Design and analysis considerations for deployment mechanisms in a space environment

On the second flight of the INTELSAT V spacecraft the time required for successful deployment of the north solar array was longer than originally predicted. The south solar array deployed as predicted. As a result of the difference in deployment times a series of experiments was conducted to locate the cause of the difference. Deployment rate sensitivity to hinge friction and temperature levels was investigated. A digital computer simulation of the deployment was created to evaluate the effects of parameter changes on deployment. Hinge design was optimized for nominal solar array deployment time for future INTELSAT V satellites. The nominal deployment times of both solar arrays on the third flight of INTELSAT V confirms the validity of the simulation and design optimization

HypTrails: A Bayesian Approach for Comparing Hypotheses About Human Trails on the Web

When users interact with the Web today, they leave sequential digital trails on a massive scale. Examples of such human trails include Web navigation, sequences of online restaurant reviews, or online music play lists. Understanding the factors that drive the production of these trails can be useful for e.g., improving underlying network structures, predicting user clicks or enhancing recommendations. In this work, we present a general approach called HypTrails for comparing a set of hypotheses about human trails on the Web, where hypotheses represent beliefs about transitions between states. Our approach utilizes Markov chain models with Bayesian inference. The main idea is to incorporate hypotheses as informative Dirichlet priors and to leverage the sensitivity of Bayes factors on the prior for comparing hypotheses with each other. For eliciting Dirichlet priors from hypotheses, we present an adaption of the so-called (trial) roulette method. We demonstrate the general mechanics and applicability of HypTrails by performing experiments with (i) synthetic trails for which we control the mechanisms that have produced them and (ii) empirical trails stemming from different domains including website navigation, business reviews and online music played. Our work expands the repertoire of methods available for studying human trails on the Web.Comment: Published in the proceedings of WWW'1

Reasoning About Vote Counting Schemes Using Light-weight and Heavy-weight Methods

We compare and contrast our experiences in specifying, implementing and verifying the monotonicity property of a simple plurality voting scheme using modern light-weight and heavy-weight verification tools

Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

The role of computed tomography in the evaluation of cerebrovascular accidents

Background:Cerebrovascular accidents (CVA) or stroke ranks first in frequency and important among all the neurological diseases of adult life. 50% of neurological disorders in a hospital are of this type. It is the third leading cause of death throughout the world. The prolonged morbidity and extended hospitalization required by these patients makes the disease one of the most devastating in medicine. The purpose of the present study was to document the presence or absence of hemorrhage or infarct, to determine the size, location of infarct, reasonably assessing the territory to blood vessels involved and to detect the incidence of negative cases of clinically suspected stroke.Methods:100 cases admitted to KIMS, Hubli and those referred to the NMR scan centre, Hubli with the clinical diagnosis of acute stroke were taken up for the study. The study was done from May 2010 to April 2012.Results:Out of 100 patients clinically suspected of CVA, submitted for CT scan study of the brain, 69 patients had infarcts, 21 patients had hemorrhage, 8 patients had CVT, 1 patient had SAH and 1 patient had normal scans. Infarcts (69%) formed the major group of the CVA cases involving most commonly the LMCA territory in 10 (14.49%) patients. Hemorrhage (21%) formed the second major group of CVA cases involving most commonly the RMCA territory 9 (42.85%) patients.Conclusions:CT scanning is a gold standard technique for the diagnosis and management of stroke and can be ideally done in all cases.The role of computed tomography in the evaluation of                cerebrovascular accident

Connection between Tutoring Format Type and Reading Scores of Elementary Aged Children

Extant research shows that response to intervention (RTI) individual and small group interventions increase children’s reading skills; however, little information is available that investigates whether the type of intervention format makes a difference in learning to read. The Early Childhood Longitudinal Study, Kindergarten class (ECLS-K) database was used to identify third-grade children who received individual, small group, or combined individual and small group tutoring, to increase their reading skills. The current study compared reading scores associated with each intervention type to determine which reading intervention format was most beneficial. The results from this study showed that children receiving small group intervention had higher reading scores than those receiving individual or combined interventions. In addition, a significant difference was found between the small group and combined formats. These results show the benefits of small group tutoring for elementary-aged children that could be beneficial in early prevention and identification of children who are struggling in reading