1,465 research outputs found

    Implementation of Early Voting

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    We examine the early voting process in Tennessee during the election of 1994. By conducting a mail survey of all 95 county registrars, we ascertained the methods and costs of early voting implementation. Generally, the survey reveals a strong belief that early voting encourages greater participation by voters, with turnout data supporting this belief. We find that the ballot type and location of early voting sites play an important role in determining both the costs of early voting and the rate of voter participation

    Using Adaptive Mesh Refinement to Study Grid Resolution Effects for Shock-Boundary Layer Interactions

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    Adaptive Mesh Refinement (AMR) promises a much more computationally efficient means to obtain a discrete approximation to a continuous boundary value problem of a specified accuracy than classic isotropic grid refinement. The AMR capability of OVERFLOW (a computational fluid dynamics (CFD) code) is utilized to provide estimates of the exact analytical solutions to problems of interest to turbulence modeling. Predictions of surface pressure and skin friction, essentially the state of stress at the surface, shows little difference with grids believed to be "grid resolved." Velocity profiles, on the other hand, show marked differences in flows with shocks. The AMR method, as implemented in OVERFLOW 2.2k, appears to provide the ability to produce arbitrarily accurate solutions at a predictable cost much smaller than classic uniform mesh refinement

    Turnout and Partisanship in Tennessee Elections

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    To understand the forces shaping current Tennessee politics, we discuss two fundamental concepts of Tennessee\u27s electoral system: voting turnout and partisanship. These two concepts are easily illustrated by two questions. First, how many people participate in elections in the state? Second, whom do Tennesseans elect to represent them? While we use a historical perspective to inform the analysis, we are generally more interested in the forces shaping politics in Tennessee today

    Early Voting in Tennessee: Removing Barriers to Participation

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    In 1994. the Tennessee General Assembly mandated a new early voting system that allowed voters to cast a ballot in a two-week period prior to any election. Unlike absentee balloting, which requires registrants to justify why they cannot participate on election day, early voting is available to any registered voter who chooses to do so. By enacting early voting in Tennessee, the state legislature hoped to achieve increased turnout and easier access for citizens unable to vote at a regular polling site on election day. The purpose of this chapter is to ascertain whether the program was able to increase access for senior citizens and other citizens disadvantaged by a single election day voting period. Using county level-census data and voting returns from the 1996 election in Tennessee, we examine early voting participation by different socioeconomic groups

    Improvement of Reynolds-Stress and Triple-Product Lag Models

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    The Reynolds-stress and triple product Lag models were created with a normal stress distribution which was defined by the accepted 4:3:2 distribution of streamwise, spanwise and wall normal stresses, and a ratio of (sub w) = 0.3k in the log layer region of high Reynolds number flat plate flow, which implies R11(+) = 4/(9/2).3 2.96. More recent measurements show a more complex picture of the log layer region at high Reynolds numbers. The first cut at improving these models along with the direction for future refinements is described. Comparison with recent high Reynolds number data shows areas where further work is needed, but also shows inclusion of the modeled turbulent transport terms improve the prediction where they influence the solution. Additional work is needed to develop a model that better matches experiments, but there is significant improvement in many of the details of the log layer behavior

    Turbulent Axial Odometer Model

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    A Galilean-invariant field equation is proposed and tested on standard turbulence model test cases. The field equation provides an additional non-dimensional outer scale which allows the turbulence models to reproduce the axial normal stress increase with Re seen in high Reynolds numbers experiments. The field equation provides a Reynolds number for every point based on the length of turbulent flow upstream of that point in the domain. This outer scale equation can be considered an odometer that gives a length scale conjectured to be related to the large stream wise structures that are seen in turbulent flow and that require run length to develop. A new RANS model using this additional scale is able to match the Reynolds number variation of the normal stresses seen at high Reynolds number. Furthermore, the good attached flow prediction capabilities of current RANS models appears to be attained. Using this scale equation, the entire Reynolds-stress state appears to be predicted correctly, over a large run length Reynolds number range such as experienced in aircraft design

    The lagRST Model: A Turbulence Model for Non-Equilibrium Flows

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    This study presents a new class of turbulence model designed for wall bounded, high Reynolds number flows with separation. The model addresses deficiencies seen in the modeling of nonequilibrium turbulent flows. These flows generally have variable adverse pressure gradients which cause the turbulent quantities to react at a finite rate to changes in the mean flow quantities. This "lag" in the response of the turbulent quantities can t be modeled by most standard turbulence models, which are designed to model equilibrium turbulent boundary layers. The model presented uses a standard 2-equation model as the baseline for turbulent equilibrium calculations, but adds transport equations to account directly for non-equilibrium effects in the Reynolds Stress Tensor (RST) that are seen in large pressure gradients involving shock waves and separation. Comparisons are made to several standard turbulence modeling validation cases, including an incompressible boundary layer (both neutral and adverse pressure gradients), an incompressible mixing layer and a transonic bump flow. In addition, a hypersonic Shock Wave Turbulent Boundary Layer Interaction with separation is assessed along with a transonic capsule flow. Results show a substantial improvement over the baseline models for transonic separated flows. The results are mixed for the SWTBLI flows assessed. Separation predictions are not as good as the baseline models, but the over prediction of the peak heat flux downstream of the reattachment shock that plagues many models is reduced

    Turbulent Axial Odometer Model

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    A Galilean-invariant field equation is proposed and tested on standard turbulence model test cases. The field equation provides an additional non-dimensional outer scale which allows the turbulence models to reproduce the axial normal stress increase with Re seen in high Reynolds numbers experiments. The field equation provides a Reynolds number for every point based on the length of turbulent flow upstream of that point in the domain. This outer scale equation can be considered an odometer that gives a length scale conjectured to be related to the large streamwise structures that are seen in turbulent flow and that require run length to develop. A new RANS model using this additional scale is able to match the Reynolds number variation of the normal stresses seen at high Reynolds number. Furthermore, the good attached flow prediction capabilities of current RANS models appears to be attained. Using this scale equation, the entire Reynolds-stress state appears to be predicted correctly, over a large run length Reynolds number range such as experienced in aircraft design

    A composite axion from a supersymmetric product group

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    A global U(1)PQU(1)_\text{PQ} symmetry is protected from gravitational effects in the s-confining SU(N)kSU(N)^k product group theory with A+4Q+NQA+4Q +N\overline{Q} matter. If the SU(4)SU(4) family symmetry is gauged and an appropriate tree-level superpotential is added, then the dynamically generated superpotential spontaneously breaks SU(4)×U(1)PQSU(3)cSU(4)\times U(1)_\text{PQ} \rightarrow SU(3)_c and produces a QCD axion. Small values of the CPCP-violating θ\theta parameter are then possible without any fine-tuning, as long as the product group is suitably large. By introducing a second copy of the s-confining SU(N)SU(N) product group also coupled to the gauged SU(4)SU(4), we find that values as small as N=7N=7 are consistent with θˉ<1010\bar\theta<10^{-10}, even under the pessimistic assumption that the dominant contribution to the axion quality is at tree level.Comment: 16 pages, 3 figures, 4 tables, 2 appendice

    Making sense of social pretense: The effect of the dyad, sex and language ability in a large observational study of children’s behaviors in a social pretend play context

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    Pretend play with peers is purportedly an important driver of social development in the preschool period, however, fundamental questions regarding the features of children’s pretend play with a peer, and the effect of the dyad for pretend play, have been overlooked. The current study undertook detailed behavioral coding of social pretend play in 134 pairs of 5-year-old children (54% boys) in order to address three main aims: (i) describe the duration and proportion of children engaging in key social pretend play behaviors, namely, calls for attention, negotiation (comprising role assignment and joint proposals) and enactment of pretend play, (ii) examine the effect of the dyad in influencing the occurrence of different social pretend play behaviors, and (iii) assess the independent and combined effect of individual child characteristics (i.e., language ability and sex) that may influence social pretend play behaviors beyond the influence of the dyad. Results demonstrated the overwhelming effect of the dyad in shaping children’s social pretend play behaviors, with language ability and sex explaining relatively little of the total variability in play behaviors. Results are discussed considering the contribution that this type of study can make to theories of associations between children’s social development and social pretend play.LEGO Foundatio
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