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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

A Study of the Torque Compensating Phase on the Positioning Accuracy of Indexing Tables

Ho, Sheng-Ying 05 July 2001 (has links)
Recently, many industries pursue the goal of automatic high-speed assembly and manufacturing. So how to meet the requirement of high-precision and high-speed automatic assembly equipment is an important issue. In automatic assembly equipment, the high-speed indexing devices have been widely used because of their features of high precision, no backlash, and compactness. With increasing operating speeds, the problems of shortage of motor power, poor indexing accuracy, vibration, and noise shall be solved. The torque compensation mechanism that is to be developed here is applied to keep motors operating at constant speeds by compensating the required torque. In previous researches, the researchers all devote to study torque compensation based on synchronous time chart. In this paper, it is aimed at compensation of the time control chart according the point of view of energy and the system model is built to simulate dynamic response of the system. Through the results of simulation and experiment, we will discover the relations between the compensation time chart and parameters about the high-speed indexing devices. It is expected to improve the precision of indexing devices according to those effective compensation time control charts.
162

Evaluation of a theoretical model of perceptual accuracy and self-management behavior in pediatric diabetes

Lane, Mariella Marie 01 November 2005 (has links)
This study evaluated a model of perceptual accuracy and self-management behavior in pediatric diabetes. Participants were 169 children and adolescents (10-18 years) attending diabetes summer camps. Error grid analysis quantified global perceptual accuracy and specific blood glucose estimation errors. The mean accuracy index was 15%, failure to detect hyperglycemia being the most frequent error. Path analysis evaluated models for failure to detect hypoglycemia, failure to detect hyperglycemia, and overestimation of normal blood glucose. Results reflected relatively good fit of the data with the models; however, results did not support mediational hypotheses and explained minimal variance in perceptual error. In sum, participants made considerable estimation errors that may affect self-management; however, results did not support the theoretical models in this sample.
163

Accuracy and precision of a technique to assess residual limb volume with a measuring-tape

Jarl, Gustav January 2003 (has links)
<p>Transtibial stump volume can change dramatically postoperatively and jeopardise prosthetic fitting. Differences between individuals make it hard to give general recommendations of when to fit with a definitive prosthesis. Measuring the stump volume on every patient could solve this, but most methods for volume assessments are too complicated for clinical use.</p><p>The aim of this study was to evaluate accuracy and intra- and interrater precision of a method to estimate stump volume from circumferential measurements. The method approximates the stump as a number of cut cones and the tip as a sphere segment.</p><p>Accuracy was evaluated theoretically on six scanned stump models in CAPOD software and manually on six stump models. Precision was evaluated by comparing measurements made by four CPOs on eight stumps. Measuring devices were a wooden rule and a metal circumference rule. The errors were estimated with intraclass correlation coefficient (ICC), where 0,85 was considered acceptable, and a clinical criterion that a volume error of ±5% was acceptable (5% corresponds to one stocking).</p><p>The method was accurate on all models in theory but accurate on only four models in reality. The ICC was 0,95-1,00 for intrarater precision but only 0,76 for interrater precision. Intra- and interrater precision was unsatisfying when using clinical criteria. Variations between estimated tip heights and circumferences were causing the errors.</p><p>The method needs to be developed and is not suitable for stumps with narrow ends. Using a longer rule (about 30 cm) with a set square end to assess tip heights is recommended to improve precision. Using a flexible measuring-tape (possible to disinfect) with a spring-loaded handle could improve precision of the circumferential measurements.</p>
164

Investigation and calibration of pulsed time-of-flight terrestrial laser scanners

Reshetyuk, Yuriy January 2006 (has links)
<p>This thesis has two aims. The first one is the investigation and analysis of the errors occurring in the measurements with pulsed time-of-flight (TOF) terrestrial laser scanners (TLS). A good understanding of the error sources and the relationships between them is necessary to secure the data accuracy. We subdivide these errors into four groups: instrumental, object-related, environmental and methodological. Based on our studies and the results obtained by other researchers, we have compiled an error model for TLS, which is used to estimate the single-point coordinate accuracy of a point in the point cloud, transformed to the specified coordinate system.</p><p>The second aim is to investigate systematic instrumental errors and performance of three pulsed TOF laser scanners – Callidus 1.1, Leica HDS 3000 and Leica HDS 2500 – and to develop calibration procedures that can be applied by the users to determine and correct the systematic errors in these instruments. The investigations have been performed at the indoor 3D calibration field established at KTH and outdoors. The systematic instrumental errors, or calibration parameters, have been estimated in a self-calibration according to the parametric least-squares adjustment in MATLAB®. The initial assumption was that the scanner instrumental errors are similar to those in a total station. The results have shown that the total station error model is applicable for TLS as a first approximation, but additional errors, specific to the scanner design, may appear. For example, we revealed a significant vertical scale error in the scanner Callidus 1.1, caused by the faults of the angular position sensor. The coordinate precision and accuracy of the scanners, estimated during the self-calibration, is at the level of several millimetres for Callidus 1.1 and Leica HDS 3000, and at the submillimetre level for Leica HDS 2500.</p><p>In other investigations, we revealed a range drift of up to 3 mm during the first few hours of scanning, presumably due to the changes in the temperature inside the scanners. The angular precision depends on the scanner design (“panoramic” or “camera-like”), and the angular accuracy depends on the significant calibration parameters in the scanner. Investigations of the influence of surface reflectance on the range measurements have shown that the indoor illumination and surface wetness have no tangible influence on the results. The type of the material does not affect, in general, the ranging precision for Callidus 1.1, but it affects the ranging precision and accuracy of the scanners Leica HDS 3000 and Leica HDS 2500. The reason may be different wavelength and, possibly, different design of the electronics in the laser rangefinders. Materials with high reflectance and those painted with bright “warning” colours may introduce significant offsets into the measured ranges (5 – 15 cm), when scanned from close ranges at normal incidence with the scanner Leica HDS 3000. “Mixed pixels” at the object edge may introduce a range error of several centimetres, on the average, depending on the type of the material. This phenomenon leads also to the distortions of the object size, which may be reduced by the removal of the “mixed pixels” based on their intensity. The laser beam intensity recorded by the scanner tends to decrease with an increased incidence angle, although not as assumed by the popular Lambertian reflectance model. Investigations of the scanner Leica HDS 2500 outdoors have revealed no significant influence of the “normal” atmospheric conditions on the range measurements at the ranges of up to 50 m.</p><p>Finally, we have developed and tested two simple procedures for the calibration of the vertical scale (and vertical index) error and zero error in laser scanners. We have also proposed an approach for the evaluation of the coordinate precision and accuracy in TLS based on the experiences from airborne laser scanning (ALS).</p>
165

Killar, ni ligger steget efter! : Empatisk avläsningsförmåga hos gymnasieelever.

Eriksson, Jimmy, Trulsson, Jennie January 2010 (has links)
W. Ickes, L. Stinson, V, Bisonette och S. Garcia (1990) standard stimulus paradigm är en metod för att mäta avläsning av en individs tankar och känslor. För att undersöka tjejer och killars empatiska avläsningsförmåga testades gymnasieelever med Ickes metod. Nittioåtta elever fick se en film som stannades av undersökningsledarna vid tio tillfällen. Deltagarna skulle vid varje stopp försöka läsa av kvinnan i filmens tankar och känslor och skriva ner dessa. Resultaten visade att tjejer är bättre än killar på att läsa av andra. Betyg i svenska och samhällskunskap, men inte matematik hade positivt samband med empati. Studien visade också att individer som gråter ofta har bra avläsningsförmåga. Tjejer med bra betyg och nära till gråt verkar ha de bästa intellektuella och emotionella verktygen för empatisk avläsning.
166

The Role of Emotional Intelligence in the Judgmental Accuracy of Neuroticism

Permack, Daniella 27 September 2011 (has links)
Recently there has been increased interest in using employment interviews to judge personality (Christiansen, 2005; Powell & Goffin, 2009). However, not all personality traits are accurately detected. Previous research has demonstrated that Neuroticism is a trait that is difficult to correctly identify (Lippa & Dietz, 2000; Powell & Goffin, 2009; Watson, 1989). Neuroticism differs from the other Big Five traits because it is more affective in nature. It is proposed that those that are superior at detecting emotions in others will be better at judging Neuroticism in others. The purpose of the current research is to examine the relationship between emotional intelligence(specifically accuracy at detecting emotions) and accuracy in making personality judgments. A significant relation was found between emotional intelligence and accuracy in detecting Neuroticism. Implications for research and practice are discussed.
167

Comparison of vertical scaling methods in the context of NCLB

Gotzmann, Andrea Julie Unknown Date
No description available.
168

Short-term Saccadic Adaptation in Patients with Amblyopia

Raashid, Rana Arham 16 July 2013 (has links)
This thesis investigates sensorimotor adaptive mechanisms that maintain the accuracy of goal-directed saccades in amblyopia, a developmental disorder characterized by impairment of spatiotemporal visual processing. Saccadic adaptation was induced by displacing the visual target toward initial fixation during the saccade. Eleven visually normal controls and seven patients with amblyopia were tested binocularly and monocularly with the amblyopic and fellow eye (non-dominant and dominant eye in controls) in three separate sessions. Patients with amblyopia exhibited reduced adaptation of saccadic gain compared to controls when viewing with the amblyopic eye and binocularly. Initiation of saccades was also delayed in patients when viewing with the amblyopic eye. It is proposed that the adaptive ability to modify the initial saccadic motor commands for maintaining short-term saccadic accuracy is impaired in amblyopia due to imprecise error signals. Moreover, this thesis reaffirms the notion that the error signals driving saccadic adaptation are visual in nature.
169

Short-term Saccadic Adaptation in Patients with Amblyopia

Raashid, Rana Arham 16 July 2013 (has links)
This thesis investigates sensorimotor adaptive mechanisms that maintain the accuracy of goal-directed saccades in amblyopia, a developmental disorder characterized by impairment of spatiotemporal visual processing. Saccadic adaptation was induced by displacing the visual target toward initial fixation during the saccade. Eleven visually normal controls and seven patients with amblyopia were tested binocularly and monocularly with the amblyopic and fellow eye (non-dominant and dominant eye in controls) in three separate sessions. Patients with amblyopia exhibited reduced adaptation of saccadic gain compared to controls when viewing with the amblyopic eye and binocularly. Initiation of saccades was also delayed in patients when viewing with the amblyopic eye. It is proposed that the adaptive ability to modify the initial saccadic motor commands for maintaining short-term saccadic accuracy is impaired in amblyopia due to imprecise error signals. Moreover, this thesis reaffirms the notion that the error signals driving saccadic adaptation are visual in nature.
170

Examining Accuracy : Drönare och drönarangrepp: retorik, praktik och historia

Elvander, Adam January 2014 (has links)
The military conflicts of the early 21st century have seen the introduction and rise of a new military technology: the armed drone. With the United States acting as the driving force behind this technological advancement, the U.S Air Force and intelligence agency CIA have madedrones their weapon of choice for pursuing suspected terrorists and insurgents in various remotelocations. American military leaders and policy makers assert that the armed drone’s high levelof accuracy make it the best available weapons platform for this task. However, new researchshows that the use of drones may result in more civilian casualties than previously thought, andmay in fact be more fallible than conventional aircraft in this respect. This paper examines this discrepancy between rhetoric and practice, and attempts to find potential causes for this in the development and early use of the first armed drone, the MQ-1 Predator. The paper cites statements from President Barack Obama and CIA director John Brennan and contrasts them with a recent research report on drone-caused civilian casualties, as well as examples of drone strikes where the wrong targets were struck. The analysis of the development and early use of the Predator Drone draws comparisons to Donald Mackenzie’s account of the development of accuracy for cold-war-era intercontinental ballistic missiles, applying the science and technology-concepts he uses to the case of the armed drone. The paper concludes with the argument that the accuracy of the early armed drones is fundamentally misunderstood or overestimated by U.S leaders, and that there are circumstances in the development-history of the system that may have contributed to this inconsistency.

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