Conceptual damage-sensitive features for structural health monitoring: Laboratory and field demonstrations

The use of damage-sensitive features to evaluate structural condition or health is a very critical aspect of structural health monitoring. The purpose of this paper is to investigate the potential of two different damage-sensitive features for detecting damage. Different damage scenarios are simulated on a large-scale laboratory structure and a three-span highway bridge for demonstration. The features presented in this paper are the modal flexibility-based deflection and curvature both of which are obtained directly from dynamic properties. In the literature, flexibility associated with mode shapes and mode shapes curvatures have been mostly explored. In this study, multi-input–multi-output dynamic data are used to obtain modal flexibility, which is a close approximation to the actual flexibility. A main novelty is that the curvature is calculated from the deflected shapes using the modal flexibility as opposed to using modal vectors. In this paper, the theory of the methodology is explained and then experimental studies and results are presented. For the experimental studies, the laboratory specimen and the three-span bridge were gradually damaged. It is shown that both deflection and curvature are conceptual and physically meaningful features for damage detection and localization. The issues and the requirements for these features to perform successfully are also presented.     

Models of high velocity impact phenomena

Models of craters formed by impacts at velocities of up to 24.5 km/sec have been computed using the Smooth Particle Hydrodynamics, MESA, EPIC and CALE codes. These modeling efforts are compared to data obtained from the Hypervelocity Microparticle Impact project at Los Alamos using the van de Graaff accelerator. A factor of 5 increase in yield strength was needed to account for high strain rate effects and to match the data. Structure in the data is addressed by using crater volume instead of crater diameter cubed. Detailed code comparisons were made between the four codes with good agreement found.     

Inclusion of fatigue effects in human reliability analysis

The effect of fatigue on human performance has been observed to be an important factor in many industrial accidents. However, defining and measuring fatigue is not easily accomplished. This creates difficulties in including fatigue effects in probabilistic risk assessments (PRA) of complex engineering systems that seek to include human reliability analysis (HRA). Thus the objectives of this paper are to discuss (1) the importance of the effects of fatigue on performance, (2) the difficulties associated with defining and measuring fatigue, (3) the current status of inclusion of fatigue in HRA methods, and (4) the future directions and challenges for the inclusion of fatigue, specifically sleep deprivation, in HRA.     

Examining the correlates of psychological aggression among a community sample of couples.

In this study, the authors examined the correlates of psychological aggression victimization and perpetration among a community sample of 145 heterosexual couples. For both women and men, psychological aggression victimization was associated with greater psychological distress, anxiety, and physical health symptoms beyond the effects of physical aggression. Psychological aggression victimization was also uniquely associated with higher levels of depression for women. Trait anger and poor relationship adjustment were the strongest correlates of psychological aggression perpetration across genders. Childhood father-to-child and father-to-mother aggressions were associated with psychological aggression perpetration for men only, suggesting possible distinct etiologies across genders. These data highlight the importance of the further development of models for psychological aggression in both women and men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

INCLUDING SOFT INFORMATION IN EISs

Although much of executive decision making is based on soft information—opinions, predictions, news, and even rumors—executive information systems (EISs) have only recently begun to augment factual data with such information. A study of current use of soft information in EISs yields 15 propositions designed to help EIS developers determine what kinds of soft information are most valuable and how best to capture and deliver this information.     

Innovative Food Procurement Strategies of Women Living in Khayelitsha,Cape Town

The combination of persistent levels of inequality and poverty, alongside the advent of rapid urbanisation, mean urban food insecurity is set to be one of the biggest development challenges of this century. As women play a crucial role in the food security status of urban poor households, understanding and supporting the life-sustaining food procurement practices used by women ought to be a key strategy in addressing urban food insecurity. Particularly, the paper draws on primary qualitative research I conducted with women from Khayelitsha, Cape Town’s largest informal settlement. This case study explored the beliefs, practices and preferences that govern women’s food procurement choices. The study found that women adopt a range of innovative food procurement strategies, which significantly improve household food security prospects. These include buying in bulk, skilfully navigating the informal and the formal food economies, utilising their social networks and trading off food with other important non-food expenses. Understanding these practices can provide greater insight into how best to enhance urban food security. The implications are that women need to be better supported rather than, as most mainstream programmes suggest, encouraged to take on more work outside the household, whilst still faced with the lion’s share of housework.     

Posttraumatic stress disorder and intimate relationship problems: A meta-analysis.

Objective: The authors conducted a meta-analysis of empirical studies investigating associations between indices of posttraumatic stress disorder (PTSD) and intimate relationship problems to empirically synthesize this literature. Method: A literature search using PsycINFO, Medline, Published International Literature on Traumatic Stress (PILOTS), and Dissertation Abstracts was performed. The authors identified 31 studies meeting inclusion criteria. Results: True score correlations (ρ) revealed medium-sized associations between PTSD and intimate relationship discord (ρ = .38, N = 7,973, K = 21), intimate relationship physical aggression perpetration (ρ = .42, N = 4,630, K = 19), and intimate relationship psychological aggression perpetration (ρ = .36, N = 1,501, K = 10). The strength of the association between PTSD and relationship discord was higher in military (vs. civilian) samples, and when the study was conducted in the United States (vs. other country), and the study represented a doctoral dissertation (vs. published article). The strength of the association between PTSD and physical aggression was higher in military (vs. civilian) samples, males (vs. females), community (vs. clinical) samples, studies examining PTSD symptom severity (vs. diagnosis), when the physical aggression measure focused exclusively on severe violence (vs. a more inclusive measure), and the study was published (vs. dissertation). For the PTSD–psychological aggression association, 98% of the variance was accounted for by methodological artifacts such as sampling and measurement error; consequently, no moderators were examined in this relationship. Conclusions: Findings highlight a need for the examination of models explaining the relationship difficulties associated with PTSD symptomatology and interventions designed to treat problems in both areas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incremental Validity in the Psychological Assessment of Children and Adolescents.

Incremental validity in the process of psychological assessment of children and adolescents is explored. The authors highlight the dependence of the incremental validity of assessment information on factors such as goal of assessment, other information available, base rate of the problem or outcome, age or gender of the child, and type of problem being assessed. The authors discuss the incremental validity of assessment information from alternate sources, methods, and constructs. In view of the limited number of studies directly relevant to incremental validity in child clinical assessments, the authors call for more clinically relevant research. To have the greatest impact on child and adolescent services, this research must be readily generalized and immediately relevant to actual clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)