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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

New Large Neighborhood Interior Point Methods For Semidefinite Optimization

Li, Yang January 2008 (has links)
<p>In this thesis, we extend the Ai-Zhang direction to the class of semidefinite optimization problems. We define a new wide neighborhood N(τ1 ,τ2 ,η) and, as usual, we utilize symmetric directions by scaling the Newton equation with special matrices. After defining the "positive part" and the "negative part" of a symmetric matrix, we solve the Newton equation with its right hand side replaced first by its positive part and then by its negative part, respectively. In this way, we obtain a decomposition of the usual Newton direction and use different step lengths for each of them.</p><p>Starting with a feasible point (X^0 , y^0 , S^0) in N(τ1, τ2 , η ), the algorithm terminates in at most 0(η√( κ∞n)log(1/ε) iterations, where κ∞ is a parameter associated with the scaling matrix and ε is the required precision. To our best knowledge, when the parameter η is a constant, this is the first large neighborhood path-following Interior Point Method (IPM) with the same complexity as small neighborhood path-following IPMs for semidefinite optimization that use the Nesterov-Todd direction. In the case when η is chosen to be in the order of √η, our complexity bound coincides with the known bound for classical large neighborhood IPMs.</p><p>To make this thesis more accessible to readers who are new in this area, we start with a brief introduction to IPMs and SDO. The basic concepts and principles of IPMs and SDO are presented in Chapter 2 and 3.</p> / Thesis / Master of Applied Science (MASc)
242

Individual, home and neighborhood factors related to childhood obesity intervention

Silva, Fabiana Brito 29 June 2016 (has links)
Obesity is one of the most pressing global population health issues, and importantly one that affects racial/ethnic minorities and those of low socioeconomic status disproportionately. Obesity tracks from childhood into adulthood and is related to serious medical and economic consequences throughout the life course. Childhood obesity is well recognized as a complex and multifaceted problem influenced by broader social, geographic and environmental factors. A social ecological framework that is transdisciplinary is needed to address individual-level influences and choices that lead to energy imbalance, but also to address the complex interactions among home and neighborhood environmental features that provide the context for health-related behavior change. The overall goal of this dissertation is to investigate multilevel factors that could influence outcomes of an intervention program aimed at addressing childhood obesity. Including studies that investigated the use of clear communication strategies to facilitate parents comprehension, home media environment related to change in children weight status and the neighborhood environmental context of families. This dissertation draws upon a social ecological model that acknowledges multiple levels of human interaction with the environment and represents a comprehensive approach to designing, implementing and evaluating interventions that which target multiple influences on health behaviors. The iChoose is a 3-month family-based childhood obesity treatment program developed under a community-based participatory research approach led by the Partnering for Obesity Planning and Sustainability (POPS) Community Advisory Board (CAB). The studies within this dissertation use clear communication evaluation and qualitative feedback from focus groups, intervention outcome data and home environmental surveys, as well as environmental audits of neighborhoods. To investigate multilevel factors could influence intervention outcomes, we used both multiple statistical analytical techniques and a Geographic Information System (GIS) spatial analysis to evaluate the iChoose program. / Ph. D.
243

Lenses of Connectivity: Adapting the Impact of Urban Highways on American Cities

Hayes, Andrew Michael 30 September 2016 (has links)
Once thriving neighborhoods in mid-sized American cities have been decimated, scarred and disrupted by the serpentine free form highways that have touched them. This product of technological innovation from the 1950s and 60s has had a profound and disturbing affect upon American cities. The collective history, cultural rituals and organic urban fabric of life has been almost completely extinguished in these cities by the false opportunity and instant gratification that comes with so-called 'technological progress.' This, yes this, epitomizes the urban core of a majority of cities across the United States early in the early 21st century. What is to be the future legacy of these American cities upon the life of their residents? It quickly became apparent that to develop a deep understanding of this urban challenge, it was going to be necessary to carefully examine cites that have been acutely affected by urban highways. The neighborhoods at the core of these damaged American cities trudge on'.. Why? Because they have no other option'. The question currently at hand is how can these damaged neighborhoods adjacent to urban highways, and their associated cities, be regenerated? The research phase of this thesis exposed four critical elements of a thriving and organic urban neighborhood; connectivity, realness, livability and performativity. I was encouraged to focus upon and explore this notion of connectivity by my thesis committee, as it represents the element offering the most agency for the design professions. Through interrogating the [dis]connectivity of four specific neighborhoods in Baltimore, Buffalo, Richmond and St Petersburg certain operational systems began to evolve. These systems center around three critical lenses of focus; the economic, social and physical operations that occur within and adjacent to an urban neighborhood. Due to its acute condition, the Gilpin neighborhood of Richmond, Virgina was chosen as a case study to employ the lenses of connectivity through close examination and intervention. / Master of Science
244

The NIMBY Syndrome and Low-Cost Manufactured Housing Developments: Can Landscape Architecture Help Overcome Community Opposition?

Bean, Janet L. 31 March 2004 (has links)
Decent housing available to the working class in America is in very short supply. Manufactured housing could help to meet this basic need. But community groups and politicians often reject manufactured housing because they fear it will have a negative impact upon property values and the aesthetic character of their community. This thesis examines the reasons behind these fears, how the history of manufactured housing has fed into these fears and what design elements can allay these fears. Three site planning typologies are developed using the factors found in the research, that create a good neighborhood for both the residents and outside observers. The typologies inform three designs that illustrate how manufactured housing developments can be designed to fit compatibly into existing communities. / Master of Landscape Architecture
245

Tolerance of Diversity, Collective Efficacy, and Criminal Victimization on a College Campus

Spradlin, Jamie Lynn 15 August 2006 (has links)
Victimization and hate crimes are becoming more prominent on America's college campuses. Indeed, nearly 20,000 crimes of violence, and over 600 hate crimes, occurred on and around university campuses in 2003 (Department of Education 2004). Given its inverse relationship to crime at the aggregate level, (Sampson et al 1997), one possible means of reversing this trend would be to increase levels of collective efficacy across U.S. campuses. The purpose of this research is to determine if an individual's tolerance of diversity is related to their willingness to intervene in criminal or potentially criminal situations. That is, is tolerance of diversity related to collective efficacy at Virginia Tech? The research on collective efficacy is based on neighborhood level variables. This research, conducted in the "neighborhood" of Virginia Tech, focuses on collective efficacy and tolerance of diversity at the individual level. This research is unique in that it fills gaps in existing literature; to date, no research has analyzed the potential causes of collective efficacy at the individual level. Participants in this study will be asked to complete a survey regarding issues of diversity, tolerance and integration, and sense of belonging to community. The results will then be analyzed in order to gain some insight into this phenomenon. The main questions that will be explored in this research are: Does an individual's sense of belonging to his or her community and tolerance of diversity lead to their willingness to intervene if they see someone doing something wrong? That is, is sense of belonging to community and tolerance of diversity related to collective efficacy? Routine Activities Theory and studies of Collective Efficacy will be used to explore these questions. / Master of Science
246

A change in perspective: new priorities for neighborhood design in Johnson County, Kansas

Vogel, David L. January 1900 (has links)
Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Timothy D. Keane / The fundamental purpose of this project, a suburban infill endeavor in southern Overland Park, Kansas, is to create connections on a number of levels and scales through the implementation of traditional neighborhood design principles within the context of the natural and man-made conditions affecting the site. Beginning at the smallest scale, the project examines what kinds of conditions are best suited for connecting people to one another within the site itself in terms of circulation networks, outdoor public spaces, civic uses, and the relationships of buildings and blocks. On a larger scale, the project explores methods for creating connections between the site and the wider community, both locally and regionally, through the integration of trail systems, land uses, and road networks. It also examines the principles for designing a mixed-use component intended to draw people from a wide geographic area and to serve as a center of activity for residents and visitors alike because of its distinctive qualities. Finally, the project examines principles for creating connections between people and the natural environment through the preservation of existing stream corridors, drainage channels, and woodlands and the restoration of the prairie systems that once characterized the land. Instead of sitting in isolation and addressing only the needs of its own residents while turning its back on adjacent land uses and the wider community, the project utilizes a design that directly engages that community through the full integration of its program elements. Traditional neighborhood design principles are therefore best applied not as a formula but rather as a flexible framework for the design components that define the form of the project. Ultimately the project seeks to achieve its goals and objectives not by simply replicating previous efforts but by developing and applying its own creative design solutions.
247

Drought, pollen and nectar availability, and pollination success

Waser, Nickolas M., Price, Mary V. 06 1900 (has links)
Pollination success of animal-pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar "neighborhoods" of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per-flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.
248

Milneburg, New Orleans: An Anthropological History of a Troubled Neighborhood

Smallwood, Betty A. 17 December 2011 (has links)
For nearly 200 years, there has been a neighborhood in New Orleans, Louisiana named Milneburg, which has been constantly reimagined by its inhabitants and others. From its inception as a port of entry in 1832 until the 2011, it has been called a world-class resort, the poor-man's Riviera, a seedy red-light district, a cradle of jazz, a village, a swath of suburbia and a neighborhood. It has been destroyed eight times due to storms, fires, and civic or governmental neglect. Each time its residents have rebuilt it. In its last iteration as a post-Katrina neighborhood, the residents reestablished the Milneburg Neighborhood Association in order to define its boundaries, gain control of its redevelopment and restrict who lived there as well as what activities were permitted. This is a case study of the trajectory of Milneburg and the cultural adaptations of its residents to keep it distinct, vital and respectable.
249

Evaluer les éco-quartiers : analyses comparatives internationales / Assessing sustainable neighborhoods : international comparative analysis

Doussard, Claire 01 December 2017 (has links)
Les éco-quartiers contribuent, depuis la fin du XXe siècle, à l'essor d'un modèle de ville durable à travers le monde. Cependant, si les grands principes théoriques du développement durable font relativement consensus à l'échelle internationale, les modalités de leur application au niveau local sont multiples et diverses. Suite à ce constat, de nombreux acteurs déploient dès la fin des années 2000 des référentiels de suivi et d'évaluation des éco-quartiers. Ces derniers permettent d'orienter la conception et la construction des quartiers durables tout en justifiant les choix retenus, et ce grâce à la mesure de leur performance selon plusieurs critères consensuels et mesurables dans le temps. Ces référentiels, conçus à l'échelle locale et souvent standardisés, sont en outre susceptibles d'être exportés à l'international, indépendamment du milieu naturel et culturel dans lequel ils s'appliquent. Ceci représente un paradoxe vis à vis du concept de développement durable qui promeut l'intégration des projets à un territoire spécifique. Aussi, le travail de thèse interroge l'impact des référentiels d'évaluation sur l'intégration territoriale des éco-quartiers au travers de l'analyse de trois études de cas en France, aux Etats-Unis et au Brésil: Clichy Batignolles localisé à Paris et labellisé EcoQuartier, Melrose Commons développé à New York et certifié LEED-ND, et llha Pura construit à Rio de Janeiro à la fois certifié LEED-ND et AQUA -HQE-A. Notre étude examine également succinctement un quatrième cas, le quartier de Vinhomes Riverside ayant reçu le prix de l'architecture ve1te du Vietnam et construit à Hanoï, dont l'étude n'a pu être complètement aboutie faute d'accès à des données essentielles à notre analyse. Nous énonçons le postulat qu'il existe des divergences entre les objectifs de performance fixés par le référentiel, ceux exigés par les acteurs du projet menant à une évaluation donnée, et enfin la réalité de l'éco-quartier une fois construit au sein d'un territoire plus large. Ces divergences sont particulièrement fortes en cas d'export du référentiel. Elles sont en outre mesurables et témoignent de différences de niveau d'intégration. Aussi, notre recherche s'appuie sur la comparaison des cas selon trois phases à savoir: 1) le choix du référentiel 2) l'évaluation du projet d'éco-quartier par le référentiel dont il estime la performance, et enfin 3) le résultat opérationnel, c'est à dire l'éco­quartier construit. La méthodologie de recherche est multidisciplinaire et déploie des outils associés aux statistiques, à l'ingénierie du territoire, à la géographie, mais aussi à l'analyse architecturale, urbaine et paysagère. Nous observons que les référentiels s'appuient sur diverses stratégies relatives à la sélection et à la mesure d'indicateurs permettant de planifier l'intégration du quartier au sein d'un territoire donné. Cette intégration est néanmoins extrêmement variable non seulement en fonction des critères et des échelles d'analyse choisis, mais aussi des jeux d'acteurs qui adaptent leur démarche aux spécificités d'un site. Les référentiels d'évaluation occultent alors la complexité, et sous-estiment la richesse de la diversité des éco-quartiers contemporains. / Since the end of the 20th century, eco-neighborhoods have contributed to the international development of a sustainable city paradigm. However, while the concept of sustainable development is today the result of an international consensus, its urban applications at the local level are multiple and diverse. Following this observation, many stakeholders have designed neighborhood sustainability assessment tools (NSAT) in the past ten years. The latter contribute to the design and construction of sustainable neighborhoods while justifying stakeholders choices. Those tools also measure the eco-neighborhood performance, using several consensual and measurable criteria over time. Moreover, NSA T which are locally designed and often standardized, are likely to be exported internationally. However, internationally exporting a NSAT designed locally is paradoxical, in relation to sustainable development principles. Our research examines the impact of NSAT on eco-neighborhoods' territorial integration. It analyses three case studies located in France, the United States and Brazil. Clichy Batignolles was developed in Paris and received the EcoQuartier label. Melrose Commons was built in New York and is LEED-ND certified. Ilha Pura is located in Rio de Janeiro, and is both LEED-ND and AQUA-HQE-A certified. Our study also briefly examines a fow1h case. Vinhomes Riverside was built in Hanoi, and received the Vietnam Green Architecture Award. However, our analysis could not be completed due to the Jack of access to essential data. From the data we do have, we extrapolate that there are discrepancies between the objectives set by the NSA T, those requested by the project's stakeholders leading to a given assessment, and finally the reality of the built eco­neighborhood. These discrepancies are more important when the NSA T has been exported. They are also measurable, and enlighten different levels of projects' territorial integration. Our research is based on the comparison of the cases. This comparison is following three steps: 1) analyzing the chosen NSA T 2) studying the eco-neighborhood performance score and 3) analyzing the built project. Our methodology is multidisciplinary and uses tools related to statistics, territorial engineering, geography, and architectural, urban and landscape analysis. We conclude that NSAT use various strategies related to the selection and measurement of indicators to integrate a neighborhood within a given territory. However, this integration is extremely variable. This is not only due to criteria and scale selection, but also to stakeholders who adapt their strategies to their territory. Finally, NSAT conceals urban complexities, and underestimates the diversity of contemporary eco-neighborhoods.
250

The Impact of Mother–Father Relationship, Social Support and Neighborhood Context on Preterm Birth

Ihongbe, Timothy O. 01 January 2018 (has links)
Background: Preterm birth is a major public health concern in the US. Previous studies have suggested that quality of the mother-father relationship, social support, and neighborhood violence may be associated with preterm birth; however, findings are equivocal. Objectives: The main objectives of this dissertation were: 1) to determine the modifying effect of perceived residential environment on the association between quality of mother–father relationship and preterm birth in a sample of African-American women, 2) to examine whether the receipt of social support modifies the association between neighborhood violence exposure and preterm birth in a nationally representative sample of US women, and 3) to determine the extent to which neighborhood violence mediates the association between neighborhood deprivation and preterm birth in a geographic cohort of women in Richmond city, Virginia. Methods: Data were obtained from three sources – 1) Life-course Influences on Fetal Environments (LIFE) study, 2) National Longitudinal Study of Adolescent to Adult Health, and 3) live birth records, police crime reports and census data for Richmond city, Virginia. Multivariable log-binomial regression models were used to examine the modifying effect of perceived residential environment on the association between quality of mother–father relationship and preterm birth, as well as the modifying effect of social support on the association between neighborhood violence exposure and preterm birth. Multilevel structural equation modeling was used to examine the mediational influence of neighborhood violence on the association between neighborhood deprivation and preterm birth. Results: For the association between neighborhood violence exposure and preterm birth, maternal receipt of social support modified the association [(Tertile 1: adjusted prevalence ratio (APR)=1.12; 95% CI=1.11-1.13, p<.0001); (Tertile 2: APR=1.07; 95% CI=1.06-1.08, p<.0001); and (Tertile 3: APR=0.88; 95% CI=0.86-0.89, p<.0001)] in a nationally representative sample of US women. No significant interaction was observed between any domain of the mother–father relationship and perceived maternal residential environment (all p > 0.05) in a sample of African American women. Additionally, no significant association was found between the quality of mother–father relationship and preterm birth (Trust domain: APR=1.03, 95% CI=0.99-1.07; dependability domain: APR=1.01, 95% CI=0.98-1.06; criticism domain: APR=1.03, 95% CI=0.99-1.07). The association between neighborhood deprivation and preterm birth in a geographic cohort of women in Richmond city, Virginia, was not mediated by neighborhood violence (β=0.063, 95% CI= –0.025, 0.151). Conclusions: Rates of preterm birth in women exposed to neighborhood violence may be improved by providing adequate social support during the pregnancy period. Insufficient evidence was found to support the modifying effect of perceived residential environment on the association between the mother-father relationship and preterm birth, as well as the mediational effect of neighborhood violence on the association between neighborhood deprivation and preterm birth. Future studies are needed to confirm these findings.

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