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Wilberforce, OH, United States

Wilberforce University is a private, coed, liberal arts historically black university located in Wilberforce, Ohio. Affiliated with the African Methodist Episcopal Church, it was the first college to be owned and operated by African Americans. It participates in the United Negro College Fund.The founding of the college was unique as a collaboration in 1856 by the Cincinnati, Ohio Conference of the Methodist Episcopal Church and the African Methodist Episcopal Church . They planned a college to provide classical education and teacher training for black youth. Leaders of both races made up the first board members.When the number of students fell due to the American Civil War and financial losses closed the college in 1863, the AME Church purchased the institution to ensure its survival. Its first president, AME Bishop Daniel A. Payne, was one of the original founders. Prominent supporters and the US government donated funds for rebuilding after a fire in 1865. When the college added an industrial department in the late 19th century, state legislators could sponsor scholarship students.The college attracted the top professors of the day, including W. E. B. Du Bois. In the 19th century, it enlarged its mission to include students from South Africa. The university supports the national Association of African American Museums to broaden the reach of its programs and assist smaller museums with professional standards. Wikipedia.

Ivanov P.B.,RAS Lebedev Physical Institute | Papaloizou J.C.B.,Wilberforce University | Chernov S.V.,RAS Lebedev Physical Institute
Monthly Notices of the Royal Astronomical Society | Year: 2013

We determine the response of a uniformly rotating star to tidal perturbations due to a companion. General periodic orbits and parabolic flybys are considered. We evaluate energy and angular momentum exchange rates as a sum of contributions from normal modes allowing for dissipative processes. We consider the case when the response is dominated by the contribution of an identifiable regular spectrum of low-frequency modes, such as rotationally modified gravity modes.We evaluate this response in the limit of very weak dissipation, where individual resonances can be significant and also when dissipative effects are strong enough to prevent wave reflection from the neighbourhood of either the stellar surface or stellar centre, making radiation conditions more appropriate. The former situation may apply to Sun-like stars with radiative cores and convective envelopes and the latter to more massive stars with convective cores and radiative envelopes.We provide general expressions for transfer of energy and angular momentum that can be applied to an orbit with any eccentricity. Detailed calculations require knowledge of the mode spectrum and evaluation of the mode overlap integrals that measure the strength of the tidal interaction. These are evaluated for Sun-like stars in the slow rotation regime where centrifugal distortion is neglected in the equilibrium and the traditional approximation is made for the normal modes. We use both a Wentzel-Kramers-Brillouin-Jeffreys (WKBJ) procedure and a direct numerical evaluation which are found to be in good agreement for regimes of interest. The former is used to provide expressions for the mode spectrum and overlap integrals as a function of mode frequency and stellar rotation rate. These can be used to find the tidal energy and angular momentum exchange rates and hence the orbital evolution. Finally we use our formalism to determine the evolution time scales for an object, in an orbit of small eccentricity, around a Sun-like star in which the tidal response is assumed to occur. Systems with either no rotation or synchronous rotation are considered. Only rotationally modified gravity modes are taken into account under the assumption that wave dissipation proceeds close to the stellar centre. It is noted that inertial waves excited in the convective envelope may produce a comparable amount of tidal dissipation in the latter case for sufficiently large orbital periods. © 2013 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

WARNKE L.,Wilberforce University
Combinatorics Probability and Computing | Year: 2015

Concentration inequalities are fundamental tools in probabilistic combinatorics and theoretical computer science for proving that functions of random variables are typically near their means. Of particular importance is the case where f(X) is a function of independent random variables X = (X 1, . . ., Xn ). Here the well-known bounded differences inequality (also called McDiarmid's inequality or the Hoeffding–Azuma inequality) establishes sharp concentration if the function f does not depend too much on any of the variables. One attractive feature is that it relies on a very simple Lipschitz condition (L): it suffices to show that |f(X) − f(X′)| ⩽ ck whenever X, X′ differ only in Xk . While this is easy to check, the main disadvantage is that it considers worst-case changes ck , which often makes the resulting bounds too weak to be useful. In this paper we prove a variant of the bounded differences inequality which can be used to establish concentration of functions f(X) where (i) the typical changes are small, although (ii) the worst case changes might be very large. One key aspect of this inequality is that it relies on a simple condition that (a) is easy to check and (b) coincides with heuristic considerations as to why concentration should hold. Indeed, given an event Γ that holds with very high probability, we essentially relax the Lipschitz condition (L) to situations where Γ occurs. The point is that the resulting typical changes ck are often much smaller than the worst case ones. To illustrate its application we consider the reverse H-free process, where H is 2-balanced. We prove that the final number of edges in this process is concentrated, and also determine its likely value up to constant factors. This answers a question of Bollobás and Erdős. Copyright © Cambridge University Press 2015 Source

Nam D.H.,Wilberforce University
WMSCI 2015 - 19th World Multi-Conference on Systemics, Cybernetics and Informatics, Proceedings | Year: 2015

A prediction model of the efficient measurement for air foil self-noise data using the system reduction processing is presented. The prediction model is built by data reduction techniques based on the data set of the total noise produced when an airfoil encounters smooth non-turbulent inflow with diminishing the original parameters. Each subset of parameters is selected using the various multivariate analysis techniques. Applying the reduced data, the comparison between the prediction results of multivariate analysis techniques are presented in this paper. The model performance by different algorithms with reduced parameter metrics is measured by the neurofuzzy systems with applying the Adaptive Neuro-Fuzzy Inference System. In addition, the estimated results are examined to find the best fitting technique through the comparison of the various statistical criteria. Source

LETZTER S.,Wilberforce University
Combinatorics Probability and Computing | Year: 2015

Answering a question raised by Dudek and Prałat, we show that if pn → ∞, w.h.p., whenever G = G(n, p) is 2-edge-coloured there is a monochromatic path of length (2/3 + o(1))n. This result is optimal in the sense that 2/3 cannot be replaced by a larger constant. As part of the proof we obtain the following result. Given a graph G on n vertices with at least (Formula presented.) edges, whenever G is 2-edge-coloured, there is a monochromatic path of length at least (Formula presented.). This is an extension of the classical result by Gerencsér and Gyárfás which says that whenever Kn is 2-coloured there is a monochromatic path of length at least 2n/3. Copyright © Cambridge University Press 2015 Source

TAKAGI D.,Wilberforce University | BALMFORTH N.J.,University of British Columbia
Journal of Fluid Mechanics | Year: 2011

A mathematical model is developed for long peristaltic waves propelling a suspended rigid object down a fluid-filled axisymmetric tube. The fluid flow is described using lubrication theory and the deformation of the tube using linear elasticity. The object is taken to be either an infinitely long rod of constant radius or a parabolic-shaped lozenge of finite length. The system is driven by a radial force imposed on the tube wall that translates at constant speed down the tube axis and with a form chosen to generate a periodic wave train or a solitary wave. These waves exert a traction on the enclosed object, forcing it into motion. Periodic waves drive the infinite rod at a speed that attains a maximum at a moderate forcing amplitude and approaches approximately one quarter of the wave speed in the large-amplitude limit. The finite lozenge can be entrained and driven at the same speed as a solitary wave or periodic wave train if the forcing is sufficiently strong. For weaker forcing, the lozenge is either left behind the solitary wave or interacts repeatedly with the waves in the periodic train to generate stuttering forward progress. The threshold forcing amplitude for entrainment increases weakly with the radial span of the enclosed object, but strongly with the axial length, with entrainment becoming impossible if the object is too long. Source

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