Parent’s self-reported indoor environment-related symptoms and health worry increase symptom reports among their children at school—Study in two independent populations

Little is known whether parent's indoor environment quality (IEQ)-related symptoms or health perceptions influence the risk of self- or parent-reported symptoms in their children. We assessed (i) the association of parents’ IEQ-related symptoms with IEQ-related symptoms in their children at school and (ii) whether parental IEQ-related health worry increases the risk for children's symptoms. We used two Finnish studies: a national, population-based survey of indoor air and related health problems (n = 611 parents) and a subset of survey for all primary school pupils (grade 3–6) and their parents in Helsinki, which also included school IEQ-related symptoms reported by children (n = 1617 parent-child dyads). In the school survey, parent's own symptoms increased strongly their reporting of their children's symptoms at school (aOR 4.0, 95% CI 2.7–6.0 for parents experiencing a lot of symptoms) and also symptoms reported by the child itself (aOR 2.2, 95% CI 1.5–3.1). Similar, but slightly weaker associations were seen with parental IEQ-related health worries. Results remained unchanged when adjusted for the IEQ of school buildings or parental and children's allergic diseases. Similar associations were seen in the national survey between parent's symptoms at work and child's symptoms at school. The results suggest that parents’ health perceptions may increase the reporting of children's IEQ-related symptoms even more than is typically seen for many indoor air contaminants.     

Greenhouse impact assessment of peat-based Fischer–Tropsch diesel life-cycle

New raw materials for transportation fuels need to be introduced, in order to fight against climate change and also to cope with increasing risks of availability and price of oil. Peat has been recognised suitable raw material option for diesel produced by gasification and Fischer–Tropsch (FT) synthesis. The energy content of Finnish peat reserves is remarkable. In this study, the greenhouse impact of peat-based FT diesel production and utilisation in Finland was assessed from the life-cycle point of view. In 100 year's time horizon the greenhouse impact of peat-based FT diesel is likely larger than the impact of fossil diesel. The impact can somewhat be lowered by producing peat from the agricultural peatland (strong greenhouse gas emissions from the decaying peatlayer are avoided) with new peat production technique, and utilising the produced biomass from the after-treatment area for diesel also. If diesel production is integrated with pulp and paper mill to achieve energy efficiency benefits and if the electricity demand can be covered by zero emission electricity, the greenhouse impact of peat-based FT diesel reduces to the level of fossil diesel when agricultural peatland is used, and is somewhat higher when forestry-drained peatland is used as raw material source.     

A prognostic method for the embedded failure monitoring of solder interconnections with 1149.4 test bus architecture

This paper describes the feasibility of accurate low frequency measurements in predicting the breakdown of modern lead free ball grid array (BGA) interconnections. In these measurements, performed partly with 1149.4 analogue boundary scan, ceramic BGA modules measuring 15×15 mm in width, with 9×9 ball matrixes, were attached on an FR-4 printed wiring board (PWB) and thermally cycled over a temperature range of −40 to +125 °C. The condition of corner interconnections was monitored using the developed measurement methods and construction. In-situ measurements were performed with a datalogger during temperature cycling, accompanied with 1149.4 mixed-signal test bus measurements of corner interconnections performed between cycling intervals. In addition, the measurements were complemented by scanning acoustic microscopy and, X-ray. Monitoring corner interconnections by a simple, low-frequency voltage measurement method with embedded test constructions gives an early warning indication well before the electrical interconnection failures. Of two studied interconnection compositions, the ones with plastic core solder balls (PCSB) proved to be more reliable than the ones with 90/10 PbSn balls.     

Strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye

We demonstrate a strong coupling between surface plasmon polaritons and Sulforhodamine 101 dye molecules. Dispersion curves for surface plasmon polaritons on samples with a thin layer of silver covered with Sulforhodamine 101 molecules embedded in SU-8 polymer are obtained experimentally by reflectometry measurements and compared to the dispersion of samples without molecules. Clear Rabi splittings, with energies up to 360 and 190 meV, are observed at the positions of the dye absorption maxima. The split energies are dependent on the number of Sulforhodamine 101 molecules involved in the coupling process. Transfer matrix and coupled oscillator methods are used to model the studied multilayer structures with a great agreement with the experiments. Detection of the scattered radiation after the propagation provides another way to obtain the dispersion relation of the surface plasmon polaritons and, thus, provides insight into dynamics of the surface plasmon polariton/dye interaction, beyond the refrectometry measurements.PACS: 42.50.Hz, 33.80.-b, 78.67.-n     

Imputation of single-tree attributes using airborne laser scanning-based height, intensity, and alpha shape metrics

Forest inventories based on single-tree interpretation of airborne laser scanning (ALS) data often rely on an allometric estimation chain in which inaccuracies in the estimates of the diameter at breast height (DBH) propagate to other characteristics of interest such as the stem volume. Our purpose was to test nearest neighbor imputation by the k-Most Similar Neighbor (k-MSN) and the Random Forest (RF) methods for the simultaneous estimation of species, DBH, height and stem volume using ALS data. The predictors included computational alpha shape metrics and variables based on the height and intensity distributions in the ALS data. Separate data sets covering 1898 and 1249 dominant to intermediate trees in a typical Scandinavian stand structure were used for training and validation, respectively. RF proved to be a flexible method with an ability to handle 1846 predictors with no need for their reduction. Classification of Scots pine, Norway spruce and deciduous trees showed an accuracy of 78%, and the estimates of DBH, height and volume had root mean square errors of 13%, 3%, and 31%, respectively, when evaluated against the validation data. The two selection strategies implemented here reduced the number of candidate variables effectively without any substantial effect on the accuracy relative to the use of all predictors. Differences in k-MSN and RF imputations were marginal when the reduced sets of variables were used. Estimation accuracies could be maintained practically unchanged with only 12.5% of the initial reference data (237 trees), provided the distribution of the observations was similar in the reference and target data. Since we used information collected in the field for extracting the ALS point clouds for individual trees, our results represent an optimal case and should nevertheless be validated against automated tree delineation.     

Methods for quantitative usability requirements: a case study on the development of the user interface of a mobile phone

Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed.

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Complex-valued ICA based on a pair of generalized covariance matrices

It is shown that any pair of scatter and spatial scatter matrices yields an estimator of the separating matrix for complex-valued independent component analysis (ICA). Scatter (resp. spatial scatter) matrix is a generalized covariance matrix in the sense that it is a positive definite hermitian matrix functional that satisfies the same affine (resp. unitary) equivariance property as does the covariance matrix and possesses an additional IC-property, namely, it reduces to a diagonal matrix at distributions with independent marginals. Scatter matrix is used to decorrelate the data and the eigenvalue decomposition of the spatial scatter matrix is used to find the unitary mixing matrix of the uncorrelated data. The method is a generalization of the FOBI algorithm, where a conventional covariance matrix and a certain fourth-order moment matrix take the place of the scatter and spatial scatter matrices, respectively. Emphasis is put on estimators employing robust scatter and spatial scatter matrices. The proposed approach is one among the computationally most attractive ones, and a new efficient algorithm that avoids decorrelation of the data is also proposed. Moreover, the method does not rely upon the commonly made assumption of complex circularity of the sources. Simulations and examples are used to confirm the reliable performance of our method.     

Optimism and Pessimism as Predictors of Change in Health After Death or Onset of Severe Illness in Family.

The authors prospectively examined changes in health after a major life event (death or onset of severe illness in family) among 5,007 employees (mean age=44.8 years) whose optimism and pessimism levels were assessed in 1997 and major life events in 2000. Health was indicated by sickness absence days during a period covering 36 months prior to the event and 18 months after the event. Increase in sick days after the event was smaller and returned to the preevent level more quickly among highly optimistic individuals than among their counterparts with low optimism. Parallel changes were not observed in relation to pessimism. These findings suggest that optimism may reduce the risk of health problems and may be related to a faster recovery after a major life event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flexible view recognition for indoor navigation based on Gabor filters and support vector machines

Real-world scenes are hard to segment into (relevant) objects and (irrelevant) background. In this paper, we argue for view-based vision, which does not use segmentation, and demonstrate a practical approach for recognizing textured objects and scenes in office environments.

A small set of Gabor filters is used to preprocess texture combinations from input images. The impulse responses of the filters are transformed into feature vectors that are fed to support vector machines. Pairwise feature comparisons decide the classification of views.

We validate the approach on a robot platform using three different types of target objects and indoor scenes: people, doorways, and written signs. The general-purpose system can run in real time, and that recognition accuracies of practical utility are obtained.