Objective: To predict shoulder belt fit and lap belt fit as a function of child age, vehicle seat characteristics, and belt geometry.
Methods: In a previous study, the lap belt and shoulder belt fit of 44 children aged 5–12 were measured in a simulated vehicle seat while varying cushion length, cushion angle, seatback angle, and belt anchorage geometry. A regression model was developed to predict lap belt fit and shoulder belt fit as a function of vehicle parameters and child stature. These regression models were applied to the stature distribution of 6- to 12-year-olds using a range of vehicle geometry data to predict the proportion of children expected to achieve good belt fit in the second-row, outboard seating positions of 46 vehicles when not using belt-positioning boosters.
Results: Across the ranges observed in vehicles, lap belt angle had the strongest effect on lap belt fit, although vehicle cushion length also contributed. Shoulder belt fit was most strongly affected by D-ring location. Vehicles with the geometric conditions most suitable for children are estimated to provide good lap belt fit for 25% of children aged 6 to 12. In 20% of vehicles, the shoulder belt is too far inboard for the target child population; 20% of vehicles are estimated to have shoulder belt fit too far outboard for children ages 6 to 12.
Conclusions: Based on this geometric analysis, the rear seats of most vehicles are unlikely to provide good lap belt fit for up to 75% of children ages 6–12. Shoulder belt fit is outside the target range for 40% of children. Consequently, children under 12 years of age are likely to experience markedly poorer belt fit when transitioning out of a booster seat. 相似文献
Population viability analysis (PVA) is widely used to assess population‐level impacts of environmental changes on species. When combined with sensitivity analysis, PVA yields insights into the effects of parameter and model structure uncertainty. This helps researchers prioritize efforts for further data collection so that model improvements are efficient and helps managers prioritize conservation and management actions. Usually, sensitivity is analyzed by varying one input parameter at a time and observing the influence that variation has over model outcomes. This approach does not account for interactions among parameters. Global sensitivity analysis (GSA) overcomes this limitation by varying several model inputs simultaneously. Then, regression techniques allow measuring the importance of input‐parameter uncertainties. In many conservation applications, the goal of demographic modeling is to assess how different scenarios of impact or management cause changes in a population. This is challenging because the uncertainty of input‐parameter values can be confounded with the effect of impacts and management actions. We developed a GSA method that separates model outcome uncertainty resulting from parameter uncertainty from that resulting from projected ecological impacts or simulated management actions, effectively separating the 2 main questions that sensitivity analysis asks. We applied this method to assess the effects of predicted sea‐level rise on Snowy Plover (Charadrius nivosus). A relatively small number of replicate models (approximately 100) resulted in consistent measures of variable importance when not trying to separate the effects of ecological impacts from parameter uncertainty. However, many more replicate models (approximately 500) were required to separate these effects. These differences are important to consider when using demographic models to estimate ecological impacts of management actions. 相似文献
Cinema offers a substantial opportunity to share messages with a wide audience. However, there is little research or evidence about the potential benefits and risks of cinema for conservation. Given their global reach, cinematic representations could be important in raising awareness of conservation issues and species of concern, as well as encouraging greater audience engagement due to their heightened emotional impact on viewers. Yet there are also risks associated with increased exposure, including heightened visitor pressure to environmentally sensitive areas or changes to consumer demand for endangered species. Conservationists can better understand and engage with the film industry by studying the impact of movies on audience awareness and behavior, identifying measurable impacts on conservation outcomes, and engaging directly with the movie industry, for example, in an advisory capacity. This improved understanding and engagement can harness the industry's potential to enhance the positive impacts of movies featuring species, sites, and issues of conservation concern and to mitigate any negative effects. A robust evidence base for evaluating and planning these engagements, and for informing related policy and management decisions, needs to be built. 相似文献
This paper is a case study which describes the application of game-theoretic approach in resource management with specific
emphasis on developing optimal strategies of phosphorus applications for soil fertilisation. The approach adopted allows resource
managers to consider not only competitive strategies, which were treated as the Nash equilibrium game solutions, but also
strategies which imply cooperation between farmers. These strategies were modelled as the cooperative Pareto optima of the
game. The objective function of the game has been developed in order to reflect both economic advantages of phosphorus applications
and the environmental losses associated with these applications expressed as dollar values. The paper presents algorithms
for finding competitive and cooperative solutions of the game for the particular case when no time scheduling is included
in the game parametrisation. The results obtained in the paper showed that the cooperative solutions lead to much lesser environmental
impacts than that in the case of non-cooperative strategies. 相似文献
Environmental Fluid Mechanics - The generation and evolution of tidally-induced vortices in coastal and estuarine regions can influence water quality and sedimentary processes. These effects must... 相似文献
For a variety of technical and conceptual reasons, biologists have come to use several different methods to quantify the colors
of animals. However, the relative abilities of these different color-scoring procedures to capture variation in the actual
color-generating mechanisms—pigment or structural composition of the integument—have never been tested systematically. Here,
we examined which commonly employed color metrics predict carotenoid content of ornaments in three avian species (house finch
Carpodacus mexicanus, mallard duck Anas platyrhynchos, and zebra finch Taeniopygia guttata). We used spectrophotometry to measure reflectance spectra from beak and feather tissue, calculated numerous color metrics
(e.g., hue, chroma, brightness, principal components, and tetrahedral color space position) from these spectra, and determined
carotenoid content at the site of color measurement with high-performance liquid chromatography. We found that several principal
component, tristimulus, and avian visual model metrics significantly correlated with carotenoid content of house finch feathers
and duck beaks. Carotenoid content of mallard beaks was most closely correlated with brightness and saturation metrics, whereas
in house finch feathers, carotenoid concentration was best captured by hue and saturation metrics. According to tristimulus
scores and visual models, we found that the ultraviolet portion of the spectrum was not an essential predictor of variation
in carotenoid content. Also, visual model chromatic contrasts generally were not significant predictors of carotenoid content,
although some achromatic contrasts and tetrahedral color space vector parameters were. Our results indicate that numerous
methods, especially tristimulus scores, are suitable for capturing pigment-based color variation in two carotenoid-containing
ornaments, and we discuss the merits and shortcomings of these different approaches. In contrast, there were no significant
relationships between any color metrics and the carotenoid content of zebra finch beaks, suggesting that other color-generating
mechanisms besides carotenoids may contribute to color variability in this species. 相似文献