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We examine in this paper so-called B-critical points of linear, time-varying differential-algebraic equations (DAEs) of the form A(t)(D(t)x(t)) + B(t)x(t) = q(t). These critical or singular points, which cannot be handled by classical projector methods, require adapting a recently introduced framework based on Π-projectors. Via a continuation of certain(More)
An optimal feedback control has been obtained for linear-quadratic optimal control problems with constraints described by differential-algebraic equations. For that purpose, a new implicit Riccati equation (Riccati differential algebraic system) is provided, and its solvability is investigated. It is shown that one can do without those strong consistency(More)
New pharmacological and clinical studies show that standardized willow bark extracts (WRE) is not only the natural form of salicylic acid. Willow bark extract has comparable antiinflammatory activities as higher doses of acetylsalicylic acid (ASS), and it shows antinociceptive and antipyretic activities. Under the pharmacologically active doses, no adverse(More)
dedicated to C. W. Gear on the occasion of his 60th anniversary Abstract. In electric circuit simulation the charge oriented modiied nodal analysis may lead to highly nonlinear DAEs with low smoothness properties. They may have index 2 but they do not belong to the class of Hessenberg form systems that are well understood. In the present paper, on the(More)
Higher order finite element methods are applied to 2D and 3D second order elliptic interface problems with smooth interfaces, and their convergence is analyzed in the H 1-and L 2-norm. The error estimates are expressed explicitly in terms of the approximation order p and a parameter δ that quantifies the mismatch between the smooth interface and the finite(More)
On the basis of therapy with antibiotics and nasal decongestants the efficacy of an additional treatment with the herbal combination Sinupret containing gentian root, cowslip flowers, sour dock herbs, elder flowers and shop vervain wort herbs was assessed in a randomized, placebo-controlled double-blind clinical trial involving 160 patients with acute(More)
Complex combinations of botanical drugs are usually regarded as non-rational medicines. In the case of Sinupret, a combination of 5 botanical drugs, the pharmacological profile was investigated thoroughly with respect to activities on secretion of the respiratory epithelium, with respect to anti-inflammatory activities and to effects against a murine(More)