Design Characteristics of the 224 kW Magdalen Islands VAWT

The evolution of the main design features of the Magdalen Islands vertical axis wind turbine (VAWT) is described. The turbine has a rotor height of 120 ft (36.58 m) and diameter 80 ft (24.38 m). It was operated as a joint project between NRC and Hydro-Quebec in grid-coupled mode from July 1977 to July 1978 when the rotor was destroyed in an accident. The accident, although unfortunate, tested the basic integrity of the design in a gross overspeed condition, and the rotor is being rebuilt with minor modifications. Some directions for future VAWT research are suggested

OPTIMIZING VLS FIRING POLICY: AN ENUMERATION OF HETEROGENEOUS SEQUENCES TO INFORM EXPENDITURE

The U.S. Navy (USN) utilizes the Vertical Launch System (VLS) to store and launch both their offensive and defensive missiles. Since the number of VLS silos on a given ship is fixed, to maximize offensive capability the USN needs to minimize the number of interceptors required to combat incoming anti-surface missiles. Current firing policies may be overly conservative and expend too many interceptors per incoming threat, which results in a substantial fraction of VLS silos dedicated to defensive missiles. Decision makers need an analysis tool to explore the trade-off between missile consumption and probability of raid annihilation (PRA) for various firing policies and would also benefit from a prescriptive algorithm to help inform missile expenditure. This thesis provides a model to optimize VLS firing policy using a set of multiple interceptor types while accounting for range limitations, travel time, multi-interceptor salvos, battle damage assessment, and range dependent probability of kill. Additionally, the thesis derives analytical results for the optimal, lowest-cost allocation of interceptors in the single interceptor case, which, in turn, generates insight into how to structure sequential salvos.N81, Washington DCEnsign, United States NavyApproved for public release. Distribution is unlimited

Estimating national poverty rates and their effect on mortality: 129 countries, 1990–2013

AbstractBackgroundA country's wealth is an established predictor of population health outcomes. The distribution of wealth within a country is also associated with health outcomes, yet the relation between poverty and health outcomes has not been as widely assessed in cross-country studies because of insufficient data. In this study, we construct 22 complete, yet distinct, poverty data series and test how poverty can explain variation in health.MethodsThe World Bank's International Comparison Program estimates the number of people living at or below US$1·25 per day using more than 800 household surveys. However, this data series is far from complete. We build from the World Bank dataset and use covariates and intertemporal trends to generate a complete data series for 129 countries for 1990–2013. We used a variable selection process based on linear regression and Bayesian model selection to derive a tractable set of predictors. To predict national poverty rates at 51 different income thresholds, we used 20 variants of three models and relied on out-of-sample validation to choose the best model. Finally, we use fixed-effects linear regression techniques to test how national poverty rates are associated with changes in adult and child mortality.FindingsA three-stage model based on multiple imputation, hierarchical random-effects estimation, and Gaussian process regression out performs all other methods used to estimate national poverty rates. We noted that the number of people living on$1·25 per day is being reduced in most parts of the world, although in some regions of Africa the extreme poverty count is increasing. When poverty is defined as living on $5·00 per day, we see that the number of people living in poverty is increasing in 88 countries (68·2$1·25 per day, is not sufficient to produce great improvements in population health. When poverty is redefined at a larger income threshold, reductions in national poverty rates predict more substantial population health gains.InterpretationSince 1990, there has been a great deal of progress made in reducing the number of people living at or below $1·25 per day. We provide evidence that increasing an individual's income above$1·25 is not associated with dramatically improved health. Instead, an income closer to $5·00 per day seems to be more closely associated with improved population health. This research highlights that, while reducing the number of people living at or below$1·25 per day is important for better health outcomes, more income is required for substantial improvements in population health.FundingThe Bill and Melinda Gates Foundation

Iraq’s tough governance setting: Examining the importance of self-sacrifice over institutions to public service motivation

©Alobaydi, Dhirgham; Johnson, Bonnie J.; Templin, Jonathan, 2019. The definitive, peer reviewed and edited version of this article is published in Journal of Contemporary Iraq & the Arab World, Volume 13, Numbers 2-3, pp. 181-203(23), 2019, https://doi.org/10.1386/jciaw_00007_1.Public service motivation (PSM) is understudied within ‘tough governance settings’ such Iraq’s, as it transitioned from dictatorship to democracy amidst civil unrest. Debates surrounding a universal construct of PSM currently focus on whether a love of public institutions is an essential component, or if measures of self-sacrifice will suffice. Results from a multidimensional PSM measure previously utilized in western settings are used here in Iraq. The results demonstrate that items from typical PSM dimensions remain in the model, but the pro-social, self-sacrifice dimension is the only reliable subscale. Reinforcing a pro-social foundation of PSM, a pro-social unidimensional measure fits the data well and respondents themselves define ‘public service’ in pro-social terms. Showing little connection to institutions, PSM in Iraq correlates with public servants determining the public interest based on their knowledge of their communities and of citizens and less on professional expertise, adopted plans or on guidance from elected officials. Contrary to reports of a divided Iraq, PSM scores are similar across regions. These insights have implications for PSM measurement, governance choices in developing countries, and comparative public administration research

Testing the Psychometric Properties of the Modeling Self-Efficacy Scale

The Modeling Self-Efficacy Scale was developed to measure middle and high school students’ confidence in understanding and solving modeling tasks. The scale was administered to 225 eighth- and ninth-grade students. Participants read modeling tasks adapted from Programme for International Student Assessment’s 2003 problem-solving assessment and rated their confidence on a 100-point self-efficacy scale. Confirmatory factor analysis indicated that modeling self-efficacy is a unidimensional construct, best elicited by a repeated-measures-style survey design in which participants responded to the same self-efficacy items across multiple modeling problems. The omega reliability coefficient for the scale was .88. The findings suggest that the Modeling Self-Efficacy Scale is a reliable and valid instrument for middle and high school mathematics students

Design of Tools for Press-countersinking or Dimpling 0.040-inch-thick-24S-T Sheet

A set of dimpling tools was designed for 0.040-inch 24S-T sheet and flush-type rivets 1/8 inch in diameter with 100 degree countersunk heads. The dimples produced under different conditions of pressure, sheet thickness, and drill diameter are presented as cross-sectional photographs magnified 20 times. The most satisfactory values for the dimpling tools were found to be: maximum punch diameter, 0.231 inch; maximum die diameter, 0.223 inch; maximum mandrel diameter, 0.128 inch; dimple angle, 100 degree; punch springback angle, 1 1/2 degree; and die springback angle, 2 degree

AMST: Alignment to Median Smoothed Template for Focused Ion Beam Scanning Electron Microscopy Image Stacks

Alignment of stacks of serial images generated by focused ion Beam Scanning electron Microscopy (FIB-SEM) is generally performed using translations only, either through slice-by-slice alignments with SIFT or alignment by template matching. However, limitations of these methods are two-fold: the introduction of a bias along the dataset in the z-direction which seriously alters the morphology of observed organelles and a missing compensation for pixel size variations inherent to the image acquisition itself. These pixel size variations result in local misalignments and jumps of a few nanometers in the image data that can compromise downstream image analysis. We introduce a novel approach which enables affine transformations to overcome local misalignments while avoiding the danger of introducing a scaling, rotation or shearing trend along the dataset. Our method first computes a template dataset with an alignment method restricted to translations only. This pre-aligned dataset is then smoothed selectively along the z-axis with a median filter, creating a template to which the raw data is aligned using affine transformations. Our method was applied to FIB-SEM datasets and showed clear improvement of the alignment along the z-axis resulting in a significantly more accurate automatic boundary segmentation using a convolutional neural network

Das Potential von Virtual Communities auf Basis von Distributed Virtual Environments für Kundengewinnung und -bindung

Zusammenfassung: 'In diesem Artikel soll der Einsatz von Distributed Virtual Environments (DVE) zur Bildung von Virtual Communities (VC) für kommerzielle Interessen untersucht werden. Nach der Charakterisierung von VC und DVE wird deren Symbiose zum Zweck der Kundengewinnung und -bindung im Consumer-Bereich untersucht. Dabei wird eine kritische Bewertung erster Prototypen und die Analyse der damit verbundenen technologischen, psychologisch-soziologischen und marketing-strategischen Probleme vorgenommen. Auf dieser Basis erfolgt abschließend die Diskussion eines Vorgehensmodells für den Aufbau DVE-basierter Gemeinschaften zur kommerziellen Nutzung und die Spezifikation eines Anforderungskataloges für erfolgreiche DVE in diesem Sektor