Probabilistic analysis of concrete cracking using neural networks and random fields

In this paper an algorithm for the probabilistic analysis of concrete structures is proposed which considers material uncertainties and failure due to cracking. The fluctuations of the material parameters are modeled by means of random fields and the cracking process is represented by a discrete approach using a coupled meshless and finite element discretization. In order to analyze the complex behavior of these nonlinear systems with low numerical costs a neural network approximation of the performance functions is realized. As neural network input parameters the important random variables of the random field in the uncorrelated Gaussian space are used and the output values are the interesting response quantities such as deformation and load capacities. The neural network approximation is based on a stochastic training which uses wide spanned Latin hypercube sampling to generate the training samples. This ensures a high quality approximation over the whole domain investigated, even in regions with very small probability.     

Assessment of structural simulation models by estimating uncertainties due to model selection and model simplification

In this paper several methods for model assessment considering uncertainties are discussed. Sensitivity analysis is performed to quantify the influence of the individual model input parameters. In addition to the well-known analysis of a single model, a new procedure for quantifying the influence of the model choice on the uncertainty of the model prediction is proposed. Furthermore, a procedure is presented which can be used to estimate the model framework uncertainty and which enables the selection of the optimal model with the best compromise between model input and framework uncertainty. Finally Bayesian methods for model selection are extended for model assessment without measurements using model averaging as reference.     

A comparison of stress measures in an experimental analogue of public speaking.

Observed 80 undergraduates (previously assessed for public speaking anxiety) in either an audience or no-audience condition created through instructions. Finger sweat prints and 2 self-ratings of stress were taken prior to, during, and after speaking. All stress measures were significantly affected over measurement periods. Self-reported stress was sensitive to preassessed anxiety levels. Instructions did not yield a significant main effect but did interact with both measurement period and anxiety level. Dependent measures were intercorrelated in a multitrait-multimethod matrix; self-reports were interrelated but were not correlated with the sweat measure. Other comparisons between the measures are made and discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A novel approach to authenticity control of whole grain durum wheat (Triticum durum Desf.) flour and pasta,based on analysis of alkylresorcinol composition

Since durum wheat is ∼20% more expensive than common wheat and considered of superior quality for the manufacture of pasta products, efficient methods for the detection of accidental or intentional admixtures of common wheat to durum wheat products are required. This paper describes a novel approach for the detection and quantification of whole grain common wheat adulteration in whole grain durum flour and dried pasta. We found that differences in the C17:0 to C21:0 alkylresorcinol homologue ratios between the two cereal species may serve as a suitable tool for whole grain durum product authentification. To detect and estimate adulteration, the C17:0/C21:0 ratios of flour and pasta admixtures with added whole grain flour of common wheat were analysed. A linear relationship between C17:0/C21:0 ratios and level of admixture in pasta samples showed that adulteration can be estimated within the range of 5–100% of admixture. Furthermore, di- and triunsaturated as well as oxygenated alk(en)ylresorcinols are reported to occur in Triticum durum Desf. for the first time.     

Characterization of E- and Z-ajoene obtained from different varieties of garlics

Synthesised E- and Z-ajoene were used to determine their amounts in food oils containing various fresh garlics. The best yield of E-ajoene (172.0 μg/g of garlic) and Z-ajoene (476.0 μg/g of garlic) was obtained from freshly prepared Japanese garlic with rice oil which was heated at 80 °C. Determination of E- and Z-ajoene from soybean oil containing 15% Japanese garlic samples prepared at 80 °C for 0.5 h gave the amount of E-ajoene (170.0 μg/g of garlic) and Z-ajoene (127.0 μg/g of garlic). After 9-month storage, 54.0% E- and 11.0% Z-ajoene remained in Japanese garlic with rice oil. Ajoene (0.1 mM) in ethyl acetate was incubated under UV-light (253.7 nm) for 3 days, 81.7% E- and 56.9% Z-ajoene remained. 4.3% and 0.5% E- and Z-ajoene remained when ajoene (0.1 mM in ethyl acetate) was incubated at 100 °C.     

Assessment of test user qualifications: A research-based measurement procedure.

The qualifications of test purchasers have been a concern of the American Psychological Association since 1950, when ethical standards for test distribution, on the basis of a 3-level classification of tests, were developed. The standards relied on professional credentials and on occupational titles to screen test purchasers. In response to widespread recognition that credentials and titles were inadequate to screen test purchasers, the Test User Qualifications Working Group used 2 job analysis methods to determine test user competencies. This article describes the results of that research that can be applied to improving testing practices, including (a) 86 test user competencies and 7 factors accounting for much test misuse, (b) a test classification system based on critical incidents of test misuse, and (c) empirically based test purchaser qualification forms. These products are designed to help achieve responsible test use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Life‐history traits of three Ambassid fishes (Chanda nama,Parambassis lala and Parambassis ranga) from the Mathabhanga River,southwestern Bangladesh

The present study provides the first indication of the life‐history traits, including, population structure, growth pattern, condition factor, form factor (a_3.0), size at first sexual maturity (L_m), natural mortality (M_W) and optimum catchable length (L_opt), of three Ambassid (Chanda nama, Parambassis lala and Parambassis ranga) fishes from the Mathabhanga River in southwest Bangladesh. A total of 370 individuals were occasionally collected from August 2017 to July 2018 with cast nets, gill nets, square lift nets, and conical‐ and box‐traps. The total length (TL) ranged from 2.4 to 7.5 cm for C. nama, 1.9–3.8 cm for P. lala and 1.8–6.5 cm for P. ranga. The length‐frequency distributions (LFDs) showed the 4.0–5.0 cm TL size group for C. nama and the 3.0–4.0 cm TL size group were numerically dominant for P. lala and P. ranga. The length–weight relationships (LWRs) indicated isometric growth for C. nama, and positive allometric growth for P. lala and P. ranga. All the LWR values were very significant (p < .001), with all r² values > .950. Based on the Spearman rank correlation test, body weight (BW) versus Fulton's‐condition factor (K_F) was extremely correlated (p < .001), indicating a better wellbeing for these species. The a_3.0 value was 0.0082, 0.0138 and 0.0104 for C. nama, P. lala and P. ranga, respectively. Based on the maximum length (L_max), the L_m was 4.4 cm TL for C. nama, 2.5 cm TL for P. lala, and 4.0 cm TL for P. ranga. Based on the asymptotic length (L_∞), the L_m was 4.88 cm TL for C. nama, 2.63 cm TL for P. lala, and 4.28 cm TL for P. ranga. The M_W value was 2.2, 3.3 and 2.7/year for C. nama, P. lala and P. ranga, respectively. The optimum catchable length (L_opt) was 5.36 cm TL for C. nama, 2.75 cm TL for P. lala and 4.65 cm TL for P. ranga. The findings of the present study should be very useful for effective and sustainable management of these fishes in the Mathabhanga River and the connecting ecosystems.     

Psychosocial elements in the work environment of a large call center operation

The author investigates psychosocial factors that prevent early detection of injuries and the effect of late reporting on the long-term health of workers.     

Antioxidant Functions of E- AND Z-Ajoene Derived from Japanese Garlic

Antioxidative activities of E- and Z-ajoene prepared from Japanese garlic were studied using various radical scavenging effects. Among the various antioxidative activities tested, ajoene was found to show the highest hydroxyl radicals scavenging activity (E-ajoene = 50% and Z-ajoene = 63%). These ajoene were 5.2-13 times less efficient at reducing DPPH radical and 1.1-1.4 times less efficient at hydroxyl radical as compared with authentic α–tocopherol. Essentially E- and Z-ajoene were capable of scavenging superoxide anion (E- ajoene = 0.11%, Z-ajoene = 3.74%), but 80 minutes later antioxidant activity could not be detected. The effectiveness of Z-ajoene is significantly higher than E-ajoene.