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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.
301

Cosmological applications of multi-grid methods

Green, Andrew David January 2000 (has links)
No description available.
302

Development and Refinement of New Products from Multi-angle Remote Sensing to Improve Leaf Area Index Retrieval

Pisek, Jan 03 March 2010 (has links)
Remote sensing provides methods to infer vegetation information over large areas at a variety of spatial and temporal resolutions that is of great use for terrestrial carbon cycle modeling. Understory vegetation and foliage clumping in forests present a challenge for accurate estimates of vegetation structural information. Multi-angle remote sensing was used to derive and refine new information about the vegetation structure for the purpose of improving global leaf area index mapping. A field experiment with multi-angle, high resolution airborne observations over modified and natural backgrounds (understory, moss, litter, soil) was conducted in 2007 near Sudbury, Ontario to test a methodology for the background reflectivity retrieval. The experiment showed that it is feasible to retrieve the background information, especially over the crucial low to intermediate canopy density range where the effect of the understory vegetation is the largest. The tested methodology was then applied to background reflectivity mapping over conterminous United States, Canada, Mexico, and Caribbean land mass using space-borne Multi-angle Imaging SpectroRadiometer (MISR) data. Important seasonal development of the forest background vegetation was observed across a wide longitudinal and latitudinal span of the study area. The previous first ever global mapping of the vegetation clumping index with a limited eight-month multi-angular POLDER 1 dataset was expanded by integrating new, complete year-round observations from POLDER 3. A simple topographic compensation function was devised to correct negative bias in the data set cause by topographic effects. The clumping index reductions can reach up to 30% from the topographically non-compensated values, depending on terrain complexity and land cover type. The new global clumping index map is compared with an assembled set of field measurements, covering four continents and diverse biomes. Finally, inclusion of the new vegetation structural information, including background reflectivity and clumping index, gained from the multi-angle remote sensing was then shown to improve the performance of LAI retrieval algorithms over forests.
303

Ultrasound to CT Registration of the Lumbar Spine: a Clinical Feasibility Study

Nagpal, Simrin 19 August 2013 (has links)
Spine needle injections are widely applied to alleviate pain and to remove nerve sensation through anesthesia. Current treatment is performed either blindly having no image guidance or using fluoroscopy or computed tomography (CT). Both CT and fluoroscopy guidance expose patients to ionizing radiation. Alternatively, ultrasound (US) guidance for spine needle procedures is becoming more prevalent since US is a non-ionizing and more accessible image modality. An inherent challenge to US imaging of the spine is the acoustic shadows created by the bony structures of the vertebra limiting visibility. It is challenging to use US as the sole imaging modality for intraoperative guidance of spine needle injections. However, it is possible to enhance the anatomical information through a preoperative diagnostic CT. To achieve this, image registration between the CT and the US images is proposed in this thesis. Image registration integrates the anatomical information from the CT with the US images. The aligned CT augments anatomical visualization for the clinician during spinal interventions. To align the preoperative CT and intraoperative US, a novel registration pipeline is presented that involves automatic global and multi-vertebrae registration. The registration pipeline is composed of two distinct phases: preoperative and intraoperative. Preoperatively, artificial spring points are selected between adjacent vertebrae. Intraoperatively, the lumbar spine is first aligned between the CT and US followed by a multi-vertebrae registration. The artificial springs are used to constrain the movement of the individually transformed vertebrae to ensure the optimal alignment is a pose of the lumbar spine that is physically possible. Validation of the algorithm is performed on five clinical patient datasets. A protocol for US data collection was created to eliminate variability in the quality of acquired US images. The registration pipeline was able to register the datasets from initial misalignments of up to 25 mm with a mean TRE of 1.17 mm. From these results, it is evident that the proposed registration pipeline offers a robust registration between clinical CT and US data. / Thesis (Master, Computing) -- Queen's University, 2013-08-19 12:50:54.521
304

The modification of natural occuring polymers for the removal of heavy metal ions

Runacres, Selwyn Mark January 2000 (has links)
No description available.
305

Personality assessment of three species of captive monkey, Macaca nigra, Macaca sylvanus, and Saimiri sciureus : cross-species comparisons of personality and implications for captive management

Baker, Kathy January 2012 (has links)
The study of animal personality, i.e. consistent individual differences in animal behaviour, is a rapidly growing research field. The construct of personality has been studied in many different scientific disciplines including ethology, behavioural ecology, psychology, animal management and physiology. Studying personality using a comparative framework is important for establishing whether phylogeny and/or ecology are a driving force in personality development. The applied use of personality assessments to aid captive animal management could also have far reaching ramifications, as recent studies have demonstrated that personality has relationships with variables such as health, welfare and breeding success. Within the animal personality literature three main methods of assessing personality have been developed: i) coding behavioural data under natural conditions, ii) coding animals’ responses during novelty tests and iii) rating animals on sets of behaviourally defined traits. In the current study personality was investigated in three primate species, Sulawesi black crested macaques (Macaca nigra), barbary macaques (Macaca sylvanus) and common squirrel monkeys (Saimiri sciureus). The two macaque species are closely related, being from the same genus, but show some differences in their ecology and behaviour while S. sciureus are phylogentically distinct but exhibit some similarities to the two macaque species in certain aspects of their ecology and behaviour. The aims of the study were twofold: i) establish whether phylogeny or socioecology has an impact on the development of personality structure by comparing the study species with other primate species, and ii) evaluate the use of personality assessments as a tool for the management of the study species in captivity. Personality was assessed using the trait rating method. Questionnaires consisting of 38 personality traits, with accompanying definitions, were sent to all European institutions holding any of the study species. Keepers were required to rate animals on each trait using a 1 – 7 interval scale. Personality assessments were tested for inter-observer reliability. For each species a Principal Components Analysis (PCA) was carried out using only traits that exhibited good inter-observer reliability and scores for animals on each of the resulting components (personality dimensions) were calculated. Construct validity of the personality dimensions was assessed by evaluating the relationships between personality dimension scores and, i) behaviour under natural conditions, and ii) behaviour during a novel object test. In order to assess the management implications of personality assessments further analyses were carried out using the personality dimension data, i) a MANOVA was used to assess whether personality dimension scores were affected by Zoo, Age and Sex, ii) Generalised Linear Mixed Models (GLMMs) were used to assess which, if any, specific Zoo variables effect mean personality scores, iii) multiple regression and ANOVA analyses were carried out to establish whether personality dimension scores could predict breeding variables in M. nigra, iv) parent-offspring regressions were used to assess the heritability of personality dimensions in M. nigra, and v) correlation and General Linear Model (GLM) analyses were used to assess whether personality dimension scores effected behavioural measures of enrichment use in aM. nigra group. Twenty four traits in M. nigra (N= 64), 25 traits in M. sylvanus (N= 62) and 18 traits in S. sciureus (N= 69)were rated reliably by human observers. When reliable traits were entered into a PCA for each species, results revealed three personality dimensions for M. nigra, Sociability, Dominance, and Emotionality; four personality dimensions for M. sylvanus, Sociability, Dominance, Emotionality and Human-Animal Sociability (HA-Sociability); and three personality dimensions for S. sciureus, Sociability, Dominance, and Cautiousness. Construct validity of each species personality ratings, in terms of relationships with observable behaviour, was demonstrated for each species. Validity was affected by contextual variables such as Zoo, Age and Sex, which, as personality can vary with the variables (see below) was to be expected. MANOVA results showed that the variable ‘Zoo’ had significant effects on personality dimension scores in all three species. Further investigation using GLMMs revealed that i) in M. nigra mean Sociability scores were higher in groups with a lower mean age, ii) in S. sciureus mean Sociability scores were higher in groups where keepers had a high mean experience (months) working with the animals, and iii) again in S. sciureus mean Cautiousness scores were higher in groups with a small total group size. Multiple regression showed that personality dimension scores could not predict breeding success variables in either male or female M. nigra individuals. Of the three variables that could affect the breeding success of a male/female partnership, Male, Female and Zoo, only Male identity significantly affected breeding success but this could not be assessed against personality.Of the three M. nigra personality dimensions only one, Sociability, appears to have a heritable component. There were no significant correlations between personality dimension scores of individual M. nigra and measures of enrichment use across a range of enrichment devices. Repeated measures GLM revealed that while the individuals did spend significantly different amounts of time interacting with each of the enrichment devices this did not vary as a function of either repetition number or personality. When comparing the three study species with other primate species, the Sociability and Dominance dimensions were comparable with previous research on non-human primates (NHP), except that aggressive-type traits found in other studies were not present in the Dominance dimension in M. nigra and M. sylvanus. This may be attributed to data suggesting they have more tolerant social systems compared to other primate species. The Emotionality dimension was similar across the two macaque species and was comparable to analogous dimensions in other NHP species. The Cautiousness dimension in S. sciureus was found to be similar to dimensions such as fearfulness and bold/shy in other NHP species. The HA-Sociability dimension found in M. sylvanus could not be compared with other primate studies as, to date, there has been limited investigation of human-directed personality dimensions in captive primates. Quantitative analyses using partial Mantel tests were conducted to evaluate if either phylogenetic similarity or similarity in socioecological variables significantly correlated with similarities in personality structure for 11 primate species (including the three study species). The results of this analysis were inconclusive as neither phylogenetic similarity nor socioecological similarity had a significant correlation with personality similarity. However the effect of socioecology was approaching significance, indicating that, selection pressures related to socioecology may play an important role in shaping personality structure but further data collection on a wider range of species is needed to explore these relationships further. In terms of the management of the study species in the current study, it was demonstrated that the captive environment, particularly the social environment and human-animal relationships (HARs), has a significant impact on personality and so personality could prove to be a valuable management tool. Breeding success of M. nigra could not be predicted by personality and this could be an indicator that M. nigra actually adapt to life in captivity relatively well compared to some other species.
306

An Open Software Architecture for UNIX Based Data Acquisition/Telemetry Systems

Dawson, Daniel 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / Veda Systems Incorporated has recently completed the development of a completely open architecture, UNIX-based software environment for standard telemetry and more generic data acquisition applications. The new software environment operates on many state-of-the-art high-end workstations and provides a workstation independent, multiuse platform for front-end system configuration, database management, real-time graphic data display and data, logging.
307

The Short and Long-Run Impacts of the Financial Crisis on the Allocation of Air Passenger Traffic in Multi-Airport Regions

Li, Yuexi 01 January 2017 (has links)
As one of the most important economic sectors, the air-traveling industry was severely affected by the 2007 to 2008 financial crisis. However, the crisis did not affect entities (airports and airlines) with different market shares of passenger traffic equally. This paper implements regression models to explore key determinants of how the market shares of large entities evolve to get a better understanding of the allocation of air passenger traffic in multi-airport regions, both in the short and long-run post crisis (2009- 2015). Results from this paper show that the pre-crisis share and the traffic change on the set of routes being considered have significant effects on the change of share for large airport and airline entities in multi-airport regions. The large entities’ normalized change in share is higher if the pre-crisis share is higher an/or if total traffic fasslWe also find that low-cost carrier (LCC) large airlines gain more from the crisis than non-LCC airlines, and large airports from regions that have more than two airports have larger changes in market shares during and post crisis. In evaluating the long-term persistence of effects from the demand shock in the market, we observe that explanatory variables for airports tend to have lasting effects on the shares of large airports.
308

The Multi-Functionality of Professional and Business Associations in a Transitional Context: Empirical Evidence from Russia

Ivanova, Ekaterina, Neumayr, Michaela January 2017 (has links) (PDF)
In the literature it is generally assumed that activities of voluntary membership based associations operating in stable institutional environments are multi-faceted, contributing simultaneously to societal, economic and political spheres. This article, drawing on the concept of functions of non-profit organizations investigates, whether the multi-functional character of associations holds true in the context of transitional Russia. The paper examines the relative importance of the advocacy, community building and service delivery functions, fulfilled by different types of associations. The original empirical data from exploratory interviews with 15 leading experts on associational activities was triangulated by a confirmatory survey of 215 associations across Russia. The results confirm that the absolute majority of the examined associations are multifunctional. Advocacy is considered to be the most important function for all types of associations. The findings suggest that business associations and intermediary unions are more active in policy advocacy directed toward the government, while liberal professional societies are more engaged in public advocacy addressing society at large. This study highlights importance of domestic associations for countries in transition as an institutional infrastructure of organized civil society, democratic development and market economy.
309

Design and implementation of robotic end-effectors for a prototype precision assembly system

Schöndorfer, Sebastian January 2016 (has links)
Manufacturers are facing increasing pressure to reduce the development costs and deployment times for automated assembly systems. This is especially true for a variety of precision mechatronic products. To meet new and changing market needs, the difficulties of integrating their systems must be significantly reduced. Since 1994, the Microdynamic Systems Laboratory at Carnegie Mellon University has been developing an automation framework, called Agile Assembly Architecture (AAA). Additionally to the concept, a prototype instantiation, in the form of a modular tabletop precision assembly system termed Minifactory, has been developed. The platform, provided by the Minifactory and AAA, is able to support and integrate various precision manufacturing processes. These are needed to assemble a large variety of small mechatronic products. In this thesis various enhancements for a second generation agent-based micro assembly system are designed, implemented, tested and improved. The project includes devising methods for tray feeding of precision high-value parts, micro fastening techniques and additional work on visual- and force-servoing. To help achieving these functions, modular and reconfigurable robot end-effectors for handling millimeter sized parts have been designed and built for the existing robotic agents. New concepts for robot end effectors to grasp and release tiny parts, including image processing and intelligent control software, were required and needed to be implemented in the prototype setup. These concepts need to distinguish themselves largely from traditional handling paradigms, in order to solve problems introduced by electrostatic and surface tension forces, that are dominant in manipulating parts that are millimeter and less in size. In order to have a modular system, the factory the main part of this project was the initialization and auto calibration of the different agents. The main focus, of this research, is on improving the design, deployment and reconfiguration capabilities of automated assembly systems for precision mechatronic products. This helps to shorten the development process as well as the assembly of factory systems.  A strategic application for this approach is the automated assembly of small sensors, actuators, medical devices and chip-scale atomic systems such as atomic clocks, magnetometers and gyroscopes.
310

Multi-level multi-scaled metabolites simulation

Li, Hao January 2016 (has links)
Diabetes is a world-wide health problem with 415 millions of people suffering from the disease. Most diabetics are suffering from Type 2 Diabetes, which is preceded by insulin resistance in glucose utilizing tissues, such as adipose, liver, and muscle tissues. Diabetes is diagnosed when the insulin control of the glucose levels fails, which leads to high glucose levels in the blood. To better understand the insulin control of blood glucose, mathematical modeling has been used for many years to simulate the dynamics of glucose and insulin levels in the blood. Models have also been used to understand the intracellular insulin-signaling network in the insulin responding tissues. There have also been attempts to connect models from these different layers of control into a multi-level and multi-scale simulation model. However, to do such connections, several assumptions must be made about the comparability of the data from the different levels. Here, I aim for a deeper understanding of these assumptions and to use more advanced data for glucose uptake dynamics than in earlier work. I used data from the literature for the dynamics of glucose uptake in adipose and muscle tissues and improve the model in several steps to have a better agreement with these data. In particular, I refined the sub-division of the glucose uptake between the organs, to also account for liver uptake, a correction that implied a reduction by 50% for the muscle and adipose tissue glucose uptake. Unlike previous models, the updated model also describes blood flow. Finally, because of the connection to the intracellular level, the model can be used to simulate the response to anti-diabetic drugs.

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