en aplicacions complexes.[EN] With the development of Cloud Computing, the delivery of virtualized resources over the Internet has greatly grown in recent years. Functions as a Service (FaaS), one of the newest service models within Cloud Computing, allows the development and implementation of event-based applications that cover managed services in public and on-premises Clouds. Public Cloud Computing providers adopt the FaaS model within their catalog to provide event-driven highly-scalable computing for applications. On the one hand, developers specialized in this technology focus on creating open-source serverless frameworks to avoid the lock-in with public Cloud providers. Despite the development achieved by serverless computing, there are currently fields related to data processing and execution performance optimization where the full potential has not been explored. In this doctoral thesis three serverless computing strategies are defined that allow to demonstrate the benefits of this technology for data processing. The implemented strategies allow the analysis of data with the integration of accelerated devices for the efficient execution of scientific applications on public and on-premises Cloud platforms. Firstly, the CloudTrail-Tracker platform was developed to extract and process learning analytics in the Cloud. CloudTrail-Tracker is an event-driven open-source platform for serverless data processing that can automatically scale up and down, featuring the ability to scale to zero for minimizing the operational costs. Next, the integration of GPUs in an event-driven on-premises serverless platform for scalable data processing is discussed. The platform supports the execution of applications as serverless functions in response to the loading of a file in a file storage system, which allows the parallel execution of applications according to available resources. This processing is managed by an elastic Kubernetes cluster that automatically grows and shrinks according to the processing needs. Certain approaches based on GPU virtualization technologies such as rCUDA and NVIDIA-Docker are evaluated to speed up the execution time of the functions. Finally, another solution based on the serverless model is implemented to run the inference phase of previously trained machine learning models on theAmazon Web Services platform and in a private platform with the OSCAR framework. The system grows elastically according to demand and is scaled to zero to minimize costs. On the other hand, the front-end provides the user with a simplified experience in obtaining the prediction of machine learning models. To demonstrate the functionalities and advantages of the solutions proposed during this thesis, several case studies are collected covering different fields of knowledge such as learning analytics and Artificial Intelligence. This shows the wide range of applications where serverless computing can bring great benefits. The results obtained endorse the use of the serverless model in simplifying the design of architectures for the intensive data processing in complex applications.Naranjo Delgado, DM. (2021). Serverless Computing Strategies on Cloud Platforms [Tesis doctoral]. Universitat Polit√®cnica de Val√®ncia. https://doi.org/10.4995/Thesis/10251/160916TESI

    I\u27ve Been Sucked into American Culture and Look What It\u27s Done to Me!: The Charms of Living in the Shadows and the Closet

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    Brought to the US from Peru as a young child, Diana Delgado discovers that she is fated to be ni de aqui ni de alla¬ł neither from here nor there, eternally straddling two worlds. As her family‚Äôs legal status hangs in the balance, Diana struggles to grow up juggling the dichotomies between class, culture, and sexuality, eventually caught between coming out of the shadows to her friends, and coming out of the closet to her family. As her high school career draws to a close, she is forced out of both secrets in the worst way possible

    Exemplifying mathematics teacher’s specialised knowledge in university teaching practices

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    International audienceExtant research on the teachers’ knowledge includes limited studies focusing on teachers at university level. In this work, based on the Mathematics Teacher’s Specialised Knowledge (MTSK) model and through an instrumental case study, knowledge of a lecturer in a real analysis course for prospective mathematics teachers is analyzed. We exemplified lecturer knowledge in different subdomains of the MTSK model. These results contribute to the understanding and characterization of the components of mathematics teacher’s specialised knowledge at the university level

    Evaluación probabilística del peligro por lahares en el flanco NE del Volcán Popocatépetl

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    This study shows the results of a probabilistic evaluation of laharic hazard to Santiago Xalitzintla, locality in Puebla, at the NE flank of the Popocatépetl volcano in México. The TITAN2F software was used for lahars modeling. The program forecasts were compared with data obtained in the field for the laharic event of 2001 in order to evaluate the reliability of its use on a digital elevation model. The results obtained with TITAN2F are comparable with information reported previously in other studies of this lahar; coming to the conclusion that modeling with TITAN2F is reliable. This investigation provides a useful tool for the knowledge of laharic hazards. Also, it shows the probability of the affected area by inundation as well as the probability distribution of dynamic-pressure levels, which is an important parameter for assessment risk in a lahar flow. To make a probabilistic analysis is required a number of statistically representative hypothetic scenarios, covering all possible cases. According to historical events recorded, two possible sources for a laharic flow were defined, and they correspond to the Huiloac and Alseseca gorges. Based on the geological information, the ranges of initial conditions that TITAN2F requires (velocity, concentration and volume) were defined for each one of the basins. A stratified sampling was carried out using the Latin Hypercube method (LHS). This method generates a representative sample of hundreds of combinations from the initial conditions, in order to modeling laharic events with TITAN2F. The probabilistic analysis was made through Bayesian inference, and programming routines in OCTAVE. The probabilistic distribution indicates that there is a nearly 80 % probability to be reached by lahars at community areas of Santiago Xalitzintla. However it is characterized by low dynamic-pressure levels. The final section of the Huiloac gorge was identified as a critical zone, where the probability that dynamic-pressures surpassing destructive levels is high

    Allergic Rhinitis and Sports

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    Remote Sensing in the Design of Urban Planning Strategies, Case Study Urban Heat Island of the Metropolitan District of Quito, Ecuador

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    This study analyzed the urban heat island (UHI)of the Metropolitan District of Quito with the calculation ofsurface temperature of multispectral Landsat 7 ETM andLandsat 8 OLI/TIRS. With these imagens were calculatedindices of vegetation NDVI and constructions NDBI, andare established the relationship of these variables withArticle history:Received 26 Februeary 2018Accepted 28 May 2018Este trabajo fue apoyado por la Universidad Internacional SEK, Facultad deCiencias Naturales y Ambientales.Diana Paola Ba√Īo Saltos, Autor Jr. pertenece a la Universidad InternacionalSEK del Ecuadortemperature surface through application of the correlationlinear of Pearson. The results indicate that heat islands aremore pronounced towards rural areas where there is acombined land use between horizontal construction,industries and equipment, compared to urban areas wherethere is prevalence of vertical developments. The NDVIvegetation index presents an inverse correlation withsurface temperature and the rate of constructions, directcorrelation, while surface temperatures obtained fromLandsat 7 and 8 Landsat images are not comparable. Ingeneral, characterization of urban heat islands is bestexplained through the analysis of the relationship betweensurface temperature and land use
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