Search results for "temes"
showing 10 items of 75 documents
Tècniques de separació
2013
El text forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València. Temes per l'estudi de les tècniques de separació més rellevants. Contenen un tema d'introducció (extracció líquid-líquid, extracció en fase sòlida, fases estacionàries, i altres tòpics), un tema de teoria de la cromatografia, i temes de cromatografia de gasos, de líquids (repartiment, HPLC) i iònica. Finalitza amb una col·lecció de problemes. The most important separation techniques in Analytical Chemistry are introduced. The introduction includes liquid-liquid extraction, solid phase extraction, stationary phases, and other topics. This is followed by the…
El valor educativo de la interioridad. Un enfoque desde Charles Taylor
2010
Ante el malestar y desorientación que está viviendo el mundo educativo, son muchos los intentos de dar una respuesta satisfactoria. Guiado por el hilo conductor de la interioridad he recorrido la obra de Charles Taylor en búsqueda de las huellas de la identidad moderna, con el propósito de recuperar la instancia de lo interior. Esa parte de la persona que no se puede percibir a simple vista, pero que es esencial para entender lo que ocurre en el exterior. En el diagnóstico sobre los conflictos de la cultura moderna, se ha confirmado que las concepciones de bien suprimidas deben ser recuperadas, pues alguna opciones tienen auténtico valor cuando aportan la significación que requiere una vida…
Direct lookup and hash-based metadata placement for local file systems
2013
New challenges to file systems' metadata performance are imposed by the continuously growing number of files existing in file systems. The total amount of metadata can become too big to be cached, potentially leading to multiple storage device accesses for a single metadata lookup operation. This paper takes a look at the limitations of traditional file system designs and discusses an alternative metadata handling approach, using hash-based concepts already established for metadata and data placement in distributed storage systems. Furthermore, a POSIX compliant prototype implementation based on these concepts is introduced and benchmarked. A variety of file system metadata and data operati…
Robotic assistance for industrial sanding with a smooth approach to the surface and boundary constraints
2021
[EN] Surface treatment operations, such as sanding, deburring, finishing, grinding, polishing, etc. are progressively becoming more automated using robotic systems. However, previous research in this field used a completely automatic operation of the robot system or considered a low degree of human-robot interaction. Therefore, to overcome this issue, this work develops a truly synergistic cooperation between the human operator and the robot system to get the best from both. In particular, in the application developed in this work the human operator provides flexibility, guiding the tool of the robot system to treat arbitrary regions of the workpiece surface; while the robot system provides…
A Novel Systolic Parallel Hardware Architecture for the FPGA Acceleration of Feedforward Neural Networks
2019
New chips for machine learning applications appear, they are tuned for a specific topology, being efficient by using highly parallel designs at the cost of high power or large complex devices. However, the computational demands of deep neural networks require flexible and efficient hardware architectures able to fit different applications, neural network types, number of inputs, outputs, layers, and units in each layer, making the migration from software to hardware easy. This paper describes novel hardware implementing any feedforward neural network (FFNN): multilayer perceptron, autoencoder, and logistic regression. The architecture admits an arbitrary input and output number, units in la…
El software libre y Universidad
2009
Desde el punto de vista pedagógico la sitiuación se complica aún más cuando parece que lo que la sociedad nos demanda son profesionales formados en software propietario. El caso del mundo SIG es pardigmático, una empresa que gasta miles de euros en licencias de software privativo, espera que los técnicos que contrate conozcan ese software al dedillo.
File system scalability with highly decentralized metadata on independent storage devices
2016
This paper discusses using hard drives that integrate a key-value interface and network access in the actual drive hardware (Kinetic storage platform) to supply file system functionality in a large scale environment. Taking advantage of higher-level functionality to handle metadata on the drives themselves, a serverless system architecture is proposed. Skipping path component traversal during the lookup operation is the key technique discussed in this paper to avoid performance degradation with highly decentralized metadata. Scalability implications are reviewed based on a fuse file system implementation. Peer Reviewed
GekkoFS — A Temporary Burst Buffer File System for HPC Applications
2020
Many scientific fields increasingly use high-performance computing (HPC) to process and analyze massive amounts of experimental data while storage systems in today’s HPC environments have to cope with new access patterns. These patterns include many metadata operations, small I/O requests, or randomized file I/O, while general-purpose parallel file systems have been optimized for sequential shared access to large files. Burst buffer file systems create a separate file system that applications can use to store temporary data. They aggregate node-local storage available within the compute nodes or use dedicated SSD clusters and offer a peak bandwidth higher than that of the backend parallel f…
Octreotide compared with placebo in a treatment strategy for early rebleeding in cirrhosis. A double blind, randomized pragmatic trial.
1998
beta-Blockers and sclerotherapy prevent long-term upper digestive rebleeding in cirrhosis but they seem ineffective for early rebleeding. We compared octreotide with a placebo for the prevention of early rebleeding in cirrhotic patients. After control of acute upper digestive bleeding, 262 consecutive cirrhotic patients were randomized to octreotide 100 microgram subcutaneously three times a day for 15 days (n = 131) or to the placebo (n = 131), in a double blind pragmatic trial in which beta-blockers and/or sclerotherapy were allowed together with the experimental treatment. Separate randomization and analysis were performed according to whether patients were eligible for beta-blockers and…
The microbiome of the ice-capped Cayambe Volcanic Complex in Ecuador
2023
A major challenge in microbial ecology is to understand the principles and processes by which microbes associate and interact in community assemblages. Microbial communities in mountain glaciers are unique as first colonizers and nutrient enrichment drivers for downstream ecosystems. However, mountain glaciers have been distinctively sensitive to climate perturbations and have suffered a severe retreat over the past 40 years, compelling us to understand glacier ecosystems before their disappearance. This is the first study in an Andean glacier in Ecuador offering insights into the relationship of physicochemical variables and altitude on the diversity and structure of bacterial communities…