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An evaluation of the accuracy of community-based automated blood pressure machinesVogel, Elisa, Bowen, Shannon January 2010 (has links)
Class of 2010 Abstract / OBJECTIVES: The purpose of this study was to evaluate the accuracy of automated blood pressure machines located within community-based pharmacies.
METHODS: A descriptive, prospective study was performed comparing blood pressure readings obtained from community-based automated blood pressure machines to readings from a mercury manometer for 2 different arm sizes. Mercury manometer readings were obtained using the standardized technique and a standard cuff recommended by the American Heart Association
RESULTS: For the subject with the small arm size, the automated blood pressure machines reported systolic pressure readings that were, on average, 16.1 mmHg higher than those obtained manually by the researcher. The mean systolic and pressure readings for the subject with the medium arm size were not significantly different between the automated machine and manual manometer readings, and the diastolic pressure readings were modestly different.
CONCLUSIONS: We found that automated blood pressure machines located within a sample of representative community pharmacies were neither accurate nor reliable. The accuracy of the readings are especially inaccurate for subjects with a smaller than average arm size.
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Citation Accuracy in the Journal Literature of Four Disciplines : Chemistry, Psychology, Library Science, and English and American LiteratureSassen, Catherine J. (Catherine Jean) 05 1900 (has links)
The primary purpose of this study was to determine if there is a relationship between the bibliographic citation practices of the members of a discipline and the emphasis placed on citation accuracy and purposes in the graduate instruction of the discipline.
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On the Accuracy of Wireless Capsule Endoscope RF and Visual LocalizationZhou, Mingda 29 April 2015 (has links)
Wireless capsule endoscope (WCE) is becoming one of the most patient-friendly inspection device which provides visual investigation of entire gastrointestinal (GI) tract, while the other traditional (wired) endoscopic devices are usually designed for colon inspection. Locating abnormalities tract such as tumors, polyps and bleedings with wire-connected endoscope in GI tract is simple as long as we could measure the length of the wires inside human body. When WCE is applied, however, this becomes a critical challenge of examination since there is no wires connected to WCE while physicians need to find the exact locations of WCE to identify the position of abnormalities. To locate the WCE accurately, methods have come up in last decade including time of arrival (TOA) based methods, received signal strength (RSS) based methods, phase difference of arrival (PDOA) based methods, electromagnetic methods and video-based tracking methods, etc.. In this thesis, time of arrival (TOA), phase difference of arrival (PDOA) and video based localization methods are proposed and their performance are analyzed. We first propose an novel video-based tracking technique based on maximum mutual information. With this technique, we can tell the displacement and rotation between consecutive frames. Then in TOA chapter, the Cramer-Rao lower bound (CRLB) of TOA ranging inside homogeneous tissue is calculated first then three TOA ranging methods are proposed and compared with the CRLB which is used as the performance guideline. After that, PDOA based ranging technique is applied exploiting phase difference of two signals. Since the phase difference is taken into consideration, the ranging ambiguity is eliminated. We also evaluate the performance of the proposed PDOA ranging method. Finally, these ranging methods are evaluated in non-homogeneous tissues, the results of which are also compared to that in homogeneous tissue to analyze the impact of non-homogeneity.
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Dynamic Written Corrective Feedback: Achieving ManageabilityShelley, Angela 13 June 2014 (has links)
This thesis provides reflections on a practice of corrective feedback known as dynamic Written Corrective Feedback (dynamic WCF). First addressing 20 years of concerns regarding the highly-debated topic of feedback in second language (L2) writing and then outlining dynamic WCF as a pedagogical practice founded on four principles, the thesis finally introduces a recently developed handbook for instructors. This handbook presents the four foundational principles of dynamic WCF (timeliness, manageability, meaningfulness, and constancy) to first-time instructors and supports the implementation of dynamic WCF to optimize benefit and enhance manageability in written corrective feedback.
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Accuracy of Emergency Department Nurse Triage Level Designation and Delay in Care of Patients with Symptoms Suggestive of Acute Myocardial InfarctionSammons, Susan S 14 February 2012 (has links)
More than 6 million people present to emergency departments (EDs) across the US annually with chief complaints of chest pain or other symptoms suggestive of acute myocardial infarction (AMI). Of the million who are diagnosed with AMI, 350,000 die during the acute phase. Accurate triage in the ED can reduce mortality and morbidity, yet accuracy rates are low and delays in patient care are high. The purpose of this study was to explore the relationship between (a) patient characteristics, registered nurse (RN) characteristics, symptom presentation, and accuracy of ED RN triage level designations and (b) delay of care of patients with symptoms suggestive of AMI. Constructs from Donabedian’s Structure-Process-Outcome model were used to guide this study.
Descriptive correlational analyses were performed using retrospective triage data from electronic medical records. The sample of 286 patients with symptoms suggestive of AMI comprised primarily Caucasian, married, non-smokers, of mean age of 61 with no prior history of heart disease. The sample of triage nurses primarily comprised Caucasian females of mean age of 45 years with an associate’s degree in nursing and 11 years’ experience in the ED.
RNs in the study had an accuracy rate of 54% in triage of patients with symptoms suggestive of AMI. The older RN was more accurate in triage level designation. Accuracy in triage level designations was significantly related to patient race/ethnicity. Logistic regression results suggested that accuracy of triage level designation was twice as likely (OR 2.07) to be accurate when the patient was non-Caucasian. The patient with chest pain reported at triage was also twice as likely (OR 2.55) to have an accurate triage than the patient with no chest pain reported at triage. Electrocardiogram (ECG) delay was significantly greater in the patient without chest pain and when the RN had more experience in ED nursing. Triage delay was significantly related to patient gender and race/ethnicity, with female patients and non-Caucasian patients experiencing greater delay. An increase in RN years of experience predicted greater delay in triage. Further studies are necessary to understand decisions at triage, expedite care, improve outcomes, and decrease deaths from AMI.
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Real-time transit information accuracy: impacts and proposed solutionsGooze, Aaron Isaac 10 April 2013 (has links)
When presented in a practical format, real-time transit information can improve sustainable travel methods by enhancing the transit experience. Larger shifts towards public transportation have cascading effects on the environment, health and urban form. The research will identify the positive shift realized by the continued development of a set of real-time transit information tools, specifically in the Seattle region. In addition, it will analyze real-time prediction errors and their effects on the rider experience. Three years after the development of location-aware mobile applications for OneBusAway - a suite of real-time information tools - a survey of current users was conducted by the author in 2012 in order to compare the results to a 2009 study. The results show significant positive shifts in satisfaction with transit, perceptions of safety and ridership frequency as a result of the increased use of real-time arrival information. However, the research will also provide a perspective of the margin of error riders come to expect and the negative effects resulting from inaccuracies with the real-time data. While riders on average will ride less when they have experienced errors, a robust issue-reporting system as well as the resolution of the error can mitigate the initial negative effects. In response, the research provides a framework for a crowd-sourced error reporting process in order to improve the level of accuracy by means of a Transit Ambassador Program. Finally, a pilot program developed by the author is assessed against this framework and insight is provided within the context of the real-time information system.
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Drawing Accuracy, Quality and ExpertiseCarson, Linda Christine January 2012 (has links)
Drawing from a still-life is a complex visuomotor task. Nevertheless, experts depict three-dimensional subjects convincingly with two-dimensional images. Drawing research has previously been limited by its general dependence on qualitative assessment of drawings by human critics and on retrospective self-report of expertise by drawers. Accuracy measures cannot hope to encompass all the properties of “goodness” in a drawing but this thesis will show that they are consistent with the expertise of the drawers and with the quality ratings of human critics, they are robust enough to support analysis of ecologically valid drawing tasks from complex three-dimensional stimuli, and they are sensitive enough to study global and local properties of drawings.
Drawing expertise may depend to some extent on more accurate internal models of 3D space. To explore this possibility we had adults with a range of drawing experience draw a still life. We measured the angles at intersecting edges in the drawings to calculate each person's mean percentage magnitude error across angles in the still life. This gave a continuous objective measure of drawing accuracy which correlated well with years of art experience. Participants also made perceptual judgements of still lifes, both from direct observation and from an imagined side view. A conventional mental rotation task failed to differentiate drawing expertise. However, those who drew angles more accurately were also significantly better judges of slant, i.e., the pitch of edges in the still life. Those with the most drawing experience were significantly better judges of spatial extent, i.e., which landmarks were leftmost, rightmost, nearest, farthest etc.. The ability to visualize in three dimensions the orientation and relationships of components of a still life is related to drawing accuracy and expertise.
In our second study, we set out to extend our understanding of drawing accuracy and to
develop measures that would support more complex research questions about both drawing and visual perception. We developed and applied novel objective geometric measures of accuracy to analyze a perspective drawing task. We measured the deformation of shapes in drawings relative to the ground truth of a reference photograph and validated these measures by showing that they discriminate appropriately between experts and novices. On all measures—orientation, proportionality, scale and position of shapes—experts outperformed novices. However, error is not uniform across the image. Participants were better at capturing the proportions and positions of objects (the “positive space”) than of the spaces between those objects (the “negative space”) and worse at orienting those objects than shapes in the negative space, but scale error did not differ significantly between positive and negative space. We have demonstrated that objective geometric measures of drawing accuracy are consistent with expertise and that they can be applied to new levels of analysis, not merely to support the conventional wisdom of art educators but to develop new, evidence-based means of training this fundamental skill.
Most or all prior research into drawing was based on human ratings of drawing quality, but we cannot take for granted that the “goodness” of a drawing is related to its accuracy. In order to determine whether our objective measures of accuracy are consistent with drawing quality, we invited more than one hundred participants to grade the quality of all of the drawings we had collected and measured. We showed participants photographs of the still lifes on which the drawings were based and asked them to grade the quality of each drawing on a scale from 1 (“Poor”) to 10 (“Excellent”). People's quality ratings were consistent with one another. People without drawing experience rated drawings slightly more highly than the drawing experts did, but the ratings of both groups correlated well. As we predicted, the more drawing experience the artist had, the more highly rated the drawing was, and the more accurate the drawing was, the more highly rated it was. Furthermore, scaling error (but not proportionality, orientation or position) also predicted drawing quality. In perspective drawing, accuracy—as measured by angle error or polygon error—is related to drawing quality.
If drawing practice strengthens an artist's model of 3D space, we would expect the three-dimensionality of drawings to be disrupted by damage to the dorsal stream or the connection between the dorsal and ventral streams. A former illustrator and animator, DM, who had suffered a right hemisphere stroke and presented with spatial neglect, performed modified versions of the angle judgement, spatial judgement and indirect drawing tasks of our second study. Despite his previous experience, he showed weaknesses in his mental model of 3D space, weaknesses that were not evident in his drawings before the stroke.
Taken together, the thesis has developed and validated two objective measures of drawing accuracy that both capture expert/novice differences well and provide superior measures when contrasted with self-reported expertise. The performance of a single patient with neglect highlights the potential involvement of the dorsal stream in drawing. The novel quantitative measures developed here allow for testable hypotheses concerning the cognitive and neural mechanisms that support the complex skill of drawing to be objectively measured.
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Inventory valuation : Difficulties in manufacturing companies; what & why?Friberg, Lina, Nilsson, Sofia, Wärnbring, Sofia January 2006 (has links)
Master Thesis, School of Management and Economics, Växjö University, Advanced Concepts in Logistics Management, FED370, Spring 2006 Authors: Lina Friberg, Sofia Nilsson and Sofia Wärnbring Tutor: Petra Andersson Examiner: Lars-Olof Rask Title: Inventory Valuation - difficulties; what & why? Background: It is important to value inventories accurately in order to meet shareholder needs and demands for financial information. For manufacturing companies, inventories usually represent approximately 20 to 60 percent of their assets; hence it affects companies’ profits. It is essential in which way assets are valued, however, it will be a waste of time if the record accuracy level is poor. Research Questions: Why do companies experience problems when valuing inventories? In order to answer this research question, the following question also has to be answered: What problems can be identified? Purpose: The purpose of this master thesis is to describe and explain difficulties when valuing inventories. Limitations: We are not considering work-in-process and finished goods inventories, only raw material inventory. Neither are we looking at the companies’ internal calculation system, as we believe this will not be relevant for raw material. Method: We chose a positivistic view since we were studying our problem from a process perspective. A case study approach was suitable for us as our thesis was written in the form of a project, and we combined our empirical and theoretical data through the deductive approach. Conclusions: The problem of inventory valuation does not exist in the pricing aspect. Most problems are connected to quantity. Especially the daily routines were found to be insufficient, thus creating inaccuracies between the physical quantity in inventory and the quantity displayed in the system. Company B, the larger company, was found not to have as many problems as the smaller Company A has. Continued research: We believe an overall picture regarding valuation is needed, including the work-in-process and the finished goods inventories. Moreover, deficiencies are often not just found in the processes, but also the humans involved, and how they are motivated to secure accuracy. In addition, an implementation of cycle counting could be interesting to investigate.
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Chirurgische Genauigkeit eines optoelektrischen Navigationssystems in der Kopf- und Hals- ChirurgieKlappstein, Andrea 29 November 2012 (has links) (PDF)
Einleitung
Die Navigation in der Nasennebenhöhlenchiurgie hat bereits Einzug in den klinischen Alltag gehalten. Zur Evaluierung ihrer Leistungsfähigkeit bedarf es der Überprüfung der chirurgischen Genauigkeit am Patienten. Die Durchführung einer Genauigkeitsstudie am Patienten ist aus ethischen und methodischen Gründen nicht zu realisieren. Eine Phantomstudie soll eine realistische und ausführliche Genauigkeitsstudie ermöglichen. Besonderes Augenmerk wird in dieser Studie auf die Registrierung gelegt.
Material und Methoden
Gegenstand der Untersuchungen ist ein optoelektrisches Navigationssystem der Firma Karl Storz (NPU). Zur Evaluierung der Auswirkung der Registrierung auf die Navigationsgenauigkeit wurden die Registrierungspunkte in verschiedenen Mustern angeordnet. Es wurde das Registrierungsmuster der Standardregistrierung zwei weiteren gegenübergestellt. Zum einen wurden die Registrierungspunkte enger und zum anderen weiter gesetzt. Es standen zwölf HNO-ärztliche Probanden zur Verfügung. Die Aufgabe bestand darin, insgesamt zehn mit einer Titanschraube markierten Landmarken unter endoskopischer Kontrolle mit der Pointerspitze zu berühren. Die korrespondierenden Koordinaten wurden dokumentiert. Durch eine Vektorrechnung wird die Abweichung vom Soll- und Ist-Wert berechnet.
Ergebnisse
Es konnten insgesamt 1800 gültige Messdaten für die Abweichung aus 5400 Koordinaten ermittelt werden. Die Ergebnisse sind überwiegend normalverteilt. Die durchschnittliche Genauigkeit für die Standardregistrierung betrug 3,51 mm bei einer Präzision von 1,17 mm und einer maximalen Abweichung bis 5,87 mm. Für die Registrierung mit dem größeren Volumen konnte eine chirurgische Genauigkeit ermittelt werden von 3,43 mm mit einer Präzision von 0,83 mm und maximalen Abweichung von 4,78 mm. Für die Registrierung mit dem betrug die chirurgische Genauigkeit 4,15 mm, die Präzision 1,55 mm und die maximale Abweichung 7,11 mm.
Schlussfolgerungen
Die vorliegende Studie konnte zeigen, dass mit der derzeit durchgeführten Standardregistrierung ausreichende, konstante und zuverlässige Navigationsgenauigkeiten erzielt werden können. Es konnten keine signifikanten Unterschiede zur Registrierung mit dem größeren Volumen, jedoch zur Registrierung mit dem kleineren Volumen, nachgewiesen werden. Die Navigationsgenauigkeit ist keine konstante Größe. Die Genauigkeit variiert nach Lage der anatomischen Struktur, abhängig davon, ob sie im Zentrum der Referenzpunkte liegt. Es konnte gezeigt werden, dass über die Qualität der Registrierung Einfluss auf die Navigationsgenauigkeit genommen werden kann. Desweiteren kann von einer Abhängigkeit vom Anwender ausgegangen werden. Hier sind jedoch weiterführende Untersuchungen mit größeren Probandenzahlen erforderlich. Die in dieser Studie erzielten Ergebnisse sind mit Angaben anderer Studien vergleichbar.
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Experimental Characterization and Molecular Study of Natural Gas MixturesCristancho Blanco, Diego Edison 2010 May 1900 (has links)
Natural Gas (NG) plays an important role in the energy demand in the United States and throughout the world. Its characteristics as a clean, versatile and a sustainable source of energy makes it an important alternative within the spectra of energy resources. Addressing industrial and academic needs in the natural gas research area requires an integrated plan of research among experimentation, modeling and simulation. In this work, high accuracy PpT data have been measured with a high pressure single sinker magnetic suspension densimeter. An entire uncertainty analysis of this apparatus reveals that the uncertainty of the density data is less that 0.05% across the entire ranges of temperature (200 to 500) K and pressure (up to 200 MPa). These characteristics make the PpT data measured in this study unique in the world. Additionally, both a low pressure (up to 35 MPa) and a high pressure (up to 200 MPa) isochoric apparatus have been developed during the execution of this project. These apparatuses, in conjunction with a recently improved isochoric technique, allow determination of the phase envelope for NG mixtures with an uncertainty of 0.45% in temperature, 0.05% in pressure and 0.12% in density. Additionally, an innovative technique, based upon Coherent Anti-Stokes Raman Scattering (CARS) and Gas Chromatography (GC), was proposed in this research to minimize the high uncertainty introduced by the composition analyses of NG mixtures. The collected set of P?T and saturation data are fundamental for thermodynamic formulations of these mixtures. A study at the molecular level has provided molecular data for a selected set of main constituents of natural gas. A 50-50% methane-ethane mixture was studied by molecular dynamics simulations. The result of this study showed that simulation time higher than 2 ns was necessary to obtain reasonable deviations for the density determinations when compared to accurate standards. Finally, this work proposed a new mixing rule to incorporate isomeric effects into cubic equations of state.
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