Accounting history research and its diffusion in an international context

Drawing on extensive evidence gathered from all accounting history papers published in major research journals during the 1990s, it is argued that extant patterns of dissemination of accounting history research in international contexts are less than efficient, which in turn results in a glaring neglect of the 'majority' in 'international' journals in the English language. My understanding of the term majority refers to the subjects who conduct research (i.e., men and women affiliated to non-Anglo-Saxon institutions), the research settings (i.e., non-Anglo-Saxon environments), and the observation periods (i.e., those different from 1850-1940). At best, some of historiographies have a superficial visibility in the international arena, whereas most of them are fully neglected. I shall argue that accounting history research would gain in strength if other scholars, settings, and periods of study were added to those regularly reflected in 'international' journals. I contend that such broadening of the discipline represents the most important challenge for accounting historians in the years to come

Boundedness of the extremal solutions in dimension 4

In this paper we establish the boundedness of the extremal solution u^* in dimension N=4 of the semilinear elliptic equation $-\Delta u=\lambda f(u)$, in a general smooth bounded domain Omega of R^N, with Dirichlet data $u|_{\partial \Omega}=0$, where f is a C^1 positive, nondecreasing and convex function in [0,\infty) such that $f(s)/s\rightarrow\infty$ as $s\rightarrow\infty$. In addition, we prove that, for N>=5, the extremal solution $u^*\in W^{2,\frac{N}{N-2}}$. This gives $u^\ast\in L^\frac{N}{N-4}$, if N>=5 and $u^*\in H_0^1$, if N=6.Comment: 9 page

Idiosyncrasy as an explanation for power laws in nature

Complex systems theory pays much attention to simple mechanisms producing nontrivial patterns, especially power laws. However, power laws with exponent close to one also result from complex mixtures of mechanisms that, in isolation, would not necessarily give this type of distribution. Probably, both paths to the power law are relevant in nature. The second gives a plausible explanation for some instances of power laws emerging in extremely complex systems, such as ecosystems.Comment: To be published in Trends in Mathematics. 6 pages, 0 figure

SOCP relaxation bounds for the optimal subset selection problem applied to robust linear regression

This paper deals with the problem of finding the globally optimal subset of h elements from a larger set of n elements in d space dimensions so as to minimize a quadratic criterion, with an special emphasis on applications to computing the Least Trimmed Squares Estimator (LTSE) for robust regression. The computation of the LTSE is a challenging subset selection problem involving a nonlinear program with continuous and binary variables, linked in a highly nonlinear fashion. The selection of a globally optimal subset using the branch and bound (BB) algorithm is limited to problems in very low dimension, tipically d<5, as the complexity of the problem increases exponentially with d. We introduce a bold pruning strategy in the BB algorithm that results in a significant reduction in computing time, at the price of a negligeable accuracy lost. The novelty of our algorithm is that the bounds at nodes of the BB tree come from pseudo-convexifications derived using a linearization technique with approximate bounds for the nonlinear terms. The approximate bounds are computed solving an auxiliary semidefinite optimization problem. We show through a computational study that our algorithm performs well in a wide set of the most difficult instances of the LTSE problem.Comment: 12 pages, 3 figures, 2 table