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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.
71

Learning Physical Descriptions from Functional Definitions, Examples, and Precedents

Winston, Patrick H., Binford, Thomas O., Katz, Boris, Lowry, Michael 01 November 1982 (has links)
It is too hard to tell vision systems what things look like. It is easier to talk about purpose and what things are for. Consequently, we want vision systems to use functional descriptions to identify things when necessary, and we want them to learn physical descriptions for themselves, when possible. This paper describes a theory that explains how to make such systems work. The theory is a synthesis of two sets of ideas: ideas about learning from precedents and exercises developed at MIT and ideas about physical description developed at Stanford. The strength of the synthesis is illustrated by way of representative experiments. All of these experiments have been performed with an implemented system.
72

How Hot or Cool is It to Speak Two Languages: Executive Function Advantages in Bilingual Children

Weber, Rachel Christiane 2011 August 1900 (has links)
According to the 2009 U.S. Census Bureau, approximately 57 million individuals, ages five and older, living in the United States spoke a language other than English at home. There is a clear and growing number of bilingual individuals and English Language Learners (ELL) in the United States. With these growing numbers, especially within the school-aged population, it is crucial that a clear understanding exist regarding the development of children who are bilingual or learning English as their second language. There is evidence that bilingual children differ from their monolingual peers in the development of executive function (EF), and specifically demonstrate some advantages on EF tasks. This research has not been expanded to include the new conceptualization of EF as hot and cool. This study seeks to examine bilingual EF advantages in EF in light of this recent conceptualization. A second goal of this study is to identify other psychosocial variables that predict EF in children and, thus, might impact its development. The variables of interest include socioeconomic status (SES), economic stress, parenting practices (e.g., disciplinary practices and relational frustration), and cultural beliefs (e.g., individualism/collectivism). A sample of 67 bilingual and monolingual English speaking children and their parents/guardians participated in this study. Children completed 4 EF tasks and parents completed a battery which included measures of the psychosocial variables and the BRIEF Parent Form. A MANCOVA model was utilized to examine bilingual differences in EF. Multiple regression models were also used to test for significant predictors of hot and cool EF and general EF (as measured by the BRIEF GEC) among the psychosocial variables. No significant group differences were found in multivariate analyses. Significant predictors of specific EF measures and hot and cool total scores were identified, including economic stress, age, relational frustration, vertical individualism, and vertical collectivism. These are discussed in light of current literature and clinical applications.
73

Investigating Structure in Turing Categories

Vinogradova, Polina 05 January 2012 (has links)
The concept of a computable function is quite a well-studied one, however, it is possible to capture certain important properties of computability categorically. A special type of category used for this purpose is called a Turing category. This thesis starts with a brief overview of Turing categories, followed by a study of additional categorical structure they may contain, based on the types of structure found in the world of computable functions, and how this is reflected in the underlying combinatorial structures.
74

Investigating Structure in Turing Categories

Vinogradova, Polina 05 January 2012 (has links)
The concept of a computable function is quite a well-studied one, however, it is possible to capture certain important properties of computability categorically. A special type of category used for this purpose is called a Turing category. This thesis starts with a brief overview of Turing categories, followed by a study of additional categorical structure they may contain, based on the types of structure found in the world of computable functions, and how this is reflected in the underlying combinatorial structures.
75

Characterizing the Immune Function of the Brown Bullhead (Ameiurus nebulosus) from Less Contaminated and Highly Contaminated Locations along the Detroit River

Robinson, Kevin January 2011 (has links)
Some fish populations are able to adapt and thrive in contaminated habitats. Survival of populations depends on the ability of the organism to elicit resistance, either due to genetic adaptation or physiological acclimations. Brown Bullheads (Ameiurus nebulosus) are able to survive in very contaminated areas and their benthic and philopatric characteristics make them a model organism to study chronic exposure. This research assesses the immune function of brown bullhead collected at four pre-determined sites along the Detroit River, which are characterized by high or low concentrations of environmental toxicants. Clean and contaminated sediment used for contaminant exposure was collected by ponar at designated sites of the river. The bullheads were vaccinated with heat-killed V. anguillarum in order to induce an immune response, before the vaccinated bullheads were randomly divided into corresponding contaminant exposure tanks. Respiratory burst assays to assess innate oxygen radical production 24hrs post vaccination and sediment exposure identified an inhibition of neutrophil oxidative activity in adult 6 month cleared of contaminant bullheads collected from a clean (Peche Island) site exposed to contaminated sediment, and of F1 raised populations from a contaminated (Trenton Channel) site. Results also showed overall inhibition on contaminated sediment in both PI and TC recently captured fish. Enzyme linked immunosorbant assay (ELISA) to assess antibody production revealed no difference between those fish exposed to either sediment. Results did show a lower expression of total antibody in chronically contaminant exposed bullheads (acute adults). Real time PCR to assess immune gene expression was conducted using cloned Major Histocompatibility Class II Beta (MHIIB), Interleukin-8 (IL-8) and Interleukin-1 Beta (IL-1B) 24hr post vaccination and sediment exposure. No contaminant induced immunosuppression of MHIIB was observed, while a reduction in IL-8 and IL-1B in acute adults may signify a delayed response due to chronic sediment exposure or of a normal functioning delayed response in wild bullheads. Results of the present study indicate negative environmental impacts on the innate immune response, leading to physiological adaptations in the brown bullhead, which can be reversed upon removal of the contaminants.
76

Mutual Diffusion of Poly(4-vinylpyridine) in Chloroform Probed by Quasielastic Light Scattering

Chen, Kuo-Wei 01 July 2004 (has links)
A light scattering study of dilute solutions consisting of poly(4-vinylpyridine) dissolved in chloroform has been carried out. Chloroform is a good solvent for P4VP. Dynamic light scattering measurements show only a diffusion mode in the intensity autocorrelation function for freshly prepared solutions, but two modes are present as the solution ages. The two modes found in P4VP/CHCl3 solution both show a clear q dependence, q being the magnitude of the scattering wave vector, thus indicating that both are diffusive modes. For this system, the diffusion coefficient is found to be mainly determined by the osmotic modulus, with the solution stress modulus making a negligible contribution. A decrease of mutual diffusion coefficient with increasing polymer concentration is observed. As the temperature of the solution is lowered, the mutual diffusion coefficient decreases linearly. Extrapolation of the mutual diffusion coefficient to zero yields the critical temperature, at which the P4VP/CHCl3 solution undergoes a phase transition.
77

Design of 3D Object with Implicit function on Pocket PC

Chiang, Chien-hsien 13 October 2004 (has links)
In this thesis, we develops a Pocket PC-based 3D object design system using implicit functions, which allows users to design and view 3D objects easily at anytime and anywhere. With the growing wireless techniques, Pocket PC can easily connect to the Internet via WLAN, GPRS, WCDMA, etc. The problems of insufficient computing power caused by the limited hardware on Pocket PCs can be solved by the client-server model, which performs complex computation on the workstation, and transmit polygon mesh data to the Pocket PC. Via the proposed system, one can design and visualize his any innovative ideas instantly wherever he is.
78

Replication of Influenza B Virus: Biological Functions of Viral Neuraminidase

MAENO, KOICHIRO 25 March 1994 (has links)
No description available.
79

The dependence of the sticking property of aC gas-phase atom on C(100) on the initial velocity

Sun, Chen-Cheng 08 July 2002 (has links)
Abstract We have performed ab initio molecular-dynamics (MD) calculations for the dependence of the sticking property of a C gas-phase atom ( ) on C(100) on the initial velocity. We have considered initial velocities of 0.0082, 0.0117 and 0.0185 . The largest velocity considered corresponds to a kinetic energy of 0.2142 eV, which is comparable with the chemisorption energy of an order of 1eV. For the three initial velocities considered, can settle on C(100) easily. The relatively quick settlement of even with a large initial velocity can be attributed to an efficient transfer of kinetic energy from to the H atom. We also find that the higher initial velocity, the deeper penetrates into the substrate, which renders to stay closer to the impact position.
80

A Study of Signal Model Building for Optical Transfer Function

Wu, Jhong-yang 11 September 2008 (has links)
Kalman filter addresses an estimation problem defined by two models: the signal model and the observation model. In this thesis, the signal model is obtained from a ratio of the defected and clean pictures in frequency domain. The observation model is built for an additive measurement noise from electronic sampling. The statistics of the generating noise for the signal model is important in Kalman filtering. The focus of this thesis is to derive the variance of the generating noise in the middle band for the signal model. By this derived variance, the Kalman filter is thus possible to be applied to estimate the optical transfer function for a defected imaging system in the future.

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