"Civil War Cinema in New Deal America"

During the early decades of the 20th century, Hollywood filmmakers both shaped and reflected the popular understanding of the Confederacy, slavery, and Abraham Lincoln.Accepted manuscrip

An ordinal approach to the measurement of inequality in asset ownership: methodology and an application to Mexican data.

Asset indices based on durable goods ownership and housing characteristics are widely used to proxy wealth when income or expenditure data are not available. In this paper, we propose an ordinal approach to using data on assets when estimating the wealth of a household (or individual). Using Correspondence Analysis, we derive a ranking of the correlations between the various assets and the first factor, a latent variable assumed to represent the standard of living. We then use this correlation ranking of the assets to derive indices of ordinal inequality that have been recently proposed in the literature. We also use the information on the proportion of individuals holding each type of assets to derive again ordinal measures of inequality in asset ownership. Our empirical analysis, based on data covering the various states of Mexico in 2000 and 2010, shows that the correlation between measures of ordinal inequality in asset ownership derived from correspondence analysis and traditional Gini indices of household income is high, and even higher than that between these Gini indices and ordinal inequality indices based on the percentage ownership of the different assets.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Reunion and reconciliation, reviewed and reconsidered

At the close of the Civil War in 1865, many Americans began talking about “reunion” and “reunification,” even “healing” and “reconciliation,” although the precise meaning of those words would remain elusive. From 1865 down to the present day, these sentiments have reverberated in American culture and American politics, and they sounded at gatherings of Union and Confederate veterans and then of their descendants, in the pages of newspapers and magazines in the late nineteenth and early twentieth centuries, in the speeches of presidents and politicians, and in countless films and theatrical productions that imagined northern and southern men joining hands in unity and fraternal love. Two years after the surrender at Appomattox, the former abolitionist Gerrit Smith told of his longing “for a heart-union between the North and the South.” Seventy-one years later, in a final gathering of ancient soldiers on the once-blood-soaked fields of Gettysburg, Franklin D. Roosevelt dedicated an Eternal Light Peace Memorial and honored the “joint and precious heritage” that Gettysburg had come to symbolize. Speaking in July 1938 to the “men who wore the blue and men who wore the gray,” fdr praised all the soldiers, “not asking under which flag they fought then—thankful that they stand together under one flag now.” Roosevelt’s tribute to a peace-loving and unified America, coming at this moment when the world was poised on the brink of an even more catastrophic war, may have offered its own small measure of comfort to anxious Americans.Accepted manuscrip

Design of Parametrically Forced Patterns and Quasipatterns

The Faraday wave experiment is a classic example of a system driven by parametric forcing, and it produces a wide range of complex patterns, including superlattice patterns and quasipatterns. Nonlinear three-wave interactions between driven and weakly damped modes play a key role in determining which patterns are favored. We use this idea to design single and multifrequency forcing functions that produce examples of superlattice patterns and quasipatterns in a new model PDE with parametric forcing. We make quantitative comparisons between the predicted patterns and the solutions of the PDE. Unexpectedly, the agreement is good only for parameter values very close to onset. The reason that the range of validity is limited is that the theory requires strong damping of all modes apart from the driven pattern-forming modes. This is in conflict with the requirement for weak damping if three-wave coupling is to influence pattern selection effectively. We distinguish the two different ways that three-wave interactions can be used to stabilize quasipatterns, and we present examples of 12-, 14-, and 20-fold approximate quasipatterns. We identify which computational domains provide the most accurate approximations to 12-fold quasipatterns and systematically investigate the Fourier spectra of the most accurate approximations

On the uniqueness of invariant tori in D4*S1 symmetric systems

The uniqueness of the branch of two-tori in the D4-equivariant Hopf bifurcation problem is proved in a neighbourhood of a particular limiting case where, after reduction, the Euler equations for the rotation of a free rigid body apply

Resonances and superlattice pattern stabilization in two-frequency forced Faraday waves

We investigate the role weakly damped modes play in the selection of Faraday wave patterns forced with rationally-related frequency components m*omega and n*omega. We use symmetry considerations to argue for the special importance of the weakly damped modes oscillating with twice the frequency of the critical mode, and those oscillating primarily with the "difference frequency" |n-m|*omega and the "sum frequency" (n+m)*omega. We then perform a weakly nonlinear analysis using equations of Zhang and Vinals (1997, J. Fluid Mech. 336) which apply to small-amplitude waves on weakly inviscid, semi-infinite fluid layers. For weak damping and forcing and one-dimensional waves, we perform a perturbation expansion through fourth order which yields analytical expressions for onset parameters and the cubic bifurcation coefficient that determines wave amplitude as a function of forcing near onset. For stronger damping and forcing we numerically compute these same parameters, as well as the cubic cross-coupling coefficient for competing waves travelling at an angle theta relative to each other. The resonance effects predicted by symmetry are borne out in the perturbation results for one spatial dimension, and are supported by the numerical results in two dimensions. The difference frequency resonance plays a key role in stabilizing superlattice patterns of the SL-I type observed by Kudrolli, Pier and Gollub (1998, Physica D 123).Comment: 41 pages, 13 figures; corrected figure 1b and minor typos in tex

Feedback Control of Traveling Wave Solutions of the Complex Ginzburg Landau Equation

Through a linear stability analysis, we investigate the effectiveness of a noninvasive feedback control scheme aimed at stabilizing traveling wave solutions of the one-dimensional complex Ginzburg Landau equation (CGLE) in the Benjamin-Feir unstable regime. The feedback control is a generalization of the time-delay method of Pyragas, which was proposed by Lu, Yu and Harrison in the setting of nonlinear optics. It involves both spatial shifts, by the wavelength of the targeted traveling wave, and a time delay that coincides with the temporal period of the traveling wave. We derive a single necessary and sufficient stability criterion which determines whether a traveling wave is stable to all perturbation wavenumbers. This criterion has the benefit that it determines an optimal value for the time-delay feedback parameter. For various coefficients in the CGLE we use this algebraic stability criterion to numerically determine stable regions in the (K,rho) parameter plane, where rho is the feedback parameter associated with the spatial translation and K is the wavenumber of the traveling wave. We find that the combination of the two feedbacks greatly enlarges the parameter regime where stabilization is possible, and that the stability regions take the form of stability tongues in the (K,rho)--plane. We discuss possible resonance mechanisms that could account for the spacing with K of the stability tongues.Comment: 33 pages, 12 figure

Bostonia Magazine. Volume 56

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

New stability results for long-wavelength convection patterns

We consider the transition from a spatially uniform state to a steady, spatially-periodic pattern in a partial differential equation describing long-wavelength convection. This both extends existing work on the study of rolls, squares and hexagons and demonstrates how recent generic results for the stability of spatially-periodic patterns may be applied in practice. We find that squares, even if stable to roll perturbations, are often unstable when a wider class of perturbations is considered. We also find scenarios where transitions from hexagons to rectangles can occur. In some cases we find that, near onset, more exotic spatially-periodic planforms are preferred over the usual rolls, squares and hexagons.Comment: 25 pages, 8 figure

Relative deprivation, reference groups and the assessment of standard of living

This paper proposes two new indices of relative deprivation, derived from an extension of the concept of the generalized Gini for the measurement of distributional change. Population- and income-weighted relative deprivation indices are then defined and, using panel data from the Consortium of Household Panels for European Socio-Economic Research, this paper checks which of the various ways of defining individual deprivation best fits the answers given by individuals on the degree of their satisfaction with income. The analysis finds that the deprivation indices proposed are consistently and negatively correlated with income satisfaction as reported by respondents, that income weighted measures fit better than population weighted measures, and that this fit improves with countries that experienced deep institutional changes such as the transitional economies of Eastern Europe.Inequality,Economic Theory&Research,Poverty Impact Evaluation,Labor Policies,Emerging Markets