1,104 research outputs found
Modeling heat transfer from quench protection heaters to superconducting cables in Nb3Sn magnets
We use a recently developed quench protection heater modeling tool for an
analysis of heater delays in superconducting high-field Nb3Sn accelerator
magnets. The results suggest that the calculated delays are consistent with
experimental data, and show how the heater delay depends on the main heater
design parameters.Comment: 8 pages, Contribution to WAMSDO 2013: Workshop on Accelerator Magnet,
Superconductor, Design and Optimization; 15 - 16 Jan 2013, CERN, Geneva,
Switzerlan
The impact of acculturation and human capital on the information search process of immigrant consumers
This study examines the impact of acculturation and human capital on the degree of external information search among recently arrived immigrants when selecting a service provider. The variables ‘acculturation’, ‘human capital’, ‘perceived risk’, ‘involvement’, ‘degree of external information search’, ‘satisfaction with the decision made’ and ‘willingness to recommend’ (the service provider) are included in the analysis. The main interest is to examine the application of acculturation and human capital theory to the information search process. Prior research on acculturation has considered variables such as language and length of time in the host country to measure the acculturation level of immigrants. However, these studies have used single variables and have not been rigorously tested. The present study uses a measurement instrument developed in psychology which measures acculturation through four dimensions: assimilation, separation, integration and marginalisation. Human capital was measured in a broader sense than has been done in previous studies. Past research has measured human capital through prior knowledge, perceived ability and market knowledge separately, but an integrative approach has not been empirically tested. This study considers all three aspects when measuring the human capital of recently arrived immigrants. The majority of acculturation studies have been conducted in the United States with Hispanic populations and little research has been done in Australia, despite the significant immigrant population. Thus, this research examines the level of acculturation and the human capital of recently arrived immigrants and the influence of these variables on the external information search process when selecting a service provider. A paper-based self-administered survey was conducted using a random sample of 153 immigrants. It was hypothesised that the degree of external information search would be influenced by acculturation, human capital, perceived risk, and involvement. In addition, human capital and involvement would affect perceived risk. Finally, it was hypothesised that the degree of external information search would influence satisfaction with the decision made, which in turn would lead to willingness to recommend. Internal reliabilities were assessed to determine construct validity, obtaining acceptable Alpha coefficients. The proposed scales were assessed first by using exploratory factor analysis to examine the dimensionality of the constructs, and then by using confirmatory factor analysis to check the discriminant validity. Furthermore, a regression analysis was conducted to test the hypothesised relationships. Finally, structural equation modelling was used to analyse the interrelationships among the hypotheses and a series of t-tests were conducted to determine the differences within each construct. The results indicate that acculturation positively influences the degree of external information search undertaken by immigrants. Human capital also has a positive influence on the degree of external information search as does involvement. Further, the degree of acculturation has a positive effect on the level of human capital. Finally, satisfaction has a positive effect on the willingness to recommend. This study contributes to the body of knowledge related to the information search process of immigrant consumers, by conceptualising and empirically testing to the influence of acculturation and human capital on the degree of external information search for a service provider. Furthermore, this research has marketing implications for organisations interested in targeting this growing segment of the population
Object Contour and Edge Detection with RefineContourNet
A ResNet-based multi-path refinement CNN is used for object contour
detection. For this task, we prioritise the effective utilization of the
high-level abstraction capability of a ResNet, which leads to state-of-the-art
results for edge detection. Keeping our focus in mind, we fuse the high, mid
and low-level features in that specific order, which differs from many other
approaches. It uses the tensor with the highest-levelled features as the
starting point to combine it layer-by-layer with features of a lower
abstraction level until it reaches the lowest level. We train this network on a
modified PASCAL VOC 2012 dataset for object contour detection and evaluate on a
refined PASCAL-val dataset reaching an excellent performance and an Optimal
Dataset Scale (ODS) of 0.752. Furthermore, by fine-training on the BSDS500
dataset we reach state-of-the-art results for edge-detection with an ODS of
0.824.Comment: Keywords: Object Contour Detection, Edge Detection, Multi-Path
Refinement CN
The Potential of Restarts for ProbSAT
This work analyses the potential of restarts for probSAT, a quite successful
algorithm for k-SAT, by estimating its runtime distributions on random 3-SAT
instances that are close to the phase transition. We estimate an optimal
restart time from empirical data, reaching a potential speedup factor of 1.39.
Calculating restart times from fitted probability distributions reduces this
factor to a maximum of 1.30. A spin-off result is that the Weibull distribution
approximates the runtime distribution for over 93% of the used instances well.
A machine learning pipeline is presented to compute a restart time for a
fixed-cutoff strategy to exploit this potential. The main components of the
pipeline are a random forest for determining the distribution type and a neural
network for the distribution's parameters. ProbSAT performs statistically
significantly better than Luby's restart strategy and the policy without
restarts when using the presented approach. The structure is particularly
advantageous on hard problems.Comment: Eurocast 201
Hierarchical micro-/mesoporous zeolite microspheres prepared by colloidal assembly of zeolite nanoparticles
A novel template-free colloidal assembly method that combines colloidal zeolite (silicalite-1) suspensions in a water-in-oil emulsion with an evaporation-induced assembly process has been developed for preparing hierarchical micro-/mesoporous zeolite microspheres (MZMs). Such particles have an interconnected mesoporosity and large mesopore diameters (25-40 nm) combined with 5.5 \uc5 diameter micropores of the zeolite nanoparticles. The method developed has the advantages of employing mild synthesis conditions, a short preparation time, and not requiring the use of a mesoporogen template or post-treatment methods. The method provides a new range of micro-/mesoporous zeolites with tunable mesoporosity dictated by the size of the zeolite nanoparticles. It also offers the possibility of combining several zeolite particle sizes or optionally adding amorphous silica nanoparticles to tune the mesopore size distribution further. It should be generally applicable to other types of colloidal zeolite suspensions (e.g. ZSM-5, zeolite A, beta) and represents a new route amenable for cost-effective scale-up
Anatomically Constrained Video-CT Registration via the V-IMLOP Algorithm
Functional endoscopic sinus surgery (FESS) is a surgical procedure used to
treat acute cases of sinusitis and other sinus diseases. FESS is fast becoming
the preferred choice of treatment due to its minimally invasive nature.
However, due to the limited field of view of the endoscope, surgeons rely on
navigation systems to guide them within the nasal cavity. State of the art
navigation systems report registration accuracy of over 1mm, which is large
compared to the size of the nasal airways. We present an anatomically
constrained video-CT registration algorithm that incorporates multiple video
features. Our algorithm is robust in the presence of outliers. We also test our
algorithm on simulated and in-vivo data, and test its accuracy against
degrading initializations.Comment: 8 pages, 4 figures, MICCA
Evolución de la equidad en el sistema colombiano de salud
Las reformas a los sistemas de salud en el mundo, están a la orden del dÃa; los desafÃos que enfrentan los formuladores de polÃtica en casi todos los paÃses, son bastante similares: hacer un sistema de salud en el que tanto la financiación como la prestación de servicios de salud sean equitativos; buscar un mejoramiento en la eficiencia tanto en la financiación como en el gasto sectorial; mejorar la calidad de los servicios de salud; y lograr sistemas de salud que sean viables y sostenibles financiera y polÃticamente (Hsiao, 1998). El sistema de salud colombiano es uno de los que han iniciado el camino de la reforma, desde la sanción de la Ley 100 de 1993, mediante la cual se creó el Sistema General de Seguridad Social en Salud. Durante los seis años de vida del nuevo sistema de salud, han surgido interrogantes sobre cómo enfrenta la reforma los desafÃos comunes a todos los sistemas del mundo, pero pocas han sido las respuestas, al menos las soportadas en investigaciones realizadas técnicamente; esta escasez de respuestas se debe en parte a que el tiempo transcurrido no es lo suficientemente largo para detectar cambios relevantes, pero también se debe a una importante escasez de datos que permitan documentar sólidamente un argumento a favor o en contra de los cambios esperados. En cuanto a los escasos análisis realizados a los datos existentes, éstos no han arrojado respuestas satisfactorias a los interrogantes planteados, lo que se explica en parte porque que no existe un sistema de monitoreo que haya establecido una lÃnea de base y que permita hacer seguimiento a los indicadores claves; adicionalmente, la escasa información existente está dispersa, y no estandarizada, lo que no permite hacer comparaciones más exactas. Uno de los aspectos que mas preguntas ha generado, es el de la equidad; en este sentido, aunque la cobertura de aseguramiento se incrementó sustancialmente, encontrándose las mayores ganancias en los quintiles de ingreso mas bajos, aún no es claro si el acceso efectivo a los servicios de salud ha mejorado de la misma manera, como consecuencia de la mayor cobertura de aseguramiento. Tampoco está claro si la reforma ha tenido impacto positivo sobre el gasto de bolsillo de los hogares 1 o sobre la tenencia de seguros privados, las dos fuentes más inequitativas de financiamiento de un sistema de salud. Por esta razón, se ha llevado a cabo este estudio en el cual se analizan los datos sobre gasto fiscal en salud y gasto de los hogares en servicios de salud, obtenidos apartir de encuestas de hogares, con el fin de detectar posibles cambios positivos o negativos en términos de: - Equidad en la distribución geográfica de recursos para la atención en salud de los pobres. - Equidad en la cobertura de aseguramiento obligatorio. - Equidad en el acceso a los servicios de salud. - Comportamiento del gasto de bolsillo para pagos a proveedores de servicios de salud. - Comportamiento del gasto de los hogares para adquirir pólizas privadas de seguros de salud. Las respuestas a las preguntas planteadas en este estudio servirán para orientar la formulación de polÃticas sectoriales y para formular hipótesis para futuros estudios que permitan una visión más integral y de mas largo plazo sobre la evolución de la reforma a la salud en Colombia.
Developing an effective construction training program for Hispanic supervisors and craft workers
Hispanics make up a growing percentage of the craft workers entering the construction industry, and this has created several challenges for American construction companies. This study addresses the situation by investigating training needs for Hispanic construction craft workers and developing a training program for them within the industry. In order to evaluate current craft workers\u27 conditions within the construction industry, Iowa State University researchers conducted a survey, with 98 Hispanic craft workers as respondents from 10 construction companies, to determine current working conditions. The results confirm that the language barrier is an obstacle for both the Hispanic workers and the English-speaking employees involved in construction projects. As a part of this research, two training courses were designed to help both American construction companies and their Hispanic labor force to overcome the barriers that keep them from succeeding safely and productively. A training course titled, English as a Second Language Survival Course , was developed to facilitate basic communication between Hispanic workers and their American supervisors using construction-focused terminology. This course was delivered once as a trial run for a two-hour duration and twice for a full-length duration of eight hours. Important feedback was obtained from participants as part of the evaluations of the course. How much of the course contents will be useful in your working environment was asked; 40% of workers said all of it and 60% of workers said most of it. Another question was Was it worth taking the time to attend the course? to which 94% answered definitely and 6% answered yes. A second training course titled, Stepping Up to Supervisor Course for Hispanic Construction Workers , was also developed to provide an effective tool to help companies promote those Hispanic craft workers whose willingness and skills meet the requirements to advance to a supervisory position in an American construction company. This course will be offered in the spring of 2004
Climbing: A Unified Approach for Global Constraints on Hierarchical Segmentation
International audienceThe paper deals with global constraints for hierarchical segmentations. The proposed framework associates, with an input image, a hierarchy of segmentations and an energy, and the subsequent optimization problem. It is the first paper that compiles the different global constraints and unifies them as Climbing energies. The transition from global optimization to local optimization is attained by the h-increasingness property, which allows to compare parent and child partition energies in hierarchies. The laws of composition of such energies are established and examples are given over the Berkeley Dataset for colour and texture segmentation
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