Overlapping Schwarz and Spectral Element Methods for Linear Elasticity and Elastic Waves

The classical overlapping Schwarz algorithm is here extended to the spectral element discretization of linear elastic problems, for both homogeneous and heterogeneous compressible materials. The algorithm solves iteratively the resulting preconditioned system of linear equations by the conjugate gradient or GMRES methods. The overlapping Schwarz preconditioned technique is then applied to the numerical approximation of elastic waves with spectral elements methods in space and implicit Newmark time advancing schemes. The results of several numerical experiments, for both elastostatic and elastodynamic problems, show that the convergence rate of the proposed preconditioning algorithm is independent of the number of spectral elements (scalability), is independent of the spectral degree in case of generous overlap, otherwise it depends inversely on the overlap size. Some results on the convergence properties of the spectral element approximation combined with Newmark schemes for elastic waves are also presented.     

Optimal detection of visual evoked potentials

The authors consider the problem of detecting visual evoked potentials (VEP's). A matched subspace filter is applied to the detection of the VEP and is demonstrated to perform better than a number of other evoked potential detectors. Unlike single-harmonic detectors, the matched subspace filter (MSF) detector is suitable for detecting multiharmonic VEP's. Moreover, the MSF is optimal in the uniformly most powerful sense for multiharmonic signals with unknown noise variance     

Longitudinal relations between forgiveness and conflict resolution in marriage.

Does forgiveness predict later conflict resolution in married couples? Twelve-month follow-up data on conflict resolution were collected from the couples studied by F. D. Fincham, S. R. Beach, and J. Davila (see record 2004-11293-007), who had provided earlier reports of forgiveness and conflict resolution. For wives, the positive dimension of forgiveness or benevolence predicted husbands' later reports of better conflict resolution controlling for initial levels of conflict resolution. This finding was independent of wives' marital satisfaction and the degree of hurt engendered by husbands' transgressions. For husbands, the only predictor of wives' reports of later conflict resolution was initial level of conflict resolution. The findings are discussed in terms of the direction of effect between forgiveness and conflict resolution and of the mechanisms that might link them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Output feedback trajectory stabilization of the uncertainty DC servomechanism system

This work proposes a solution for the output feedback trajectory-tracking problem in the case of an uncertain DC servomechanism system. The system consists of a pendulum actuated by a DC motor and subject to a time-varying bounded disturbance. The control law consists of a Proportional Derivative controller and an uncertain estimator that allows compensating the effects of the unknown bounded perturbation. Because the motor velocity state is not available from measurements, a second-order sliding-mode observer permits the estimation of this variable in finite time. This last feature allows applying the Separation Principle. The convergence analysis is carried out by means of the Lyapunov method. Results obtained from numerical simulations and experiments in a laboratory prototype show the performance of the closed loop system.     

Forgiveness and Conflict Resolution in Marriage.

Two studies examined whether forgiveness in married couples is associated with better conflict resolution. Study 1 examined couples in their 3rd year of marriage and identified 2 forgiveness dimensions (retaliation and benevolence). Husbands' retaliatory motivation was a significant predictor of poorer wife-reported conflict resolution, whereas wives' benevolence motivation predicted husbands' reports of better conflict resolution. Examining longer term marriages, Study 2 identified three forgiveness dimensions (retaliation, avoidance and benevolence). Whereas wives' benevolence again predicted better conflict resolution, husbands' avoidance predicted wives' reports of poorer conflict resolution. All findings were independent of both spouses' marital satisfaction. The findings are discussed in terms of the importance of forgiveness for marital conflict and its implications for spouse goals. Future research directions on forgiveness are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Non‐minimum phase switched systems: HOSM‐based fault detection and fault identification via Volterra integral equation

In this paper, the problem of continuous and discrete state estimation for a class of linear switched systems with additive faults is studied. The class of systems under study can contain non‐minimum phase zeroes in some of their ‘operating modes’. The conditions for exact reconstruction of the discrete state are given using structural properties of the switched system. The state space is decomposed into the strongly observable part, the non‐strongly observable part, and the unobservable part, to analyze the effect of the unknown inputs. State observers based on high‐order sliding mode to exactly estimate the strongly observable part and Luenberger‐like observers to estimate the remaining parts are proposed. For the case when the exact estimation of the state cannot be achieved, the ultimate bounds on the estimation errors are provided. The proposed strategy includes a high‐order sliding‐mode‐based fault detection and a fault identification scheme via the solution of a Volterra integral equation. The feasibility of the proposed method is illustrated by simulations. Copyright © 2013 John Wiley & Sons, Ltd.     

Secure base processes in couples: Daily associations between support experiences and attachment security.

The authors examined secure base functioning in couples by studying the association between daily social support experiences and attachment security in a 14-day daily experiences study of 114 heterosexual dating couples. Both members of each couple reported on daily relationship-specific attachment security and support sought, provided, and received, as well as felt support. Within- and cross-partner associations were examined, as were reciprocal associations between support and security. Results of over-time Actor-Partner Interdependence Model analyses indicated that security (in the form of high comfort with intimacy and low anxiety about abandonment) was associated with the most adaptive support experiences, whereas high anxiety about abandonment was associated with the least, and particularly with a lack of sensitive caregiving. Implications for understanding secure base dynamics in couples are discussed and guidelines for where to intervene as well as what to target in relationship distress prevention programs are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)