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Validation of the Expanded McCarron-Dial System for Diagnosis of Neuropsychological Dysfunction in AdultsColaluca, Beth 08 1900 (has links)
The McCarron-Dial System (MDS) has successfully predicted vocational and independent living outcomes with neuropsychologically disabled individuals receiving rehabilitation services. In addition, preliminary validation studies suggest that the abbreviated MDS is useful for clinical neuropsychological diagnosis. The present study represents part of an ongoing research project aimed at validating the expanded version of the MDS for diagnosis of neuropsychological dysfunction. Specifically, it was hypothesized that the expanded MDS would be able to accurately discriminate between brain-damaged and non-brain-damaged individuals. Accurate diagnosis facilitates rehabilitation efforts for individuals with neuropsychological disabilities and the data profile provided by the expanded version of the MDS can consequently form the basis from which more complete individual treatment and rehabilitation plans can be conceptualized.
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Assessment of Brain Damage: Discriminant Validity of a Neuropsychological Key Approach with the McCarron-Dial SystemNorton, Carole Lynn 12 1900 (has links)
The present study investigates the predictive accuracy of a key approach to interpretation of the verbal-spatialcognitive (VSC) and sensorimotor (SM) factors of the McCarron-Dial System (MDS). The subjects include 99 brain damaged and 30 normal adults. The following research questions are addressed: (a) Does the neuropsychological key classify brain damaged and non-brain damaged subjects at a level significantly above chance? (b) Among the brain damaged subjects, does the neuropsychological key identify right brain damage, left brain damage and diffuse brain damage at an accuracy level significantly above chance? (c) Is the neuropsychological key approach superior to the empirical model derived from discriminant function analysis in predictive accuracy? The neuropsychological key correctly classifies 90% of the cases as brain damaged and 90% of the cases as non-brain damaged, for a total of 89.9% predictive accuracy. The obtained Kappa coefficient of .74 is statistically significant. The key accurately classifies 71.4% of the brain damaged group as right damage, 70% as left damage, and 93.8% as diffuse damage, for a total predictive accuracy of 7 9.5%. The Kappa coefficient of .68 is statistically significant. Chi square analysis of the difference between the key approach and multiple discriminant function analysis reveals that no significant difference is present between the accuracy of the two approaches in differentiating between brain damaged and non-brain damaged, or in differentiating among left, right and diffuse brain damage. The results support the validity of a neuropsychological key approach to interpretation of the McCarron-Dial System, although cross-validation is indicated to confirm the stability of these results. Differences in sex, educational level and racial composition of the comparison groups may have affected the results obtained. Refinement of the key in future research and the addition of test instruments assessing memory, auditory processing, attention and emotional/behavioral variables are recommended.
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Finite Element Analysis of Defects in Cord-Rubber Composites and Hyperelastic MaterialsBehroozinia, Pooya 24 August 2017 (has links)
In recent years, composite materials have been widely used in several applications due to their superior mechanical properties including high strength, high stiffness, and low density. Despite the remarkable advancements in theoretical and computational methods for analyzing composites, investigating the effect of lamina properties and lay-up configurations on the strength of composites still remains an active field of research. Finite Element Method (FEM) and Extended Finite Element Method (XFEM) are powerful tools for solving the boundary value problems. One of the objectives of this work is to employ XFEM as a defect identification tool for predicting the crack initiation and propagation in composites. Another major objective of this study is to investigate the damage development in hyperelastic materials. Two Finite Element models are adopted to study this phenomenon: multiscale modeling of the cord-rubber composites in tires and modeling of intelligent tires for evaluating the feasibility of the proposed defect detection technique.
A new three-dimensional finite element approach based on the multiscale progressive failure analysis is employed to provide the theoretical predictions for damage development in the cord-rubber composites in tires. This new three-dimensional model of the cord-rubber composite is proposed to predict the different types of damage including matrix cracking, delamination, and fiber failure based on the micro-scale analysis. This process is iterative and data is shared between the finite element and multiscale progressive failure analysis. It is shown that the proposed cord-rubber composite model solves the problems corresponding to embedding the rebar elements to the solid elements and also increases the fidelity of numerical analysis of composite parts since the laminate characteristic variables are determined from the microscopic parameters. A tire rolling analysis is then conducted to evaluate the effects of different variables corresponding to the cord-rubber composite on the performance of tires.
Tires operate on the principle of safe life and are the only parts of the vehicle which are in contact with the road surface. Establishing a computational method for defect detection in tire structures will help manufacturers to fix and develop more reliable tire designs. A Finite Element model of a tire with a tri-axial accelerometer attached to its inner-liner was developed and the effects of changing the normal load, longitudinal velocity and tire-road contact friction on the acceleration signal were investigated. Additionally, using the model, the acceleration signals obtained from several accelerometers placed in different locations around the inner-liner of the intelligent tire were analyzed and the defected areas were successfully identified. Using the new intelligent tire model, the lengths, locations, and the minimum number of accelerometers in damage detection in tires are determined. Comparing the acceleration signals obtained from the damaged and original tire models results in detecting defects in tire structures. / PHD / In recent years, composite materials have been widely used in several applications due to their superior mechanical properties. Studying the effect of different configurations and thicknesses on the strength of composites still remains an active field of research. Finite Element Method (FEM) is a powerful tool for simulating real problems. One of the objectives of this work is to employ FEM to show the damage development in the composite and rubber-based materials. Two Finite Element models are adopted to study this phenomenon: multiscale modeling of the cord-rubber composites in tires and modeling of intelligent tires, which are tires with sensors attached to the inner-liner, for evaluating the feasibility of the proposed defect detection technique.
A new three-dimensional finite element approach based on the multiscale progressive failure analysis is employed to provide the theoretical predictions for damage development in the cord-rubber composites in tires. This new three-dimensional model of the cord-rubber composite is proposed to predict the different types of damage based on the micro-scale analysis. This process goes through the damage prediction formulations in each step to check whether damage happened or not. If damage happened, the stiffness of materials will be decreased. The fidelity of analysis is increased since the macro-scale mechanical properties are calculated based on the micro-scale properties. A tire rolling analysis is then conducted to evaluate the effects of different variables corresponding to the cord-rubber composite on the performance of tires.
Tires operate on the principle of safe life and are the only parts of the vehicle which are in contact with the road surface. Establishing a computational method for defect detection in tire structures will help manufacturers to fix and develop more reliable tire designs. A tire with a sensor attached to its inner-liner was developed and the effects of changing the normal load, velocity and tire-road contact friction on the acceleration signal were investigated. Additionally, using the model, the acceleration signals obtained from several sensors placed in different locations around the inner-liner of the tire were analyzed. The defected areas were successfully identified by comparing the acceleration signals obtained from the damaged and original tire models.
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Performance of Children With and Without Traumatic Brain Injury on the Process Scoring System for the Intermediate Category TestBass, Catherine 05 1900 (has links)
The clinical utility of the Intermediate Category Test, a measure of executive functioning in children 9 to 14 years of age, is currently limited by the availability of only a Total Error score for normative interpretation. The Process Scoring System (PSS) was developed to provide a standardized method of assessing specific processing patterns and problem-solving errors. The purpose of this study was to determine the ability of the PSS scores to discriminate between children with and without suspected executive deficits, thereby providing evidence of criterion-related validity.
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Neuropsychological Assessment of Brain Damage: A Validation Study of the McCarron-Dial SystemDial, Jack Grady 08 1900 (has links)
The present study investigates the effect of brain damage on verbal-spatial-cognitive (VSC) and sensorimotor (SM) measures included in the McCarron-Dial System (MDS). The subjects include 141 brain damaged adults and 42 psychiatric controls. The following research questions are addressed: (a) Does the brain damaged group differ significantly from controls? (b) Are there significant differences among left, right, anterior, posterior, and diffuse brain damaged groups? (c) Do early onset, late onset, acute, and chronic damaged groups differ significantly? and (d) Does a cerebral palsy group differ significantly from a non-CP brain damaged group?
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Assessment of Visual Memory and Learning by Selective RemindingCummins, Shirley Jean 08 1900 (has links)
A test of free recall visual memory and learning was developed for the present study. The purpose of the study was to determine the utility of the Visual Selective Reminding Test and the Verbal Selective Reminding Test for differentiating among groups of patients having memory impairments with organic etiologies. It was hypothesized that neurologically impaired patients would perform differently on the Visual and Verbal Selective Reminding Tests, the difference depending on the location of the underlying brain damage. Forty right handed male patients at a Veterans Administration hospital served as subjects. The patients were grouped according to the location of their brain damage; left hemisphere, right hemisphere, diffuse damage, and no brain damage. There were 10 patients in each group. Each patient was given the verbal and the visual memory tests in counterbalanced order and the Shipley estimate of intelligence.
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Advanced functional and sequential statistical time series methods for damage diagnosis in mechanical structures / Εξελιγμένες συναρτησιακές και επαναληπτικές στατιστικές μέθοδοι χρονοσειρών για την διάγνωση βλαβών σε μηχανολογικές κατασκευέςΚοψαυτόπουλος, Φώτης 01 February 2013 (has links)
The past 30 years have witnessed major developments in vibration based damage detection and identification, also collectively referred to as damage diagnosis. Moreover, the past 10 years have seen a rapid increase in the amount of research related to Structural Health Monitoring (SHM) as quantified by the significant escalation in papers published on this subject. Thus, the increased interest in this engineering field and its associated potential constitute the main motive for this thesis.
The goal of the thesis is the development and introduction of novel advanced functional and sequential statistical time series methods for vibration based damage diagnosis and SHM. After the introduction of the first chapter, Chapter II provides an experimental assessment and comparison of vibration based statistical time series methods for Structural Health Monitoring (SHM) via their application on a lightweight aluminum truss structure and a laboratory scale aircraft skeleton structure. A concise overview of the main non-parametric and parametric methods is presented, including response-only and excitation-response schemes. Damage detection and identification are based on univariate (scalar) versions of the methods, while both scalar (univariate) and vector (multivariate) schemes are considered. The methods' effectiveness for both damage detection and identification is assessed via various test cases corresponding to different damage scenarios, multiple experiments and various sensor locations on the considered structures. The results of the chapter confirm the high potential and effectiveness of vibration based statistical time series methods for SHM.
Chapter III investigates the identification of stochastic systems under multiple operating conditions via Vector-dependent Functionally Pooled (VFP) models. In many applications a system operates under a variety of operating conditions (for instance operating temperature, humidity, damage location, damage magnitude and so on) which affect its dynamics, with each condition kept constant for a single commission cycle. Typical examples include mechanical structures operating under different environmental conditions, aircrafts under different flight conditions (altitude, velocity etc.), structures under different structural health states (various damage locations and magnitudes). In this way, damage location and magnitude may be considered as parameters that affect the operating conditions and as a result the structural dynamics. This chapter's work is based on the novel Functional Pooling (FP) framework, which has been recently introduced by the Stochastic Mechanical Systems \& Automation (SMSA) group of the Mechanical Engineering and Aeronautics Department of University of Patras. The main characteristic of Functionally Pooled (FP) models is that their model parameters and innovations sequence depend functionally on the operating parameters, and are projected on appropriate functional subspaces spanned by mutually independent basis functions. Thus, the fourth chapter of the thesis addresses the problem of identifying a globally valid and parsimonious stochastic system model based on input-output data records obtained under a sample of operating conditions characterized by more than one parameters. Hence, models that include a vector characterization of the operating condition are postulated. The problem is tackled within the novel FP framework that postulates proper global discrete-time linear time series models of the ARX and ARMAX types, data pooling techniques, and statistical parameter estimation. Corresponding Vector-dependent Functionally Pooled (VFP) ARX and ARMAX models are postulated, and proper estimators of the Least Squares (LS), Maximum Likelihood (ML), and Prediction Error (PE) types are developed. Model structure estimation is achieved via customary criteria (Bayesian Information Criterion) and a novel Genetic Algorithm (GA) based procedure. The strong consistency of the VFP-ARX least squares and maximum likelihood estimators is established, while the effectiveness of the complete estimation and identification method is demonstrated via two Monte Carlo studies.
Based on the postulated VFP parametrization a vibration based statistical time series method that is capable of effective damage detection, precise localization, and magnitude estimation within a unified stochastic framework is introduced in Chapter IV. The method constitutes an important generalization of the recently introduced Functional Model Based Method (FMBM) in that it allows, for the first time in the statistical time series methods context, for complete and precise damage localization on continuous structural topologies. More precisely, the proposed method can accurately localize damage anywhere on properly defined continuous topologies on the structure, instead of pre-defined specific locations. Estimator uncertainties are taken into account, and uncertainty ellipsoids are provided for the damage location and magnitude. To achieve its goal, the method is based on the extended class of Vector-dependent Functionally Pooled (VFP) models, which are characterized by parameters that depend on both damage magnitude and location, as well as on proper statistical estimation and decision making schemes. The method is validated and its effectiveness is experimentally assessed via its application to damage detection, precise localization, and magnitude estimation on a prototype GARTEUR-type laboratory scale aircraft skeleton structure. The damage scenarios considered consist of varying size small masses attached to various continuous topologies on the structure. The method is shown to achieve effective damage detection, precise localization, and magnitude estimation based on even a single pair of measured excitation-response signals.
Chapter V presents the introduction and experimental assessment of a sequential statistical time series method for vibration based SHM capable of achieving effective, robust and early damage detection, identification and quantification under uncertainties. The method is based on a combination of binary and multihypothesis versions of the statistically optimal Sequential Probability Ratio Test (SPRT), which employs the residual sequences obtained through a stochastic time series model of the healthy structure. In this work the full list of properties and capabilities of the SPRT are for the first time presented and explored in the context of vibration based damage detection, identification and quantification. The method is shown to achieve effective and robust damage detection, identification and quantification based on predetermined statistical hypothesis sampling plans, which are both analytically and experimentally compared and assessed. The method's performance is determined a priori via the use of the analytical expressions of the Operating Characteristic (OC) and Average Sample Number (ASN) functions in combination with baseline data records, while it requires on average a minimum number of samples in order to reach a decision compared to most powerful Fixed Sample Size (FSS) tests. The effectiveness of the proposed method is validated and experimentally assessed via its application on a lightweight aluminum truss structure, while the obtained results for three distinct vibration measurement positions prove the method's ability to operate based even on a single pair of measured excitation-response signals.
Finally, Chapter VI contains the concluding remarks and future perspectives of the thesis. / Κατά τη διάρκεια των τελευταίων 30 ετών έχει σημειωθεί σημαντική ανάπτυξη στο πεδίο της ανίχνευσης και αναγνώρισης βλαβών, το οποίο αναφέρεται συνολικά και σαν διάγνωση βλαβών. Επίσης, κατά την τελευταία δεκαετία έχει σημειωθεί σημαντική πρόοδος στον τομέα της παρακολούθησης της υγείας (δομικής ακεραιότητας) κατασκευών. Στόχος αυτής της διατριβής είναι η ανάπτυξη εξελιγμένων συναρτησιακών και επαναληπτικών μεθόδων χρονοσειρών για τη διάγνωση βλαβών και την παρακολούθηση της υγείας κατασκευών υπό ταλάντωση. Αρχικά γίνεται η πειραματική αποτίμηση και κριτική σύγκριση των σημαντικότερων στατιστικών μεθόδων χρονοσειρών επί τη βάσει της εφαρμογής τους σε πρότυπες εργαστηριακές κατασκευές. Εφαρμόζονται μη-παραμετρικές και παραμετρικές μέθοδοι που βασίζονται σε ταλαντωτικά σήματα διέγερσης και απόκρισης των κατασκευών. Στη συνέχεια αναπτύσσονται στοχαστικά συναρτησιακά μοντέλα για την στοχαστική αναγνώριση κατασκευών υπό πολλαπλές συνθήκες λειτουργίας. Τα μοντέλα αυτά χρησιμοποιούνται για την αναπαράσταση κατασκευών σε διάφορες καταστάσεις βλάβης (θέση και μέγεθος βλάβης), ώστε να είναι δυνατή η συνολική μοντελοποίσή τους για όλες τις συνθήκες λειτουργίας. Τα μοντέλα αυτά αποτελούν τη βάση στην οποία αναπτύσσεται μια συναρτησιακή μέθοδος η οποία είναι ικανή να αντιμετωπίσει συνολικά και ενιαία το πρόβλημα της ανίχνευσης, εντοπισμού και εκτίμησης βλαβών σε κατασκευές. Η πειραματική αποτίμηση της μεθόδου γίνεται με πολλαπλά πειράματα σε εργαστηριακό σκελετό αεροσκάφους. Στο τελευταίο κεφάλαιο της διατριβής προτείνεται μια καινοτόμος στατιστική επαναληπτική μέθοδο για την παρακολούθηση της υγείας κατασκευών. Η μέθοδος κρίνεται αποτελεσματική υπό καθεστώς λειτουργικών αβεβαιοτήτων, καθώς χρησιμοποιεί επαναληπτικά και στατιστικά τεστ πολλαπλών υποθέσεων. Η αποτίμηση της μεθόδου γίνεται με πολλαπλά εργαστηριακά πειράματα, ενώ η μέθοδος κρίνεται ικανή να λειτουργήσει με τη χρήση ενός ζεύγους ταλαντωτικών σημάτων διέγερσης-απόκρισης.
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