Ostensive signals support learning from novel attention cues during infancy

Social attention cues (e.g., head turning, gaze direction) highlight which events young infants should attend to in a busy environment and, recently, have been shown to shape infants' likelihood of learning about objects and events. Although studies have documented which social cues guide attention and learning during early infancy, few have investigated how infants learn to learn from attention cues. Ostensive signals, such as a face addressing the infant, often precede social attention cues. Therefore, it is possible that infants can use ostensive signals to learn from other novel attention cues. In this training study, 8-month-olds were cued to the location of an event by a novel non-social attention cue (i.e., flashing square) that was preceded by an ostensive signal (i.e., a face addressing the infant). At test, infants predicted the appearance of specific multimodal events cued by the flashing squares, which were previously shown to guide attention to but not inform specific predictions about the multimodal events (Wu and Kirkham, 2010). Importantly, during the generalization phase, the attention cue continued to guide learning of these events in the absence of the ostensive signal. Subsequent experiments showed that learning was less successful when the ostensive signal was absent even if an interesting but non-ostensive social stimulus preceded the same cued events

Canadian Estimate of Bird Mortality Due to Collisions and Direct Habitat Loss Associated with Wind Turbine Developments

We estimated impacts on birds from the development and operation of wind turbines in Canada considering both mortality due to collisions and loss of nesting habitat. We estimated collision mortality using data from carcass searches for 43 wind farms, incorporating correction factors for scavenger removal, searcher efficiency, and carcasses that fell beyond the area searched. On average, 8.2 ± 1.4 birds (95% C.I.) were killed per turbine per year at these sites, although the numbers at individual wind farms varied from 0 - 26.9 birds per turbine per year. Based on 2955 installed turbines (the number installed in Canada by December 2011), an estimated 23,300 birds (95% C.I. 20,000 - 28,300) would be killed from collisions with turbines each year. We estimated direct habitat loss based on data from 32 wind farms in Canada. On average, total habitat loss per turbine was 1.23 ha, which corresponds to an estimated total habitat loss due to wind farms nationwide of 3635 ha. Based on published estimates of nest density, this could represent habitat for ~5700 nests of all species. Assuming nearby habitats are saturated, and 2 adults displaced per nest site, effects of direct habitat loss are less than that of direct mortality. Installed wind capacity is growing rapidly, and is predicted to increase more than 10-fold over the next 10-15 years, which could lead to direct mortality of approximately 233,000 birds / year, and displacement of 57,000 pairs. Despite concerns about the impacts of biased correction factors on the accuracy of mortality estimates, these values are likely much lower than those from collisions with some other anthropogenic sources such as windows, vehicles, or towers, or habitat loss due to many other forms of development. Species composition data suggest that < 0.2% of the population of any species is currently affected by mortality or displacement from wind turbine development. Therefore, population level impacts are unlikely, provided that highly sensitive or rare habitats, as well as concentration areas for species at risk, are avoided

Design for latitude

"The purposes of this thesis are threefold: (1) to provide an introduction to the Taguchi philosophy and its methodologies, (2) to integrate the Taguchi philosophy of quality loss with nonlinear programming both without and with constraints, and (3) to compare the conventional Taguchi approach and the nonlinear programming approach to engineering design optimization. Part I of the thesis provides an introduction to Taguchi methods. Chapter One introduces Taguchi1s perspective of quality and losses attributable to poor quality. Also covered are different design objectives and how these are related to quality. Chapter Two develops the methods for implementing Taguchi's concepts of quality. Part II considers the Taguchi concept of quality loss as the optimization criterion. Chapter Three uses the Taguchi quality loss function given in the first chapter as the objective function; however nonlinear programming, not experimental design, is the vehicle used to perform the design optimization. Chapter Four investigates the fully constrained optimization problem by treating constraints as additional objective terms thereby creating an equivalent multicriterion problem. Part III completes the thesis by summarizing the results of the work. The comparison of results is given in Chapter Five. Chapter Six discusses these results. Chapter Seven concludes the thesis and suggests topics for additional work. Dr. Taguchi1s methods are based on fundamental concepts in statistics. However, because this work is not oriented towards the statistician, statistics will be introduced only when absolutely necessary. Appendix A covers the basic statistical and probabilistic concepts required by the thesis. Appendix B contains the derivations of the mathematical expectations of formulae used in the thesis. Computer listings of example problem runs are given in Appendix C. These appendices are contained, along with the references, in Part IV."--Preface.Includes bibliographical references

Circles of Influence: Rational decision-making, strategic positioning, and the formation of charter school clusters in New Jersey

A major focus of charter school research has been the potential impact of increased school choice on student sorting by race/ethnicity and socio-economic status. Researchers have argued that charter schools may increase segregation by allowing families to separate into more homogeneous school communities. Yet surprisingly, little attention has been paid to the role charter schools themselves may play in determining student enrollments. Emerging evidence suggests that charter schools may frequently take into account nearby educational and demographic characteristics when choosing school locations and avoid neighborhoods with high-proportions of at-risk students who are more costly and challenging to educate. While this behavior is not incompatible with traditional notions of how education marketplaces function, such "positioning strategies" serve as important reminders that charter schools benefit most by locating in areas where they hold clear competitive advantages, not necessarily areas of greatest demand or educational need. In this dissertation, I examined the potential for New Jersey charter schools to effectively distribute educational opportunities to all students, particularly those most frequently targeted by previous approaches to school reform, across varied and often segregated landscapes. Drawing on rational choice theory and previous research into the profit maximizing behavior of firms, I argued that charter schools have strong incentives to locate in areas that allow them to effectively balance consumer demand with the potential negative effects of increased competition in high needs areas. I used geographic information systems (GIS) and logistic regression to map the location of charter schools in New Jersey and examine potential associations with supply side factors. New Jersey's charter school supply showed two distinct clustering patterns. First, charter schools tended to circle Abbott districts or low-performing school districts in a narrow five mile band characterized by greater educational need and, presumably, consumer demand. Second, charter schools in Abbott districts tended to circle, but not locate within, neighborhoods with higher levels of educational and economic disadvantage, and particularly neighborhoods with higher proportions of African American residents. Logistic regression confirmed statistically significant associations among charter school clusters and proxies for market demand, educational need, and neighborhood diversity, although estimates for race/ethnicity were less conclusive. Further analysis indicated that observed clustering patterns were primarily driven by more market savvy or entrepreneurial schools partnered with charter management organizations (CMOs)

A Scanning Hartmann Focus Test for the EUVI Telescopes aboard STEREO

The Solar TErrestrial RElations Observatory (STEREO), the third mission in NASA's Solar Terrestrial Probes program, was launched in 2006 on a two year mission to study solar phenomena. STEREO consists of two nearly identical satellites, each carrying an Extreme Ultraviolet Imager (EUVI) telescope as part of the Sun Earth Connection Coronal and Heliospheric Investigation instrument suite. EUVI is a normal incidence, 98mm diameter, Ritchey-Chretien telescope designed to obtain wide field of view images of the Sun at short wavelengths (17.1-30.4nm) using a CCD detector. The telescope entrance aperture is divided into four quadrants by a mask near the secondary mirror spider veins. A mechanism that rotates another mask allows only one of these sub-apertures to accept light over an exposure. The EUVI contains no focus mechanism. Mechanical models predict a difference in telescope focus between ambient integration conditions and on-orbit operation. We describe an independent check of the ambient, ultraviolet, absolute focus setting of the EUVI telescopes after they were integrated with their respective spacecraft. A scanning Hartmann-like test design resulted from constraints implied by the EUVI aperture select mechanism. This inexpensive test was simultaneously coordinated with other NASA integration and test activities in a high-vibration, clean room environment. The total focus test error was required to be better than +/-0.05 mm. We describe the alignment and test procedure, sources of statistical and systematic error, and then the focus determination results using various algorithms. The results are consistent with other tests of focus alignment and indicate that the EUVI telescopes meet the ambient focus offset requirements. STEREO is functioning well on-orbit and the EUVI telescopes meet their on-orbit image quality requirements

An Intercomparison of Microphysical Retrieval Algorithms for Upper Tropospheric Ice Clouds

The large horizontal extent, location in the cold upper troposphere, and ice composition make cirrus clouds important modulators of the earth's radiation budget and climate. Cirrus cloud microphysical properties are difficult to measure and model because they are inhomogeneous in nature and their ice crystal size distribution and habit are not well characterized. Accurate retrievals of cloud properties are crucial for improving the representation of cloud scale processes in large-scale models and for accurately predicting the earth's future climate. A number of passive and active remote sensing retrieval algorithms exist for estimating the microphysical properties of upper tropospheric clouds. We believe significant progress has been made in the evolution of these retrieval algorithms in the last decade, however, there is room for improvement. Members of the Atmospheric Radiation measurement program (ARM) Cloud properties Working Group are involved in an intercomparison of optical depth(tau), ice water path, and characteristic particle size in clouds retrieved using ground-based instruments. The goals of this intercomparison are to evaluate the accuracy of state-of-the-art algorithms, quantify the uncertainties, and make recommendations for improvement

Cloud analysis using NOAA-7 AVHRR multispectral imagery

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984.Microfiche copy available in Archives and Science.Bibliography: leaves 78-79.by Robert Paul d'Entremont.M.S