5,944 research outputs found
Dragging Themselves Through the Negro Streets at Dawn : The Influence of African American Culture on the Beats
Following its victory in the Second World War, America paradoxically faced a period of prosperity and peace coupled with many underlying insecurities and tensions. There was a great deal of anxiety caused by the advent of the atom bomb, the great destruction of Europe during the war, and the growing fear of Soviet aggression. Just as there had been an effort to unite Americans against the earlier threats of German and Japanese hostility, Americans attempted to create a united front in the United States to combat the growing fear of Communism throughout the world. Members of the American middle class felt tremendous pressure to conform to mainstream culture, and this push toward homogeneity further ostracized those on the margins of society, such as African Americans. Many African Americans who fought for civil rights, such as Langston Hughes, Richard Wright, and Amiri Baraka, were branded as Communists. Along with a growing sense of conformity, technological advances, increased nationalism and economic growth helped to strengthen the middle class in the United States. This provided the middle class with increased wealth and a strong sense of identity. The Beats, reacting to society\u27s emphasis on homogeneity, created a counter culture literary movement that was strongly influenced by African American culture, especially the uniquely African American genres of music: blues and jazz. The incorporation of African American traditions by the Beats in turn created a rich multi-cultural form of American literature that resulted in the inclusion of a myriad of voices in mainstream discourse, voices that had hitherto been silenced by mainstream society
Preparation of bismuth telluride based thermoelectric nanomaterials via low-energy ball milling and their property characterizations
Thermoelectric materials are able to convert energy between heat and electricity with no moving parts, making them very appealing for power generation purposes. This is particularly appealing since many forms of energy generation lose energy to waste heat. The Livermore National Laboratory estimates that up to 55% of the energy created in traditional power plants is lost through heat generation [1]. As greenhouse gas emissions become a more important issue, large sources of waste like this will need to be harnessed. ^ Adoption of these materials has been limited due to the cost and efficiency of current technology. Bismuth telluride based alloys have a dimensionless figure of merit, a measure of efficiency, near one at room temperature, which makes it the best current material. In order to compete with other forms of energy generation, this needs to be increased to three or higher [2]. Recently, improvements in performance have come in the form of random nanostructured materials [3]. Bulk bismuth telluride is subjected to particle size reduction via high-energy ball milling in order to scatter phonons between grains. This reduces the lattice thermal conductivity which in turn increases the performance of the material. ^ In this work, we investigate the use of low-energy ball milling as a method of creating nanoparticles of n-type and p-type Bi2Te3 alloys for thermoelectric applications. Optimization of parameters such as milling containers, milling media, contamination and milling time has resulted in creating 15nm particles of bismuth telluride alloys. After creating solid pellets of the resulting powders via hot pressing, the material\u27s thermal and electrical conductivities as well as Seebeck coefficients were measured. The ZT of n-type Bi2Te2.7Se3 created using this method is 0.32, while the p-type Bi0.5Sb1.5Te3 exhibits a higher ZT of 1.24, both at room temperature
Firing the Canon: Multiple Insularities in Jazz Criticism
Whereas many jazz scholars focus on jazz criticism's construction and implications of a single, or insular, jazz canon, this dissertation argues that what many jazz critics do is precisely the opposite. These critics disrupt the sense of a singular and insular jazz canon by challenging it through the creation of what I call an insularity, which is a bounded collection of artists and music with a definable tradition, values and established criteria which regulates what is suitable for inclusion. This dissertation argues that jazz does not consist of a single canon and music that exists beyond the canon's boundaries; rather, jazz contains multiple insularities that challenge the canon and vie for the opportunity to overthrow the canon in order to reach canonical status. This dissertation conceptualizes jazz critics as cultural authorities who create or deconstruct insularities through a variety of race, gender and nation projects. It examines the criticism of Leonard Feather, Val Wilmer and Nathaniel Mackey to highlight the numerous ways in which critics engage with multiple insularities. Feather believed that jazz was university and that it transcended social difference. As such, he worked to create an insularity where female musicians deserved acceptance by the jazz world. Wilmer emphasizes that jazz is a social practice and that it belongs to those who created it. Working to counter the marginalization of African American musicians, she constructed an insularity that showed musicians as real people as opposed to mythological figures. Mackey rejects the concept of insularities and this dissertation shows how his novel Bedouin Hornbook works to deconstruct insularities. Feather's, Wilmer's and Mackey's criticism attempts to solve perceived social exclusion marginalization wrought by the jazz canon. Multiple insularities in jazz criticism exist as a byproduct of the complexity of jazz's cultural space, the problems which exist in that space, and the multitude of ways in which critics attempt to address these problems. A heterodox practice involving innumerable methods and strategies to address social problems, jazz criticism, itself a diverse practice involving people of many social backgrounds and experiences, manifests itself in the construction and challenging of multiple insularities
Recruitment and Retention of Immigrants in a Global Labour Market: Implications for Policy
Bio:
Chris Robinson studied economics at the London School of Economics and the University of Chicago, and has been a faculty member at the University of Western Ontario since 1977. His research has focused on human capital and wage issues including human capital specificity, labour supply, migration, and unions and he has published a wide range of articles on these topics in scholarly journals. From 1993 to 2003 he served as associate editor of the Journal of Labor Economics. From 2001 to 2010 he held the CIBC Chair in Human Capital and Productivity at the University of Western Ontario and was responsible for the overall direction of the CIBC Project in Human Capital and Productivity and CIBC Centre for Human Capital and Productivity. In 2010 he was awarded the H. Gregg Lewis Prize for the best paper published in the Journal of Labor Economics for 2008 and 2009
Variable autonomy assignment algorithms for human-robot interactions.
As robotic agents become increasingly present in human environments, task completion rates during human-robot interaction has grown into an increasingly important topic of research. Safe collaborative robots executing tasks under human supervision often augment their perception and planning capabilities through traded or shared control schemes. However, such systems are often proscribed only at the most abstract level, with the meticulous details of implementation left to the designer\u27s prerogative. Without a rigorous structure for implementing controls, the work of design is frequently left to ad hoc mechanism with only bespoke guarantees of systematic efficacy, if any such proof is forthcoming at all. Herein, I present two quantitatively defined models for implementing sliding-scale variable autonomy, in which levels of autonomy are determined by the relative efficacy of autonomous subroutines. I experimentally test the resulting Variable Autonomy Planning (VAP) algorithm and against a traditional traded control scheme in a pick-and-place task, and apply the Variable Autonomy Tasking algorithm to the implementation of a robot performing a complex sanitation task in real-world environs. Results show that prioritizing autonomy levels with higher success rates, as encoded into VAP, allows users to effectively and intuitively select optimal autonomy levels for efficient task completion. Further, the Pareto optimal design structure of the VAP+ algorithm allows for significant performance improvements to be made through intervention planning based on systematic input determining failure probabilities through sensorized measurements. This thesis describes the design, analysis, and implementation of these two algorithms, with a particular focus on the VAP+ algorithm. The core conceit is that they are methods for rigorously defining locally optimal plans for traded control being shared between a human and one or more autonomous processes. It is derived from an earlier algorithmic model, the VAP algorithm, developed to address the issue of rigorous, repeatable assignment of autonomy levels based on system data which provides guarantees on basis of the failure-rate sorting of paired autonomous and manual subtask achievement systems. Using only probability ranking to define levels of autonomy, the VAP algorithm is able to sort modules into optimizable ordered sets, but is limited to only solving sequential task assignments. By constructing a joint cost metric for the entire plan, and by implementing a back-to-front calculation scheme for this metric, it is possible for the VAP+ algorithm to generate optimal planning solutions which minimize the expected cost, as amortized over time, funds, accuracy, or any metric combination thereof. The algorithm is additionally very efficient, and able to perform on-line assessments of environmental changes to the conditional probabilities associated with plan choices, should a suitable model for determining these probabilities be present. This system, as a paired set of two algorithms and a design augmentation, form the VAP+ algorithm in full
Amenities, Walkability, and Neighborhood Stability: A Mixed Methods Analysis
The decline of the United States housing market in late 2006 produced a momentous shift in land values and home prices across the country. Evidence of this collapse was widespread by 2008, which helped spark a global recession that nearly brought the financial world to a standstill. Much of the early attention paid to these events focused on the root causes of this collapse, yet a gap in knowledge remained as to how some urban places thrived in response while others struggled to rebound. For the purposes of this study, urban and neighborhood stability are positive terms used to describe a host of economic and community outcomes. The dissertation examines stability at the city and neighborhood scale through a longitudinal, mixed methods study, which includes multiple regression analysis, hedonic pricing models, spatial analytics, and case study methods. In the first phase of research, the research uses regression analysis to examine areas within cities that demonstrated neighborhood stability. The second phase focuses specifically on the association between housing prices, the proximity to public and private amenities, and internal and external characteristics; specifically, this assesses the extent to which spatial relationships are statistically significant. The third phase of research employs qualitative methods, using case study research and environmental psychology to triangulate data. The research finds that, while there is some evidence of a relationship between specific types of amenities and housing market stability in some cities, there is substantial evidence that variability across cities informs these associations. In terms of direct lessons for city planning, there is strong evidence supporting the value--both with respect to housing prices and community stability--of publicly funded amenities and positive urban design interventions. Further, the findings provide a counter-argument to leading theories on walkable urbanism, and the research provides insight as to the role of city planning and public policy in seeking greater outcomes for urban and neighborhood stability
Clifford v. Commonwealth: Admission of Racial Voice Identification Testimony, Regressive or Progressive?
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