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Odložilík, Daniel. "Zařízení pro testování diferenciálů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-445172.
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This master’s thesis deals with the design of equipment for testing differentials. The aim of the thesis is therefore the design of a special device that will be able to measure the steady and transient characteristics of differentials. Master’s thesis is divided into four chapters. The first chapter points out the disadvantages of fully open and closed differentials, the second deals with a basic overview of the structures and design of self-locking differentials. The third chapter deals with research of existing devices that test and measure the characteristics of differentials. The fourth chapter then discusses the possible drives of the tested unit. The fifth chapter focuses on the actual construction design of the test equipment. The subsequent sixth chapter then solves the strength calculations of the chosen structural elements of this device.
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Noller, Yannic. "Hybrid Differential Software Testing." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21968.
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Differentielles Testen ist ein wichtiger Bestandteil der Qualitätssicherung von Software, mit dem Ziel Testeingaben zu generieren, die Unterschiede im Verhalten der Software deutlich machen. Solche Unterschiede können zwischen zwei Ausführungspfaden (1) in unterschiedlichen Programmversionen, aber auch (2) im selben Programm auftreten. In dem ersten Fall werden unterschiedliche Programmversionen mit der gleichen Eingabe untersucht, während bei dem zweiten Fall das gleiche Programm mit unterschiedlichen Eingaben analysiert wird. Die Regressionsanalyse, die Side-Channel Analyse, das Maximieren der Ausführungskosten eines Programms und die Robustheitsanalyse von Neuralen Netzwerken sind typische Beispiele für differentielle Softwareanalysen.
Eine besondere Herausforderung liegt in der effizienten Analyse von mehreren Programmpfaden (auch über mehrere Programmvarianten hinweg). Die existierenden Ansätze sind dabei meist nicht (spezifisch) dafür konstruiert, unterschiedliches Verhalten präzise hervorzurufen oder sind auf einen Teil des Suchraums limitiert.
Diese Arbeit führt das Konzept des hybriden differentiellen Software Testens (HyDiff) ein: eine hybride Analysetechnik für die Generierung von Eingaben zur Erkennung von semantischen Unterschieden in Software. HyDiff besteht aus zwei parallel laufenden Komponenten: (1) einem such-basierten Ansatz, der effizient Eingaben generiert und (2) einer systematischen Analyse, die auch komplexes Programmverhalten erreichen kann. Die such-basierte Komponente verwendet Fuzzing geleitet durch differentielle Heuristiken. Die systematische Analyse basiert auf Dynamic Symbolic Execution, das konkrete Eingaben bei der Analyse integrieren kann.
HyDiff wird anhand mehrerer Experimente evaluiert, die in spezifischen Anwendungen im Bereich des differentiellen Testens ausgeführt werden. Die Resultate zeigen eine effektive Generierung von Testeingaben durch HyDiff, wobei es sich signifikant besser als die einzelnen Komponenten verhält.<br>Differential software testing is important for software quality assurance as it aims to automatically generate test inputs that reveal behavioral differences in software. The concrete analysis procedure depends on the targeted result: differential testing can reveal divergences between two execution paths (1) of different program versions or (2) within the same program. The first analysis type would execute different program versions with the same input, while the second type would execute the same program with different inputs. Therefore, detecting regression bugs in software evolution, analyzing side-channels in programs, maximizing the execution cost of a program over multiple executions, and evaluating the robustness of neural networks are instances of differential software analysis with the goal to generate diverging executions of program paths.
The key challenge of differential software testing is to simultaneously reason about multiple program paths, often across program variants, in an efficient way. Existing work in differential testing is often not (specifically) directed to reveal a different behavior or is limited to a subset of the search space.
This PhD thesis proposes the concept of Hybrid Differential Software Testing (HyDiff) as a hybrid analysis technique to generate difference revealing inputs. HyDiff consists of two components that operate in a parallel setup: (1) a search-based technique that inexpensively generates inputs and (2) a systematic exploration technique to also exercise deeper program behaviors. HyDiff’s search-based component uses differential fuzzing directed by differential heuristics. HyDiff’s systematic exploration component is based on differential dynamic symbolic execution that allows to incorporate concrete inputs in its analysis.
HyDiff is evaluated experimentally with applications specific for differential testing. The results show that HyDiff is effective in all considered categories and outperforms its components in isolation.
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Noller, Yannic [Verfasser]. "Hybrid Differential Software Testing / Yannic Noller." Berlin : Humboldt-Universität zu Berlin, 2020. http://d-nb.info/1219903949/34.
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Gulati, Parul. "Testing for Differential Expression in Small Sample Microarray Experiments." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1262280121.
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Osth, Adam F. "Create or differentiate? Testing the boundary conditions of differentiation." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1321390746.
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Hui, Qin. "Testing an Assumption of Non-Differential Misclassification in Case-Control Studies." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/math_theses/103.
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One of the issues regarding the misclassification in case-control studies is whether the misclassification error rates are the same for both cases and controls. Currently, a common practice is to assume that the rates are the same (“non-differential” assumption). However, it is suspicious that this assumption is valid in many case-control studies. Unfortunately, no test is available so far to test the validity of the assumption of non-differential misclassification when the validation data are not available. We propose the first such method to test the validity of non-differential assumption in a case-control study with 2 × 2 contingency table. First, the Exposure Operating Characteristic curve is defined. Next, two non-parametric methods are applied to test the assumption of non-differential misclassification. Three examples from practical applications are used to illustrate the methods and a comparison is made.
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Barrera-Gonzalez, Claudia Patricia. "Testing platform for a low voltage differential signal gigabit communication module." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 53 p, 2007. http://proquest.umi.com/pqdweb?did=1342743431&sid=1&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Leung, Kin-sang, and 梁建生. "A rapid molecular testing system for differential diagnosis of myeloproliferative neoplasms." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48334145.
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Myeloproliferative neoplasms include a heterogeneous group of stem cell disorders with overproduction of myeloid cells. They have very different clinical courses and prognosis and are amenable to specific targeted therapy. A prompt and accurate diagnosis is therefore very important. Genetic characterisation plays an important role in diagnosis and classification of these disorders. BCR-ABL1fusion gene and JAK2V617F mutation are the particular major molecular markers to be detected because of availability of targeted therapy.
In this study, a new molecular testing system was developed for the differential diagnosis of myeloproliferative neoplasms. A multiplex reverse-transcriptase polymerase chain reaction was developed for fast detection of JAK2 V617F mutation and BCR-ABL1fusion simultaneously. It was demonstrated to be fast and highly sensitive and specific for the mutations as validated by analysis of clinical samples. The sensitivity limit was well suited for clinical diagnosis. There was great potential saving in consumables and manpower with a much shortened turn-around-time in most cases when compared to conventional diagnostic protocol.<br>published_or_final_version<br>Pathology<br>Master<br>Master of Medical Sciences
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Kamphaus, Mary Ann. "The differential abilities scales : validation using a gifted sample." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/862275.
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The pupose of this study was to examine the validity of the Differential Abilities Scale with a gifted sample. Subjects consisted of 111 students identified as gifted by Indiana S-4. They were in grades 1 thru 6 and ranged in age from 6-8 to 12-11 with a mean age of 9-8. There were 60 females and 51 males who participated. Approximately, 1% of the population was minority which closely resembled the school population. Data from previously administered WISC-III and WIAT (The Psychological Corporation, 1992) were available for 21 of the 111 students.The first aspect of this study was to assess the construct validity of the DAS through investigation of the internal structure. Several different models were proposed. These analyses revealed that the proposed models were not good explanations of the relationships among obtained scores because convergence could not be obtained. A respecified two factor model was obtained where loadings on a Verbal Factor were constrained as recommended by Maxwell (1977). For this sample of gifted students a two-factor model with the first factor being primarily composed of Word Definitions was found to be a tenable one for the DAS.The second aspect of this study was to examine the convergent and predictive validity of the DAS by comparing these scores with the WISC-III and WIAT scores. Verbal factors for the two intelligence tests were the most highly correlated. Although there is overlap between the two intelligence measures, each test measures something unique. While one might expect these two instruments would not correlate perfectly, this correlation is lower than predicted.The DAS cognitive portion was more highly related to the other ability measure, the WISC-III, than it was to achievement as measured by the WIAT. In addition, achievement portions of both instruments were more highly related than they were to the ability measures.<br>Department of Educational Psychology
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Mann, Heather Marie. "Testing for differentially functioning indicators using mixtures of confirmatory factor analysis models." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9170.
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Thesis (Ph.D.) -- University of Maryland, College Park, 2009.<br>Thesis research directed by: Dept. of Measurement, Statistics and Evaluation. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Wong, Yu-lok, and 黃宇樂. "Differential changes in lumbar muscle activity and paraspinal stiffness during asymmetrical leg movement." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43572376.
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Postles, Phillip Anthony. "Construction and testing of a low temperature differential Stirling engine for power generation 2." Thesis, University of Canterbury. Electrical and Electronic Engineering, 2015. http://hdl.handle.net/10092/10839.
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This thesis presents the design and construction of a low temperature differential (LTD) Stirling engine for electric power generation. The target energy sources were geothermal, industrial waste heat or solar heated water. These sources would supply a source temperature of around 90 °C. Assuming that the sink is kept at around 20 °C, the engine was designed based on a temperature difference of approximately 70 °C. The initial design and basic structure of the engine was completed in a previous project utilising first order design methods. The goal was to develop a low cost prototype engine capable of producing up to 500W electrical output power. A novel gamma type engine was proposed
utilising a rotary reciprocating displacer and industrial steam piping to form a low cost pressurised chamber. This project concentrated on advancing the design and construction towards completion with particular emphasis on the electrical control, measurement/instrumentation components, and gas flow through the regenerator. At the completion of this project the displacer piston actuation system has been redesigned. In order to achieve the displacer’s specified 2 ㎐ actuation, both the displacer’s structure and the actuation system were altered. The displacer’s aluminium shell and foam centre were removed and replaced with a pine superstructure coated in depron foam, reducing the moment of inertia from 0.4488 ㎏ ∙ ㎡ to 0.0984 ㎏ ∙ ㎡. A secondary motor was added to the actuation system to increase the actuation power. The gearing ratio was also altered from 10:1 to 2:1 to increase the peak displacer speed. The regenerator was designed and built to suit the unusual wedge shape requirements of
the original design. A ribbed structure was conceived to allow fluid flow to be manipulated within separate sections, producing an even pressure drop over varying regenerator lengths. Simulations were run to optimise both the number of sections and the mass of wire wool to be placed in each segment. The final regenerator design has axial ribs placed at radii
of 93, 134, 192, 276 and 392mm, creating four sections. These sections are filled with 0.68, 0.97, 1.40 and 1.90kg of #0 mild steel wire wool.
As Stirling engines are not self-starting the generator was required to be run as a motor when starting the Stirling engine. To achieve bidirectional flow of current within the starter motor/generator control system, a field oriented control (FOC) inverter from Texas Instruments was purchased and set up to run the 1kW, 3 phase, permanent magnet generator in both motor and generation modes. This will allow the Stirling engine to be brought up to speed with the generator operating as a motor and then switch to generation mode when the motoring current falls below a set limit. Both pressure and temperature measurement systems were developed, constructed and tested in order to collect information about the performance of the engine under operation. Three pressure transducer circuits were designed and constructed with measurement ranges of 10 ㎪, ±0.99 ㎪ and ±6.66 ㎪. These circuits were integrated with a PiocLog1012 analog to digital converter and PicoLog recording software. Eight K-type thermocouples were used for temperature recording. These were sampled with a Pico Technology TC-08 temperature thermocouple data logger which in turn was connected, via USB, to a computer running PicoLog Recorder software. Thus far all component testing has been carried out with test rigs that model the relevant parts of the engine. The displacer actuation system and phase angle control of the displacer and power piston has been tested. Temperature and pressure measurement systems have been independently tested. Motor/generator speed control and switching has been simulated and tested. Unfortunately completion of the engine assembly was not achieved within the scope of this project and therefore fully integrated testing of all components was not carried out. Once mechanical assembly is completed fully integrated testing of displacer actuation, piston position, generator speed control and measurement systems can be achieved.
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SARTOR, MAUREEN A. "TESTING FOR DIFFERENTIALLY EXPRESSED GENES AND KEY BIOLOGICAL CATEGORIES IN DNA MICROARRAY ANALYSIS." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195656673.
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Au, Kwok-cheong Ricky, and 歐國昌. "Are recognition errors and deceptive responses differentiable?" Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B41758043.
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Husseini, A. H. "Design and testing of a new microprocessor-based current differential protection scheme for teed circuits." Thesis, University of Bath, 1991. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760616.
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Hurley, Joshua Daniel. "AN EXPERIMENTAL INVESTIGATION OF THERMAL BEHAVIOR OF AN AUTOMOTIVE REAR AXLE." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244483779.
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Schrock, Ken, Todd Freestone, and Leon Bell. "GPS RECEIVER SELECTION AND TESTING FOR LAUNCH AND ORBITAL VEHICLES." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/608283.
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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California<br>NASA Marshall Space Flight Center’s Bantam Robust Guidance Navigation & Control Project is investigating off the shelf navigation sensors that may be inexpensively combined into Kalman filters specifically tuned for launch and orbital vehicles. For this purpose, Marshall has purchased several GPS receivers and is evaluating them for these applications. The paper will discuss the receiver selection criteria and the test equipment used for evaluation. An overview of the analysis will be presented including the evaluation used to determine their success or failure. It will conclude with goals of the program and a recommendation for all GPS users.
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Kyei-Blankson, Lydia S. "Predictive Validity, Differential Validity, and Differential Prediction of the Subtests of the Medical College Admission Test." Ohio University / OhioLINK, 2005. http://www.ohiolink.edu/etd/view.cgi?ohiou1125524238.
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Kim, Jihye. "Controlling Type 1 Error Rate in Evaluating Differential Item Functioning for Four DIF Methods: Use of Three Procedures for Adjustment of Multiple Item Testing." Digital Archive @ GSU, 2010. http://digitalarchive.gsu.edu/eps_diss/67.
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In DIF studies, a Type I error refers to the mistake of identifying non-DIF items as DIF items, and a Type I error rate refers to the proportion of Type I errors in a simulation study. The possibility of making a Type I error in DIF studies is always present and high possibility of making such an error can weaken the validity of the assessment. Therefore, the quality of a test assessment is related to a Type I error rate and to how to control such a rate. Current DIF studies regarding a Type I error rate have found that the latter rate can be affected by several factors, such as test length, sample size, test group size, group mean difference, group standard deviation difference, and an underlying model. This study focused on another undiscovered factor that may affect a Type I error rate; the effect of multiple testing. DIF analysis conducts multiple significance testing of items in a test, and such multiple testing may increase the possibility of making a Type I error at least once. The main goal of this dissertation was to investigate how to control a Type I error rate using adjustment procedures for multiple testing which have been widely used in applied statistics but rarely used in DIF studies. In the simulation study, four DIF methods were performed under a total of 36 testing conditions; the methods were the Mantel-Haenszel method, the logistic regression procedure, the Differential Functioning Item and Test framework, and the Lord’s chi-square test. Then the Bonferroni correction, the Holm’s procedure, and the BH method were applied as an adjustment of multiple significance testing. The results of this study showed the effectiveness of three adjustment procedures in controlling a Type I error rate.
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McNally, Kelly A. "Application of Signal Detection Theory to Verbal Memory Testing for the Differential Diagnosis of Psychogenic Nonepileptic and Epileptic Seizures." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1178883120.
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Rini, Pietro. "Analysis of differential diffusion phenomena in high enthalpy flows, with application to thermal protection material testing in ICP facilities." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210893.
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This thesis presents the derivation of the theory leading to the determination of the governing equations of chemically reacting flows under local thermodynamic equilibrium, which rigorously takes into account effects of elemental (de)mixing. As a result, new transport coefficients appear in the equations allowing a quantitative predictions and helping to gain deeper insight into the physics of chemically reacting flows at and near local equilibrium. These transport coefficients have been computed for both air and carbon dioxide mixtures allowing the application of this theory to both Earth and Mars entry problems in the framework of the methodology for the determination of the catalytic activity of Thermal Protections Systems (TPS) materials.<p>Firstly, we analyze the influence of elemental fraction variations on the computation of thermochemical equilibrium flows for both air and carbon dioxide mixtures. To this end, the equilibrium computations are compared with several chemical regimes to better analyze the influence of chemistry on wall heat flux and to observe the elemental fractions behavior along a stagnation line. The results of several computations are presented to highlight the effects of elemental demixing on the stagnation point heat flux and chemical equilibrium composition for air and carbon dioxide mixtures. Moreover, in the chemical nonequilibrium computations, the characteristic time of chemistry is artificially decreased and in the limit the chemical equilibrium regime, with variable elemental fractions, is achieved. Then, we apply the closed form of the equations governing the behavior of local thermodynamic equilibrium flows, accounting for the variation in local elemental concentrations in a rigorous manner, to simulate heat and mass transfer in CO2/N2 mixtures. This allows for the analysis of the boundary layer near the stagnation point of a hypersonic vehicle entering the true Martian atmosphere. The results obtained using this formulation are compared with those obtained using a previous form of the equations where the diffusive fluxes of elements are computed as a linear combination of the species diffusive fluxes. This not only validates the new formulation but also highlights its advantages with respect to the previous one :by using and analyzing the full set of equilibrium transport coefficients we arrive at a deep understanding of the mass and heat transfer for a CO2/N2 mixture.<p>Secondly, we present and analyze detailed numerical simulations of high-pressure inductively coupled air plasma flows both in the torch and in the test chamber using two different mathematical formulations: an extended chemical non-equilibrium formalism including finite rate chemistry and a form of the equations valid in the limit of local thermodynamic equilibrium and accounting for the demixing of chemical elements. Simulations at various operating pressures indicate that significant demixing of oxygen and nitrogen occurs, regardless of the degree of nonequilibrium in the plasma. As the operating pressure is increased, chemistry becomes increasingly fast and the nonequilibrium results correctly approach the results obtained assuming local thermodynamic equilibrium, supporting the validity of the proposed local equilibrium formulation. A similar analysis is conducted for CO2 plasma flows, showing the importance of elemental diffusion on the plasma behavior in the VKI plasmatron torch.<p>Thirdly, the extension of numerical tools developed at the von Karman Institute, required within the methodology for the determination of catalycity properties for thermal protection system materials, has been completed for CO2 flows. Non equilibrium stagnation line computations have been performed for several outer edge conditions in order to analyze the influence of the chemical models for bulk reactions. Moreover, wall surface reactions have been examined, and the importance of several recombination processes has been discussed. This analysis has revealed the limits of the model currently used, leading to the proposal of an alternative approach for the description of the flow-surface interaction. Finally the effects of outer edge elemental fractions on the heat flux map is analyzed, showing the need to add them to the list of parameters of the methodology currently used to determine catalycity properties of thermal protection materials.<br>Doctorat en sciences appliquées<br>info:eu-repo/semantics/nonPublished
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Wright, Keith D. "Improvements for Differential Functioning of Items and Tests (DFIT): Investigating the Addition of Reporting an Effect Size Measure and Power." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/eps_diss/80.
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Standardized testing has been part of the American educational system for decades. Controversy from the beginning has plagued standardized testing, is plaguing testing today, and will continue to be controversial. Given the current federal educational policies supporting increased standardized testing, psychometricians, educators and policy makers must seek ways to ensure that tests are not biased towards one group over another.
In measurement theory, if a test item behaves differently for two different groups of examinees, this test item is considered a differential functioning test item (DIF). Differential item functioning, often conceptualized in the context of item response theory (IRT) is a term used to describe test items that may favor one group over another after matched on ability. It is important to determine whether an item is functioning significantly different for one group over another regardless as to why. Hypothesis testing is used to determine statistical significant DIF items; an effect size measure quantifies a statistical significant difference.
This study investigated the addition of reporting an effect size measure for differential item functioning of items and tests’ (DFIT) noncompensatory differential item functioning (NCDIF), and reporting empirically observed power. The Mantel-Haenszel (MH) parameter served as the benchmark for developing NCDIF’s effect size measure, for reporting moderate and large differential item functioning in test items. In addition, by modifying NCDIF’s unique method for determining statistical significance, NCDIF will be the first DIF statistic of test items where in addition to reporting an effect size measure, empirical power can also be reported.
Furthermore, this study added substantially to the body of literature on effect size by also investigating the behavior of two other DIF measures, Simultaneous Item Bias Test (SIBTEST) and area measure. Finally, this study makes a significant contribution to the body of literature by verifying in a large-scale simulation study, the accuracy of software developed by Roussos, Schnipke, and Pashley (1999) to calculate the true MH parameter. The accuracy of this software had not been previously verified.
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Sanders, Sarah J. "A joint confirmatory factor analysis of the Differential Ability Scales and the Woodcock-Johnson Tests of Cognitive Abilities-third edition." Virtual Press, 2004. http://liblink.bsu.edu/uhtbin/catkey/1292039.
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Hofman, Veronica M. "An investigation of the affects of typefaces upon reader's perception of the meanings of messages using the semantic differential testing technique /." Online version of thesis, 1988. http://hdl.handle.net/1850/10430.
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Cameron, Jessie Marie. "Identification, by differential display RT-PCR and cDNA selection, of genes expressed in human testis." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300119.
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Parker, Kathy L. "Construct validity of the Differential Ability Scales with a mentally handicapped population : an investigation into the interpretability of cluster scores." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/1019480.
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The purpose of the present study was to investigate the construct validity of the Differential Ability Scales (DAS) with a mentally handicapped population. The DAS is an individually administered, standardized test of intelligence. The stated purposes of the DAS are to provide a composite measure of conceptual reasoning abilities for classification and placement decisions and to provide a reliable profile of relative strengths and weaknesses for diagnostic purposes. With these goals in mind, it follows that this cognitive measure would be used often with mentally handicapped students. The DAS was developed using an hierarchical model based upon exploratory and confirmatory factor analyses. The model assumes that ability measures or subtests will load on a general factor g and will form subfactors at a lower level. The model also assumes that as children get older, the number of subfactors will increase because of development and differentiation of abilities. How mentally handicapped children would fit into this model was the subject of the current research.Using a sample of 100 mildly and moderately handicapped children ages 8 years, 0 months to 17 years, 5 months, confirmatory factor analysis was used to explore the factor structure of the DAS with this population. Three separate models were investigated: Model I, in which a one factor solution was proposed, Model II, in which two factors, Verbal Ability and Nonverbal Ability, were proposed, and Model III, in which three factors, Verbal Ability, Nonverbal Reasoning Ability, and Spatial Ability, as proposed by the test's authors, were investigated. Results of the analyses support the use of a one factor interpretation when using the DAS with mentally handicapped students. In practice, only the broadest score, the General Conceptual Ability Score (GCA), can be interpreted with confidence. Further, case study investigation illustrates the inconsistencies encountered in scoring at the lower end of the norms, as well as in using the outof-level procedure proposed by the test's authors.<br>Department of Educational Psychology
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Duis, Sandra S. "Differential performances on the wide range assessment of memory and learning of children diagnosed with reading disorder, attention- deficit/hyperactivity disorder, and traumatic brain injury." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1063200.
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The purpose of this investigation was to compare the performances on the Wide Range Assessment of Memory and Learning (WRAML; Sheslow & Adams, 1990) of children with different developmental and neurological disorders. The primary question was whether the WRAML subtests significantly differentiate among children with Developmental Reading Disorders (RD; n = 44), with Attention-Deficit/Hyperactivity Disorder (ADHD; n = 37), with Traumatic Brain Injury (TBI; n = 30), and without developmental or neurological disabilities (n = 103). Archival data from the TBI Project at James Whitcomb Riley Hospital for Children and from the Division of Psychology at Alfred I. duPont Institute was analyzed. The results of a discriminant functions analysis indicated that significant differences among the groups do exist on the WRAML and that the groups were discriminated from one another by three distinct types of tasks (i.e., functions): rote memory, verbal learning, and meaningful memory. Furthermore, based on WRAML performance alone, participants had a 63% chance of being classified into their proper diagnostic group. In addition to supporting the use of multi-dimensional tasks to assess memory, the results of this study have clinical relevance for developing diagnosis-specific recommendations for memory and learning problems.<br>Department of Educational Psychology
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Hinton, Daniel. "Uncovering the root cause of ethnic difference in ability testing : differential test functioning, test familiarity and trait optimism as explanations of ethnic group differences." Thesis, Aston University, 2015. http://publications.aston.ac.uk/28680/.
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The present research represents a coherent approach to understanding the root causes of ethnic group differences in ability test performance. Two studies were conducted, each of which was designed to address a key knowledge gap in the ethnic bias literature. In Study 1, both the LR Method of Differential Item Functioning (DIF) detection and Mixture Latent Variable Modelling were used to investigate the degree to which Differential Test Functioning (DTF) could explain ethnic group test performance differences in a large, previously unpublished dataset. Though mean test score differences were observed between a number of ethnic groups, neither technique was able to identify ethnic DTF. This calls into question the practical application of DTF to understanding these group differences. Study 2 investigated whether a number of non-cognitive factors might explain ethnic group test performance differences on a variety of ability tests. Two factors – test familiarity and trait optimism – were able to explain a large proportion of ethnic group test score differences. Furthermore, test familiarity was found to mediate the relationship between socio-economic factors – particularly participant educational level and familial social status – and test performance, suggesting that test familiarity develops over time through the mechanism of exposure to ability testing in other contexts. These findings represent a substantial contribution to the field’s understanding of two key issues surrounding ethnic test performance differences. The author calls for a new line of research into these performance facilitating and debilitating factors, before recommendations are offered for practitioners to ensure fairer deployment of ability testing in high-stakes selection processes.
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Catalano, Rob D. "Isolation and characterisation of a haploid expressed testis-specific cDNA in mouse using the differential display technique." Thesis, University of Warwick, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264903.
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Bichat, Antoine. "Prise en compte de l’organisation hiérarchique des espèces pour la découverte de signatures métagénomiques multi-échelles. Incorparating phylogenetic information in microbiome differential abundance studies has no effect on detection power and FDR control." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASM016.
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Cette thèse porte sur l'inclusion d'informations hiérarchiques dans des procédures de détection d'abondance différentielle sur des données métagénomiques. Les différents taxons qui composent le microbiote sont généralement accompagnés d'un arbre, comme la taxonomie ou la phylogénie, qui traduit une proximité biologique entre eux. Il est alors naturel de vouloir tirer parti de cette information hiérarchique afin d'augmenter la puissance des tests de détection de taxons différentiellement abondants. Dans un premier temps, nous nous sommes intéressés aux performances des procédures hiérarchiques existantes et à l'impact du choix de l'arbre sur celles-ci. Dans un second temps, nous avons développé notre propre méthode hiérarchique de détection d'abondance différentielle. Celle-ci modélise les z-scores associés à chaque taxon comme la réalisation d'un processus d'Ornstein-Uhlenbeck sur arbre avec sauts dans la valeur optimale du processus puis effectue une régression de type lasso pour déterminer les positions et intensités optimales des sauts<br>This thesis deals with the use of hierarchical information in differential abundance analyses in metagenomics. Taxa that make up the microbiome are usually associated with a tree, like the taxonomy or the phylogeny, that reflects a biological link between them. It is therefore natural to exploit this hierarchical information to increase the statistical power of differential abundance techniques. We first investigated the efficiency of existing hierarchical differential abundance detection procedures and the impact of tree choice on those. We then developed our own hierarchical differentially abundance detection procedure. It models the taxaassociated z-scores as realization of an Ornstein- Uhlenbeck process on a tree with shifts on its optimal value then a lasso-like regression is used to identify optimal positions and intensities of the shifts
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Caplen, Mark J. S. "The development and testing of a new integration method for the solution of stiff differential equations arising in the digital simulation of fluid power systems." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383310.
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Hong, Jung Ki. "Effect of Cellulose Nanocrystals on the Rheology, Curing Behavior, and Fracture Performance of Phenol-Formaldehyde Resol Resin." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/46189.
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The purpose of this research was to determine the effects of cellulose nanocrystals (CNCs), as potential additives, on the properties and performance of phenolâ formaldehyde (PF) adhesive resin. The steady-state viscosity of a commercial PF resol resin and three CNCâ resin mixtures, containing 1â 3 wt % CNCs, based on solids content, was measured with a rheometer as a function of shear rate. The viscosity of the PF resin itself was independent of shear rate. The viscosityâ shear rate curves of the CNCâ resin mixtures showed two regions, a shear thinning region at lower shear rates and a Newtonian region at higher shear rates. The low-shear-rate viscosity of the resin was greatly increased by the CNCs.
The structure of the CNCâ resin mixtures under quiescent conditions was analyzed by polarized light microscopy. The mixtures contained CNC aggregates, which could be disrupted by ultrasound treatment. The curing progressions of the resin and CNCâ resin mixtures were analyzed by non-isothermal differential scanning calorimetry (DSC). The DSC curves showed two exotherms followed by an endotherm. The energy of activation for the first exotherm was reduced by the CNCs whereas the energy of activation for the second exotherm was not affected by the CNCs. Increasing CNC contents caused higher degrees of reaction conversion during the first curing stage and a greater loss of sample mass, attributed to formaldehyde release during resin cure.
For analysis of the mechanical properties during and after cure, sandwich-type test specimens were prepared from southern yellow pine strips and the resin and CNCâ resin mixtures. The mechanical properties of the test specimens were measured as a function of time and temperature by dynamic mechanical analysis (DMA). The time to incipient storage modulus increase decreased and the rate of relative storage modulus increase increased with increasing CNC content. The ultimate sample stiffness increased with increasing CNC content for CNC contents between 0 and 2 wt %, which was attributed to mechanical reinforcement of the resin by the CNCs. At a CNC content of 3 wt %, the ultimate sample stiffness was lower than at a CNC content of 2 wt % and the second tan δ maximum occurred earlier in the experiment, indicating an earlier onset of vitrification. The lower ultimate sample stiffness was attributed to premature quenching of the curing reactions through CNC-induced depression of the vitrification point.
For analysis of the fracture performance, double cantilever beam test specimens were prepared from southern yellow pine beams and the resin and CNCâ resin mixtures, using different hot-pressing times. Fracture energies were measured by mode I cleavage tests. Bondline characteristics were analyzed by light microscopy. At a hot-pressing time of 10 min, the fracture energy decreased with increasing CNC content, whereas it stayed constant for CNC contents between 1 and 3 wt % at a hot-pressing time of 8 min. The bondlines of resin mixtures containing CNCs exhibited voids, whereas those of the pure resin did not. CNCs had both benefitial and detrimental effects on the properties and performace of PF resin.<br>Master of Science
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Handy, Andrea Renee. "Acute Toxicity and Immunotoxicity Testing of Total Petroleum Hydrocarbons in Aquatic and Terrestrial Organisms." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1185910580.
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Turse, Carol Louise. "Testing the hydrogen peroxide-water hypothesis of life on Mars using the differential scanning calorimeter as an analog for the TEGA instrument on the Mars Phoenix lander." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Summer2009/c_turse_072309.pdf.
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Thesis (M.S. in environmental science)--Washington State University, August 2009.<br>Title from PDF title page (viewed on Sept. 22, 2009). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 92-97).
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Ladejobi, Olufunmilayo Olubukola. "Testing new genetic and genomic approaches for trait mapping and prediction in wheat (Triticum aestivum) and rice (Oryza spp)." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277449.
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Advances in molecular marker technologies have led to the development of high throughput genotyping techniques such as Genotyping by Sequencing (GBS), driving the application of genomics in crop research and breeding. They have also supported the use of novel mapping approaches, including Multi-parent Advanced Generation Inter-Cross (MAGIC) populations which have increased precision in identifying markers to inform plant breeding practices. In the first part of this thesis, a high density physical map derived from GBS was used to identify QTLs controlling key agronomic traits of wheat in a genome-wide association study (GWAS) and to demonstrate the practicability of genomic selection for predicting the trait values. The results from GBS were compared to a previous study conducted on the same association mapping panel using a less dense physical map derived from diversity arrays technology (DArT) markers. GBS detected more QTLs than DArT markers although some of the QTLs were detected by DArT markers alone. Prediction accuracies from the two marker platforms were mostly similar and largely dependent on trait genetic architecture. The second part of this thesis focused on MAGIC populations, which incorporate diversity and novel allelic combinations from several generations of recombination. Pedigrees representing a wild rice MAGIC population were used to model MAGIC populations by simulation to assess the level of recombination and creation of novel haplotypes. The wild rice species are an important reservoir of beneficial genes that have been variously introgressed into rice varieties using bi-parental population approaches. The level of recombination was found to be highly dependent on the number of crosses made and on the resulting population size. Creation of MAGIC populations require adequate planning in order to make sufficient number of crosses that capture optimal haplotype diversity. The third part of the thesis considers models that have been proposed for genomic prediction. The ridge regression best linear unbiased prediction (RR-BLUP) is based on the assumption that all genotyped molecular markers make equal contributions to the variations of a phenotype. Information from underlying candidate molecular markers are however of greater significance and can be used to improve the accuracy of prediction. Here, an existing Differentially Penalized Regression (DiPR) model which uses modifications to a standard RR-BLUP package and allows two or more marker sets from different platforms to be independently weighted was used. The DiPR model performed better than single or combined marker sets for predicting most of the traits both in a MAGIC population and an association mapping panel. Overall the work presented in this thesis shows that while these techniques have great promise, they should be carefully evaluated before introduction into breeding programmes.
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Faure, Jacqueline J. "Repetitive stressors at various lifetime periods differentially affect the HPA axis, neuronal neurotrophic factors and behavioural responses." Thesis, Stellenbosch : University of Stellenbosch, 2006. http://hdl.handle.net/10019.1/1755.
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Thesis (MSc (Physiological Sciences))--University of Stellenbosch, 2006.<br>Early adverse life events appear to increase the susceptibility of developing psychiatric disorders later in life. The molecular mechanisms involved in the development of pathological behaviour remain unclear. Dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in neurotrophic factors have been implicated.
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Luedtke, Chad C. "Osteopontin and cathepsin A are expressed in a cell and region-specific manner in the testis and epididymis and are differentially regulated by testicular factors." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0029/MQ64397.pdf.
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Urbina, Josue N. "The Relationship between Selected Standardized Test Scores and Performance in Advanced Placement Math and Science Exams: Analyzing the Differential Effectiveness of Scores for Course Identification and Placement." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1208.
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There is a national need to increase the STEM-related workforce. Among factors leading towards STEM careers include the number of advanced high school mathematics and science courses students complete. Florida’s enrollment patterns in STEM-related Advanced Placement (AP) courses, however, reveal that only a small percentage of students enroll into these classes. Therefore, screening tools are needed to find more students for these courses, who are academically ready, yet have not been identified.
The purpose of this study was to investigate the extent to which scores from a national standardized test, Preliminary Scholastic Assessment Test/ National Merit Qualifying Test (PSAT/NMSQT), in conjunction with and compared to a state-mandated standardized test, Florida Comprehensive Assessment Test (FCAT), are related to selected AP exam performance in Seminole County Public Schools. An ex post facto correlational study was conducted using 6,189 student records from the 2010 - 2012 academic years.
Multiple regression analyses using simultaneous Full Model testing showed differential moderate to strong relationships between scores in eight of the nine AP courses (i.e., Biology, Environmental Science, Chemistry, Physics B, Physics C Electrical, Physics C Mechanical, Statistics, Calculus AB and BC) examined. For example, the significant unique contribution to overall variance in AP scores was a linear combination of PSAT Math (M), Critical Reading (CR) and FCAT Reading (R) for Biology and Environmental Science. Moderate relationships for Chemistry included a linear combination of PSAT M, W (Writing) and FCAT M; a combination of FCAT M and PSAT M was most significantly associated with Calculus AB performance.
These findings have implications for both research and practice. FCAT scores, in conjunction with PSAT scores, can potentially be used for specific STEM-related AP courses, as part of a systematic approach towards AP course identification and placement. For courses with moderate to strong relationships, validation studies and development of expectancy tables, which estimate the probability of successful performance on these AP exams, are recommended. Also, findings established a need to examine other related research issues including, but not limited to, extensive longitudinal studies and analyses of other available or prospective standardized test scores.
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Strapko, Miroslav. "Návrh systému chránění s použitím elektronických přístrojových transformátorů (senzorů) v rozvodně vysokého napětí." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219395.
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Master's thesis deals with use of electronic instrument transformers (sensors) in the protection system in medium-voltage substation. Substation consists of 2 incoming feeders, 2 outgoing feeders for motors, 2 outgoing feeders for power transformers, measuring, bus coupler and bus riser feeder. Incoming feeders are connected to distribution system E.ON by cable lines which were proposed. Protected machines (power transformers and motors with rated power) are connected to switchgear panels of UniGear ZS1 type by cable lines too. Proposed protection system is based on the short-circuit conditions, standard CSN 33 3051 recommendations as well as theoretical backgrounds acquired from technical papers and other publicated literature according to the bibliography. For selected protection functions are defined their parameters. Control, monitoring and protection functions provides REF 542plus relay. Consequently, secondary tests which are part of the commissioning, are given in the practical part of thesis. Secondary tests were performed by relay test system FREJA 300 by Megger. Results of tests are displayed in tripping characteristics.
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Anderson, Hannah Ruth. "A Psychometric Investigation of a Mathematics Placement Test at a Science, Technology, Engineering, and Mathematics (STEM) Gifted Residential High School." Kent State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=kent1594656968297342.
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Ratamero, Leandro de Amorim. "Caracterização térmica e óptica por espectroscopia fotoacústica: um método inverso." Universidade do Estado do Rio de Janeiro, 2007. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=553.
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A espectroscopia fotoacústica é uma técnica muito utilizada na caracterização de materiais. Ela é baseada no efeito fotoacústico, que consiste na geração de som a partir da incidência de radiação eletromagnética intermitente numa amostra confinada numa pequena câmara fechada e preenchida com algum gás. O efeito fotoacústico depende de muitos parâmetros como a freqüência de modulação da radiação eletromagnética incidente e de parâmetros ópticos e térmicos do material em estudo. O modelo de Rosencwaig-Gersho (RG) tem sido empregado na estimativa de parâmetros ópticos e térmicos da amostra utilizando os casos especiais de opacidade e de comportamento térmico do material. Há o interesse em utilizar o modelo RG para a estimativa de dois ou mais parâmetros, simultaneamente. Houve algum sucesso com a aplicação do método inverso utilizando dados experimentais sintéticos, ou seja, utilizando dados gerados pelo modelo RG (método direto), aos quais adiciona-se ruído com o intuito de simular dados experimentais. O objetivo do presente trabalho é a utilização de dados experimentais reais nesta abordagem do método inverso. Para isso foi realizado um projeto de experimento onde se estudou a possibilidade de estimação simultânea de parâmetros a partir das condições gerais do experimento real. Neste projeto de experimento, o estudo dos coeficientes de sensibilidade modificados desempenha um papel central. Desta forma, foi elaborado um algoritmo para o projeto de experimento, onde é estudada a relação entre tais coeficientes e a estimação dos parâmetros feita pelo método inverso. Como exemplo, é apresentada a execução de um projeto de experimento simples, realizado qualitativamente, porém capaz de apontar para um experimento fotoacústico que fornecerá dados experimentais reais para estimativa de um determinado parâmetro físico da amostra. Com esses dados experimentais o problema inverso foi aplicado para a estimação da difusividade térmica da amostra. Por fim, uma discussão é feita com relação ao valor da difusividade térmica obtida pelo método inverso e com relação à abordagem do método inverso na espectroscopia fotoacústica.<br>Photoacoustic spectroscopy is a very effective technique for optical and thermal characterization of materials. This technique is based on photoacoustic effect. It occurs when a material sample placed inside a closed cell filled with any gas is illuminated with periodically interrupted light. This effect depends on many parameters as modulation frequency of the incident electromagnetic radiation and on optical and thermal properties of the material studied. The Rosencwaig-Gersho (RG) model has been used for parameter estimation where special cases of opaqueness and thermal behavior of the material are considered. One has interest in the use of the general RG model to estimate two or more parameters, simultaneously. In this way, the inverse problem approach has been applied with the direct problem modeled with the general RG model. However, synthetic experimental data has been used in such approach, e.g., noise is added on the data, obtained from direct problem, in order to simulate real experimental data. The main goal of this work is to use the real experimental data in the inverse problem approach. It was needed to carry out the sensitivity study of the parameters with respect to the overall experimental conditions. The modified sensitivity coefficients play an important role in such study. Therefore, an algorithm was built up to study the relationship between modified sensitivity coefficients for the successful inverse approach of parameter estimation. As an example, a simple and qualitative study of sensitivity of the parameters was done, using such algorithm. It pointed out the conditions of the real experimental arrangement in which experimental data were obtained to estimate a unique parameter of the sample. With these experimental data the inverse problem was applied for determining the thermal diffusivity of the sample. Finally, a discussion is presented on the value obtained for the thermal diffusivity by this approach and on the application of the inverse method on the photoacoustic spectroscopy.
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Guarneri, Giovanni Alfredo. "Identificação de descontinuidades em peças metálicas utilizando sinais ultrassônicos e técnicas de problemas inversos." Universidade Tecnológica Federal do Paraná, 2015. http://repositorio.utfpr.edu.br/jspui/handle/1/1370.
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CNPQ; LASCA<br>Este trabalho propõe um algoritmo para identificar descontinuidades internas em uma peça metálica a partir de sinais A-scan provenientes de um ensaio não-destrutivo por ultrassom. As descontinuidades são identificadas por seu formato, dimensões, orientação e localização. Esse algoritmo é baseado na resolução de problemas inversos. O problema da identificação de descontinuidades é modelado utilizando uma abordagem inédita, em que a descontinuidade é caracterizada por dois elementos distintos: a sua amplitude de espalhamento e a localização de seu centro. Com essa nova forma de representação, o problema de identificação da descontinuidade passa a ser dividido em dois subproblemas. O primeiro é o problema de reconstrução para encontrar a localização do centro da descontinuidade e o segundo é o problema de caracterização para estimar os parâmetros geométricos da descontinuidade. Os ensaios realizados comprovam que o problema de localização é resolvido de forma satisfatória utilizando o algoritmo de reconstrução de imagens esparsas UTSR (ultrasonic sparse reconstruction). A caracterização da descontinuidade é realizada por um algoritmo baseado no método dos mínimos quadrados não-lineares, com a inclusão de um termo de regularização não-quadrático utilizando norma l1. Os resultados obtidos tanto com dados simulados como com dados experimentais mostram que esse algoritmo estima as descontinuidades de forma satisfatória.<br>The present work proposes an algorithm to identify internal discontinuities in metallic specimen from A-scan ultrasonic signals. Discontinuities are identified by their shape, size, orientation and location. This algorithm is based on inverse problems. The identification of discontinuities is modeled using a novel approach. The discontinuity is modeled by two distinct elements: its scattering amplitude and its center location. Through this approach, the identification problem is split into two sub problems. The first is a reconstruction problem to find the location of the discontinuity. The second is a model identification problem to estimate geometric parameters of the discontinuity. Simulations and experimental validation show that the localization problem is satisfactorily solved using the UTSR (ultrasonic sparse reconstruction) algorithm. The characterization of discontinuities is carried out by an algorithm based on non-linear least squares with l1 norm regularization. The results obtained with simulated data as well with experimental data show a fine estimation of discontinuities.
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Buba, Ondřej. "Praktické testování metod analýzy spolehlivosti v konkrétních obvodových aplikacích." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241037.
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This diploma thesis deals with the method which are useful for analysis of reliability in specific circuit applications. It also deals with fault analysis in frequency, time and DC domain. Methods for these domains are described in other chapter of this thesis. Finally methods for diagnostics analog circuit are evaluated based on simulation and practical testing of selected methods.
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Jeunesse, Paulien. "Estimation non paramétrique du taux de mort dans un modèle de population générale : Théorie et applications. A new inference strategy for general population mortality tables Nonparametric adaptive inference of birth and death models in a large population limit Nonparametric inference of age-structured models in a large population limit with interactions, immigration and characteristics Nonparametric test of time dependance of age-structured models in a large population limit." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLED013.
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L’étude du taux de mortalité dans des modèles de population humaine ou en biologie est le cœur de ce travail. Cette thèse se situe à la frontière de la statistique des processus, de la statistique non-paramétrique et de l’analyse.Dans une première partie, centrée sur une problématique actuarielle, un algorithme est proposé pour estimer les tables de mortalité, utiles en assurance. Cet algorithme se base sur un modèle déterministe de population. Ces nouvelles estimations améliorent les résultats actuels en prenant en compte la dynamique globale de la population. Ainsi les naissances sont incorporées dans le modèle pour calculer le taux de mort. De plus, ces estimations sont mises en lien avec les travaux précédents, assurant ainsi la continuité théorique de notre travail.Dans une deuxième partie, nous nous intéressons à l’estimation du taux de mortalité dans un modèle stochastique de population. Cela nous pousse à utiliser des arguments propres à la statistique des processus et à la statistique non-paramétrique. On trouve alors des estimateurs non-paramétriques adaptatifs dans un cadre anisotrope pour la mortalité et la densité de population, ainsi que des inégalités de concentration non asymptotiques quantifiant la distance entre le modèle stochastique et le modèle déterministe limite utilisé dans la première partie. On montre que ces estimateurs restent optimaux dans un modèle où le taux de mort dépend d’interactions, comme dans le cas de la population logistique.Dans une troisième partie, on considère la réalisation d’un test pour détecter la présence d’interactions dans le taux de mortalité. Ce test permet en réalité de juger de la dépendance temporelle de ce taux. Sous une hypothèse, on montre alors qu’il est possible de détecter la présence d’interactions. Un algorithme pratique est proposé pour réaliser ce test<br>In this thesis, we study the mortality rate in different population models to apply our results to demography or biology. The mathematical framework includes statistics of process, nonparametric estimations and analysis.In a first part, an algorithm is proposed to estimate the mortality tables. This problematic comes from actuarial science and the aim is to apply our results in the insurance field. This algorithm is founded on a deterministic population model. The new estimates we gets improve the actual results. Its advantage is to take into account the global population dynamics. Thanks to that, births are used in our model to compute the mortality rate. Finally these estimations are linked with the precedent works. This is a point of great importance in the field of actuarial science.In a second part, we are interested in the estimation of the mortality rate in a stochastic population model. We need to use the tools coming from nonparametric estimations and statistics of process to do so. Indeed, the mortality rate is a function of two parameters, the time and the age. We propose minimax optimal and adaptive estimators for the mortality and the population density. We also demonstrate some non asymptotics concentration inequalities. These inequalities quantifiy the deviation between the stochastic process and its deterministic limit we used in the first part. We prove that our estimators are still optimal in a model where the mortality is influenced by interactions. This is for example the case for the logistic population.In a third part, we consider the testing problem to detect the existence of interactions. This test is in fact designed to detect the time dependance of the mortality rate. Under the assumption the time dependance in the mortality rate comes only from the interactions, we can detect the presence of interactions. Finally we propose an algorithm to do this test
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Antelo, Junior Ernesto Willams Molina. "Estimação conjunta de atraso de tempo subamostral e eco de referência para sinais de ultrassom." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2616.
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CAPES<br>Em ensaios não destrutivos por ultrassom, o sinal obtido a partir de um sistema de aquisição de dados real podem estar contaminados por ruído e os ecos podem ter atrasos de tempo subamostrais. Em alguns casos, esses aspectos podem comprometer a informação obtida de um sinal por um sistema de aquisição. Para lidar com essas situações, podem ser utilizadas técnicas de estimativa de atraso temporal (Time Delay Estimation ou TDE) e também técnicas de reconstrução de sinais, para realizar aproximações e obter mais informações sobre o conjunto de dados. As técnicas de TDE podem ser utilizadas com diversas finalidades na defectoscopia, como por exemplo, para a localização precisa de defeitos em peças, no monitoramento da taxa de corrosão em peças, na medição da espessura de um determinado material e etc. Já os métodos de reconstrução de dados possuem uma vasta gama de aplicação, como nos NDT, no imageamento médico, em telecomunicações e etc. Em geral, a maioria das técnicas de estimativa de atraso temporal requerem um modelo de sinal com precisão elevada, caso contrário, a localização dessa estimativa pode ter sua qualidade reduzida. Neste trabalho, é proposto um esquema alternado que estima de forma conjunta, uma referência de eco e atrasos de tempo para vários ecos a partir de medições ruidosas. Além disso, reinterpretando as técnicas utilizadas a partir de uma perspectiva probabilística, estendem-se suas funcionalidades através de uma aplicação conjunta de um estimador de máxima verossimilhança (Maximum Likelihood Estimation ou MLE) e um estimador máximo a posteriori (MAP). Finalmente, através de simulações, resultados são apresentados para demonstrar a superioridade do método proposto em relação aos métodos convencionais.<br>Abstract (parágrafo único): In non-destructive testing (NDT) with ultrasound, the signal obtained from a real data acquisition system may be contaminated by noise and the echoes may have sub-sample time delays. In some cases, these aspects may compromise the information obtained from a signal by an acquisition system. To deal with these situations, Time Delay Estimation (TDE) techniques and signal reconstruction techniques can be used to perform approximations and also to obtain more information about the data set. TDE techniques can be used for a number of purposes in the defectoscopy, for example, for accurate location of defects in parts, monitoring the corrosion rate in pieces, measuring the thickness of a given material, and so on. Data reconstruction methods have a wide range of applications, such as NDT, medical imaging, telecommunications and so on. In general, most time delay estimation techniques require a high precision signal model, otherwise the location of this estimate may have reduced quality. In this work, an alternative scheme is proposed that jointly estimates an echo model and time delays for several echoes from noisy measurements. In addition, by reinterpreting the utilized techniques from a probabilistic perspective, its functionalities are extended through a joint application of a maximum likelihood estimator (MLE) and a maximum a posteriori (MAP) estimator. Finally, through simulations, results are presented to demonstrate the superiority of the proposed method over conventional methods.
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Wu, Jiyuan. "Testing revised differential association models." 1990. http://catalog.hathitrust.org/api/volumes/oclc/23045306.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1990.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 40-45).
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Syal, Ashish. "Differential testing of CMOS integrated circuits." Thesis, 2002. http://hdl.handle.net/2429/13251.
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As CMOS technologies scale down, background leakage current increases inexorably,
primarily due to device sub-threshold leakage. As a result, conventional single-threshold
pass/fail IDDQ testing may no longer be valid for deep sub-micron technology. A number
of alternatives to single threshold IDDQ testing have been proposed. A testing technique to
complement IDDQ testing that has shown promise is thermal signature testing.
The validity of using temperature as a test observable was investigated. After establishing
this, the use of differential thermal sensing as a possible way of detecting bridging faults in
CMOS gates was studied. Differential sensing provides high sensitivity to temperature
changes generated by internal changes of the power distribution due to defects and
immunity to ambient temperature changes. Different topologies for such sensors have been
proposed targeting bipolar and BiCMOS. The novelty of the work is that these were the
first such sensors to have been developed in CMOS technology. The thermal sensors were
designed, simulated, fabricated and the chips that came back were tested. Three different
types of sensors were designed and developed. They have the advantage that the
performance of the CUT is unaffected by the sensors, as there is no direct electrical loading
of the circuit due to them. Since these sensors do not directly load the circuit under test,
they allow a non-intrusive methodology for testing. Also the sensors allow for on-line and
off-line test, and diagnosis capabilities.
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LinHui-an and 林慧銨. "Performance Simulation and Testing of Differential Protective Relays." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/40450296835134442267.
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碩士<br>崑山科技大學<br>電機工程研究所<br>94<br>The differential relays are the fast movement types to protect the electric systems. Therefore, it can be the main protection using in the power system, and doesn’t need to coordinate with the other electric protection. In addition, the differential relays protected the electric system is similar to the over-current relays. Both apply to the protection of different kinds of electric equipment in power system. However, when the electric equipment, which is protected by over-current relays, occurs troubles, it takes more time to alienate and remove those faults. Hence, it lighter changes structure due to electromagnetic and mechanical strength. It may get serious to produce electric arc and fire in electric equipment so as to result in the destruction of the switch equipment or the explosion of sleeve pipe. Hence, the electric differential relays are the most efficent way to rapidly isolate inner troubles in electric equipment and to protect power system.
This thesis is using electromagnetic transients program to combine with simulator F6150 in order to investigate the influence of temporary behavior in accidental process of power system on the electric differential relays, and then to improve the electric relays to mark and put, and to prevent and protect electric mistakes in the process of troubles. The project is based on practical model to realize the digitalization of protecting the electric transients performance.
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陳進忠. "Modeling the GPS Doppler Measurement and Testing the Differential Method." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/18900356202156442114.
Full textAbstract:
碩士<br>國立成功大學<br>航空太空工程學系<br>88<br>Global Position System( GPS ) has been known for its capability in providing real-time high-accuracy position information. However, its potential can be extended to provide a highly accurate velocity as well.
The aim of this study is to derive a suitable mathematical model for GPS Doppler measurements and to implement the differential technique to the measurements. The derived model and technique have been tested through the static and dynamic experiments. The dynamic test has been performed on an X-table.
Before the United States government decided to turn off the use of SA ( Selective Availability), the result from the static test indicates that an accuracy of 60 cm /sec for the derived model can be expected. With the differential method, the accuracy is improved to be within 0.5cm/sec. After the U.S. turned off the use of SA starting from May 01,2000, the result from the static test indicates that an accuracy of 10 cm/sec which is 80% improvement for the derived model can be expected. With the differential method, the accuracy is within 0.5 cm/sec. The dynamic result also shows the similar level of accuracy.
The Doppler-derived velocity can also be applied to car drag and vehicle orientation estimation. The result from the dynamic test indicates within one degree.
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Zhang, Yanqiao. "Estimation and Hypothesis Testing for Stochastic Differential Equations with Time-Dependent Parameters." Thesis, 2012. http://hdl.handle.net/10012/7009.
Full textAbstract:
There are two sources of information available in empirical research in finance: one corresponding to historical data and the other to prices currently observed in the markets. When proposing a model, it is desirable to use information from both sources. However in modern finance, where stochastic differential equations have been one of the main modeling tools, the common models are typically different for historical data and for current market data. The former are usually assumed to be time homogeneous, while the latter are typically time in-homogeneous. This practice can be explained by the fact that a time-homogeneous model is stationary and easier to estimate, while time-inhomogeneous model are required in order to replicate market data sufficiently well without creating arbitrage opportunities.
In this thesis, we study methods of statistical inference, both parametric and non-parametric, for stochastic differential equations with time-dependent parameters. In the first part, we propose a new class of stochastic differential equation with time-dependent drift and diffusion terms, where some of the parameters change according to a hidden Markov process. We show that under some technical conditions this innovative way of modeling switching times renders the resulting model stationary. We also explore different approaches to estimate parameters in our proposed model. Our simulation studies demonstrate that the parameters of the model can be efficiently estimated by using a version of the filtering method proposed in the literature. We illustrate our model and the proposed estimation method by applying them to interest rate data, and we detect significant time variations in early 1980s, when targets of the monetary policy in the United States were changed.
One of the known drawbacks of parametric models is the risk of model misspecification. In the second part of the thesis, we allow the drift to be time-dependent and nonparametric, and our objective is to estimate it using a single trajectory of the process. The main idea underlying this method is to approximate the time-dependent function with a sequence of polynomials. Since we can estimate efficiently only a finite number of parameters for any finite length of data, in our method we propose to relate the number of parameters to the length of the observed trajectory. This idea is similar to the method of sieves proposed by Grenander (Abstract Inference, 1981). The asymptotic analysis that we present is based on the assumption that the length of available data $T$ increases to infinity. We investigate two cases, one is a Brownian motion with time-dependent drift and the other corresponds to a class of mean-reverting stochastic differential equations with time-dependent mean-reversion level. In both cases we prove asymptotic consistency and normality of a modified maximum likelihood estimator of the projected time-dependent component. The main challenge in proving our results in the second case stems from two features of the problem: one is due to the fact that coefficients of projections change with $T$ and the other is related to the confounding effect between the mean-reversion speed and the level function. By applying our method to the same interest rate data we use in the first part, we find another evidence of time-variation in the drift term.