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Model robust designs for binary response experimentsHuang, Shih-hao 06 July 2004 (has links)
The binary response experiments are often used in many areas. In many investigations, different kinds of optimal designs are discussed under an assumed model. There are also some discussions on optimal designs for discriminating models. The main goal in this work is to find an optimal design with two support points which minimizes the maximal probability differences between possible models from two types of symmetric location and scale families. It is called the minimum bias two-points design, or the $mB_2$ design in short here. D- and A-efficiencies of the $mB_2$ design obtained here are evaluated under an assumed model. Furthermore, when the assumed model is incorrect, the biases and the mean square errors in evaluating the true probabilities are computed and compared with that by using the D- and A-optimal designs for the incorrectly assumed model.
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Improving the Motion Vector Searching Algorithm and Estimating Criteria in Video CompressionHuang, Jen-Yi 07 October 2004 (has links)
Motion estimation is the key issue in video compressing. Several methods for motion estimation based on the center biased strategy and minimum mean square error trend searching have been proposed, such as TSS, FSS, UCBDS and MIBAS, but these methods yield poor estimates or find local minima. Many other methods predict the starting point for the estimation, these can be fast but are inaccurate. This study addresses the causes of wrong estimates, local minima and incorrect predictions in the prior estimation methods. The Multiple Searching Trend (MST) is proposed to overcome the problems of ineffective searches and local minima, and the Adaptive Dilated Searching Field (ADSF) is described to prevent prediction from wrong location. Applying MST and ADSF to the listed estimating methods, such as UCBDS, a fast and accurate can be reached. For this this reason, the method is called CockTail Searching (CTS).
In another proposed method, we try to define the new criteria used to determine a referent macro block within the search window in a referent frame, which matches the estimated current macro block in the current frame, in motion estimation process used in MPEG standard. The Prediction Error(PE) in the Pixel Difference(PD) between the referent macro block and the current macro block is defined to be a new criterion which can get better performance in compressed data length than the Mean Square Error(MSE) used by most of motion estimation methods. The other criterion combined PE and MSE is proposed to get better performance than the PE. Two new criteria is applied to a famous motion estimation method, UCBDS, to show the performance of the new criteria. The evaluation results show that using new criteria in UCBDS can get more 40% reduction in compressed data size than the UCBDS with MSE.
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CPIM, an Improved Element Free method for Engineering ApplicationLiu, Chang-jung 13 January 2006 (has links)
Abstract
To improve the application of Point Interpolation Method (PIM) in Element Free Galerkin Method (EFG) is the aim of this study. The trait of EFG is using overlap of influence domain between different nodes to construct discretization nodes¡¦ connection. EFG just uses nodal data, but not element.
For constructing shape function, EFG has two types of methods, Fitting and Interpolation. Fitting uses Moving Least Square Method (MLS). MLS-EFG has stable effect on numerical analysis; however, users who use it need to choose more numerical parameters and do more computation. Besides, users can not apply boundary conditions directly when using MLS-EFG. Interpolation method applies nodal coordinates to proceed computation, and it called PIM. Boundary conditions could be used directly and less computation is needs while using PIM. However, the coefficient of interpolation function of sample is singular.
This study tries to construct Coordination Point Interpolation Method. It owns advantages of both methods that mentioned above, and extra numerical parameters are not needed. It applies the notion of influence domain of MLS-EFG, then search correlative efficient nodes which are contained in near field of sample. The correlative efficient nodes make up matrix that con cause inverse matrix. In addition, via numerical simulations, it shows that CPIM has excellent convergence and accurate solution, and is better that MLS-EFG.
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The Vertical Specialization and Business Cycles Synchronization among Industrial CountriesChung, Wan-lai 26 June 2007 (has links)
Business cycle is an important issue for economist. Because the fluctuations of product and employment have deep influences on people¡¦s life and social stability, almost every government tries to reduce the volatility of national business cycles. If we want to make it, we must realize it first. Since countries communicate with each other more frequently in recent decades, the volatility of national product cycles is not only influenced by domestic economic variables but also foreign ones. The purpose of this paper is to analyze the effect of transmission mechanism on international business cycles synchronization (BCCs).
The major purpose of this paper is to analyze the effect of international vertical specialization on BCCs among industrial countries. There are two kinds of effect. One is indirect effect. Vertical specialization happens between industrial countries and developing countries, so it can reduce bilateral trade intensity among industrial countries. Through this way, BCCs among industrial countries will reduce. The other one is direct effect. Vertical specialization changes the economic structure of industrial countries. Industrial countries can focus on product development and market research. This kind of economic structure is less capital intensive, which lessens the effect of common shocks to industrial country¡¦s business cycles. BCCs among industrial countries will reduce.
We measured the effect using the data from G6 (Canada, France, Germany, Japan, UK and US). The result is consistent with our inferance. Vertical specialization can reduce BCCs by reducing bilateral trade intensive among industrial countries. There is a negative relation between Vertical specialization and BCCs among industrial countries.
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Identifying Factors That Facilitate The Use Of Multi-purpose Smart Cards By University Students: An Empirical InvestigationTeker, Mahmut 01 February 2011 (has links) (PDF)
The aim of this thesis is to identify factors that affect the university students&rsquo / acceptance of multi-purpose Smart Cards. The findings of this study will be beneficial to facilitate the use of Smart-Card enabled system both n universities and in other institutions which either have these systems in use or plan to invest on these systems in the future. The research methodology employed within this study is based on quantitative methods. A survey instrument comprising 51 5-point Likert-type questions has been developed and applied to 207 university Middle East Technical University students.
The data collected has been analyzed using Exploratory Factor Analysis to categorize factors having items. According to analysis results, the data classified under 5 factors / Perceived Usefulness, Perceived Ease of Use, Behavioral Intention, Anxiety, and Technological Complexity. Then, the relations between these 5 factors identified and a measurement model was created. For assessing the proposed model Discriminant and Convergent Validity scores were calculated by Confirmatory Factor Analysis. Then, Structural Equation Modeling was conducted with Partial Least Squares for validating the model&rsquo / s estimated influence. The study has shown that the main Technology Acceptance Model constructs fit for determining the university students&rsquo / intention of Smart Card usage except for Perceived Ease of Use over Behavioral Intention. Moreover, study showed that Anxiety and Technological Complexity were the external factors that have effect on willingness of using multi-purpose Smart Cards. If students have Anxiety, this affects their perception of easiness of the system and it has negative indirect effect on the perceived usefulness and direct effect on intention. Technological Complexity is another factor which has direct affect on the perception of easiness and usefulness and intention.
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Taksim Republican Square: A Field Study On Socio-economic, Form, Use And Meaning DimensionsKirmizi, Meric 01 August 2011 (has links) (PDF)
This study aims to ask what meaning the current users of Taksim Republican Square (TRS) in Istanbul attach to it, besides an understanding of the socio
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Modelling And Simulation Of Friction In Deep DrawingBaspinar, Murat 01 September 2011 (has links) (PDF)
Different contact surface parameters and operating characteristics are observed during the deep drawing process. It is not possible to find a formulation that can be used for all lubrication regimes. Therefore, several friction models have been developed in order to overcome this problem. In this study, a math program is developed which combines Wilson&rsquo / s and Khonsari&rsquo / s friction models in a new model in order to increase accuracy and efficiency in friction calculations. By comparing the results of both friction models, the film thickness ratio of 0.035 is introduced for 0.15 &mu / m standard deviation of surface summits. Below the ratio of 0.035, Khonsari&rsquo / s model gives more accurate results since asperity friction is dominant and the model is based on asperity contact. Above the ratio of 0.035, Wilson&rsquo / s model gives more accurate results since hydrodynamic friction is dominant and the model is based on lubricant flow.
In this study, a finite element program is used to simulate 50 mm cylindrical and 50.5x50.5 mm square shallow drawing processes which are performed in single stage. The final cup depths are selected as 18 mm and 23 mm for square and cylindrical cup drawing respectively. The FEM model and the program codes developed are verified by the previous studies in literature. After verification, the simulation results of the cylindrical and square cup drawing are input to a math program which calculates local friction coefficients using the combined friction model. Finally, the combined friction model and the results are further discussed.
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Study of Tidal Phase and Amplitude Characteristic in Kaohsiung Harbor and Central Taiwan StraitWang, Wei-hua 10 February 2009 (has links)
In recent year, tidal gauge has progressed in temporal resolution or measurement accuracy, so that the quality of observational data tends to stable and reliable. However, setting up tidal gauge in the offshore areas restricts may apply due to many factors such as seabed topography, weather, sea state and leveling survey from land to gauge. Good tidal correction is one of key factors to the accuracy of bathymetric survey and to the area where tidal range is large.
This study tried to use tide prediction data derived from the Yu(1993)¡¦s tide numerical model and verified with actual observed tide data, and further establishing a tidal zone of Taiwan Strait by tidal characteristic. Using Taichung and Mailiao tide stations as a reference tidal station, the direct tide station correction, tidal zone correction, nearest model grid correction, and virtual station correction methods were applied to evaluate the accuracy of tide calculating value by amplitude ratio and tidal phase difference. The tidal zone correction is not totally depending on the spatial distance from reference tidal station, and it is found that correction result of this approach is one of the best. However, further improvement in tide correction may need to explore due to different spatial resolution applied in different numerical models.
In addition, the boundary condition of a harbor for tidal model is very complicated. This is why it is hard to make a numerical model for a harbor. In this study, two additional high accuracy radar tidal gauge were installed in Kaohsiung harbor and first-class leveling survey was performed in order to maintain tidal measurement accuracy, also to avoid the effect of errors propagation. According to the results from experiment, average tidal phase of second entrance of the Kaohsiung harbor is earlier than that of first entrance about 6 minutes, and average difference of tidal height is approximately 2-3cm. For this reason, we should pay attention to decide a proper reference tide station for tidal correction for dredging hydrographic surveying. And any possible tidal observation errors, such as meteorological tide. If two additional tidal gauges of this study are removed in the future, we still can predict tide height from fixed tidal gauge.
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Designing a cost estimation method for the design of prototype systemsHolmes, Jonathan Frank 09 April 2012 (has links)
There are unique cases when designing products where a prototype is required to demonstrate critical operations of a system or subsystem such that it will serve as a basis for how the design will move forward. These prototypes are oftentimes on the critical design path. Due to the fact there is typically some aspect of a prototype that is not well understood there can be a considerable amount of uncertainty associated with the amount of resources needed to design such a prototype. The goal of this thesis is to address how to systematically reduce uncertainty for the purpose of creating a robust cost estimate. This statement does highlight the problem of defining what a robust estimate is, which results in addressing the key question driving this research: "When is enough information gathered to generate a robust estimate for the design of prototype systems?"
The crux of the problem lies in how to characterize the interactions and uncertainty associated with cost, schedule, and performance. Additionally, the breakdown of a prototype system into its subsystems results in errors exist at each division. The result is a cost estimation method that has been generated by leveraging the principles of design methodology. Two test cases are applied including one theoretical model, and one project from the Georgia Tech Research Institute (GTRI). The GTRI project was work performed for the Georgia Department of Transportation related to the filling of cracks on asphalt road surfaces. These examples are evaluated from the view point of the Validation Square in order to verify the effectiveness beyond example problems.
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Contribution à l'étude et à l'application des voltamétries à échelons de potentielKrulic, Denise 18 November 2005 (has links) (PDF)
Le travail présenté est le fruit de 15 ans de recherche, à compter de l'obtention de ma thèse, sur l'étude et la mise en œuvre de méthodes électrochimiques à échelons de potentiel destinées à l'électroanalyse et à la détermination de mécanismes réactionnels. <br />Dans le manuscrit, sont développés principalement, mes travaux relatifs aux réactions électrochimiques simples en régime transitoire ou stationnaire. Les points originaux et les applications de ces travaux se résument par catégorie comme suit.<br /><br />CONTROLE DU COURANT PAR LA DIFFUSION<br /><br />Electrode plane<br /><br /> Traitement unifié des méthodes mono et multi-impulsionnelles dans le cas des réactions électrochimiques réversibles. La recherche d'équivalents mathémati-ques à des solutions sous forme de séries conduit à des formules d'analyse simples. Ceci est particulièrement important pour la voltamétrie à signaux carrés (SWV) et la voltamétrie impulsionnelle différentielle (DPV) qui sont des techniques analytiques performantes.<br /> Etude de la voltamétrie à escalier de potentiel en mode différentiel. L'expression du courant s'adapte à la voltamétrie à balayage linéaire. <br /> Introduction de la voltamétrie impulsionnelle normale (NPV) en mode différentiel qui supprime l'effet de déplétion sur l'électrode non-renouvelée (goutte de mercure ou électrode solide) et permet l'emploi d'impulsions de courte durée. <br /> Présentation dans un but pédagogique d'un traitement simplifié de la polarographie impulsionnelle différentielle (DPP) basé sur le concept de la couche de diffusion.<br />Electrode sphérique<br /><br /> Traitement des méthodes mono et multi-impulsionnelles sur l'électrode à goutte de mercure pour des réactions réversibles avec ou sans formation d'amalgame. <br /> Etablissement d'une solution pour toute voltamétrie en l'absence d'amalgamation. <br /> Présentation d'une solution avec une correction de sphéricité au deuxième ordre qui s'applique sans restriction à toutes les polarographies mono-impulsionnelles. <br /> Etude de la SWV et de la NPV en cas d'amalgamation.<br /><br />Applications :<br /><br /> Caractérisation de la réversibilité et du nombre d'électrons de la réaction électrochimique.<br /> Détermination des coefficients de diffusion.<br /> Optimisation des paramètres expérimentaux en électroanalyse. <br /> Séparation des réponses interférentes par le choix du motif de polarisation et utilisation des expressions littérales pour la déconvolution des réponses.<br /> Prise en compte de la sphéricité de l'électrode à goutte de mercure en électroanalyse.<br /> Description du courant stationnaire sur microélectrode.<br /><br />CONTROLE DU COURANT PAR LA DIFFUSION ET PAR LE TRANSFERT DE CHARGE<br /><br /> Analyse des courbes irréversibles en DPP, SWV et DPV. L'expression du courant en DPP a été établie dans le cadre du modèle de l'électrode plane. L'effet de la sphéricité de la goutte de mercure est donné par une formule empirique.<br /> Introduction des balayages inverses en SWV.<br /> Analyse de la SWV effectuée avec des balayages dans le sens négatif et dans le sens positif. Pour le courant de pic obtenu avec un balayage négatif (Ox initialement présent en solution) des formules empiriques sont proposées à la fois pour l'électrode plane et sphérique.<br /><br />Applications<br /><br /> Détermination des paramètres cinétiques d'une réaction électrochimique irréversible à partir de la largeur et de la position des pics cathodique et anodique obtenus en SWV lors des balayages négatif et positif.<br /> Optimisation des paramètres expérimentaux en électroanalyse (amplitude des impulsions en DPP et en SWV, rapport des temps de polarisation en DPP et en DPV).<br /><br />COURANT STATIONNAIRE SOUS CONVECTION FORCEE <br /><br /> Analyse des voltammogrammes en SWV ou en DPV sur électrode à disque tournant quelle que soit la vitesse de transfert de charge.<br /><br />Applications<br /><br /> Détermination aisée du coefficient de transfert de charge à partir de la hauteur ou de la largeur des courbes différentielles irréversibles.<br /> Détermination de faibles concentrations (de l'ordre de 10-7 M) avec des électrodes solides. <br /><br /> Mes autres travaux, concernant des réactions électrochimiques avec des complications chimiques et de surface sont brièvement commentés dans le manuscrit.
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