1,373 research outputs found

    An Analysis of the Effectiveness of Pollution Prevention in Reducing Environmental Compliance Costs

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    The objective of the Air Force\u27s compliance through pollution prevention (CTP2) program is to reduce overall environmental compliance (EC) cost and risk (compliance burden) associated with maintaining compliance at an installation through increased pollution prevention (P2) efforts. However, no quantifiable evidence has been produced that suggests P2 projects are actually reducing compliance burden. Therefore, this research attempts to determine if projects categorized as P2 truly reduce compliance burden. This research demonstrated that, under the current burden calculation methodology, the compliance Site inventory data should not be used to measure or track compliance burden reductions. The time value of money, net present value, and correlations were used to analyze the Wright-Patterson AFB (WPAFB) and Air Force Materiel Command (AFMC) EC and P2 programs from 1995 through 2000. Overall, this research showed that CTP2 is effective because EC costs are falling, EC Savings are greater than the P2 investments, and EC Savings are highly correlated to P2 investments. The analysis of WPAFB provided the strongest evidence; however, the AFMC analysis provided mixed results, which were explained by relatively high laboratory and product center P2 costs and mission changes due to base closures. When the analysis focused on Arnold, Edwards, Kirtland, and Wright-Patterson AFB, the results were supportive. Each of these bases saw a decline in EC costs, had a net positive overall Savings, and had a moderate to strong correlation between EC savings and P2 expenditures

    THE MATH SELF-EFFICACY OF HOMESCHOOL PARENTS AND THE INFLUENCE OF MATH SELF-EFFICACY ON CURRICULUM CHOICE

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    The present study investigated the math self-efficacy of homeschool parents and whether there was a correlation between parental math self-efficacy (PMSE) and parents’ choice of mathematics curriculum. A simple random sample of parents with at least one child enrolled in Classical Conversations (N = 223) completed a survey to measure their math self-efficacy and provide information about their homeschool and mathematics curriculum choice. The PMSE level was a statistically significant 4.17, indicating that the sample has much confidence in their ability to learn and do mathematics. The study revealed a significant though small correlation between PMSE and the level of involvement required by the curriculum. As PMSE increased, parental involvement in the curriculum also increased. As increasing numbers of parents choose to homeschool, understanding the academic characteristics of homeschool parents will allow homeschool support organizations and curriculum developers to best meet the needs of parents as they seek to educate their children

    A distributed algorithm for 2D shape duplication with smart pebble robots

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    We present our digital fabrication technique for manufacturing active objects in 2D from a collection of smart particles. Given a passive model of the object to be formed, we envision submerging this original in a vat of smart particles, executing the new shape duplication algorithm described in this paper, and then brushing aside any extra modules to reveal both the original object and an exact copy, side-by-side. Extensions to the duplication algorithm can be used to create a magnified version of the original or multiple copies of the model object. Our novel duplication algorithm uses a distributed approach to identify the geometric specification of the object being duplicated and then forms the duplicate from spare modules in the vicinity of the original. This paper details the duplication algorithm and the features that make it robust to (1) an imperfect packing of the modules around the original object; (2) missing communication links between neighboring modules; and (3) missing modules in the vicinity of the duplicate object(s). We show that the algorithm requires O(1) storage space per module and that the algorithm exchanges O(n) messages per module. Finally, we present experimental results from 60 hardware trials and 150 simulations. These experiments demonstrate the algorithm working correctly and reliably despite broken communication links and missing modules.United States. Army Research Office (Grant W911NF-08-1-0228)National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (Grant 0735953)American Society for Engineering Education. National Defense Science and Engineering Graduate Fellowshi

    Shape formation by self-disassembly in programmable matter systems

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 225-236).Programmable matter systems are composed of small, intelligent modules able to form a variety of macroscale objects with specific material properties in response to external commands or stimuli. While many programmable matter systems have been proposed in fiction, (Barbapapa, Changelings from Star Trek, the Terminator, and Transformers), and academia, a lack of suitable hardware and accompanying algorithms prevents their full realization. With this thesis research, we aim to create a system of miniature modules that can form arbitrary structures on demand. We develop autonomous 12mm cubic modules capable of bonding to, and communicating with, four of their immediate neighbors. These modules are among the smallest autonomous modular robots capable of sensing, communication, computation, and actuation. The modules employ unique electropermanent magnet connectors. The four connectors in each module enable the modules to communicate and share power with their nearest neighbors. These solid-state connectors are strong enough for a single inter-module connection to support the weight of 80 other modules. The connectors only consume power when switching on or off; they have no static power consumption. We implement a number of low-level communication and control algorithms which manage information transfer between neighboring modules. These algorithms ensure that messages are delivered reliably despite challenging conditions. They monitor the state of all communication links and are able to reroute messages around broken communication links to ensure that they reach their intended destinations. In order to accomplish our long-standing goal of programmatic shape formation, we also develop a suite of provably-correct distributed algorithms that allow complex shape formation. The distributed duplication algorithm that we present allows the system to duplicate any passive object that is submerged in a collection of programmable matter modules. The algorithm runs on the processors inside the modules and requires no external intervention. It requires 0(1) storage and O(n) inter-module messages per module, where n is the number of modules in the system. The algorithm can both magnify and produce multiple copies of the submerged object. A programmable matter system is a large network of autonomous processors, so these algorithms have applicability in a variety of routing, sensor network, and distributed computing applications. While our hardware system provides a 50-module test-bed for the algorithms, we show, by using a unique simulator, that the algorithms are capable of operating in much larger environments. Finally, we perform hundreds of experiments using both the simulator and hardware to show how the algorithms and hardware operate in practice.by Kyle William Gilpin.Ph.D

    An analysis of the tape recorder as a learning tool for social work students

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    Thesis (M.S.)--Boston UniversityThe purpose of this thesis was to explore the feelings and attitudes of social work students and their supervisors, and to obtain viewpoints from those in the allied professions of psychiatry and psychology concerning the use of the tape recorder as an additional tool for helping the social casework student, (1) develop techniques of interviewing, and (2) gain skill in case recording. The main emphasis in this study was directed at obtaining the feelings and attitudes of the student toward tape recording an interview and playing it back under supervision

    Distributed algorithms for self-disassembly in modular robots

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    Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 225-226).We developed a modular robotic system that behaves as programmable matter. Specifically, we designed, implemented, and tested a collection of robots that, starting from an amorphous arrangement, can be assembled into arbitrary shapes and then commanded to self-disassemble in an organized manner. The 28 modules in the system were implemented as 1.77-inch autonomous cubes that were able to connect to and communicate with their immediate neighbors. Two cooperating microprocessors controlled the modules' magnetic connection mechanisms and infrared communication interfaces. We developed algorithms for the distributed communication and control of the system which allowed the modules to perform localization and distribute shape information in an efficient manner. When assembled into a structure, the modules formed a system which could be virtually sculpted using a computer interface which we also designed. By employing the sculpting process, we were able to accurately control the final shape assumed by the structure. Unnecessary modules disconnected from the structure and fell away. The results of close to 200 experiments showed the that the algorithms operated as expected and were able to successfully control the distributed system. We were able to quickly form one, two, and three dimensional structures.by Kyle W. Gilpin.M.Eng.and S.B

    Comparison of Two Detailed Models of Aedes aegypti Population Dynamics

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    The success of control programs for mosquito-­borne diseases can be enhanced by crucial information provided by models of the mosquito populations. Models, however, can differ in their structure, complexity, and biological assumptions, and these differences impact their predictions. Unfortunately, it is typically difficult to determine why two complex models make different predictions because we lack structured side-­by-­side comparisons of models using comparable parameterization. Here, we present a detailed comparison of two complex, spatially explicit, stochastic models of the population dynamics of Aedes aegypti, the main vector of dengue, yellow fever, chikungunya, and Zika viruses. Both models describe the mosquito?s biological and ecological characteristics, but differ in complexity and specific assumptions. We compare the predictions of these models in two selected climatic settings: a tropical and weakly seasonal climate in Iquitos, Peru, and a temperate and strongly seasonal climate in Buenos Aires, Argentina. Both models were calibrated to operate at identical average densities in unperturbedconditions in both settings, by adjusting parameters regulating densities in each model (number of larval development sites and amount of nutritional resources). We show that the models differ in their sensitivityto environmental conditions (temperature and rainfall) and trace differences to specific model assumptions.Temporal dynamics of the Ae. aegypti populations predicted by the two models differ more markedly under strongly seasonal Buenos Aires conditions. We use both models to simulate killing of larvae and/or adults with insecticides in selected areas. We show that predictions of population recovery by the models differ substantially, an effect likely related to model assumptions regarding larval development and (director delayed) density dependence. Our methodical comparison provides important guidance for model improvement by identifying key areas of Ae. aegypti ecology that substantially affect model predictions, and revealing the impact of model assumptions on population dynamics predictions in unperturbed and perturbed conditions.Fil: Legros, Mathieu. University of North Carolina; Estados UnidosFil: Otero, Marcelo Javier. Universidad de Buenos Aires; ArgentinaFil: Romeo Aznar, Victoria Teresa. Universidad de Buenos Aires; ArgentinaFil: Solari, Hernan Gustavo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gould, Fred. National Institutes of Health; Estados UnidosFil: Lloyd, Alun L.. National Institutes of Health; Estados Unido

    Advancing tendencies? PR leadership, general leadership, and leadership pedagogy

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    What are the best ways to advance PR leadership? In exploring answers, we consider the last two decades of PR literature and identify two main tendencies. We link those two with general leadership literature and practices, as well as with literature on leadership pedagogy. We conclude that, rather than recent moves to look within the field, without self-reflection, to existing PR perspectives and figures for solutions, looking outwards has greater potential to transform not only the PR leadership literature, and PR practice, but also to create less hierarchical, and more democratic and "leaderful," PR workplaces. © 2014

    Performance of LED-Based Fluorescence Microscopy to Diagnose Tuberculosis in a Peripheral Health Centre in Nairobi.

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    Sputum microscopy is the only tuberculosis (TB) diagnostic available at peripheral levels of care in resource limited countries. Its sensitivity is low, particularly in high HIV prevalence settings. Fluorescence microscopy (FM) can improve performance of microscopy and with the new light emitting diode (LED) technologies could be appropriate for peripheral settings. The study aimed to compare the performance of LED-FM versus Ziehl-Neelsen (ZN) microscopy and to assess feasibility of LED-FM at a low level of care in a high HIV prevalence country
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