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Sufficient conditions for exponential stability of linear infinite-dimensional port-Hamiltonian systems with dissipation are developed. These conditions are formulated in terms of the stability of an extended port-Hamiltonian system without dissipation. We investigate this question in a more general operator theoretical setting., Comment: 18 pages

The quadratic numerical range $W^2(A)$ is a subset of thestandard numerical range of a linear operator, which still contains itsspectrum. It arises naturally in operators that have a $2 \times 2$ blockstructure, and it consists of at most two connected components, none of whichnecessarily convex. The quadratic numerical range can thus reveal spectralgaps, and it can in particular indicate that the spectrum of an operator isbounded away from $0$.We exploit this property in the finite-dimensional setting to derive Krylovsubspace-type methods to solve the system $Ax = b$, in which the iteratesarise as solutions of low-dimensional models of the operator whosequadratic numerical range is contained in $W^2(A)$. This implies that theiterates are always well-defined and that, as opposed to standard FOM, largevariations in the approximation quality of consecutive iterates are avoided,although $0$ lies within the convex hull of the spectrum. We also considerGMRES variants that are obtained in asimilar spirit. We derive theoretical results on basic properties ofthese methods, review methods on how to compute the required bases in a stablemanner, and present results of several numerical experiments illustratingimprovements over standard FOM and GMRES.

Introduction Cerebral palsy is the most common paediatric motor disability in Europe [1]. It is known to cause structural and functional gait deformities, such as equinus foot and toewalking. A common surgical option to rehabilitate toewalking is Tendo Achilles Lengthening (TAL) surgery. However, this procedure can lead to plantar flexor weakening, which can develop into a drop-foot or even crouch gait post-surgery [2]. To prevent these complications, a previous study recommended adding Tibialis Anterior Tendon Shortening (TATS) to the surgical procedure [3]. The combined TAL-TATS procedure has shown improvement towards typically developing gait patterns after surgery during early and midterm evaluations regarding clinical and overall gait scores [3,4], but it remains unknown how the procedure affects muscle function of the triceps surae. As conventional gait analysis does not provide detailed information on single muscles, this study proposes a musculoskeletal modelling approach, which will allow more in-depth investigation of muscle function before and after TAL-TATS intervention. Research Question Does the TAL-TATS procedure lead to weakening of the triceps surae (as shown by a reduction in energy production) during gait? Methods 3D gait analysis outcomes of 10 patients who underwent a combined TAL-TATS procedure (5 years 6 months ± 1 year 1 month post-surgery [mean±SD]) were analysed using the Twente Lower Extremity Model v1.1 from the AnyBody repository (5 segments; 5 degrees of freedom; 159 muscle fibers in 37 muscle groups; simple muscles; polynomial recruitment solver power 3). Resulting joint moments of every muscle fiber with respect to a certain joint were determined in order to compute the power of a muscle. This enabled computation of muscle moments of biarticular muscles at both joints separately. Muscle power was computed by multiplying these moments with the corresponding joint velocity. Integration of this power over the time of interest revealed the produced or absorbed energy of a muscle per joint [5]. Pre-operative muscle power over the ankle join of the gastrocnemius and soleus were compared against postoperative findings, using paired t-tests and statistical parametric mapping. Results Outcomes showed no significant reduction in produced energy during push off over the ankle joint for both Gastrocnemius (p=0.81) and Soleus (p=0.32), while there was a significant reduction in absorbed energy by the triceps surae during the load-response phase (p

This paper examines the spatial dimension of marginal willingness to pay (MWP) for reduction of nuclear risks through increased insurance coverage. The effect of distance from a nuclear power plant on individuals' MWP is ambiguous. MWP is expected to decrease with distance because the risk of being affected by an accident decreases. However, if individuals choose their residential location taking the operational risk into account, MWP is predicted to first increase and later decrease with distance from the nuclear power plant. On the other hand, there are risks associated with transportation and disposal of nuclear waste where distance should matter only in the vicinity of the plant. These theoretical predictions are tested with data collected using a stated choice experiment. The predictions are largely confirmed by the evidence.

The objective of the study was to establish basic psychometric information on the Youth Self-Report (YSR) and a French-Canadian version of the Youth Self-Report for a non-referred Canadian sample. A survey of psychologists and psychological associates in Ontario revealed that there were few psychological instruments available to psychologists serving the Francophone population, particularly for personality and emotional assessments (Wyss, 1997). Since bilinguals tend to disclose more when they use their first language (Canino & Spurlock, 1994), the lack of appropriate psychological instruments that can be administered in French may significantly impede evaluation of Francophones. The present study compared adolescent self-report on French and English versions of Achenbach's Youth Self-Report with parent report on a parallel measure (Child Behavior Checklist, CBCL). Thirty-nine Anglophone girls and 25 Anglophone boys and their parents completed the YSR and the CBCL. Twenty-five Francophone girls and 21 Francophone boys and their parents completed the YSR, a French-Canadian translation of the YSR and the CBCL. Analyses were calculated for the 102 items common to the CBCL and YSR for three summary scores: Internalizing, Externalizing and Total Problems. Univariate analyses of variance indicated that youths reported more Internalizing problems, F (1, 109) = 52.56, p < 0.001, Externalizing problems, F (1, 109) = 99.87, p < 0.001, and Total Problems, F (1, 109) = 139.92, p < 0.001, than did their parents. Comparisons by child gender indicated no significant differences on Internalizing, Externalizing, or Total Problems (p > 0.05). The YSR and the French-Canadian YSR (FCYSR) were compared for the bilingual sample. The Pearson correlations between the two versions were significant, r = 0.96 to 0.98, p < 0.001. The intra-class correlations were negative. Paired t-tests indicated that Francophone youths for whom French was the prominent language at home reported significantly more Internalizing, t (24) = -2.859, p = 0.009 and Total Problems , t (24) = -2.757, p = 0.011 on the French version. Cronbach's coefficient alpha was 0.85 for Internalizing, 0.83 for Externalizing, and 0.92 for Total Problems. Thirty-five Francophone youths completed the French-Canadian version a second time within approximately 5 days. The test-retest correlations for the FCYSR were high, r = 0.85 to 0.87, p < 0.001. The intra-class correlations were low, r = 0.17 to 0.43, p > 0.05. Scores decreased significantly between test and retest for Internalizing , t (34) = 4.279, p < 0.001, Externalizing, t (34) = 2.989, p = 0.005, and Total Problems, t (34) = 4.124, p < 0.001. Implications for clinical assessment and research are discussed.Dept. of Clinical Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .W97. Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4811. Adviser: S. Voelker. Thesis (Ph.D.)--University of Windsor (Canada), 2000.