Spelling suggestions: "subject:"3dmodel"" "subject:"2dmodel""
251 |
A study of a Scale-sized Model for Analysis of Vehicular AntennasHsu, Yu-ching 20 June 2008 (has links)
In this study, we establish a car model which better resembles a real car and compare with the simplified car model as a reference. When taking the circular polarization antenna into consideration, we need the refined car model in the simulation. Besides, TPMS antenna measurements are conducted and the results are compared with the simulation to verify the accuracy of our simulation. The result of the simulation shows that the signal cannot be received when TPMS antenna is mounted on the rear tires. Proper solution is suggested to alleviate this problem. Due to the limitation of the measurement environment, we consider using scale-sized car model for the measurement of the antenna radiation pattern. Also, we compare the radiation pattern in the scale-sized car model with that in the full-sized car model. For the measurement of the vehicular antenna, we find that using the scale-sized car model for the preliminary estimation of the antenna radiation pattern is feasible and practicable.
|
252 |
Verification of a Western Pacific Circulation Model Using Global Drifter DataYu, Sing-ru 29 August 2008 (has links)
The marine currents around the Pacific Northwest are researched by lots of scholars. The methods of the on-site observation, such as the shipping measurements and data buoys, were applied by researcher in the past. However, it is difficult to get comprehensive information on space by early methods, and it is often limited by the manpower and funding. With computer technology advances, numerical models get improving the accuracy and resolution. Therefore, development of the numerical models also becomes one of the methods to understand the ocean.
There are many current models and large databases which are developed. However, few studies combine the two. Therefore, this study adopts the simulated results of POLCOMS (Proudman Oceanographic Laboratory Coastal-Ocean Modeling System) in 2002 near the northwest Pacific (9.9¢X N ~ 41.9¢X N, 104.9¢X E ~ 139.9¢X E) to analyze some situations. The result can be compared with the measured data, and test the model.
In order to evaluate the accuracy of the results of the model, the simulated tracks can be calculated by the result of the model and the initial location of the measured data. However, the resolutions of time and space are only one day and 7.5 degree. Hence, the methods of linear interpolation and bilinear interpolation are applied to interpolate the model result in the time dimension and space dimension. By using the latitude and longitude of the initial points, the azimuth, and the geographic distance, the simulated tracks can be calculated. Therefore, the results of POLCOMS can be confirmed by global drifter data from NOAA/AOML.
According to the results of evaluating, the simulation trends of the seasons are similar to measured data. It can prove that this model has a certain degree of accuracy. However, simulation and the measured data can not be completely similar when abnormal weather phenomenon occurs. It is because the model was driven by the average wind field. There are suggestions to make the model complete by adding the weather information during the periods of the typhoons. Besides, the model can simulate the temperature and salinity of the ocean. Increasing the comparison of them will make the model integrated in the future, and obtain more correct information of the flow fields around the Pacific Northwest.
|
253 |
A Design of Recognition Rate Improving Strategy for Speech Recognition System - A Case Study on Mandarin Name and Phrase Recognition SystemChen, Ru-Ping 30 August 2008 (has links)
The objective of this thesis is to design and implement a speech recognition system for Mandarin names and phrases. This system utilizes Mel frequency cepstral coefficients, hidden Markov model and lexicon search strategy to select the phrase candidates. The experimental results indicate that for the speaker dependent case, a strategy incorporating overlapping frames and hybrid training can result in an improvement of 4%, 5%, 4% and 2% on the recognition rate for the Mandarin name, two-word, three-word and four-word phrase recognition systems respectively. Under Redhat Linux 9.0 operating system, any Mandarin name or phrase can be recognized within 2 seconds by a computer with Intel Celeron 2.4 GHz CPU.
|
254 |
The study of efficiency comparison for Distance transformations with applicationsWang, Chung-wei 26 August 2009 (has links)
Euclidean distance transformation is a fundamental technique in image understanding and computer vision. Some important characteristics in image analysis such as skeleton and object boundary are based upon the distance transformation computation.
In this thesis, we compare our method of computing Euclidean distance transformations with the method of Chamfer distance transformation. Our method is faster and more accurate than the Chamfer method. The boundary detection is an interesting and challenging task in computer vision. We integrate distance transform, watershed transform and active contour model to achieve boundary detection. Our method can successfully separate the touching objects, so as to facilitate the subsequent image processing for obtaining the geometric, and texture characteristics of objects. These features are useful for further medical images applications.
|
255 |
Independence proofs in arithmetic theories with very weak inductionGarro, Ibrahim. January 1973 (has links)
Inaug. Diss.--Bonn. / Bibliography: p. [71].
|
256 |
Ferromagnetic properties of partially filled two-dimensional Ising latticesFaraggi, Eshel, Reichl, L. E. January 2003 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisor: Linda E. Reichl. Vita. Includes bibliographical references. Also available from UMI.
|
257 |
The prevalence of model-based reasoning in CSCOPE curriculum for sixth grade scienceGonzalez, Jose Ricardo 24 February 2012 (has links)
This research was conducted on model-based reasoning and its prevalence in CSCOPE curriculum. Communications with seven CSCOPE representatives out of twenty regions revealed that CSCOPE is simply a name, not an acronym. The primary focus of CSCOPE is to impact instructional practices in the classroom to improve student performance. This report discusses the history of CSCOPE, its framework, and its exemplar lessons. It also looks at model-based reasoning, taxonomy of models, and model-eliciting activities. The research also aims to determine if the exemplar lessons in CSCOPE can be classified as model-based. / text
|
258 |
Study of a share based passenger mix modelVarghese, Libin Koshy 16 August 2012 (has links)
A passenger mix model (PMM) is used by airlines to find out how many passengers will fly on a fleet schedule. There are numerous ways of modeling passenger mix models and this report studies a share based passenger mix model, proposed by Sabre, and tests its efficacy against a deterministic linear program (DLP) passenger mix model. A DLP passenger mix model cannot recapture spilled passengers and requires iterations of the same model to recapture passengers. In order to eliminate the iterative nature of the DLP model Sabre proposed a new model which eliminates iterations for recapturing passengers. This report studies the proposed share based passenger mix model and compares it with the DLP model in terms of traffic allocation and speed of solution. It is found that the share based model allocates traffic in the same manner as the tried and tested DLP model. / text
|
259 |
Two essays on asset pricingLuo, Dan, 罗丹 January 2012 (has links)
This thesis centers around the pricing and risk-return tradeoff of credit and equity derivatives.
The first essay studies the pricing in the CDS Index (CDX) tranche market, and whether these instruments
have been reasonably priced and integrated within the financial market generally, both
before and during the financial crisis. We first design a procedure to value CDO tranches using
an intensity-based model which falls into the affine model class. The CDX tranche spreads are
efficiently explained by a three-factor version of this model, before and during the crisis period.
We then construct tradable CDX tranche portfolios, representing the three default intensity factors.
These portfolios capture the same exposure as the S&P 500 index optionmarket, to a market
crash. We regress these CDX factors against the underlying index, the volatility factor, and the
smirk factor, extracted from the index option returns, and against the Fama-French market, size
and book-to-market factors. We finally argue that the CDX spreads are integrated in the financial
market, and their issuers have not made excess returns.
The second essay explores the specifications of jumps for modeling stock price dynamics and
cross-sectional option prices. We exploit a long sample of about 16 years of S&P500 returns
and option prices for model estimation. We explicitly impose the time-series consistency when
jointly fitting the return and option series. We specify a separate jump intensity process which
affords a distinct source of uncertainty and persistence level from the volatility process. Our
overall conclusion is that simultaneous jumps in return and volatility are helpful in fitting the
return, volatility and jump intensity time series, while time-varying jump intensities improve the
cross-section fit of the option prices. In the formulation with time-varying jump intensity, both
the mean jump size and standard deviation of jump size premia are strengthened. Our MCMC
approach to estimate the models is appropriate, because it has been found to be powerful by
other authors, and it is suitable for dealing with jumps. To the best of our knowledge, our study
provides the the most comprehensive application of the MCMC technique to option pricing in
affine jump-diffusion models. / published_or_final_version / Economics and Finance / Doctoral / Doctor of Philosophy
|
260 |
Ferromagnetic properties of partially filled two-dimensional Ising latticesFaraggi, Eshel 28 August 2008 (has links)
Not available / text
|
Page generated in 0.064 seconds