Voiced speech is a highly complex process involving coupled interactions between the vocal fold structure, aerodynamics, and acoustic field. Reduced-order lumped-element models of the vocal fold structure, coupled with various aerodynamic and acoustic models, have proven useful in a wide array of speech investigations. These simplified models of speech, in which the vocal folds are approximated...

We discuss various issues concerning the behaviors near the boundary (σ = 0, π) and the midpoint (σ = π/2) of the open string coordinate X(σ) and its conjugate momentum P (σ) = −iδ/δX(σ) acting on the matter projectors of vacuum string field theory. Our original interest is in the dynamical change of the boundary conditions of the open string coordinate from the Neumann one in the translational...

We analyse the fi nancial performance of small German hospitals based on balance sheet data of about 1,000 hospitals in 2007. Measures of fi nancial performance are the earnings before interest, tax, depreciation, and amortisation (EBITDA) and the probability of default (PD). We fi nd that, on average, small hospitals have more fi nancial diffi culties than large ones. However, there is conside...

In the talk we will address the problem of finding an optimal dividend policy for a class of jumpdiffusion processes. The jump component is a compound Poisson process with negative jumps, and the drift and diffusion components are assumed to satisfy some regularity and growth restrictions. With each dividend payment there is associated a fixed and a proportional cost. The aim is to maximize exp...

We analyse the fi nancial performance of small German hospitals based on balance sheet data of about 1,000 hospitals in 2007. Measures of fi nancial performance are the earnings before interest, tax, depreciation, and amortisation (EBITDA) and the probability of default (PD). We fi nd that, on average, small hospitals have more fi nancial diffi culties than large ones. However, there is conside...

* We are grateful to the many members of the MIT and Harvard economics communities who have generously provided us with insightful conversations, comments on an earlier draft of this paper and practical support. We are particularly indebted to

We analyze the investment decision of a firm that has an option to complete an investment project either in one lump or in two smaller parts at distinct points in time. The firm faces a trade-off between the cost savings that arise when the project is completed at once and the additional flexibility that arises when the firm is able to respond to resolving uncertainty by choosing optimal timing...

Water quality models combine fluid-flow relations with biological regressions, all on a spatially complex domain. For many applications, a computationally simple lumped parameter model with regressed parameters suffices, while for others where a more fundamental approach may be worth the extra development and computational effort. A simple example modelling the transport of salt in interconnect...

The present paper is an extension of Ghiglino and Shell [7] to the case of imperfect consumer credit markets. We show that with constraints on individual credit and only anonymous (i.e., non-personalized) lump-sum taxes, strong (or “global”) irrelevance of government budget deficits is not possible, and weak (or “local”) irrelevance can hold only in very special situations. This is in sharp con...