Work-Based Learning in California: Opportunities and Models for Expansion

Work-based learning is an educational strategy that links academic instruction with the world of work. By itself, it is a powerful tool for motivating students and enhancing learning. But it holds particular promise in the context of multiple pathways, an approach to high school reform in California that seeks to prepare more young people for success both in college and the workplace. This report by WestEd takes a broad look at work-based learning in California: how it is practiced, what it looks like when done well and how it could be expanded to engage more students

Gas to liquid mass transfer in rheologically complex fluids

The increase of studies relaying on gas to liquid mass transfer in digested sludge (shear thinning fluid) necessitates a better understanding of the impact of apparent viscosity (μa) and rheology in process performance. Mass transfer retardation due to μa variations was investigated in a pilot scale absorption bubble column for Newtonian and shear thinning fluids with varied superficial gas velocities (UG). A non-linear reduction of mass transfer efficiency with increasing μa was observed, being the impact higher at low μa ranges and high UG. An increase of 114 cPo in μ from 1.01 to 115 cPo in glycerol solutions saturated with UG = 1.73 cm s−1 led to a reduction of 96% in kLa (α = 0.04), while a comparable raise from 115 to 229 cPo implied a reduction of 52% (α = 0.02). Slug–annular flow regime was identified for shear thinning fluids of high μa (1.0% and 1.5% carboxymethyl cellulose sodium salt solutions), where bubble buoyancy was conditioned by the μ of the fluid at rest and the active volume for mass transfer was reduced because of the presence of stagnant areas. Conditions imitating the rheological variability of anaerobically digested sewage sludge were included within those tested, being a reduction in gas transfer efficiency of 6 percentage points (from 7.6 ± 0.3% to 1.6 ± 0.1%) recorded when increasing μa from 130 to 340 cPo. It is thus recommended that rheology and μa variability are accounted for within the design of gas to liquid mass transfer systems involving digested sewage sludge, in order to avoid reductions in process performance and active volume

Fundamentos lógicos de la Inteligencia Artificial: razonamiento no monótono

La lógica tradicional resulta muy útil para formalizar razonamientos matemáticos: teoremas, definiciones... en los que se establecen reglas que se cumplen de forma atemporal y para todos los elementos de los que se habla. Por ejemplo, al decir que todas las curvas derivables son continuas, esta afirmación se aplica a todas las curvas bien definidas y derivables; además, es cierta en todo momento, no hay posibilidad de que deje de serlo en el futuro. Sin embargo, cuando queremos formalizar razonamientos más prácticos e “inteligentes” debemos considerar la posibilidad de que las conclusiones que saquemos no se apliquen a todos los elementos del grupo del que hablemos. Por ejemplo, al decir que “todos los pájaros vuelan”, sabemos que existen excepciones, como los pingüinos. Además, debemos considerar la opción de que un pájaro que hoy puede volar podría dejar de ser capaz de volar en el futuro si, por ejemplo, pierde un ala. Para razonamientos así la lógica tradicional no es del todo adecuada y es por ello que surge la lógica no monótona. La diferencia principal entre la lógica tradicional y la lógica no monótona es que en la lógica no monótona surge la posibilidad de “retractarse” en el futuro, es decir, algo que consideramos cierto con la información que tenemos podría dejar de serlo en el futuro cuando ampliemos esta información. En este trabajo veremos varios mecanismos de lógica no monótona, entre los que destacan la hipótesis de mundo cerrado, completación de predicados y la semántica de los modelos estables para los programas lógicos; sus utilidades frente a la lógica tradicional y, finalmente, un sistema que nos permite programar con lógica no monótona: Clingo, con el que seremos capaces de resolver problemas aparentemente complejos de una forma bastante simple.Traditional logic is very useful for formalizing mathematical reasoning: theorems, definitions ... in which rules are established that are met in a timeless manner and for all the elements that are spoken of, for example, by saying that all derivable curves are continuous, this statement applies to all well-defined and derivable curves, in addition, it is true at all times, there is no possibility of it ceasing to be so in the future. However, when we want to formalize more practical and ’intelligent’ reasoning, we must consider the possibility that the conclusions we draw may not apply to all the elements of the group we are talking about, for example, by saying that ’all birds fly,’ we know that there are exceptions, such as penguins, in addition, we must consider the option that a bird that can fly today could no longer be able to fly in the future if, for example, it loses a wing. For reasoning like this, traditional logic remains short and that is why the non-monotonous logic arises. The main difference between traditional and non-monotonous logic is that in non-monotonous logic the possibility of ’retracting’ in the future arises, that is, something we consider true with the information we have could cease to be in the future when we expand this information. In this work we will see several mechanisms of non-monotonous logic among which the closed world assumption, completion of predicates and stable models semantics for logic programs stand out, their utilities compared to traditional logic and, finally, a system that allows us to program with non-monotonous logic: Clingo, with which we will be able to solve seemingly complex problems in a fairly simple way.Universidad de Sevilla. Grado en Matemática

A Robust Iterative Unfolding Method for Signal Processing

There is a well-known series expansion (Neumann series) in functional analysis for perturbative inversion of specific operators on Banach spaces. However, operators that appear in signal processing (e.g. folding and convolution of probability density functions), in general, do not satisfy the usual convergence condition of that series expansion. This article provides some theorems on the convergence criteria of a similar series expansion for this more general case, which is not covered yet by the literature. The main result is that a series expansion provides a robust unbiased unfolding and deconvolution method. For the case of the deconvolution, such a series expansion can always be applied, and the method always recovers the maximum possible information about the initial probability density function, thus the method is optimal in this sense. A very significant advantage of the presented method is that one does not have to introduce ad hoc frequency regulations etc., as in the case of usual naive deconvolution methods. For the case of general unfolding problems, we present a computer-testable sufficient condition for the convergence of the series expansion in question. Some test examples and physics applications are also given. The most important physics example shall be (which originally motivated our survey on this topic) the case of pi^0 --> gamma+gamma particle decay: we show that one can recover the initial pi^0 momentum density function form the measured single gamma momentum density function by our series expansion.Comment: 23 pages, 9 figure

Ranking Viscous Finger Simulations to an Acquired Ground Truth with Topology-aware Matchings

International audienceThis application paper presents a novel framework based on topological data analysis for the automatic evaluation and ranking of viscous finger simulation runs in an ensemble with respect to a reference acquisition. Individual fingers in a given time-step are associated with critical point pairs in the distance field to the injection point, forming persistence diagrams. Different metrics, based on optimal transport, for comparing time-varying persistence diagrams in this specific applicative case are introduced. We evaluate the relevance of the rankings obtained with these metrics, both qualitatively thanks to a lightweight web visual interface, and quantitatively by studying the deviation from a reference ranking suggested by experts. Extensive experiments show the quantitative superiority of our approach compared to traditional alternatives. Our web interface allows experts to conveniently explore the produced rankings. We show a complete viscous fingering case study demonstrating the utility of our approach in the context of porous media fluid flow, where our framework can be used to automatically discard physically-irrelevant simulation runs from the ensemble and rank the most plausible ones. We document an in-situ implementation to lighten I/O and performance constraints arising in the context of parametric studies

Myosite ossifiante du muscle temporal après polytraumatisme

Myositis ossificans traumatica (MOT) of the temporal muscle is an extremely rare disease. A limitation of mouth opening is a key symptom. Imaging is very useful for diagnosis. The computed tomography scanner of the face is the most efficient for the detection of the MOT. Complete surgical resection is the best treatment. Cases of MOT in the head and neck area are rare. Cases of isolated temporal muscle involvement are even rarer. We present the case of an isolated ossification of the left temporal muscle after polytrauma. The interest of the clinical observation of the case presented is thus to document the literature. The differential diagnosis and pathognomonic signs present on the imaging examinations will also be detailed.La myosite ossifiante traumatique (MOT) du muscle temporal est une pathologie extrêmement rare. Une limitation de l’ouverture buccale est le symptôme clé. Les examens d’imagerie sont très utiles au diagnostic, le CT-scanner de la face étant l’examen le plus performant pour la détection de la MOT. Le meilleur traitement est la résection chirurgicale complète. Les cas de myosite ossifiante traumatique dans la région de la tête et du cou sont rares. Les atteintes au niveau du muscle temporal sont encore plus rares. Nous présentons ici le cas d’une ossification isolée du muscle temporal gauche après un polytraumatisme. L’intérêt de l’observation clinique du cas présenté est donc de documenter la littérature. Le diagnostic différentiel et les signes pathognomoniques présents sur les examens d’imagerie seront également détaillés