The computer to pupil ratio has changed drastically in the past decades, from 125:1 in 1983 to less than 2:1 in 2009 (Gray, Thomas, and Lewis, 2010), allowing for teachers and students to integrate technology throughout the educational experience. The area of educational assessment has adapted to the increased use of technology. Trends in assessment and technology include a movement from paper-based to computer-based testing for all types of assessments, from large-scale assessments to teacher-created classroom tests. Computer-based testing comes with many benefits when compared to paper-based testing, but it is necessary to determine if results are comparable, especially in situations where computer-based and paper-based tests can be used interchangeably. The main purpose of this study was to expand upon the base of research comparing paper-based and computer-based testing, specifically with elementary students and mathematical fluency. The study was designed to answer the following research questions: (1) Are there differences in fluency-based performance on math computation problems presented on paper versus on the computer? (2) Are there differential mode effects on computer-based tests based on sex, grade level, or ability level? A mixed-factorial design with both within- and between-subject variables was used to investigate the differences between performance on paper-based and computer-based tests of mathematical fluency. Participants completed both paper- and computer-based tests, as well as the Group Math Assessment and Diagnostic Evaluation as a measure of general math ability. Overall findings indicate that performance on paper- and computer-based tests of mathematical fluency are not comparable and student grade-level may be a contributing factor in that difference.

An expert elicitation is a method of eliciting subjective probability distributions over key parameters from experts. Traditionally an expert elicitation has taken the form of a face-to-face interview; however, interest in using online methods has been growing. This thesis compares two elicitation modes and examines the effectiveness of an interactive online survey compared to a face-to-face interview. Differences in central values, overconfidence, accuracy and satisficing were considered. The results of our analysis indicated that, in instances where the online and face-to-face elicitations were directly comparable, the differences between the modes was not significant. Consequently, a carefully designed online elicitation may be used successfully to obtain accurate forecasts.

Thesis advisor: Ina V.S. Mullis / This dissertation describes the foundation for maintaining TIMSS’ 20 year trend measurements with the introduction of a new computer- and tablet-based mode of assessment delivery—eTIMSS. Because of the potential for mode effects on the psychometric behavior of the trend items that TIMSS relies on to maintain comparable scores between subsequent assessment cycles, development efforts for TIMSS 2019 began over three years in advance. This dissertation documents the development of eTIMSS over this period and features the methodology and results of the eTIMSS Pilot / Item Equivalence Study. The study was conducted in 25 countries and employed a within-subjects, counterbalanced design to determine the effect of the mode of administration on the trend items. Further analysis examined score-level mode effects in relation to students’ socioeconomic status, gender, and self-efficacy for using digital devices. Strategies are discussed for mitigating threats of construct irrelevant variance on students’ eTIMSS performance. The analysis by student subgroups, similar item discriminations, high cross-mode correlations, and equivalent rankings of country means provide support for the equivalence of the mathematics and science constructs between paperTIMSS and eTIMSS. However, the results revealed an overall mode effect on the TIMSS trend items, where items were more difficult for students in digital formats compared to paper. The effect was larger in mathematics than science. An approach is needed to account for the mode effects in maintaining trend measurements from previous cycles to TIMSS 2019. Each eTIMSS 2019 trend country will administer the paper trend booklets to an additional nationally representative bridge sample of students, and a common population equating approach will ensure the link between paperTIMSS and eTIMSS scores. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement and Evaluation.

Nonlinear response history analysis is considered as the most accurate analytical tool for estimating seismic response. However, there are several shortcomings in the application of nonlinear response history analysis, resulting from its complexity. Accordingly, simpler approximate nonlinear analysis procedures are preferred in practice. These procedures are called nonlinear static analysis or pushover analysis in general. The recently developed Generalized Pushover Analysis (GPA) is one of them. In this thesis study, GPA is presented and evaluated comparatively with the nonlinear time history analysis and modal pushover analysis. A generalized pushover analysis procedure was developed for estimating the inelastic seismic response of structures under earthquake ground excitations (Sucuoglu and G&uuml / nay, 2011). In this procedure, different load vectors are applied separately to the structure in the incremental form until the predefined seismic demand is obtained for each force vector. These force vectors are named as generalized force vectors. A generalized force vector is a combination of modal forces, and simulates the instantaneous force distribution on the system when a given response parameter reaches its maximum value during the dynamic response. In this method, the maximum interstory drift parameters are selected as target demand parameters and used for the derivation of generalized force vectors. The maximum value of any other response parameter is then obtained from the analysis results of each generalized force vector. In this way, this procedure does do not suffer from the statistical combination of inelastic modal responses. It is further shown in this study that the results obtained by using the mean spectrum of a set of ground motions are almost identical to the mean of the results obtained from separate generalized pushover analyses under each ground motion in the set. These results are also very close to the mean results of nonlinear response history analyses. A practical implementation of the proposed generalized pushover analysis is also developed in this thesis study where the number of pushovers is reduced in view of the number of significant modes contributing to seismic response. It has been demonstrated that the reduced generalized pushover analysis is equally successful in estimating maximum member deformations and member forces as the full GPA under a ground excitation, and sufficiently accurate with reference to nonlinear response history analysis.

Because conventional seismic force resisting systems rely on yielding of key structural members to limit seismic forces, structural damage is expected after a design-level earthquake. Repairing this damage can be very expensive, if it is possible at all. Researchers have been developing a new family of self-centring systems that avoid structural damage. One such system is a controlled rocking steel frame, which is the subject of this thesis. In a controlled rocking steel frame, the columns of a frame are permitted to uplift from the foundation, and the response is controlled by using a combination of post-tensioning and energy dissipation. Although previous studies have confirmed the viability of this system, they have also shown that rocking does not fully limit the peak seismic forces because of higher mode effects. If a structure is designed to account for these effects, it may be uneconomical, but if it is not designed to account for them, it may be unsafe. The purpose of this thesis is to develop recommendations for the design of controlled rocking steel frames, particularly with regard to higher mode effects. A theoretical framework for understanding higher mode effects is developed, and large-scale shake table testing is used to study the behaviour of a controlled rocking steel frame. Two mechanisms are proposed to mitigate the increase in structural forces due to higher mode effects, and these mechanisms are validated by shake table testing. Numerical modelling of controlled rocking steel frames is shown to become more reliable when higher mode mitigation mechanisms are used to limit the seismic response. In the final chapters, the thesis proposes and validates a new methodology for the limit states design of controlled rocking steel frames.

Because conventional seismic force resisting systems rely on yielding of key structural members to limit seismic forces, structural damage is expected after a design-level earthquake. Repairing this damage can be very expensive, if it is possible at all. Researchers have been developing a new family of self-centring systems that avoid structural damage. One such system is a controlled rocking steel frame, which is the subject of this thesis. In a controlled rocking steel frame, the columns of a frame are permitted to uplift from the foundation, and the response is controlled by using a combination of post-tensioning and energy dissipation. Although previous studies have confirmed the viability of this system, they have also shown that rocking does not fully limit the peak seismic forces because of higher mode effects. If a structure is designed to account for these effects, it may be uneconomical, but if it is not designed to account for them, it may be unsafe. The purpose of this thesis is to develop recommendations for the design of controlled rocking steel frames, particularly with regard to higher mode effects. A theoretical framework for understanding higher mode effects is developed, and large-scale shake table testing is used to study the behaviour of a controlled rocking steel frame. Two mechanisms are proposed to mitigate the increase in structural forces due to higher mode effects, and these mechanisms are validated by shake table testing. Numerical modelling of controlled rocking steel frames is shown to become more reliable when higher mode mitigation mechanisms are used to limit the seismic response. In the final chapters, the thesis proposes and validates a new methodology for the limit states design of controlled rocking steel frames.

No description available.

No description available.

Riskanalysverktyget failure mode and effects analysis (FMEA) som analyserar kompo-nenter och signaler är beroende av att designen av fordonets elsystem finns tillgängligt och utförs därför sent i utvecklingsprocessen av elsystem. Detta medför att vissa fel inte analyseras i tid och kanske måste designas bort i efterhand vilket kan leda till ökad sy-stemkomplexitet samt längre och dyrare utvecklingsprocesser.Målet med examensarbetet är att genom en litteraturstudie ta reda på om det finns me-toder eller arbetssätt som gör att Scania tidigt i utvecklingsprocessen av elsystem kan genomföra funktionsanalyser i sitt riskanalysarbete med FMEA samt analysera dessa.Resultatet av detta examensarbete visar att det är möjligt att påbörja FMEA-arbetet tidigt i utvecklingsprocessen av elsystem om ingenjörerna utgår från ett funktionsperspektiv i riskanalysarbetet där de listar och rangordnar de funktioner som tillsammans realiserar en eller flera funktionaliteter samt deras felmoder, feleffekter, feldetektering, allvarlighet, sannolikhet och frekvens. Med hjälp av en FFMEA kan ingenjörerna tidigt i utveck-lingsprocessen av elsystem snabbt och effektivt hantera de identifierade säkerhetskritiska funktionerna.En befintlig funktionalitet på Scania har brutits ned i funktioner och en FFMEA har genomförts på dessa som en demonstration på hur en FFMEA kan genomföras och se ut. / The risk analysis tool failure mode and effects analysis (FMEA) that analyzes the com-ponents and signals of a electrical system is design dependent and are therefore per-formed late in the development process of electrical systems. This could lead to that some errors are not analyzed in time and may need to be designed away which can lead to increased system complexity as well as longer and more expensive development proc-esses.The objective of this study is that through a literature review identify if there are any methods or approaches that enables Scania to implement a functional hazard analyzes early in the development process of electrical systems and to analyze these.The results of this thesis shows that it is possible to start the FMEA process early in the development process of the electrical system if the engineers have a functional perspec-tive in mind when performing the risk analysis where they list and rank the functions that is provided by the electrical system and their failure modes, failure effects, failure de-tection, severity, probability and occurrence.By using a function based FMEA, the engineer(s) can identify and promptly handle the safety critical functions early in the development process of a electrical system.A existing functionality at Scania has been broken down into functions and a functional hazard analysis has been performed on these as a demonstration of how a function based FMEA can be carried out and look like.

<p>More than twenty-five percent of the risk of failure for the 9-1-1 system can be contributed to blocked lines. The second major failure mode is unhelpful or improperly trained telecommunicators. The quick dispatch of emergency response teams in the event of any disaster or accident through the use of the 9-1-1 system is crucial to the well-being of the public. These potential failure modes prevent desperately awaited help from arriving as soon as possible. Therefore, the reliability and effectiveness of the system must be evaluated.</p> <p> The objective of this report is to identify failure modes of the 9-1-1 system, calculate their criticality, prioritize them in order of risk, and propose economical and feasible alternative solutions.</p> <p> Failure mode, effects, and criticality analysis (FMECA) is an evaluation tool that proves extremely useful when a system is desired to be kept highly effective and reliable. In this report, it is applied within the Systems Engineering Process to analyze areas of weakness throughout the New Jersey 9-1-1 system. FMECA is widely used throughout the military and commercial industry. It illustrates the interrelationships between causes and effects of failure modes, and helps to focus attention on high risk areas so that proper precautions may be taken.</p> <p> First, the use of FMECA is reviewed. The step-by-step procedures are next illustrated, and it is noted that FMECA must be tailored to each system relative to its characteristics and desired application. The New Jersey 9-1-1 system is analyzed in detail and is found to be an effective emergency communications network. However, technology has not yet provided solutions to all possible failures. In fact, technology adds to the failure possibilities. Possible future areas of development are included.</p> <p> / Master of Science