A domain-specific design architecture for composite material design and aircraft part redesign

Advanced composites have been targeted as a 'leapfrog' technology that would provide a unique global competitive position for U.S. industry. Composites are unique in the requirements for an integrated approach to designing, manufacturing, and marketing of products developed utilizing the new materials of construction. Numerous studies extending across the entire economic spectrum of the United States from aerospace to military to durable goods have identified composites as a 'key' technology. In general there have been two approaches to composite construction: build models of a given composite materials, then determine characteristics of the material via numerical simulation and empirical testing; and experience-directed construction of fabrication plans for building composites with given properties. The first route sets a goal to capture basic understanding of a device (the composite) by use of a rigorous mathematical model; the second attempts to capture the expertise about the process of fabricating a composite (to date) at a surface level typically expressed in a rule based system. From an AI perspective, these two research lines are attacking distinctly different problems, and both tracks have current limitations. The mathematical modeling approach has yielded a wealth of data but a large number of simplifying assumptions are needed to make numerical simulation tractable. Likewise, although surface level expertise about how to build a particular composite may yield important results, recent trends in the KBS area are towards augmenting surface level problem solving with deeper level knowledge. Many of the relative advantages of composites, e.g., the strength:weight ratio, is most prominent when the entire component is designed as a unitary piece. The bottleneck in undertaking such unitary design lies in the difficulty of the re-design task. Designing the fabrication protocols for a complex-shaped, thick section composite are currently very difficult. It is in fact this difficulty that our research will address

The value of psychological flexibility: Examining psychological mechanisms underpinning a cognitive behavioural therapy intervention for burnout

Little is known of the mechanisms by which interventions for burnout work. Employees of a UK government department were randomly assigned to either a worksite group-based CBT intervention called Acceptance and Commitment Therapy (ACT; n=43), which aimed to increase participants' psychological flexibility, or a waiting list control group (n=57). The ACT group received three half-day sessions of training spread over two and a half months. Data were collected at baseline (T1), at the beginning of the second (T2) and third (T3) workshops, and at six months' follow up (T4). Consistent with ACT theory, analyses revealed that, in comparison to the control group, a significant increase in psychological flexibility from T2 to T3 in the ACT group mediated the subsequent T2 to T4 decrease in emotional exhaustion in that group. Consistent with a theory of emotional burnout development, this significant decrease in emotional exhaustion from T2 to T4 in the ACT group appeared to prevent the significant T3 to T4 increase in depersonalization seen in the control group. Strain also decreased from T2 to T3 in the ACT group only, but no mediator of that improvement was identified. Implications for theory and practice in the fields of ACT and emotional burnout are discussed

Mindfulness and meditation in the workplace: An acceptance and commitment therapy approach

There is a wide-range and growing body of evidence that mental health and behavioural effectiveness are influenced more by how people interact with their thoughts and feelings than by their form (e.g., how negative they are) or frequency. Research has demonstrated this key finding in a wide-range of areas. For example, in chronic pain, psychosocial disability is predicted more by the experiential avoidance of pain than by the degree of pain (McCracken, 1998). A number of therapeutic approaches have been developed that share this key insight: distress tolerance (e.g., Brown, Lejuez, Kahler, & Strong, 2002; Schmidt, Richey, Cromer, & Buckner, 2007), thought suppression (e.g., Wenzlaff & Wegner, 2000), and mindfulness (Baer, 2003). It is also central to a number of the newer contextual cognitive behaviour therapy (CBT) approaches to treatment, such as mindfulness based cognitive therapy (MBCT; Segal, Williams, & Teasdale, 2001), dialectical behaviour therapy (DBT; Linehan, 1993), metacognitive therapy (Wells, 2000), and acceptance and commitment therapy (ACT; Hayes, Strosahl, & Wilson, 1999). The purpose of this chapter is to describe how ACT conceptualises mindfulness and tries to enhance it in the pursuit of promoting mental health and behavioural effectiveness (e.g., productivity at work). To this end, we discuss ACT’s key construct of psychological flexibility, which involves mindfulness, and how it has led to a somewhat different approach not only to conceptualising mindfulness, but also how we try to enhance it in the workplace. In so doing, we hope to show that whilst formal meditation practice is valued in ACT, it is only one strategy that is used to promote mindfulness, as well as psychological flexibility more generally

Cosmological predictions from the Misner brane

Within the spirit of five-dimensional gravity in the Randall-Sundrum scenario, in this paper we consider cosmological and gravitational implications induced by forcing the spacetime metric to satisfy a Misner-like symmetry. We first show that in the resulting Misner-brane framework the Friedmann metric for a radiation dominated flat universe and the Schwarzschild or anti-de Sitter black holes metrics are exact solutions on the branes, but the model cannot accommodate any inflationary solution. The horizon and flatness problems can however be solved in Misner-brane cosmology by causal and noncausal communications through the extra dimension between distant regions which are outside the horizon. Based on a semiclassical approximation to the path-integral approach, we have calculated the quantum state of the Misner-brane universe and the quantum perturbations induced on its metric by brane propagation along the fifth direction. We have then considered testable predictions from our model. These include a scale-invariant spectrum of density perturbations whose amplitude can be naturally accommodated to the required value 10$^{-5}-10^{-6}$, and a power spectrum of CMB anisotropies whose acoustic peaks are at the same sky angles as those predicted by inflationary models, but having much smaller secondary-peak intensities. These predictions seem to be compatible with COBE and recent Boomerang and Maxima measurementsComment: 16 pages, RevTe

Cosmological Consequences of String Axions

Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H_inf \apprge 10^13 GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T \apprle \Lambda_QCD.Comment: 27 pages, 4 figures; v2: References corrected; v3: Assumptions simplified, minor corrections, conclusions unchange

Lensing effect on the relative orientation between the Cosmic Microwave Background ellipticities and the distant galaxies

The low redshift structures of the Universe act as lenses in a similar way on the Cosmic Microwave Background light and on the distant galaxies (say at redshift about unity). As a consequence, the CMB temperature distortions are expected to be statistically correlated with the galaxy shear, exhibiting a non-uniform distribution of the relative angle between the CMB and the galactic ellipticities. Investigating this effect we find that its amplitude is as high as a 10% excess of alignement between CMB and the galactic ellipticities relative to the uniform distribution. The relatively high signal-to-noise ratio we found should makes possible a detection with the planned CMB data sets, provided that a galaxy survey follow up can be done on a sufficiently large area. It would provide a complementary bias-independent constraint on the cosmological parameters.Comment: 7 pages, 3 figures; uses emulateapj.sty; submitted to Ap

Power Spectrum Estimators For Large CMB Datasets

Forthcoming high-resolution observations of the Cosmic Microwave Background (CMB) radiation will generate datasets many orders of magnitude larger than have been obtained to date. The size and complexity of such datasets presents a very serious challenge to analysing them with existing or anticipated computers. Here we present an investigation of the currently favored algorithm for obtaining the power spectrum from a sky-temperature map --- the quadratic estimator. We show that, whilst improving on direct evaluation of the likelihood function, current implementations still inherently scale as the equivalent of the cube of the number of pixels or worse, and demonstrate the critical importance of choosing the right implementation for a particular dataset.Comment: 8 pages LATEX, no figures, corrected misaligned columns in table

Academics' Experiences of a Respite From Work: Effects of Self-Critical Perfectionism and Perseverative Cognition on Postrespite Well-Being

This longitudinal study examined relations between personality and cognitive vulnerabilities and the outcomes of a respite from work. A sample of 77 academic employees responded to week-level measures of affective well-being before, during, and on 2 occasions after an Easter respite. When academics were classified as being either high or low in a self-critical form of perfectionism (doubts about actions), a divergent pattern of respite to postrespite effects was revealed. Specifically, during the respite, the 2 groups of academics experienced similar levels of well-being. However, during postrespite working weeks, the more perfectionistic academics reported significantly higher levels of fatigue, emotional exhaustion, and anxiety. The greater deterioration in well-being experienced by perfectionist academics when first returning to work was mediated by their tendency for perseverative cognition (i.e., worry and rumination) about work during the respite itself. These findings support the view that the self-critical perfectionist vulnerability is activated by direct exposure to achievement-related stressors and manifested through perseverative modes of thinking

An Executive Appraisal of Courses Which Best Prepare One for General Management

This ongoing study summarizes 1980-81 data from 1158 newly promoted executives in the United States who answered this question: "Assuming the study of business administration best prepares a young person for a career in general management, how important are the following courses as a part of that preparation?" Business Communication-oral and written- was the course selected as Very Important more often than any of thirteen courses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68655/2/10.1177_002194368201900102.pd