Photospheric downward plasma motions in the quiet-Sun

We analyze spectropolarimetric data taken with the Hinode spacecraft in quiet solar regions at the disk center. Distorted redshifted Stokes $V$ profiles are found showing a characteristic evolution that always follows the same sequence of phases. We have studied the statistical properties of these events using spectropolarimetric data from Hinode/SP. We also examined the upper photosphere and the low chromosphere using Mg i b2 and Ca ii h data from Hinode. Finally, we have applied the SIRGAUSS inversion code to the polarimetric data in order to infer the atmospheric stratification of the physical parameters. We have also obtained these physical parameters taking into account dynamical terms in the equation of motion. The Stokes V profiles display a bump that evolves in four different time steps, and the total process lasts 108 seconds. The Stokes I shows a strongly bent red wing and the continuum signal exhibits a bright point inside an intergranular lane. This bright point is correlated with a strong redshift in the Mg i b2 line and a bright feature in Ca ii h images. The model obtained from the inversion of the Stokes profiles is hotter than the average quiet-Sun model, with a vertical magnetic field configuration and field strengths in the range of kG values. It also presents a LOS velocity stratification with a Gaussian perturbation whose center is moving to deeper layers with time. We have examined a particular type of event that can be described as a plasmoid of hot plasma that is moving downward from the top of the photosphere, placed over intergranular lanes and always related to strong magnetic field concentrations. We argue that the origin of this plasmoid could be a magnetic reconnection that is taking place in the chromosphere.Comment: 18 pages, 14 figure

CAD learning in mechanical engineering at universities

In this study, we attempt to compile all the CAD-related concepts, contents and working methods that students of mechanical engineering should learn at universities. To do so, we first study the background to CAD-related methodologies. In second place, we compile the results of surveys administered over the past three years to our students of CAD studying mechanical engineering at our university. In third place, different publications in the literature relating to the need for CAD in industry are studied to understand the sort of CAD training that is needed in industry. In fourth place, an exploratory analysis is performed of the CAD-related contents taught at the 50 universities that top the QS (Quacquarelli Symonds) ranking. In fifth place, a survey of possible CAD-related contents is administered to teachers, instructors, and experts in CAD from those 50 leading universities in the QS ranking. The basic pillars of modeling in 3D are: methodologies of modeling, solid modeling, assemblies, and the design of technical drawings. The use of 3D printers in CAD learning means that thinking, designing, and manufacturing any object is easy at university. Knowledge of top-down/bottom-up/in-context methodologies has to be widened both for industry and for students. Design intent must be introduced in CAD from the very beginning so that all the models are flexible and robust. The students expressed a preference to learn the concepts through a set of good practice exercises and to be evaluated by completing a final course assignment of their choice

A general and efficient divide-and-conquer algorithm framework for multi-core clusters

This is a post-peer-review, pre-copyedit version of an article published in Cluster Computing. The final authenticated version is available online at: https://doi.org/10.1007/s10586-017-0766-y[Abstract]Divide-and-conquer is one of the most important patterns of parallelism, being applicable to a large variety of problems. In addition, the most powerful parallel systems available nowadays are computer clusters composed of distributed-memory nodes that contain an increasing number of cores that share a common memory. The optimal exploitation of these systems often requires resorting to a hybrid model that mimics the underlying hardware by combining a distributed and a shared memory parallel programming model. This results in longer development times and increased maintenance costs. In this paper we present a very general skeleton library that allows to parallelize any divide-and-conquer problem in hybrid distributed-shared memory systems with little effort while providing much flexibility and good performance. Our proposal combines a message-passing paradigm at the process level and a threaded model inside each process, hiding the related complexity from the user. The evaluation shows that this skeleton provides performance comparable, and often better than that of manually optimized codes while requiring considerably less effort when parallelizing applications on multi-core clusters.Ministerio de Economía y Competitividad; TIN2013-42148-PMinisterio de Economía y Competitividad; TIN2016-75845-PXunta de Galicia; GRC2013/05

A framework for argument-based task synchronization with automatic detection of dependencies

[Abstract] Synchronization in parallel applications can be achieved either implicitly or explicitly. Implicit synchronization is typical of programming environments that provide predefined, and often simple, patterns of parallelism such as data-parallel libraries and languages and skeletal operations. Nevertheless, more flexible approaches that allow to express arbitrary task-level parallel computations without a predefined structure request in turn that the user explicitly specifies the synchronization needed among the parallel tasks. In this paper we present a library-based approach that enables arbitrary patterns of parallelism with minimal effort for the user. Our proposal is the first generic approach to express parallelism we know of that requires neither explicit synchronizations nor a detail of the dependencies of the parallel tasks. Our strategy relies on expressing the parallel tasks as functions that convey their dependencies implicitly by means of their arguments. These function arguments are analyzed by our library, called DepSpawn, when a parallel task is spawned in order to enforce its dependencies. Our experiments indicate that DepSpawn is very competitive, both in terms of performance and programmability, with respect to a widespread high-level approach like OpenMP.Xunta de Galicia; INCITE08PXIB105161PRMinisterio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación de España; AP2009-475

Sequential Allocation and Balancing Prognostic Factors in a Psychiatric Clinical Trial

In controlled clinical trials, each of several prognostic factors should be balanced across the trial arms. Traditional restricted randomization may be proved inadequate especially with small sample sizes. In psychiatric disorders such as obsessive compulsive disorder (OCD), small trials prevail. Therefore, procedures to minimize the chance of imbalance between treatment arms are advisable. This paper describes a minimization procedure specifically designed for a clinical trial that evaluates treatment efficacy for OCD patients. Aitchison's compositional distance was used to calculate vectors for each possibility of allocation in a covariate adaptive method. Two different procedures were designed to allocate patients in small blocks or sequentially one-by-one. Partial results of this allocation procedure as well as simulated ones are shown. In the clinical trial for which this procedure was developed, the balancing between treatment arms was achieved successfully. Simulations of results considering different arrival order of patients showed that most of the patients are allocated in a different treatment arm if arrival order is modified. Results show that a random factor is maintained with the random arrival order of patients. This specific procedure allows the use of a large number of prognostic factors for the allocation decision and was proved adequate for a psychiatric trial design

Assessing impacts of pathogen-tested sweetpotato planting materials in Central Luzon, Philippines

Sweet potato production in Central Luzon, Philippines has been plagued by a virus disease complex locally known as “camote kulot.” Aside from causing more than 50% reduction in yield, the disease was also responsible for the loss of an important variety with good and well-accepted agronomic characteristics. Interagency efforts resulted in a technology in the production of clean planting materials through thermotheraphy and meristem culture. A sweetpotato variety has been cleaned up, reproduced and multiplied for farmers use. CIP-UPWARD supported the use of participatory R&D approaches to adapt CPM in sweetpotato-associated livelihood systems in the region. The program implemented livelihood systems analysis, farmer field schools and farmer participatory researches. Several technical and socio-economic evaluation activities were also conducted to determine the contribution of these projects and CPM in livelihood systems. The results indicated the role of participatory approaches in facilitating project outputs and outcomes. PR&D approaches intensify awareness of research and development institutions about “kulot” and the potential of CPM in solving it leading to their provision of resources and other support to its solution. CPM were produced and used by 117 farmers in 19 villages of the provinces of Tarlac and Bataan. Local government units provided their own resources to so that their constituents will benefit from the technology. They build nethouses, finance FFS and mobilize communities leading to establishment of enterprises out of CPM technology. Unfortunately, there are a number of technical, socio-economic and policy issues that limits more widespread use of CPM and improvements in contributions of sweetpotato to the livelihood systems of households in the region. The paper also looks at the various elements of participatory research and development, how they have been operationalized within the project context and how they have contributed to achieving project outcomes and impacts. These elements evolved from UPWARD’s own field-based experiences and from efforts by other organizations to develop a wide range of participatory approaches. The paper explores the use of the following elements - problem-based agenda, impact-driven objectives, field-based action, user responsiveness, household orientation, livelihood systems framework, integration of scientific and local knowledge, interdisciplinary mode and inter-institutional partnerships, as touchstones for assessing PR&D processes

Deformaciones provocadas en el tercio apical de los conductos radiculares curvos durante su preparación biomecánica mediante técnicas manuales de impulsión-tracción

Los autores hacen un repaso de las deformaciones que se producen en el tercio apical de los conductos radiculares en el curso de la preparación biomecánica, fundamentalmente los 'zips' y 'elbows' de la literatura anglosajona, analizando su causa y repercusiones en la terapia endodóncica. Se estudian también las propuestas para evitar la aparición de las antedichas deformaciones

Validation of a tolerance analysis simulation procedure in assemblies

A simulation of tolerance analysis in assemblies using Sigmund Computer Aided Tolerancing (CAT) software is validated through the example of an automobile locking device. Simulation with CAT, applying criteria on both the statistical distribution and the rivet pin position in the hole used in the example, will allow us to predict the functional dimension tolerances in these assemblies with greater accuracy in the preliminary design phase. These tolerances will subsequently define the manufacturing specifications. The statistical distribution, in the example, that best fits the overall set of tolerances, is the triangular distribution followed by the normal distribution; the position of the rivet pin axis in its hole is off-centre by 53 % with regard to its maximum value

Assessment of 3D viewers for the display of interactive documents in the learning of graphic engineering

The purpose of this study is to determine which 3D viewers should be used for the display of interactive graphic engineering documents, so that the visualization and manipulation of 3D models provide useful support to students of industrial engineering (mechanical, organizational, electronic engineering, etc). The technical features of 26 3D visualization software programmes (viewers, publishers, 3D output formats) are examined, to select the three visualization configurations that best meet our needs at the Graphic Expression Department of the University of Burgos (Solidworks plus Solidworks eDrawings; Catia plus Catia eDrawings and 3DXML; several Computer-Aided Design software programmes plus Adobe Acrobat Pro Extended). These are compared using the Quality Function Deployment tool known as House of Quality. The House of Quality has enabled us to identify and quantify the importance attached by engineering teachers to each of their requirements for 3D viewers, and to identify and quantify the technical importance of each of the measurable features of these viewers