1,158 research outputs found
Relating Safety and Capacity on Urban Freeways
AbstractThis research sought to investigate the relationship between capacity and safety on freeway roadways in New Jersey. Using the State's roadway database, capacity was estimated for State roadways using the procedures in the Highway Capacity Manual. Crash prediction models were developed relating crashes and crash rates to the geometric variables used to estimate capacity as well as to capacity and v/c ratio. The research showed that as capacity increases the number of crashes and crash rate also increases. As v/c ratio increased the number of crashes and crash rate decreased indicating that congestion may result in reduced speeds and as a result a lower number of crashes and crash rates. The research points to the need to include operational parameters in performing road safety evaluations
Intellectual capital disclosures by South African companies:a longitudinal investigation
Most of the previous studies on intellectual capital disclosures have been conducted from developed countries' context. There is very limited empirical evidence in this area from the context of emerging economies in general and Africa in particular. This paper is one of the early attempts in this regard. The main purpose of this study is to examine the extent and nature of intellectual capitaldisclosures in ‘Top 20’ South African companies over a 5 years period (2002–2006). The study uses content analysis method to scrutinise the patterns of intellectual capital disclosures during the study period. The results show that intellectual capital disclosures in South Africa have increased over the 5 years study period with certain firms reporting considerably more than others. Out of the three broad categories of intellectual capital disclosures human capital appears to be the most popular category. This finding stands in sharp contrast to the previous studies in this area where external capital was found to be most popular category
Use of nasal width to estimate the mesio-distal widths of maxillary anterior teeth in a Kenyan population of African descent
Objective: To investigate the relationship between the nasal width and the mesio-distal widths of the maxillary anterior teeth in Kenyans of African descent.Study design: Descriptive cross-sectional studySetting: College of Health Sciences, University of Nairobi, Kenya. Subjects: One hundred and forty six undergraduate and postgraduate students aged 18-30 years were recruited into the study.Results: Out of the 146 participants, 78 (53.4%) were males and the rest were females. The overallmeannasal width was 39.54 ± 3.61mm with males having significantly higher mean values compared to females (41.37 ± 3.04mm and 37.45 ± 3.05mm respectively), (t=7.75, p<0.05).The mean of the combined mesio-distal width of the anterior teeth (CMDWAT) was 47.68 ± 2.55mm with males having significantly higher mean values (48.12±2.49mm)comparedtothefemales(47.16±2.55mm),(t=2.30,p<0.05).Astatistically significant but weak positive correlation was found between the NW and CMDWAT (r=0.26, r2=0.07, p<0.05).Conclusion: The results suggest a very weak positive correlation between NW and CMDWAT and NW was reliable in estimating the CMDWAT in only 7% of the population. Therefore, NW may not be a reliable guide when used to estimate the CMDWAT in the population studied
Impact of Optimally Minimizing Delay Times on Safety at Signalized Intersections in Urban Areas, Case Study: The City of Virginia Beach
Optimally minimizing delay times at signalized intersections can significantly improve both traffic flow and safety. However, most traffic flow optimizing tools do not measure the effect on safety. This study uses nonlinear programming (NLP) algorithms to optimally minimize delay times and employs both Safety performance functions (SPFs) and empirical Bayes (EB) before-after methodology to measure the impact on safety presented as a Crash Modification Factor (CMF). A crash modification factor (CMF) is a multiplicative factor used by transportation practitioners to compute the expected number of crashes at specific study site(s) after a countermeasure has been proposed or is implemented. Using 2013 traffic data from seventeen signalized intersections located in Virginia Beach, the results show that optimally minimizing intersection delay times can result in a safety improvement of approximately 26.46% that is a CMF of 0.735. This result is not conclusive, but the significance of the findings shows the need for further investigations and potential inclusion in the future editions of the Highway Safety Manual (HSM)
Measuring gender norms about relationships in early adolescence : results from the global early adolescent study
Introduction: Gender norms are increasingly recognized as drivers of health and wellbeing. While early adolescence constitutes a critical window of development, there is limited understanding about how adolescents perceive gender relations across different cultural settings. This study used a mixed-method approach, grounded in the voices of young people around the world, to construct and test a cross-cultural scale assessing the perceptions of gender norms regulating romantic relationships between boys and girls in early adolescence.
Methods: The study draws on the Global Early Adolescent study (GEAS), a study focusing on gender norms and health related outcomes over the course of adolescence in urban poor settings worldwide. In-depth interviews were first conducted among approximately 200 adolescents between 10-14 years in seven sites across 4 continents to identify common scripts guiding romantic relations in early adolescence. These scripts were then transformed into a multidimensional scale. The scale was tested among 120 adolescents in each of 14 GEAS sites, followed by a second pilot among 75 adolescents in six sites. We evaluated the psychometric criteria of each subscale using principal component analysis, and parallel analysis, followed by exploratory factor analysis to guide the selection of a more parsimonious set of items.
Results: Results suggested a two-factor structure, consisting of an "adolescent romantic expectations" subscale and a "Sexual Double Standard" subscale. Both subscales yielded high internal validity in each site, with polychoric Cronbach alpha values above 0.70 with the exception of Kinshasa for the adolescent romantic expectations scale (0.64) and Hanoi for the sexual double standard scale (0.61).
Conclusion: This study reveals common perceptions of gendered norms about romantic engagement in early adolescence, normative for both sexes, but socially valued for boys while devaluated for girls. The findings illustrate that social hierarchies of power in romantic relationships form early in adolescence, regardless of cultural setting
Environmental remediation from heavy metal pollution using polyacrylamide–grafted gum arabic, Moringa oleifera, and blended products of Moringa oleifera and polyacrylamide-grafted gum arabic
Graft copolymers of polyacrlamide-grafted gum arabic were synthesized, blended with Moringa oleifera and characterized by IR spectroscopy. The potentials of the products to remove heavy metals from aqueous solutions were studied at room temperature (30oC) and this was experimented on iron (III) ions (Fe3+). The extent of metal ions removal was determined from sorption capacity values of several sorbents. The results showed that all the polymeric products investigated displayed significant sorption capacities. The abilities of the grafted product polyacrylamide-grafted gum arabic (GA-g-PAAM) to clarify wastewater to a high degree and also remove heavy metals from contaminated water systems, are good indications of the importance of material transformation, especially gum arabic which is hitherto, an emulsifier, and other products of phytoorigin. The sorption capacities of the synthesized and natural products could lead to a blissful expansion of the spectrum of substances that can be used to detoxify our environment through well guided technologies.Keywords: Gum arabic, Moringa oleifera, sorption capacity, sorbent, phyto-products, detoxify, environmen
Preconditioned Visual Language Inference with Weak Supervision
Humans can infer the affordance of objects by extracting related contextual
preconditions for each scenario. For example, upon seeing an image of a broken
cup, we can infer that this precondition prevents the cup from being used for
drinking. Reasoning with preconditions of commonsense is studied in NLP where
the model explicitly gets the contextual precondition. However, it is unclear
if SOTA visual language models (VLMs) can extract such preconditions and infer
the affordance of objects with them. In this work, we introduce the task of
preconditioned visual language inference and rationalization (PVLIR). We
propose a learning resource based on three strategies to retrieve weak
supervision signals for the task and develop a human-verified test set for
evaluation. Our results reveal the shortcomings of SOTA VLM models in the task
and draw a road map to address the challenges ahead in improving them
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