Far Term Noise Reduction Technology Roadmap for a Large Twin-Aisle Tube-And-Wing Subsonic Transport

Interest in unconventional aircraft architectures has steadily increased over the past several decades. However, each of these concepts has several technical challenges to overcome before maturing to the point of commercial acceptance. In the interim, it is important to identify any technologies that will enhance the noise reduction of conventional tube-and-wing aircraft. A technology roadmap with an assumed acoustic technology level of a 2035 entry into service is established for a large twin-aisle, tube-and-wing architecture to identify which technologies provide the most noise reduction. The noise reduction potential of the architecture relative to NASA noise goals is also assessed. The current roadmap estimates only a 30 EPNdB cumulative margin to Stage 4 for this configuration of a tube-and-wing aircraft with engines under the wing. This falls short of reaching even the 2025 Mid Term NASA goal (32 EPNdB) in the Far Term time frame. Specifically, the lack of additional technologies to reduce the aft fan noise and the corresponding installation effects is the key limitation of the noise reduction potential of the aircraft. Under the same acoustic technology assumptions, unconventional architectures are shown to offer an 810 EPNdB benefit from favorable relative placement of the engine when integrated to the airframe

Understanding child and parent perceptions of barriers influencing children’s active school travel

Background Physical activity plays a fundamental role in the health and well-being of children. Walking is the most common form of physical activity and the journey to and from school provides an opportunity for children to be active every day. This study examines how child and parent perceptions of barriers to active school travel influences children’s behaviour. Methods Participants were recruited from 48 elementary schools in Southwestern Ontario, Canada. The study sample includes 1296 children (ages 9–14 years) who live within walking distance of their school, defined as 1.6 km network distance. Chi-square analysis examined differences between child and parent perceptions of barriers to active school travel. Logistic regression models examined how parent and child perceptions of barriers influence active school travel behaviour, while controlling for key intrapersonal, interpersonal, and physical environment factors. Results The results indicate that there are significant differences in how parents and children perceive barriers to active school travel. Model results find older children, children without siblings, households with no vehicles, and children who live closer to school are most likely to use active school travel. Parent perceptions of barriers are found to have a greater influence on children’s active school travel behaviour than children’s perceptions. Different perceptions of barriers influence active school travel to school compared to returning home from school. Conclusions Child and parent perceptions of barriers to active school travel differ and have different impacts on children’s travel behaviour. Understanding how child and parent perceptions of barriers differ can help policymakers and practitioners develop specialized interventions aimed at increasing children’s use of active school travel and children’s overall physical activity. Interventions used to promote active school travel should focus on safety, as well as perceptions of distance to break parental habits of routinely driving their children to school. Overall, this study highlights the importance of considering both child and parent perceptions to create a safe and accessible environment to allow for an increase in active school travel behaviour among elementary school children who live within walking distance of their school

Shortening the trip to school: Examining how children’s active school travel is influenced by shortcuts in London, Canada

For children and youth, the journey to and from school represents a significant opportunity to increase daily levels of physical activity by using non-motorized modes of travel, such as walking and biking. Studies of active school travel have demonstrated that the likelihood a child will walk or bike is significantly influenced by the distance they must travel between home and school, which in turn, is influenced by built environment characteristics such as the configuration of the local road network. This study examines how shortcuts can facilitate active school travel by decreasing the distance children must travel to get to and from school. A geographic information system was used to compare shortest route distances along road networks with and without shortcuts in 32 elementary school zones in London, Ontario, Canada and provide evidence on the effectiveness of shortcuts to facilitate active school travel. This study contributes two key findings: (1) shortcuts have a greater impact in areas with low street connectivity and low population density and (2) children living farther from school are more likely to benefit from shortcuts. The findings suggest that planners should consider the location and maintenance of shortcuts in school neighbourhoods in order to promote increased physical activity, health and well-being among students

Wikidata and knowledge graphs in practice: using semantic SEO to create discoverable, accessible, machine-readable definitions of the people, places, and services in libraries and archives

Libraries expand the access and visibility of data and research in support of an informed public. Search engines have limited knowledge of the dynamic nature of libraries - their people, their services, and their resources. The very definition of libraries in online environments is outdated and misleading. This article offers a solution to this metadata problem by redefining libraries for Machine Learning environments and search engines. Two ways to approach this problem include implementing local structured data in a knowledge graph model and “inside-out” definitions in Semantic Web endpoints. MSU Library has found that implementing a “Knowledge Graph” linked data model leads to improved discovery and interpretation by the bots and search engines that index and describe what libraries are, what they do, and their scholarly content. In contrast, LSE Library has found that contributing to Wikidata, a collaborative and global metadata source, can increase understanding of libraries and extend their reach and engagement. This article demonstrates that Wikidata can be used to push out data, the technical details of knowledge graph markup, and the practice of semantic Search Engine Optimization (SEO). It explores how metadata can represent an organization equitably and how this improves the reach of global information communities

The role of tundra vegetation in the Arctic water cycle

Thesis (Ph.D.) University of Alaska Fairbanks, 2019Vegetation plays many roles in Arctic ecosystems, and the role of vegetation in linking the terrestrial system to the atmosphere through evapotranspiration is likely important. Through the acquisition and use of water, vegetation cycles water back to the atmosphere and modifies the local environment. Evapotranspiration is the collective term used to describe the transfer of water from vascular plants (transpiration) and non-vascular plants and surfaces (evaporation) to the atmosphere. Evapotranspiration is known to return large portions of the annual precipitation back to the atmosphere, and it is thus a major component of the terrestrial Arctic hydrologic budget. However, the relative contributions of dominant Arctic vegetation types to total evapotranspiration is unknown. This dissertation addresses the role of vegetation in the tundra water cycle in three chapters: (1) woody shrub stem water content and storage, (2) woody shrub transpiration, and (3) partitioning ecosystem evapotranspiration into major vegetation components. In Chapter 1 I present a method to continuously monitor Arctic shrub water content. The water content of three species (Salix alaxensis, Salix pulchra, Betula nana) was measured over two years to quantify seasonal patterns of stem water content. I found that spring uptake of snowmelt water and stem water storage was minimal relative to the precipitation and evapotranspiration water fluxes. In Chapter 2, I focused on water fluxes by measuring shrub transpiration at two contrasting sites in the arctic tundra of northern Alaska to provide a fundamental understanding of water and energy fluxes. The two sites contrasted moist acidic shrub tundra with a riparian tall shrub community having greater shrub density and biomass. The much greater total shrub transpiration at the riparian site reflected the 12-fold difference in leaf area between the sites. I developed a statistical model using vapor pressure deficit, net radiation, and leaf area, which explained >80% of the variation in hourly shrub transpiration. Transpiration was approximately 10% of summer evapotranspiration in the tundra shrub community and a possible majority of summer evapotranspiration in the riparian shrub community. At the tundra shrub site, the other plant species in that watershed apparently accounted for a much larger proportion of evapotranspiration than the measured shrubs. In Chapter 3, I therefore measured partitioned evapotranspiration from dominant vegetation types in a small Arctic watershed. I used weighing micro-lysimeters to isolate evapotranspiration contributions from moss, sedge tussocks, and mixed vascular plant assemblages. I found that mosses and sedge tussocks are the major constituents of overall evapotranspiration, with the mixed vascular plants making up a minor component. The potential shrub transpiration contribution to overall evapotranspiration covers a huge range and depends on leaf area. Predicted increases in shrub abundance and biomass due to climate change are likely to alter components of the Arctic hydrologic budget. The thermal and hydraulic properties of the moss and organic layer regulate energy fluxes, permafrost stability, and future hydrologic function in the Arctic tundra. Shifts in the composition and cover of mosses and vascular plants will not only alter tundra evapotranspiration dynamics, but will also affect the significant role that mosses, their thick organic layers, and vascular plants play in the thermodynamics of Arctic soils and in the resilience of permafrost.National Science Foundation (NSF Arctic Natural Sciences award number 1418123), fellowship from the Graduate School of the University of Alaska and the National Institutes of Water ResearchGeneral introduction -- Chapter 1: Deciduous shrub stem water storage in Arctic Alaska -- Chapter 2: Transpiration and environmental controls in Arctic tundra shrub communities -- Chapter 3: Weighing micro-lysimeters used to quantify dominant vegetation contributions to evapotranspiration in the Arctic -- General conclusion

An economic impact comparative analysis of farmers’ markets in Michigan and Ontario

Farmers\u27 markets play a vital role in local economic development by providing a site for local and small business incubation, creating an economic multiplier effect to neighboring businesses, and recycling customer dollars within the community. While several studies have evaluated characteristics of farmers\u27 markets within single metropolitan areas, few have compared the impact of multiple markets in socioeconomically contrasting regions. This research compares shopping habits and economic impacts of customers at farmers\u27 markets in two North American cities: Flint, Michigan, and London, Ontario. Overall, 895 market visitors completed surveys. We conducted statistical and spatial analyses to identify differences between these markets. Though geographically proximate and similar in metropolitan size, the two cities differ greatly in recent economic development, social vitality, and public health indicators. The objectives of this article are to quantify the impact that each market has on its local economy and contextualize these impacts in light of the place-specific attributes of each market. Results indicate that customers come from a mix of urban and suburban locations, but that key urban areas do not draw a substantial share of customers. Marketing efforts in nearby disadvantaged neighborhoods, therefore, might yield new customers and increase multiplier effects within the neighborhoods. The London market drew slightly younger customers who shopped less frequently, while the Flint market drew an older crowd that attended more regularly. This may be attributable to the relative age of the markets, and certainly reflects the marketing push of each market\u27s managers. Given the opportunity to compare similarities and differences, much can be learned from each market in terms of opportunities for marketing, local economic development, and increased community vitality

Understanding factors associated with children achieving recommended amount of MVPA on weekdays and weekend days

Low levels of moderate-to-vigorous physical activity (MVPA) are consistently reported for children from industrialized countries. Perennially inadequate levels of MVPA have been linked to increased chronic disease risks. Very few studies have compared physical activity levels among children from geographically diverse places, and how they differ on weekdays versus weekends. The purpose of this research is to examine the factors that influence whether children achieve 60 min of MVPA on weekdays compared to weekend days. Data were analyzed on children (n = 532) aged 8–14 years from communities in Southern and Northern Ontario, Canada that participated in the study between 2009 and 2016. Children\u27s MVPA was measured using an Actical accelerometer, environmental features measured with a geographic information system, and demographic data came from child/parent surveys. Variables were selected using a least absolute shrinkage and selection operator. The variables were entered into logistic regression models to assess the relationship between children meeting the MVPA guidelines. During the week, boys were more active than girls (OR = 4.652 p \u3c 0.001) and as age increased children were less likely to reach the MVPA guidelines (OR = 0.758 p = 0.013). On weekends boys were still more likely to meet the guidelines (OR = 1.683 p = 0.014) and children living in rural Northern Ontario were more likely to reach the MVPA guidelines compared to all groups in Southern Ontario. The findings indicate that different variables influence whether children meet the MVPA guidelines on weekdays compared to weekends. Comparing weekdays and weekends provides more useful information for creating effective MVPA interventions

Convenience sampling of children presenting to hospital-based outpatient clinics to estimate childhood obesity levels in local surroundings

Childhood obesity is a critical public health matter associated with numerous pediatric comorbidities. Local-level data are required to monitor obesity and to help administer prevention efforts when and where they are most needed. We hypothesized that samples of children visiting hospital clinics could provide representative local population estimates of childhood obesity using data from 2007 to 2013. Such data might provide more accurate, timely, and cost-effective obesity estimates than national surveys. Results revealed that our hospital-based sample could not serve as a population surrogate. Further research is needed to confirm this finding

Dataset Search: A lightweight, community-built tool to support research data discovery

Objective: Promoting discovery of research data helps archived data realize its potential to advance knowledge. Montana State University (MSU) Dataset Search aims to support discovery and reporting for research datasets created by researchers at institutions. Methods and Results: The Dataset Search application consists of five core features: a streamlined browse and search interface, a data model based on dataset discovery, a harvesting process for finding and vetting datasets stored in external repositories, an administrative interface for managing the creation, ingest, and maintenance of dataset records, and a dataset visualization interface to demonstrate how data is produced and used by MSU researchers. Conclusion: The Dataset Search application is designed to be easily customized and implemented by other institutions. Indexes like Dataset Search can improve search and discovery for content archived in data repositories, therefore amplifying the impact and benefits of archived data

Parents’ report of canadian elementary school children’s physical activity and screen time during the COVID-19 pandemic: A longitudinal study

COVID-19 public health protocols have altered children’s daily routines, limiting their physical activity opportunities. The purpose of this study was to examine how the COVID-19 pandemic affected children’s (ages 10–12 years) physical activity and screen time, and to explore the impact of gender, socioeconomic status (SES), and public health constraints (i.e., facility use and social interaction) on the changes in children’s health behaviors. Online surveys were disseminated to parents at two time points: before COVID-19 (May 2019 to February 2020) and during COVID-19 (November to December 2020). Wilcoxon signed-rank tests were used to assess changes in physical activity and screen time, and for subgroup analyses. Parents (n = 95) reported declines in children’s physical activity (Z = −2.53, p. = 0.01, d = 0.18), and increases in weekday (Z = −4.61, p \u3c 0.01, d = 0.33) and weekend screen time (Z = −3.79, p \u3c 0.01, d = 0.27). Significant changes in physical activity and screen time behaviors were identified between gender, SES, and facility use groups. All social interaction groups underwent significant changes in screen time. Overall, COVID-19 protocols have negatively influenced children’s physical activity and screen time. Due to the negative consequences of inactivity and excessive screen time, resources must be made available to support families during the pandemic