• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 842
  • 433
  • 244
  • 154
  • 117
  • 26
  • 24
  • 18
  • 14
  • 14
  • 13
  • 11
  • 10
  • 10
  • 7
  • Tagged with
  • 2452
  • 369
  • 339
  • 249
  • 212
  • 209
  • 193
  • 155
  • 148
  • 133
  • 130
  • 117
  • 113
  • 112
  • 109
  • 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.
231

Parameter estimation and auto-calibration of the STREAM-C model

Sinha, Sumit 07 May 2005 (has links)
The STREAMC model is based on the same algorithm as implemented by the Steady Riverine Environmental Assessment Model (STREAM), a mathematical model for the dissolved oxygen (DO) distribution in freshwater streams used by Mississippi Department of Environmental Quality (MDEQ). Typically the water quality models are calibrated manually. In some cases where some objective criterion can be identified to quantify a successful calibration, an auto calibration may be preferable to the manual calibration approach. The auto calibration may be particularly applicable to relatively simple analytical models such as the steady-state STREAMC model. Various techniques of parameter estimation were identified for the model. The model was then subjected to various techniques of parameter estimation identified and/or developed. The parameter estimates obtained by different techniques were tabulated and compared. A final recommendation regarding a preferable parameter estimation technique leading to the auto calibration of the STREAMC model was made.
232

Bayesian Models for Computer Model Calibration and Prediction

Vaidyanathan, Sivaranjani 08 October 2015 (has links)
No description available.
233

AN AUTOMATIC CALIBRATION STRATEGY FOR 3D FE BRIDGE MODELS

LIU, LEI 05 October 2004 (has links)
No description available.
234

Integrated Computational Microstructure Engineering for Single-Crystal Nickel-base Superalloys

Wang, Billie January 2008 (has links)
No description available.
235

A Comparison of the GiViTI Calibration Belt to Hosmer-Lemeshow Goodness of Fit

Wasserman, Jared Robert 16 August 2012 (has links)
No description available.
236

Photogrammetric self-calibration of a scanning electron microscope /

Maune, David F. January 1973 (has links)
No description available.
237

Advanced System Monitoring with Phasor Measurements

Zhou, Ming 20 June 2008 (has links)
Phasor Measurement Units (PMUs) are widely acknowledged as one of the most promising developments in the field of real-time monitoring of power systems. By aligning the time stamps of voltage and current phasor measurements that are consistent with Coordinated Universal Time (UTC), a coherent picture of the power system state can be achieved through either direct measurements or simple linear calculations. With the growing number of PMUs planned for installation in the near future, both utilities and research institutions are looking for the best solutions to the placement of units as well as to the applications that make the most of phasor measurements. This dissertation explores a method for optimal PMU placement as well as two applications of synchronized phasor measurements in state estimation. The pre-processing PMU placement method prepares the system data for placement optimization and reduces the size of the optimization problem. It is adaptive to most of the optimal placement methods and can save a large amount of computational effort. Depth of un-observability is one of the criteria to allow the most benefit out of a staged placement of the units. PMUs installed in the system provide synchronized phasor measurements that are highly beneficial to power system state estimations. Two related applications are proposed in the dissertation. First, a post-processing inclusion of phasor measurements in state estimators is introduced. This method avoids the revision of the existing estimators and is able to realize similar results as mixing phasor data with traditional SCADA with a linear afterwards step. The second application is a method to calibrate instrument transformers remotely using phasor measurements. Several scans of phasor measurements are used to accomplish estimating system states in conjunction with complex instrument transformer correction factors. Numerical simulation results are provided for evaluation of the calibration performance with respect to the number of scans and load conditions. Conducting theoretical and numerical analysis, the methods and algorithms developed in this dissertation are aimed to strategically place PMUs and to incorporate phasor measurements into state estimators effectively and extensively for better system state monitoring. Simulation results show that the proposed placement method facilitates approaching the exact optimal placement while keep the computational effort low. Simulation also shows that the use of phasor measurement with the proposed instrument transformer correction factors and proposed state estimation enhancement largely improves the quality of state estimations. / Ph. D.
238

Internal Radioactive Source Calibration of the Borexino Solar Neutrino Experiment

Back, Henning Olling 29 September 2004 (has links)
A measurement of solar neutrinos below 1 MeV of energy will further our knowledge of the neutrino's mass and mixing properties and will provide a probe to possible physics beyond the standard model of particle physics, as well as advance our understanding of energy production in the Sun. Borexino is a liquid scintillator detector that will measure the neutrino energy spectrum to the lowest energy threshold to date. It has been designed to measure the flux of the mono-energetic neutrinos produced by electron capture on 7Be in the Sun's core, which will produce a Compton-like edge in the energy spectrum. Because of the low count rate, Borexino requires extremely low backgrounds, and a good understanding of the backgrounds that do exist. Although the purification techniques used for the scintillator lowered the radioactive contaminates to levels never before achieved, cuts must still be made to the data. At Virginia Tech, we have developed an internal source calibration program that will be able to give us a thorough understanding of both the pulse shape discrimination efficiency and the energy and time response of Borexino. Energy calibration for alphas, betas, and gammas (energy scales) can be accomplished with such sources. When the calibration source is used in conjunction with an accurate source location system any spatial dependencies can be found. The system will use different types of sources at various energies to give the required information to make the cuts needed to extract believable physics from the detector. / Ph. D.
239

Emotional Intelligence in Consumer Behavior: Ability, Confidence and Calibration as Predictors of Performance

Kidwell, Blair L. 10 May 2004 (has links)
The focus of this research is to examine the impact of emotional intelligence on consumer decision making. Several research goals are presented: 1) to develop and test a practical domain-specific scale of emotional ability, 2) to identify the influence of emotional ability on behavioral individual and group level performance in a consumer context, 3) and to identify how performance is further influenced by cognitive ability, cognitive and emotional confidence and calibration between perceived (i.e., confidence) and actual ability. Three studies were conducted to meet these goals. Study 1 involved the development and validation of a consumer emotional ability scale (CEAS), based on four underlying emotional abilities (i.e., perceiving, facilitating, understanding, managing). This instrument allowed for further examination of how emotional intelligence affected performance among consumer relationships. A proposed conceptual model was examined in an individual (study 2) and small group (study 3) context using the CEAS scale, along with additional items to assess the influence of cognitive ability, cognitive and emotional confidence, and calibration on performance in the consumer domain of healthy food choices. / Ph. D.
240

Robust remote measurement calibration

Ghassemian, Alireza 24 March 2009 (has links)
The objective of Remote Measurements Calibration (RMC) method is to minimize systematic errors through an appropriate scaling procedure. A new method for RMC has been developed. This method solves the problems of observability, multiplicity of solutions, and ambiguity of reference points associated with the already existing method proposed by Adibi et al. [6-9]. The new algorithm uses the concepts of the simulated annealing and the matroid tree to identify and minimize the number of RTUs (Remote Terminal Units) required to observe the system. After field calibration, these RTUs provide measurements that are used to estimate the whole state of the system. These estimates are then returned as a reference for remote calibrating the remaining RTUs. The calibration coefficients are estimated by means of the Least Median of Squares (LMS) estimator. The procedure results in the reduction of the cost associated with field calibration. / Master of Science

Page generated in 0.096 seconds