993 research outputs found
“Do-Not-Call-List” Testimony: Before the Senate Committee on Commerce, Science, and Transportation
Mr. Chairman, members of the Committee, thank you for the opportunity to be here with you today. My name is Jim Guest, and I am President of Consumers Union, the independent, non- profit publisher of Consumer Reports magazine and ConsumerReports.org, with over ve million subscribers
Making a Difference: Measuring the Effectiveness of Mississippi Teacher Corps Teachers as Compared to Non-Mississippi Teacher Corps Teachers
The Mississippi Teacher Corps (MTC) was founded in 1989. Over the past 23 years more than 500 MTC participants have taught in critical-needs schools in Mississippi. The purpose of this study was to examine the effectiveness of Mississippi Teacher Corps teachers as compared to non-Mississippi Teacher Corps teachers. The method of research was a quantitative analysis of standardized test scores from the Rural County School District for school year 2009–2010. The analysis shothat there is no significant difference in mean test scores of students who are taught by MTC teachers as compared to non-MTC teachers but that, in both the fall and spring, student test scores are significantly higher in MTC classrooms
Modeling Social Influence via Combined Centralized and Distributed Planning Control
Real world events are driven by a mixture of both centralized and distributed control of individual agents based on their situational context and internal make up. For example, some people have partial allegiances to multiple, contradictory authorities, as well as to their own goals and principles. This can create a cognitive dissonance that can be exploited by an appropriately directed psychological influence operation (PSYOP). An Autonomous Dynamic Planning and Execution (ADP&E) approach is proposed for modeling both the unperturbed context as well as its reaction to various PSYOP interventions. As an illustrative example, the unrest surrounding the Iranian elections in the summer of 2009 is described in terms applicable to an ADP&E modeling approach. Aspects of the ADP&E modeling process are discussed to illustrate its application and advantages for this example
Large-volume lava flow fields on Venus: Dimensions and morphology
Of all the volcanic features identified in Magellan images, by far the most extensive and really important are lava flow fields. Neglecting the widespread lava plains themselves, practically every C1-MIDR produced so far contains several or many discrete lava flow fields. These range in size from a few hundred square kilometers in area (like those fields associated with small volcanic edifices for example), through all sizes up to several hundred thousand square kilometers in extent (such as many rift related fields). Most of these are related to small, intermediate, or large-scale volcanic edifices, coronae, arachnoids, calderas, fields of small shields, and rift zones. An initial survey of 40 well-defined flow fields with areas greater than 50,000 sq km (an arbitrary bound) has been undertaken. Following Columbia River Basalt terminology, these have been termed great flow fields. This represents a working set of flow fields, chosen to cover a variety of morphologies, sources, locations, and characteristics. The initial survey is intended to highlight representative flow fields, and does not represent a statistical set. For each flow field, the location, total area, flow length, flow widths, estimated flow thicknesses, estimated volumes, topographic slope, altitude, backscatter, emissivity, morphology, and source has been noted. The flow fields range from about 50,000 sq km to over 2,500,000 sq km in area, with most being several hundred square kilometers in extent. Flow lengths measure between 140 and 2840 km, with the majority of flows being several hundred kilometers long. A few basic morphological types have been identified
Reliability-based Topology Optimization of Trusses with Stochastic Stiffness
A new method is proposed for reliability-based topology optimization of truss structures with random geometric imperfections and material variability. Such imperfections and variability, which may result from manufacturing processes, are assumed to be small in relation to the truss dimensions and mean material properties and normally distributed. Extensive numerical evidence suggests that the trusses, when optimized in terms of a displacement-based demand metric, are characterized by randomness in the stiffness that follow the Gumbel distribution. Based on this observation, it was possible to derive analytical expressions for the structural reliability, enabling the formulation of a computationally efficient single-loop reliability-based topology optimization algorithm. Response statistics are estimated using a second-order perturbation expansion of the stiffness matrix and design sensitivities are derived so that they can be directly used by gradient-based optimizers. Several examples illustrate the accuracy of the perturbation expressions and the applicability of the method for developing optimal designs that meet target reliabilities
Optimal Design of Trusses With Geometric Imperfections: Accounting for Global Instability
A topology optimization method is proposed for the design of trusses with random geometric imperfections due to fabrication errors. This method is a generalization of a previously developed perturbation approach to topology optimization under geometric uncertainties. The main novelty in the present paper is that the objective function includes the nonlinear effects of potential buckling due to misaligned structural members. Solutions are therefore dependent on the magnitude of applied loads and the direction of resulting internal member forces (whether they are compression or tension). Direct differentiation is used in the sensitivity analysis, and analytical expressions for the associated derivatives are derived in a form that is computationally efficient. A series of examples illustrate how the effects of geometric imperfections and buckling may have substantial influence on truss design. Monte Carlo simulation together with second-order elastic analysis is used to verify that solutions offer improved performance in the presence of geometric uncertainties
Optimal Design of Trusses With Geometric Imperfections
The present paper focuses on optimization of trusses that have randomness in geometry that may arise from fabrication errors. The analysis herein is a generalization of a perturbation approach to topology optimization under geometric uncertainties. The main novelty in the present paper is in the consideration of potential buckling due to misaligned structural members. The paper begins with a brief review of the aforementioned perturbation approach, then proceeds with the analysis of the nonlinear effects of geometric imperfection. The paper concludes with some numerical examples
Completing the life cycle of a broadcast spawning coral in a closed mesocosm
Studies of broadcast spawning in corals are fundamental to our understanding of early life history
characteristics, reproductive biology, restoration etc. Spawning of corals for research is routinely
conducted, but this is mostly restricted to sites adjacent to reefs and from broodstock collected
from the wild just prior to gamete release. Only recently has it been possible to induce predictable
broadcast spawning in an ex situ environment, and nobody has successfully closed the life cycle
(i.e., production of an F2 generation) of these corals. Here, for the first time, we closed the life cycle
of the broadcast spawning coral Acropora millepora in a fully closed ex situ mesocosm. This
breakthrough has numerous implications for our understanding of reproductive biology, specifically it offers potential to deepen our understanding of the genetic influence on adaptive traits
such as heat tolerance, growth and disease resistance over multiple generations
Illinois State University Wind Symphony, April 6, 2022
Center for the Performing Arts
April 6, 2022
Wednesday Evening
8:00 p.m
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