5,125 research outputs found
Cohomology ring of differential operator rings
We compute the multiplicative structure in the Hocshchild cohomology ring of
a differential operators ring and the cap product of Hochschild cohomology on
the Hochschild homology.Comment: 20 page
The Impact of Mindfulness Training on Hyperactive Behaviors Demonstrated by Elementary Age Children with a Diagnosis of Attention Deficit Hyperactivity Disorder
Attention Deficit / Hyperactivity Disorder (ADHD) is one of the most prevalent childhood disorders in the United States. Although many children with an ADHD diagnosis are prescribed medication to control symptoms, behavioral concerns are still regularly noted in the classroom, home, and other settings. Therefore, school psychologists are often called upon to assist teachers and families with developing intervention procedures. The purpose of this research was to investigate the relationship between mindfulness training, the cognitive processes of attention regulation, and behavior of children who have been diagnosed with ADHD. This study utilized a multiple baseline across participant’s design where each student was tracked over time following a baseline (pre-intervention) condition. Four 8-year-old male participants with a primary diagnosis of ADHD and a significant number of off-task classroom behaviors were included in this study. Teacher and parent ratings of the Behavior Assessment System for Children, Second Edition (BASC-2) and Behavior Rating Inventory of Executive Function (BRIEF) were completed pre- and posttest for each participant. The Reliable Change Index (RCI) was calculated to determine if the pre- to posttest change scores on the BASC-2 and BRIEF exceeded what could be accounted for by measurement error alone. Results of the analyses revealed that mindfulness training was effective in increasing the number of on-task behaviors for participants. Parent and teacher ratings on the BRIEF suggest that mindfulness training impacted ratings on the Inhibit, Initiate, and Monitor scales. Parent and teacher ratings on the BASC-2 were analyzed and scores from the Attention Problems scale did not demonstrate significant change across raters and across participants. Significant change occurred on the Hyperactivity scale. Findings are discussed in relationship to the literature on mindfulness training for students with a diagnosis of ADHD. Implications for future research and practice are also suggested
Cartesian Bicategories II
The notion of cartesian bicategory, introduced by Carboni and Walters for
locally ordered bicategories, is extended to general bicategories. It is shown
that a cartesian bicategory is a symmetric monoidal bicategory
A Reliability Study of Phased Array Ultrasonic Inspections Applied to Aluminothermic Welds in Rails
Nowadays, long welded railway rails are achieved by means of aluminothermic and flush-butt welding processes. Compared to bolted joints, welds proved to be effective in terms of reduced wheel damage, ride comfort and maintenance. However, even if the event is inexplicably not considered in relevant standards, surface cracks often initiate within the welded and the heat affected regions of the foot, leading to brittle failure. On the subject, a recent work developed a probabilistic methodology for determining day-by-day failure probability. However, apart from this structural integrity study and few others, a complete damage tolerance approach should also consider the capability of nondestructive inspections. The latter is recognized as an essential input to define maintenance inspection intervals. The present work is focused on the capability assessment of Phased Array ultrasonic inspection applied to aluminothermic-welded joints by means of Probability of Detection curves, as a result of experimental and Model Assisted data samples
Acoustic emission-based monitoring of fatigue damage in CFRP-CFRP adhesively bonded joints
Adhesively bonded joints are being increasingly applied in modern structures. However, manufacturing defects and particularly harsh operative conditions may cause local debonding and catastrophic failures. Structural health monitoring (SHM) and non-destructive testing (NDT) procedures are then needed to evaluate the in-service structural integrity of adhesively bonded joints. In this research, an adhesively bonded single-lap joint, both adherends of which are manufactured using a carbon fibre-reinforced polymer (CFRP) composite, is subjected to constant amplitude fatigue loading. During such a test, the integrity and damage condition of the joint is continuously monitored using acoustic emission (AE), while the test itself is periodically interrupted in order to apply micro-computed tomography (??CT) to the specimen, with the aim of investigating the real features of the developing fatigue damage. The results show that, after suitable elaboration and filtering by means of pattern recognition algorithms, acoustic emission-based monitoring allows for effective identification and characterisation of the development of fatigue damage in adhesively bonded joints
A cytogenetic investigation on peripheral blood lymphocytes of cattle affected by enzootic bovine leukemia
A cytogenetic investigation on peripheral blood lymphocytes of cattle affected by enzootic bovine leukemia
International audienc
A preliminary study of multi-parameter POD curves for a guided waves based SHM approach to lightweight materials
In view of an extensive literature about guided waves propagation, interaction and numerical simulation in platelike
structures made of metallic and composite materials, a lack of information is pointed out regarding their reliability in
structural health monitoring approaches. Typically, because of uncertainties in the inspection process, the capability of nondestructive
testing systems is expressed by means of suitable probability of detection curves. Based on Berens’ model, a linear
relationship is established between probability of detection and flaw size. Although the uncertain factors differ from a nondestructive
inspection technique and a structural health monitoring approach, the same mathematical framework can be
assumed. Hence, the authors investigated the application of a recently developed non-destructive testing Multi-Parameter POD
approach to a guided waves based SHM one: numerical simulations as well as experimental data from flawed plates were
combined to bring about a “master” POD curve. Once established, it can be used to build the POD curves of the single key
factors as flaw size, orientation, structural attenuation and so on
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