7,986 research outputs found
Parallelization of a Six Degree of Freedom Entry Vehicle Trajectory Simulation Using OpenMP and OpenACC
The art and science of writing parallelized software, using methods such as Open Multi-Processing (OpenMP) and Open Accelerators (OpenACC), is dominated by computer scientists. Engineers and non-computer scientists looking to apply these techniques to their project applications face a steep learning curve, especially when looking to adapt their original single threaded software to run multi-threaded on graphics processing units (GPUs). There are significant changes in mindset that must occur; such as how to manage memory, the organization of instructions, and the use of if statements (also known as branching). The purpose of this work is twofold: 1) to demonstrate the applicability of parallelized coding methodologies, OpenMP and OpenACC, to tasks outside of the typical large scale matrix mathematics; and 2) to discuss, from an engineers perspective, the lessons learned from parallelizing software using these computer science techniques. This work applies OpenMP, on both multi-core central processing units (CPUs) and Intel Xeon Phi 7210, and OpenACC on GPUs. These parallelization techniques are used to tackle the simulation of thousands of entry vehicle trajectories through the integration of six degree of freedom (DoF) equations of motion (EoM). The forces and moments acting on the entry vehicle, and used by the EoM, are estimated using multiple models of varying levels of complexity. Several benchmark comparisons are made on the execution of six DoF trajectory simulation: single thread Intel Xeon E5-2670 CPU, multi-thread CPU using OpenMP, multi-thread Xeon Phi 7210 using OpenMP, and multi-thread NVIDIA Tesla K40 GPU using OpenACC. These benchmarks are run on the Pleiades Supercomputer Cluster at the National Aeronautics and Space Administration (NASA) Ames Research Center (ARC), and a Xeon Phi 7210 node at NASA Langley Research Center (LaRC)
The riddle of hyperlactatemia
A recent observational study in a large cohort of critically ill patients confirms the association between hyperlactatemia and mortality. The mechanisms regulating the rates of lactate production and clearance in critical illness remain poorly understood. During exercise, hyperlactatemia clearly results from an imbalance between oxygen delivery and energy requirements. In critically ill patients, the genesis of hyperlactatemia is significantly more complex. Possible mechanisms include regional hypoperfusion, an inflammation-induced upregulation of the glycolitic flux, alterations in lactate-clearing mechanisms, and increases in the work of breathing. Understanding how these complex processes interact to produce elevations in lactate continues to be an important area of research
Commensal observing with the Allen Telescope array: software command and control
The Allen Telescope Array (ATA) is a Large-Number-Small-Diameter radio
telescope array currently with 42 individual antennas and 5 independent
back-end science systems (2 imaging FX correlators and 3 time domain beam
formers) located at the Hat Creek Radio Observatory (HCRO). The goal of the ATA
is to run multiple back-ends simultaneously, supporting multiple science
projects commensally. The primary software control systems are based on a
combination of Java, JRuby and Ruby on Rails. The primary control API is
simplified to provide easy integration with new back-end systems while the
lower layers of the software stack are handled by a master observing system.
Scheduling observations for the ATA is based on finding a union between the
science needs of multiple projects and automatically determining an efficient
path to operating the various sub-components to meet those needs. When
completed, the ATA is expected to be a world-class radio telescope, combining
dedicated SETI projects with numerous radio astronomy science projects.Comment: SPIE Conference Proceedings, Software and Cyberinfrastructure for
Astronomy, Nicole M. Radziwill; Alan Bridger, Editors, 77400Z, Vol 774
Marco de trabajo scrum para la gestión de proyectos de software en una empresa consultora, Lima 2023
La investigación tuvo como objetivo Determinar la influencia del marco de trabajo
Scrum en la gestión de los Proyectos de Software en una Empresa Consultora,
midiendo los resultados de la gestión de proyectos de manera tradicional y
utilizando del marco Scrum en los indicadores cantidad de fallas del sistema, tiempo
de entrega del producto y solicitudes de cambio al producto.
La investigación es aplicada con enfoque cuantitativo y diseño
cuasiexperimental, la muestra lo conformaron 50 proyectos, divididos en dos
muestras independientes, los datos se obtuvieron utilizando fichas de registro. Para
validar las hipótesis se determinará la normalidad de datos utilizando la Z de
Kolmogórov-Smirnov para cada indicador, con los resultados obtenidos se aplicó el
test paramétrico de T-Student y el test no paramétrico de U-Mann Whitney.
Los resultados arrojaron que se logró disminuir la cantidad de fallas del
sistema en 15.58%, igualmente se logró reducir el tiempo de entrega de los
productos en 9.09% y por último se redujo la cantidad de solicitudes de cambio en
28.36%. Concluyendo que la implementación del Marco de Trabajo Scrum influye
positivamente en la Gestión de los Proyectos de Software en una Empresa
Consultora de Software
Data-Driven Intelligent Tutoring System for Accelerating Practical Skills Development:A Deep Learning Approach
Radiation-induced neuroinflammation:a potential protective role for poly(ADP-ribose) polymerase inhibitors?
Radiotherapy (RT) plays a fundamental role in the treatment of glioblastoma (GBM). GBM are notoriously invasive and harbor a subpopulation of cells with stem-like features which exhibit upregulation of the DNA damage response (DDR) and are radioresistant. High radiation doses are therefore delivered to large brain volumes and are known to extend survival but also cause delayed toxicity with 50%–90% of patients developing neurocognitive dysfunction. Emerging evidence identifies neuroinflammation as a critical mediator of the adverse effects of RT on cognitive function. In addition to its well-established role in promoting repair of radiation-induced DNA damage, activation of poly(ADP-ribose) polymerase (PARP) can exacerbate neuroinflammation by promoting secretion of inflammatory mediators. Therefore, PARP represents an intriguing mechanistic link between radiation-induced activation of the DDR and subsequent neuroinflammation. PARP inhibitors (PARPi) have emerged as promising new agents for GBM when given in combination with RT, with multiple preclinical studies demonstrating radiosensitizing effects and at least 3 compounds being evaluated in clinical trials. We propose that concomitant use of PARPi could reduce radiation-induced neuroinflammation and reduce the severity of radiation-induced cognitive dysfunction while at the same time improving tumor control by enhancing radiosensitivity
Progressive Transient Photon Beams
In this work we introduce a novel algorithm for transient rendering in
participating media. Our method is consistent, robust, and is able to generate
animations of time-resolved light transport featuring complex caustic light
paths in media. We base our method on the observation that the spatial
continuity provides an increased coverage of the temporal domain, and
generalize photon beams to transient-state. We extend the beam steady-state
radiance estimates to include the temporal domain. Then, we develop a
progressive version of spatio-temporal density estimations, that converges to
the correct solution with finite memory requirements by iteratively averaging
several realizations of independent renders with a progressively reduced kernel
bandwidth. We derive the optimal convergence rates accounting for space and
time kernels, and demonstrate our method against previous consistent transient
rendering methods for participating media
Adolescencia, identidad y modernidad en la comunidad de Kamla
La adolescencia es una etapa de dudas y experimentación, donde los adolescentes dejan de ser niños para pasar a la etapa de la pubertad, esta es la fase donde ellos van implantando los valores, costumbres que seles fue enseñada por sus padres. En donde también ellos se van fortaleciendo como personas y aprendiendo de todo lo que tienen a su alrededor, por medio de los diversos espacios de socialización seles hace más atractivo otras formas de interactuar con amistades y familiares en alguno de los casos estos lo hacen a través de redes sociales y teléfonos no por medio de cartas o recados con otras personas como tradicionalmente se hacía
Lineamientos formales, funcionales y espaciales para una infraestructura urbana inclusiva en el sector 8 de Nuevo Chimbote, 2023
La investigación tuvo como objetivo determinar los lineamientos formales, funcionales
y espaciales para una infraestructura urbana inclusiva, enfocado en el peatón del
sector 8 Nuevo Chimbote. La investigación es cualitativo, básica y de diseño
descriptivo-fenomenológico, la muestra estuvo conformado por 254 participantes,
distribuidas entre personas del sector y transeúntes del AA.HH. Primero de Mayo y
Villa María del distrito de Nuevo Chimbote. Para esto se utilizó la técnica de
observación, análisis documental, entrevista y encuestas a los pobladores para saber
su necesidades o inquietudes, se analizaron diferentes casos para obtener los
beneficios que puedan ayudar al sector de estudio, donde los resultados mencionan
que el 70% consideran que en el espacio urbano no permite una incorporación a
personas discapacitadas. Además, se evidencio que su infraestructura urbana se
encuentra deteriorada en sus alamedas peatonales, vías principales y rampas que no
llegan a las calzadas, señalizaciones que no logran reconocerse, mobiliarios urbanos
insuficientes y falta de mantenimiento en el sector. Finalmente se precisa que se
debería incluir tipología de diseños en vías locales, atreves de carriles exclusivos,
donde van circular los ciclistas y autos distanciados por medio de un separador, donde
los peatones y discapacitados circularan mediante un nivel superior de manera segura
con sus respectivos parámetros, las cuales contaran con estacionamientos y espacio
comercial dentro de carril. Se concluye que es necesario mantener los espacios
públicos con una infraestructura inclusiva que logre destacarse en el desplazamiento
al discapacitado dentro del sector, por medio de señales de aviso en las veredas y
calzadas como parte de la protección y cumplimento de la normativa
SBS 1150+599A: an extremely oxygen-poor planetary nebula in the Galactic halo?
We report results of a spectrophotometric study of SBS 1150+599A and discuss
the nature of this object based upon our data. Our study shows that SBS
1150+599A is most probably a planetary nebula located in the Galactic halo and
not a cataclysmic variable as originally proposed by the authors of the Second
Byurakan Survey from low resolution spectroscopy. We have further elaborated on
the properties of SBS 1150+599A (now becoming PN G135.9+55.9) with tools used
for planetary nebula analysis. Our photoionization models show that, in order
to match the observational constraints, the oxygen abundance in the nebula is
probably extremely low, around 1/500 solar, which is one order of magnitude
lower than the most oxygen-poor planetary nebulae known so far. This finding
has strong implications on our understanding of the formation of planetary
nebulae and of the evolution of the Galactic halo.Comment: 13 pages, 5 figures, accepted for publication in Astronomy and
Astrophysic
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