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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.
81

Error Propagation Dynamics of PIV-based Pressure Field Calculation

Pan, Zhao 01 May 2016 (has links)
Particle Image Velocimetry (PIV) based pressure field calculation is becoming increasingly popular in experimental fluid dynamics due to its non-intrusive nature. Errors propagated from PIV results to pressure field calculations are unavoidable, and in most cases, non-negligible. However, the specific dynamics of this error propagation process have not been unveiled. This dissertation examines both why and how errors in the experimental data are propagated to the pressure field by direct analysis of the pressure Poisson equation. Error in the pressure calculations are bounded with the error level of the experimental data. The error bounds quantitatively explain why and how many factors (i.e., geometry and length scale of the flow domain, type of boundary conditions) determine the resulting error propagation. The reason that the type of flow and profile of the error matter to the error propagation is also qualitatively illustrated. Numerical and experimental validations are conducted to verify these results. The results and framework introduced in this research can be used to guide the optimization of the experimental design, and potentially estimate the error in the reconstructed pressure field before performing PIV experiments.
82

Algorithms for analysis of GSM phones’ modulation quality / Algoritmer för analys av GSM-telefoners modulationskvalitet

Carlstedt, Tobias January 2009 (has links)
No description available.
83

Limitations of Geometric Hashing in the Presence of Gaussian Noise

Sarachik, Karen B. 01 October 1992 (has links)
This paper presents a detailed error analysis of geometric hashing for 2D object recogition. We analytically derive the probability of false positives and negatives as a function of the number of model and image, features and occlusion, using a 2D Gaussian noise model. The results are presented in the form of ROC (receiver-operating characteristic) curves, which demonstrate that the 2D Gaussian error model always has better performance than that of the bounded uniform model. They also directly indicate the optimal performance that can be achieved for a given clutter and occlusion rate, and how to choose the thresholds to achieve these rates.
84

Convicting the innocent : when justice goes wrong /

Rattner, Arye. January 1983 (has links)
Thesis (Ph. D.)--Ohio State University, 1983. / Includes vita. Includes bibliographical references (leaves 212-219). Available online via OhioLINK's ETD Center.
85

The Effects of Viewing Angle on the Acquisition, Retention and Recognition of a Complex Dance Sequence

Smith, Jenna 30 January 2013 (has links)
The benefits of observing a model when acquiring a new motor skill are well known, however, there is little research on the influence of viewing angle of the model. The purpose of the present experiment was to assess whether a looking-glass (face on) or subjective (facing away) viewing angle would result in different acquisition and retention levels when learning a complex Zumba dance sequence. Greater cognitive effort was expected during the looking-glass condition, consequently resulting in slower acquisition but greater physical performance scores and error recognition/identification. Thirty females were evenly divided into the looking-glass or subjective group and began with the pre-test phase to assess degrees of motivation, self-efficacy, and physical performance. Participants were then lead through six acquisition dances, within which they performed the to-be-learned sequence 18 times. An assessment of cognitive effort followed, then post-test performances and error recognition/identification scores were obtained to conclude the study. While both the looking-glass and subjective conditions demonstrated equal rates of acquisition (p>.05), the looking-glass group performed significantly fewer errors during the post-test (p<.05) and were significantly better at identifying errors when a video of the dance sequence was shown from the same viewing angle as the acquisition phase (p<.05). No differences were reported between the two conditions with respect to cognitive effort (p>.05). Based on the results of this study, the looking-glass viewing angle appears to result in better learning of a dance sequence, but cannot be explained by cognitive effort.
86

Algorithms for analysis of GSM phones’ modulation quality / Algoritmer för analys av GSM-telefoners modulationskvalitet

Carlstedt, Tobias January 2009 (has links)
Instruments for analyzing radio signals are very expensive and their full capacity is seldom used outside the research and development and the type approval departments. Instrument manufacturers have historically integrated the hardware and the software into a single unit. But some instrument manufacturers are beginning to change this. The software is moved to a PC and the hardware samples the time continuous signal and sends it to the computer for analysis or for saving it on a file. Since the data from the hardware is in a raw format this opens up for other than the instrument manufacturer to supply the software. This thesis presents algorithms for calculating power, phase error and frequency error. It is shown that the results from these algorithms are comparable to the results from commercial analysis software. It is concluded that it is possible to create own analysis software at a reasonable cost with the possible downside of it being slower than commercial software.
87

Error Detection and Correction for H.264/AVC Using Hybrid Watermarking

You, Yuan-syun 19 July 2007 (has links)
none
88

Adaptive Error Control Schemes for Scalable Video Transmission over Wireless Internet

Lee, Chen-Wei 22 July 2008 (has links)
Based on the fast evolution of wireless networks and multimedia compression technologies in recent years, real-time multimedia transmission over wireless networks will be the next step for the implementation of contemporary communication system. Lower bandwidth and higher loss rate make wireless networks hard to transmit multimedia content than its wired counterpart. In addition, the common delay constraint from real-time multimedia transmission raises the challenges for the design of wireless communication system. This dissertation proposes an adaptive unequal error protection (UEP) and packet size assignment scheme for scalable video transmission over a burst error channel. An analytic model is developed to evaluate the impact of channel bit-error-rate on the quality of streaming scalable video. A video transmission scheme, which combines the adaptive assignment of packet size with unequal error protection to increase the end-to-end video quality is proposed. Several distinct scalable video transmission schemes over burst-error channel have been compared, and the simulation results reveal that the proposed transmission schemes can react to varying channel conditions with less and smoother quality degradation. Furthermore, in order to meet the real time need in many video transmission applications, this dissertation has proposed low time-complexity packet size assignment schemes. Meanwhile, from the test result, it can be seen that although this method has sacrificed a little bit video quality as compared to optimized method, yet it can adapt to all kinds of network situations and display smoother quality and performance. Moreover, as compared to optimized method, this strategy greatly reduces the calculation time-complexity.
89

Measurement error in environmental exposures: Statistical implications for spatial air pollution models and gene environment interaction tests

Ackerman-Alexeeff, Stacey Elizabeth 15 October 2013 (has links)
Measurement error is an important issue in studies of environmental epidemiology. We considered the effects of measurement error in environmental covariates in several important settings affecting current public health research. Throughout this dissertation, we investigate the impacts of measurement error and consider statistical methodology to fix that error.
90

The Effects of Viewing Angle on the Acquisition, Retention and Recognition of a Complex Dance Sequence

Smith, Jenna 30 January 2013 (has links)
The benefits of observing a model when acquiring a new motor skill are well known, however, there is little research on the influence of viewing angle of the model. The purpose of the present experiment was to assess whether a looking-glass (face on) or subjective (facing away) viewing angle would result in different acquisition and retention levels when learning a complex Zumba dance sequence. Greater cognitive effort was expected during the looking-glass condition, consequently resulting in slower acquisition but greater physical performance scores and error recognition/identification. Thirty females were evenly divided into the looking-glass or subjective group and began with the pre-test phase to assess degrees of motivation, self-efficacy, and physical performance. Participants were then lead through six acquisition dances, within which they performed the to-be-learned sequence 18 times. An assessment of cognitive effort followed, then post-test performances and error recognition/identification scores were obtained to conclude the study. While both the looking-glass and subjective conditions demonstrated equal rates of acquisition (p>.05), the looking-glass group performed significantly fewer errors during the post-test (p<.05) and were significantly better at identifying errors when a video of the dance sequence was shown from the same viewing angle as the acquisition phase (p<.05). No differences were reported between the two conditions with respect to cognitive effort (p>.05). Based on the results of this study, the looking-glass viewing angle appears to result in better learning of a dance sequence, but cannot be explained by cognitive effort.

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