Constrained multifidelity optimization using model calibration

Multifidelity optimization approaches seek to bring higher-fidelity analyses earlier into the design process by using performance estimates from lower-fidelity models to accelerate convergence towards the optimum of a high-fidelity design problem. Current multifidelity optimization methods generally fall into two broad categories: provably convergent methods that use either the high-fidelity gradient or a high-fidelity pattern-search, and heuristic model calibration approaches, such as interpolating high-fidelity data or adding a Kriging error model to a lower-fidelity function. This paper presents a multifidelity optimization method that bridges these two ideas; our method iteratively calibrates lower-fidelity information to the high-fidelity function in order to find an optimum of the high-fidelity design problem. The algorithm developed minimizes a high-fidelity objective function subject to a high-fidelity constraint and other simple constraints. The algorithm never computes the gradient of a high-fidelity function; however, it achieves first-order optimality using sensitivity information from the calibrated low-fidelity models, which are constructed to have negligible error in a neighborhood around the solution. The method is demonstrated for aerodynamic shape optimization and shows at least an 80% reduction in the number of high-fidelity analyses compared other single-fidelity derivative-free and sequential quadratic programming methods. The method uses approximately the same number of high-fidelity analyses as a multifidelity trust-region algorithm that estimates the high-fidelity gradient using finite differences.     

Maternal mental health and integrated programs for mothers with substance abuse issues.

To examine the impact of integrated treatment programs (those with substance use treatment and pregnancy-, parenting-, or child-related services) on maternal mental health, we compiled a database of studies of integrated programs published between 1990 and 2007 with outcome data on maternal mental health. There were 18 cohort studies, 3 randomized trials, and 2 quasi-experimental studies. Of the five studies comparing integrated to nonintegrated programs, three studies provided enough information to allow for them to be combined in a meta-analysis. The average effect size was 0.23 (95% CI = 0.15 to 0.31, SE = 0.04), p Q = 5.66, p = .059. This meta-analysis is the first systematic quantitative review of studies evaluating the impact of integrated programs on maternal mental health. Findings suggest that integrated programs may be associated with a small advantage over nonintegrated programs in improving maternal mental health. This review highlights the need for further research with improved methodology, study quality, and reporting to improve our understanding of how best to meet the mental health needs of mothers with substance abuse issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Zn in Athenian Black Gloss Ceramic Slips: A Trace Element Marker for Fabrication Technology

The black‐colored pottery slips produced in Athens from the 6th to 4th centuries B.C., had a consistent composition achieved through processing and refinement of raw clay. Little direct evidence has been established as to what were these refinement methods. To better understand how the slip material was prepared, the major and trace elemental compositions of 19 slips from different ceramic vessels and their corresponding bodies of Athenian red‐figure and black‐figure vases were determined using laser ablation inductively coupled plasma mass spectrometry (LA‐ICPMS). Notably higher Zn concentrations were found in the slips (271–1959 ppm) than in their corresponding body ceramics (<361 ppm). The Zn concentrations in the slips were also found to be above the natural background for typical clay (between 10 and 300 ppm) suggesting an unintentional anthropogenic enrichment of this metal. Based on the abnormally high Zn content of the slip, it is speculated that the clay was treated using vitriol (concentrated acid mine runoff which is rich in Zn), to induce flocculation and remove carbonate mineral phases from the raw material that, if present, would prevent the slip from vitrifying. This same signature of elevated levels of Zn with a corresponding Ce anomaly is also observed for black glosses produced in Corinthian and Etrurian (Italy) workshops indicating that these trace element signatures were imparted to the material by means of shared methods of manufacturing instead of being indicative of a single unique source for this material.     

Examination of radio‐opacity enhancing additives in shape memory polyurethane foams

Three microparticle additives, tungsten (W), zirconium oxide (ZrO₂) , and barium sulfate (BaSO₄) were selected to enhance the radio‐opacity in shape memory polymer (SMP) foam biomaterials. The addition of filler causes no significant alterations of glass transition temperatures, density of the materials increases, pore diameter decreases, and total volume recovery decreases from approximately 70 times in unfilled foams to 20 times (4% W and 10% ZrO₂). The addition of W increases time to recovery; ZrO₂ causes little variation in time to shape recovery; BaSO₄ increases the time to recovery. On a 2.00 mean X‐ray density (mean X.D.) scale, a GDC coil standard has a mean X.D. of 0.62 ; 4% W enhances the mean X.D. to 1.89, 10% ZrO₂ to 1.39 and 4% BaSO₄ to 0.74. Radio‐opacity enhancing additives could be used to produce SMP foams with controlled shape memory kinetics, low density , and enhanced X ‐ray opacity for medical materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42054.     

Urban crash-related child pedestrian injury incidence and characteristics associated with injury severity

Objective

Describe age-based urban pedestrian versus auto crash characteristics and identify crash characteristics associated with injury severity.

Materials and methods

Secondary analysis of the 2004–2010 National Highway and Traffic Safety Administration database for Illinois. All persons in Chicago crashes with age data who were listed as pedestrians (n = 7175 child age ≤19 yo, n = 16,398 adult age ≥20 yo) were included. Incidence and crash characteristics were analyzed by age groups and year. Main outcome measures were incidence, crash setting, and injury severity. Multivariate logistic regression analysis was performed to estimate injury severity by crash characteristics.

Results

Overall incidence was higher for child (146.6 per 100,000) versus adult (117.3 per 100,000) pedestrians but case fatality rate was lower (0.7% for children, 1.7% for adults). Child but not adult pedestrian injury incidence declined over time (trend test p < 0.0001 for <5 yo, 5–9 yo, and 10–14 yo; p < 0.05 for 15–19 yo, p = 0.96 for ≥20 yo). Most crashes for both children and adults took place during optimal driving conditions. Injuries were more frequent during warmer months for younger age groups compared to older (χ²p < 0.001). Midblock crashes increased as age decreased (p < 0.0001 for trend). Most crashes occurred at sites with sub-optimal traffic controls but varied by age (p < 0.0001 for trend). Crashes were more likely to be during daylight on dry roads in clear weather conditions for younger age groups compared to older (χ²p < 0.001). Daylight was associated with less severe injury (child OR 0.93, 95% CI 0.87–0.98; adult OR 0.90, 95% CI 0.87–0.93).

Conclusion

The incidence of urban pedestrian crashes declined over time for child subgroups but not for adults. The setting of pedestrian crashes in Chicago today varies by age but is similar to that seen in other urban locales previously. Injuries for all age groups tend to be less severe during daylight conditions. Age-based prevention efforts may prove beneficial.