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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.
11

Assessing Binary Measurement Systems

Danila, Oana Mihaela January 2012 (has links)
Binary measurement systems (BMS) are widely used in both manufacturing industry and medicine. In industry, a BMS is often used to measure various characteristics of parts and then classify them as pass or fail, according to some quality standards. Good measurement systems are essential both for problem solving (i.e., reducing the rate of defectives) and to protect customers from receiving defective products. As a result, it is desirable to assess the performance of the BMS as well as to separate the effects of the measurement system and the production process on the observed classifications. In medicine, BMSs are known as diagnostic or screening tests, and are used to detect a target condition in subjects, thus classifying them as positive or negative. Assessing the performance of a medical test is essential in quantifying the costs due to misclassification of patients, and in the future prevention of these errors. In both industry and medicine, the most commonly used characteristics to quantify the performance a BMS are the two misclassification rates, defined as the chance of passing a nonconforming (non-diseased) unit, called the consumer's risk (false positive), and the chance of failing a conforming (diseased) unit, called the producer's risk (false negative). In most assessment studies, it is also of interest to estimate the conforming (prevalence) rate, i.e. probability that a randomly selected unit is conforming (diseased). There are two main approaches for assessing the performance of a BMS. Both approaches involve measuring a number of units one or more times with the BMS. The first one, called the "gold standard" approach, requires the use of a gold-standard measurement system that can determine the state of units with no classification errors. When a gold standard does not exist, is too expensive or time-consuming, another option is to repeatedly measure units with the BMS, and then use a latent class approach to estimate the parameters of interest. In industry, for both approaches, the standard sampling plan involves randomly selecting parts from the population of manufactured parts. In this thesis, we focus on a specific context commonly found in the manufacturing industry. First, the BMS under study is nondestructive. Second, the BMS is used for 100% inspection or any kind of systematic inspection of the production yield. In this context, we are likely to have available a large number of previously passed and failed parts. Furthermore, the inspection system typically tracks the number of parts passed and failed; that is, we often have baseline data about the current pass rate, separate from the assessment study. Finally, we assume that during the time of the evaluation, the process is under statistical control and the BMS is stable. Our main goal is to investigate the effect of using sampling plans that involve random selection of parts from the available populations of previously passed and failed parts, i.e. conditional selection, on the estimation procedure and the main characteristics of the estimators. Also, we demonstrate the value of combining the additional information provided by the baseline data with those collected in the assessment study, in improving the overall estimation procedure. We also examine how the availability of baseline data and using a conditional selection sampling plan affect recommendations on the design of the assessment study. In Chapter 2, we give a summary of the existing estimation methods and sampling plans for a BMS assessment study in both industrial and medical settings, that are relevant in our context. In Chapters 3 and 4, we investigate the assessment of a BMS in the case where we assume that the misclassification rates are common for all conforming/nonconforming parts and that repeated measurements on the same part are independent, conditional on the true state of the part, i.e. conditional independence. We call models using these assumptions fixed-effects models. In Chapter 3, we look at the case where a gold standard is available, whereas in Chapter 4, we investigate the "no gold standard" case. In both cases, we show that using a conditional selection plan, along with the baseline information, substantially improves the accuracy and precision of the estimators, compared to the standard sampling plan. In Chapters 5 and 6, we investigate the case where we allow for possible variation in the misclassification rates within conforming and nonconforming parts, by proposing some new random-effects models. These models relax the fixed-effects model assumptions regarding constant misclassification rates and conditional independence. As in the previous chapters, we focus on investigating the effect of using conditional selection and baseline information on the properties of the estimators, and give study design recommendations based on our findings. In Chapter 7, we discuss other potential applications of the conditional selection plan, where the study data are augmented with the baseline information on the pass rate, especially in the context where there are multiple BMSs under investigation.
12

Srovnání Montrealského kognitivního testu a Krátkého testu kognitivních funkcí pro screeningovou diagnostiku Alzheimerovy choroby / Comparison of the Montreal Cognitive Assessment and the Mini-Mental State Examination in screening diagnostics of Alzheimer's disease

Orlíková, Hana January 2013 (has links)
This thesis deals with the neuropsychological diagnosis of Alzheimer's disease. The aim is to evaluate the psychometric characteristics ofthe new Czech translation of the Montreal Cognitive Assessment (MoCA) by comparison with the Mini-Mental State Examination (MMSE), a method widely used by doctors inscreening diagnostics of Alzheimer's disease. The theoretical part deals with the diagnostics of Alzheimer's disease and mild cognitive impairment. We describe international diagnostic criteria of cognitive disorders and provide an overview of the screening neuropsychological methods most commonly used by Czech specialists. We summarize the current psychometric and psychodiagnostic findings on these methods and focuse on description of MMSE and MoCA. In the empirical part we compare Czech version of MMSE and MoCA-CZ (the new Czech translation of the test). We examined 38 patients with Alzheimer's disease and 70 cognitively healthy seniors. The results show that MoCA-CZ is sufficiently valid and reliable screening method that accurately distinguishbetween healthy subjects and patiens with Alzheimer's disease. We believe that it can enrich screening tools that are available to Czech experts. Key words: Montreal Cognitive Assessment, Mini-Mental State Examination, Alzheimer's disease, psychodiagnostics,...
13

Srovnání alternativní verze Montrealského kognitivního testu (MoCA-CZ 2) s jeho verzí základní (MoCA-CZ 1). / Comparison of alternative version of The Montreal Cognitive Assessment (MoCA-CZ 2) with its basic version (MoCA-CZ 1).

Fayette, Dan January 2016 (has links)
The thesis discusses screening psychodiagnostics with special attention given to amnestic mild cognitive impairment and Alzheimer's disease. The theoretical part describes the concepts of healthy aging and the disorders of cognitive functions. It provides an overview of the screening methods most frequently used in the Czech Republic and the description of MoCA test. It also briefly outlines the issues of retesting in psychodiagnostics. The objective of the empirical part of the work was to verify the psychometric characteristics of the Czech alternative version MoCA-CZ and to evaluate whether it is possible to use this test in practice. The evaluation also includes a comparison of the new version with the already established standard version of MoCA-CZ test. We assigned standard and alternative versions of MoCA-CZ in a 2-month interval to 59 healthy volunteers, 35 patients with mild cognitive impairment and 41 patients with dementia resulting from Alzheimer's disease. We found a strong correlation between alternative and standard version of MoCA-CZ test. We confirmed statistically significant differences in the average scores between individual research groups in both versions of the test. We proved that the alternative version MoCA-CZ 2 is reliable. And we demonstrated that the administration and...
14

Les caractéristiques de marche en simple et double tâche sont-elles des biomarqueurs d'une phase asymptomatique du déclin cognitif ? / Relevance of walking characteristics in simple and dual task as biomarkers of asymptomatic phase in cognitive decline ?

Perrochon, Anaïck 18 January 2013 (has links)
On admet aujourd'hui que les tests psychométriques traditionnels paraissent insuffisants pour détecter précocement des troubles cognitifs. Parallèlement, des cliniciens observent une perte de l'automaticité de la marche lors du vieillissement normal ou de pathologies neurodégénératives qui peut être directement imputée au déclin des fonctions exécutives (FE) et aggravé lors des situations de double-tâche (DT). Plusieurs auteurs ont montré que la présence prématurée d'une atteinte motrice pouvait prédire une évolution défavorable vers une démence de type Alzheimer. Dans ce contexte, il devient évident que l'évaluation de la marche doit faire l'objet d'une investigation spécifique lors d'un bilan cognitif. Les travaux de cette thèse s'articulent autour du concept de troubles cognitifs légers, des FE et de l'évaluation motrice lors de diverses situations de marche.L'objectif principal est de déterminer si l'évaluation de la marche spontanée et/ou en DT constitue un outil de détection précoce des troubles cognitifs. Un objectif secondaire est de préciser les FE qui affectent la performance motrice dans les situations de DT. L'originalité de ce travail de thèse réside dans le développement de nouveaux exercices de DT de navigation spatiale basés sur l'adaptation de tests neuropsychologiques (test de Corsi, de Stroop et Trail Making Test) à la marche. Finalement, nous avons aussi proposé un « stroop écologique » qui s'intéresse à la prise de décision de traverser de rue au feu piéton.Les résultats révèlent que les interférences provoquées par les situations de DT entrainent une modification spécifique du schéma de marche du sujet âgé ayant des troubles cognitifs même lorsqu'ils sont infracliniques. De plus, la résolution des tests de DT nécessite la participation commune de plusieurs FE.En conclusion, la batterie de test que nous proposons présente un intérêt potentiel dans la détection précoce des troubles cognitifs chez les sujets âgés, mais aussi dans la compréhension des mécanismes régulant les FE. / Traditional psychometric and/or neuropsychologic tests alone, are not powerful enough to detect cognitive disturbances in aging subjects and therefore new criteria and tests should be developed to get relevant screening tools. Since walking is not anymore considered as a pure automatic motor task but as a task depending both on cognitive and executive functions (EF), clinicians became interested in studying walking disturbances in the course of neurodegenerative pathology development. Walking tasks can be complex and could be assimilated as a double-task (DT) when individuals have to simultaneously proceed with cognitive and motor tasks. Several authors have suggested that disturbances in walking abilities could predict cognitive disorders (e.g. Alzheimer Disease, Mild Cognitive Impairment (MCI)). Therefore, walking abilities should specifically be evaluated during cognitive clinical investigation.The main goal of our work is to evaluate whether a walking task alone and/or walking tasks in the context of DT could be of interest in detecting early stages of cognitive disorders in the elderly. A secondary goal is to investigate what are the executive functions that can influence walking during a DT. The originality of our approach also stems from the new motor ability tests we have developed. They are based on validated neuropsychological tests (Corsi, Stroop and Trail Making Tests) and are adapted to the context of walking. Moreover, we also present an adaptation of the Stroop test in the situation of a pedestrian at the cross light intending to cross a street ("ecological Stroop test").Our results show that DT situations induce specific changes in walking scheme in the elderly with established cognitive disorders and also -and this is one of our most important result- with borderline patients. We also show that the DT we tested required the involment of several EF.In conclusion, the new tests we present could be of interest in detecting early stages of cognitive disorders in elderly subjects and moreover can give clues to the mechanisms involved in the regulation of executive functions.
15

Perceptions and attitudes of rural women of Matebeleng Village - Limpopo Province towards cervical cancer : risk factors, screening tests and the HPV vaccines

Kwakwa, Motshidisi Mabel. January 2018 (has links)
Thesis (M. A. (Social Work)) --University of Limpopo, 2018 / Cancer of the cervix is second type of cancer among women in developing countries, and a common problem among women of low socio-economic status in rural communities. The spiral increase of the problem is aggravated by some socio-economic, structural, cultural and political factors. Understanding the risk factors associated with the disease is a step forward towards effective prevention and treatment. Numerous studies have been conducted on knowledge and perceptions of cervical cancer however the information on cervical cancer is still not reaching the majority of women. The study explored the perceptions and attitudes of rural women of Matebeleng village towards cervical cancer, the risk factors, screening tests and the HPV vaccines. A qualitative exploratory case study was conducted. Self-reported data was collected from 22 women. Two focus groups of 7 and 9 and 6 face-face individual interviews were conducted using a semi-structured interview guide. Data was analysed thematically. The research findings revealed that the majority of women in the rural area where the study was conducted never heard of cervical cancer and only few received inadequate information. Few highlighted some of the risk factors but some information was incorrect. Very few participants had only once been screened and the majority have never been tested for cervical cancer. Some became aware of the vaccine through the consent forms from school even though they did not exactly understand the content. The sources of information were the radio, health clinic and random women. The concerns of those who were screened were lack of feedback from the clinic nursing staff after the test, lack of adequate preparation and information before been screened to allay fear and doubt of the unknown and lack of reach out programmes to rural communities. The methods of disseminating information to rural women in their distinct contexts should be examined. Conventional traditional ways of reaching out to rural women could perhaps produce improved results through the integrated approach involving multi-disciplinary teams in educating communities. Key Words: Perceptions, attitudes, rural-based women, cervical cancer, risk factors, screening tests, HPV vaccine
16

Development of improved methods for the characterisation of organic chemicals emitted into indoor air by building and furnishing products

Brown, Veronica M. January 2013 (has links)
A wide range of organic compounds are released from building and furnishing products and these have the potential to adversely affect indoor air quality. There are growing international requirements for testing and controlling these emissions for the protection of public health. The test methods require specialist analytical chemistry facilities based on thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). This project has addressed the need for better performance and greater automation of the analysis, as well as development of simpler screening tests. A variety of products were tested using screening techniques, with an emission cell method being used as a reference test. Short duration tests, using a micro-scale chamber at slightly elevated temperature, were shown to have the potential to predict emissions occurring during longer term reference tests. Multi-sorbent air sampling tubes, that have the potential to extend the volatility range of compounds determined by a single TD/GC/MS analysis, were compared with Tenax TA tubes specified by current standard methods. This showed no difference in performance for the range of compounds for which Tenax is optimal, with improved performance for a number of more volatile compounds. The determination of formaldehyde was investigated using 2-hydroxymethylpiperidine as a derivatising agent, followed by TD/GC/MS. The results showed the possibility of this method being developed as an alternative to the current standard method that involves solvent elution and liquid chromatography. The performance of a newly developed time-of-flight mass spectrometer was compared with a standard quadrupole instrument. This showed its potential, with the use of re-collection, to extend the concentration range of compounds quantified from a single air sample, of particular benefit for the determination of carcinogens. New compound identification software was applied to increase automation of analysis of the TD/GC/MS data. Good correlation with manual processing was achieved, demonstrating the possibility of routine application to material emissions testing.
17

Preventivní programy nabízené zdravotními pojišťovnami / Preventive programs offered by health insurance companies

RAJČANOVÁ, Beata January 2018 (has links)
The need to provide preventive programs is highlighted by professionals across medical disciplines. Preventive programs help improve health, are an effective strategy to reduce healthcare costs, and specifically contribute to improving the quality of life of population. After all, prevention is the first thing we can do and it does not cost us anything but time. In addition, once a disease outbreaks, it may be already too late. All health insurance companies establish a prevention fund which helps to cover prevention programs for the insured. The VZP insurance company offers programs dealing with cardiovascular diseases, obesity, diabetes mellitus, vaccination, prevention of infectious diseases, medical and spa holidays, pregnancy screening tests, etc. My thesis aims to explore the use of prevention programs by the insured of the VZP insurance company. Based on the stated goal of my work, I have defined following assumed hypotheses. H1: Women use the prevention programs more than men do. H2: Insured persons who have obtained university education benefit from the preventive programs offered by the VZP health insurance company more than the insured persons without higher education. I chose qualitative research and a questionnaire survey as a suitable method for testing the set hypotheses. As a result of the research, the first hypothesis was confirmed, namely that women use preventive programs more than men. The second hypothesis was not confirmed. It has not been proven that preventive programs are used more by university educated insured persons. The thesis is focused on prevention and provides an overview of preventive programs, which are currently provided by the VZP insurance company. Therefore it is beneficial not only for VZP insured persons but also for all who are interested in prevention, and can also serve as a study material.
18

Detekční potenciál screeningových testů kognice u neurodegenerativních onemocnění / Cognitive screening tests and their potential to detect cognitive impairment in neurodegenerative diseases

Fendrych Mazancová, Adéla January 2021 (has links)
Screening of global cognitive performance is of great importance in the detection of early cognitive impairment in neurodegenerative diseases. In contrast to complex neuropsychological assessment, cognitive screening tests offer some advantages as saving time or finance and administration of screening tests makes lower demands on clinicians. Validation of cognitive screening tests for specific diagnostic groups of patients is necessary as well as Czech normative studies that enable an objective evaluation of the cognitive performance of Czech patients. In the theoretical part, we presented the syndrome of mild cognitive impairment as a pre-dementia state in neurodegenerative diseases. We focused on the assessment of mild cognitive impairment and using five different cognitive screening tests (Mini-Mental State Examination, Montreal Cognitive Assessment, Dementia Rating Scale 2. edition, Frontal Assessment Battery, Clock Drawing Test) in the detection of cognitive impairment. Then we focused on Parkinson's disease (PD), especially on the evolution of different stages of cognitive deficit in PD and their detection by cognitive assessments. The empirical research included studies analyzing the potential of the five cognitive screening tests to detect mild cognitive impairment. We provided results...
19

Problematika diagnostiky afázie v české a zahraniční odborné literatuře / Issue of aphasia diagnostics in czech and foreign literature

Stehlíková, Lenka January 2020 (has links)
The diploma thesis deals with the issue of diagnosis of phatic disorders. The aim of this work is to provide insight into the topic of phatic disorders, especially by introducing diagnostic tests that are used in the Czech Republic and some available materials that are used in English- speaking countries. Individual diagnostic tests are processed on the basis of an analysis of professional literature in Czech and English. The diploma thesis is theoretical and is divided into four parts. The first chapter describes the impaired communication ability, aphasia in terms of definition, etiology, symptomatology and classification approaches. The second chapter presents diagnostic methods created and used in the Czech environment, which differ depending on the theoretical basis of individual experts, respectively. authors of test methods. The third chapter deals with diagnostic procedures abroad, specifically in English-speaking countries. The focus is on the presentation of the most important and available current methods, part of the chapter is a theoretical introduction to the history of aphasiology and fundamental paradigms that affect the form of the diagnostic process. The final part is devoted to the analysis and comparison of these methods. Both approaches agree on the goal of the diagnostic...
20

Att sträva efter att undvika skador och öka sin prestation : Elitlängdskidåkares erfarenheter, önskemål och behov av screeningtester / Striving for avoidence of injury and increased performance : Elite cross-country skiers' experiences, desires and needs of screeningtests

Couch, Malin January 2020 (has links)
Introduction: Overload injuries are common among elite cross-country skiers. Screening tests are used in sports to prevent injuries. The tests are used extensively, however, the method has low validity. The knowledge from the current study may be used when developing new screening methods. Aim: To explore elite cross-country skiers’ own experiences, desires and needs for screening tests. Method: A qualitative method with an inductive approach was used and individual semi-structed interviews were analyzed using qualitative content analysis.. Seven elite cross-country skiers at the National Sport University in Umeå were strategically selected. Consisting of six men and one woman, the median age of the skiers was 24 years old. All had performed a Functional Movement Screen (FMS) within the last three years. Results: The result consist of one main theme, namely “Strivning for avoidence of injury and increased performance”. Within this main theme there were four categories “Insufficient challenge to improve performance”, “Physical check leading to exercise adjustments“,”Athletic posture and good technique improves skiing” and “Adapting and planning their exercise”. Each of the categories have 3-4 sub-categories respectively. The result represent the skiers’ desire to remain un-injured while increasing their performance. They request more tailor made and sport specific screening tests developed for cross-country skiing. This based on careful observations and meassurements of the specific requirements of the sport. The insights from the screening test would ideally result in suggested training schedules and individualized exercises. Conclusion: Elite cross-country skiers piont out the need for objective observations and analysis methods of the physical challenges of cross-country skiing. This in order to identify performance-enhancing measures, while at the same time avoiding overload injuries. The knowledge from this study can provide future researchers the direction in which they should focus when developing new sport-specific tests. / Introduktion: Inom längdskidåkning är överbelastning den vanligaste orsaken till skada. För att undvika skador används ofta screeningtester av idrottare men det har i litteraturen dock svag validitet. Kunskapen från aktuell studie kan användas vid utvecklande av nya anpassade screeningmetoder. Syfte: Att utforska elitlängdskidåkares egna erfarenheter, önskemål och behov av screeningtester. Metod: Metoden var kvalitativ med induktiv ansats och individuella semi-strukturerade intervjuer analyserades med kvalitativ innehållsanalys. Sju elitskidåkare vid Riksidrottsuniversitetet i Umeå valdes strategiskt ut, sex män och en kvinna deltog, medianålder var 24 år. Alla hade utfört Functional Movement Screen (FMS) inom senaste tre åren. Resultat: Resultatet består av ett tema ”Att sträva efter att undvika skador och öka sin prestation” och de fyra kategorierna ”Otillräcklig utmaning för förbättrad prestation”, ”Kroppslig check som leder till träningsjustering”, ”Atletisk hållning och god teknik förbättrar skidåkningen” och ”Anpassning och planering av sin träning” med 3-4 underkategorier var. Resultatet representerar längdskidåkarnas önskan om att hålla sig skadefria och öka sin prestation. De önskar att ett mer anpassat screeningtest bör utvecklas utifrån noggranna observationer och mätningar utefter de specifika kraven i idrotten. Det nya screeningtestet skulle kunna leda till råd om träningsupplägg och individanpassade övningar. Slutsats: Elitskidåkarna tycker det behövs objektiv observation av längdskidåkning och vilka krav som ställs på kroppen, för utvecklande av skadeförebyggande och prestationshöjande åtgärder. Kunskapen från denna studie ger riktning mot vad framtida forskning inom ämnet bör fokusera på vid utvecklandet av nytt idrottsspecifikt test.

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