Municipal Transportation

Reviews the importance of municipal transportation due to the ever growing city populations and urban areas of the United States in the 1900’s

High Poverty Schools and the Distribution of Teachers and Principals

Although many factors combine to make a successful school, most people agree that quality teachers and school principals are among the most important requirements for success, especially when success is defined by the ability of the school to raise the achievement of its students. The central question for this study is how the quality of the teachers and principals in high-poverty schools in North Carolina compares to that in the schools serving more advantaged students. A related question is why these differences emerge. The consistency of the patterns across many measures of qualifications for both teachers and principals leaves no doubt that students in the high-poverty schools are served by school personnel with lower qualifications than those in the lower poverty schools. Moreover, in many cases the differences are large. Additional evidence documents that the differences largely reflect predictable outcomes of the labor market for teachers and principals. Hence, active policy interventions are needed to counter these forces if the ultimate goal is to provide equal educational opportunity

Blogging AAS 2010 (5)

In this panel, organized by Siyen Fei (University of Pennsylvania), Mark Edward Lewis (Stanford University), Hilde De Weerdt (University of Oxford), and Fei presented papers that creatively engaged the work of G. William Skinner on how to conceptualize empire in time and space. Lewis proposed that the northern capital historically functioned as a peripheral center that connected the agricultural and economic centers found further south with the steppe, and this positioning, a prime concern of the dynasties founded by nomads, helped maintain China as a coherent empire. De Weerdt used social network analysis to mine Song dynastybiji for data that could model the level of connectivity of the elites that produced them. Fei explained her interest in emphasizing dynastic differences in the study of urbanization in China, arguing that the way rulers seek to order political/economic/social space has a strong impact on the types of urban development that take place. Discussant Kären Wigen’s comments pushed the conversation to include maritime frontiers, the merits of visual versus textual representations of data, and the intellectual dynamism within Skinner’s body of work. This panel brought together scholars from history and geography, using the Pearl River Delta as the means to explore questions of regionality

Blogging AAS 2010 (5)

In this panel, organized by Siyen Fei (University of Pennsylvania), Mark Edward Lewis (Stanford University), Hilde De Weerdt (University of Oxford), and Fei presented papers that creatively engaged the work of G. William Skinner on how to conceptualize empire in time and space. Lewis proposed that the northern capital historically functioned as a peripheral center that connected the agricultural and economic centers found further south with the steppe, and this positioning, a prime concern of the dynasties founded by nomads, helped maintain China as a coherent empire. De Weerdt used social network analysis to mine Song dynastybiji for data that could model the level of connectivity of the elites that produced them. Fei explained her interest in emphasizing dynastic differences in the study of urbanization in China, arguing that the way rulers seek to order political/economic/social space has a strong impact on the types of urban development that take place. Discussant Kären Wigen’s comments pushed the conversation to include maritime frontiers, the merits of visual versus textual representations of data, and the intellectual dynamism within Skinner’s body of work. This panel brought together scholars from history and geography, using the Pearl River Delta as the means to explore questions of regionality

Soft Origami: Classification, Constraint, and Actuation of Highly Compliant Origami Structures

Herein, we discuss the folding of highly compliant origami structures—“Soft Origami.” There are benefits to be had in folding compliant sheets (which cannot self-guide their motion) rather than conventional rigid origami. Example applications include scaffolds for artificial tissue generation and foldable substrates for flexible electronic assemblies. Highly compliant origami has not been contemplated by existing theory, which treats origami structures largely as rigid or semirigid mechanisms with compliant hinges—“mechanism-reliant origami.” We present a quantitative metric—the origami compliance metric (OCM)—that aids in identifying proper modeling of a homogeneous origami structure based upon the compliance regime it falls into (soft, hybrid, or mechanism-reliant). We discuss the unique properties, applications, and design drivers for practical implementation of Soft Origami. We detail a theory of proper constraint by which an ideal soft structure's number of degrees-of-freedom may be approximated as 3n, where n is the number of vertices of the fold pattern. Buckling and sagging behaviors in very compliant structures can be counteracted with the application of tension; we present a method for calculating the tension force required to reduce sagging error below a user-prescribed value. Finally, we introduce a concept for a scalable process in which a few actuators and stretching membranes may be used to simultaneously fold many origami substructures that share common degrees-of-freedom.United States. Air Force Office of Scientific Research (Grant 1332249)National Science Foundation (U.S.

Characterization of bioelectric potentials

Method and system for recognizing and characterizing bioelectric potential or electromyographic (EMG) signals associated with at least one of a coarse gesture and a fine gesture that is performed by a person, and use of the bioelectric potentials to enter data and/or commands into an electrical and/or mechanical instrument. As a gesture is performed, bioelectric signals that accompany the gesture are subjected to statistical averaging, within selected time intervals. Hidden Markov model analysis is applied to identify hidden, gesture-related states that are present. A metric is used to compare signals produced by a volitional gesture (not yet identified) with corresponding signals associated with each of a set of reference gestures, and the reference gesture that is closest to the volitional gesture is identified. Signals representing the volitional gesture are analyzed and compared with a database of reference gestures to determine if the volitional gesture is likely to be one of the reference gestures. Electronic and/or mechanical commands needed to carry out the gesture may be implemented at an interface to control an instrument. Applications include control of an aircraft, entry of data from a keyboard or other data entry device, and entry of data and commands in extreme environments that interfere with accurate entry