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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.
141

Monitoring and analysis of antenatal and postnatal changes in maternal vital signs

Pullon, Rebecca January 2016 (has links)
Pregnancy-related complications affect approximately 15% of pregnancies and, if severe, can have long-term consequences. Timely recognition of physiological deterioration is known to reduce the prevalence and severity of complications. However pregnancy-associated changes in vital signs (blood pressure, heart rate, temperature, oxygen saturation, and respiratory rate) complicate the detection of abnormal physiology, and these changes are not well documented. This thesis describes the development of algorithms to ensure the collection of good-quality vital-sign data during the antenatal and postnatal stages of pregnancy, and the design of an evidence-based obstetric early warning score. Vital-sign information from 1,000 pregnant women during pregnancy, labour, and after delivery was collected during the 4P study using pulse oximetry, oscillometry for blood pressure measurement and a tympanic thermometer. Dynamic time warping was used to assess beat-by-beat quality in the photoplethysmograph (PPG) waveform obtained from the pulse oximeter. The resulting signal quality index enabled the exclusion of poor-quality sections and their associated measurements of heart rate and peripheral oxygen saturation. A robust measurement of respiratory rate was obtained by combining information from the PPG waveform, and accelerometer and gyroscope waveforms from a smartphone. After processing, frequency-based techniques, such as Fourier analysis and auto-regressive modelling, and time-domain peak detection were fused to estimate respiratory rate. When compared with the reference respiratory rate obtained from midwife measurement, the lowest mean absolute error of 1.16 breaths per minute was obtained from respiratory rate estimates from the y-axis of the gyroscope. Antenatal and postnatal reference ranges for each vital sign were developed with a standard polynomial multilevel (hierarchical) model using 10,000 vital sign measurements from 620 healthy women in the 4P study. Vital-sign trajectories confirmed known trends of blood pressure and heart rate changes during pregnancy, and provided new information about other vital-sign trends. Additional covariates were included to investigate the effect of parity and body mass index (BMI) on vital-sign trends. The outer centiles of the vital sign reference ranges were used to design an obstetric early warning score (C-ObsEWS) that took into account gestational age or time after delivery. The investigations in this thesis contribute additional knowledge of pregnancy-associated vital-sign changes, and lead to an initial proposal for an evidence-based obstetric early warning score specific to the stage of pregnancy.
142

The vulnerability of laser warning systems against guided weapons based on low power lasers

Al-Jaberi, Mubarak January 2006 (has links)
Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current counter-measures are not designed to work against this threat. The aim of this project is to examine the vulnerability of laser warning systems against guided weapons, to build an evaluation tool for laser warning sensors (LWS) and seekers, and try to find suitable counter-measures for laser beam-riding missiles that use low power lasers in their guidance systems. The project comes about because of the unexpected results obtained from extensive field trials carried out on various LWRs in the United Arab Emirates desert, where severe weather conditions may be experienced. The objective was to help find a solution for these systems to do their job in protecting the tanks and armoured vehicles crews from such a threat. In order to approach the subject, a computer model has been developed to enable the assessment of all phases of a laser warning receiver and missile seeker. MATLAB & SIMULINK software have been used to build the model. During this process experimentation and field trials have been carried out to verify the reliability of the model. This project will enable both the evaluation and design of any generic laser warning receiver or missile seeker and specific systems if various parameters are known. Moreover, this model will be used as a guide to the development of reliable countermeasures for laser beam-riding missiles.
143

First-year student retention: MAP-Works[superscript]TM early warning and intervention relationships

Jackson, Derek A. January 1900 (has links)
Doctor of Philosophy / Department of Special Education, Counseling and Student Affairs / Fred O. Bradley / This study investigated the use of the MAP-Works[superscript]TM program that is designed to help retain first-year students by identifying the level of retention risk for each student early in their first semester and communicating this risk to key university faculty and staff. The participants for this study were all first semester freshman students enrolled during the academic years 2012 and 2013. This study sought to determine if the MAP-Works[superscript]TM program and resulting intervention were effective in predicting the retention of high-risk first semester freshman students to their second semester and second year. The data analysis for this study used quantitative data analysis methods. The first and second research questions asking which of the factors were significant in predicting retention were answered using independent samples t-tests. The third research question asking if the intervention was significant was answered using a 2x2 Chi-square test for independence. The fourth and final research question asked which of the factors contributed the most in predicting retention was answered using a direct (binary) logistic regression analysis. This study found for high-risk domestic students Cumulative GPA, Socio-Emotional, Test Anxiety, Peers, Homesickness: Distressed, Academic Integration, Social Integration and Environment were able to be associated significantly with retention from fall-to-spring semester. For international students GPA, Self-Efficacy and Self-Discipline were able to be associated significantly with retention. The study showed for fall-to-fall retention for domestic students that cumulative GPA, Socio-Emotional, Communication, Analytical, Social Integration and On-Campus Living Social were significant. The research found that the intervention conducted by their direct connects for high-risk domestic students was significant for fall-to-fall retention. The logistic regression analysis showed for domestic students that Cumulative GPA, Financial Means, Socio-Emotional, and ACT Composite score were significant for fall-to-fall retention. The strongest predictor of retention was Cumulative GPA followed by Socio-Emotional, Financial then ACT Composite score. The regression analysis for high-risk international students showed that Cumulative GPA, Gender, and Student Residence were significant for fall-to-fall retention. The strongest predictor of retention was cumulative GPA, Gender (Female) and Student Residence (Off Campus).
144

Development of nuclear-radiological facility monitoring system

Zakariya, Nasiru Imam January 2016 (has links)
Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / The widespread application of nuclear science and technology has been the subject of much concern as well as nuclear safety issues. And to ensure the safety of public life, property and environment, it is indispensable to improve the emergency system for nuclear accidents and the environmental monitoring system for nuclear radiation, so that the occurrence of nuclear accidents, terrorist incidents and the resulting hazards can be prevented or minimized. Due to the benefits of radiation which were earlier and now recognized in the use of X-rays for medical diagnosis and then later with the discoveries of radiation and radioactivity, there was rush in exploiting the medical benefits which eventually led fairly to the recognition of the risks and induced harm associated with it. Thus, only the most obvious harms resulting from high doses of radiation, such as radiation burns, were initially observed and protection efforts were focused on their prevention, mainly for practitioners rather than patients. Subsequently, it was gradually recognized that there were other, less obvious, harmful radiation effects such as radiation-induced cancer, for which there is certain risk even at low doses of radiation.
145

Schizofrenie: prevence relapsu a opětovné hospitalizace na psychiatrické klinice po léčbě / Schizophrenia: Prevention of relapse and re-admission to psychiatric hospital after treatment

Aarseth, Erling Becker January 2010 (has links)
It has in this review article been cited several different studies and sources, all concerning the prevention of relapse of schizophrenia and related psychotic disorders; The different approaches to treatment (programs, type of psychotherapy etc.) have been discussed according to evidence based research and randomized controlled trials. Although some explanations have been given about terms used in the literature, as well as some definitions to enable classifications in future studies, it has been focused only on the preventive measures used in schizophrenia; a detailed description of different subgroups of schizophrenia, as well as detailed descriptions of pharmacology in euroleptics is beyond the scope of this article. The recognition of relapse symptoms was first considered and defined, and the different approaches was then discussed; Outpatient treatment plans and relapse prevention plans, as well as the impact of cognitive behavioral therapy and psychotherapy have been discussed in subsequent chapters. In this section, it was especially focused on the ITAREPS program and its impact on the relapse prevention. The role of medications was then defined and supported with clinical studies and trials.
146

Mecanismos de defesa contra predadores em larvas da borboleta Methona themisto (Nymphalidae: Ithomiinae) / Anti-predator defense mechanisms in larvae of the butterfly Methona themisto (Nymphalidae: Ithomiinae)

Massuda, Kamila Ferreira, 1979- 21 February 2008 (has links)
Orientador: Jose Roberto Trigo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T19:03:33Z (GMT). No. of bitstreams: 1 Massuda_KamilaFerreira_M.pdf: 3824014 bytes, checksum: d4db5cb4afb22e7d40b4afc3d0677236 (MD5) Previous issue date: 2008 / Resumo: As defesas químicas em lepidópteros compreendem mecanismos que vão desde o seqüestro de compostos do metabolismo secundário de plantas até a biossíntese de novo de compostos que podem torná-los tóxicos ou impalatáveis. As larvas da borboleta Methona themisto (Nymphalidae: Ithomiinae), que apresentam coloração conspícua e se alimentam apenas da solanácea Brunfelsia uniflora, rica em compostos do metabolismo secundário, foram analisadas sob vários aspectos, para verificar se são quimicamente defendidas. O acompanhamento da sobrevivência das larvas indicou que a predação afeta significativamente a sobrevivência em seu ambiente natural. As defesas químicas dessas larvas são aparentemente ineficazes contra predadores invertebrados, como a aranha Lycosa erythrognatha e a formiga Camponotus crassus (100% dos indivíduos testados predaram as larvas), mas parecem ser eficazes contra os mantídeos Oxyopsis saussuurei (redução no tempo de manipulação da presa e predação em um segundo contato). Para predadores vertebrados como o lagarto Tropidurus itambere e a ave Gallus gallus, a defesa parece atuar em relação à palatabilidade e à coloração conspícua. Gallus gallus apresentou maior predação de larvas de 1o ínstar, sugerindo que há um incremento na impalatabilidade da larva no decorrer de seu desenvolvimento. Os testes de aprendizagem dos pintinhos demonstraram que com poucos contatos com a presa impalatável já se obtém uma resposta de rejeição visual. O emprego de uma larva de coloração semelhante a da Methona themisto indica que os pintinhos são capazes de relacionar a cor com o gosto desagradável, rejeitando assim uma presa palatável. Apenas extratos diclorometânicos das larvas testados com Gallus gallus foram significativamente rejeitados em relação a seus controles. Dessa forma, esses dados comprovam que as defesas químicas das larvas de Methona themisto atuam principalmente contra predadores vertebrados visualmente orientados / Abstract: Chemical defense in Lepidoptera involves several mechanisms such as sequestration of secondary metabolismcompounds of host plants and de novo synthesis of compounds that can provide some unpalatability or toxicity. The larvae of the butterfly Methona themisto (Nymphalidae: Ithomiinae) have a conspicuous coloration and feed exclusively on Brunfelsia uniflora (Solanaceae), that is rich in compounds of the secondary metabolismo These larvae were analyzed under several aspects to confirm if they are chemically defended. Survivorship data showed predation significantly affecting larval survival in natural habitat. Larvae chemical defenses are inefficient against invertebrate predators, such as the spider Lycosa erythr-ognatha and the ant Campónotus crassus (100% of predation), but it seems to be efficient against the mantid Oxyopsis saussuurei (reduction of prey manipulation time and predation in a second contact). To vertebrate predators, like the lizard Tropidurus itambere and the chick Gallus gallus, defense acts through conspicuous coloration and palatability. Predation by Gallus gallus was highest upon 1st ínstar larvae, suggesting an increase of unpalatability throughout development. Learning avoidance tests with Gallus gallus demonstrated that few contacts with distasteful and warning colored prey could make the predator reject visually Methona themisto larvae. Chicks visually rejected palatable larvae painted in the same color pattem of Methona themisto larvae confirming their ability to associate taste and color. Only dichloromethanic extracts tested with chicks showed significant rejection in relation to controls. These results confirm that Methona themisto larvae are chemical defended against visually oriented vertebrate predators / Mestrado / Mestre em Ecologia
147

Planejamento de empreendimentos imobiliários: gestão de risco orientada a gestão de prazo com ênfase na identificação de alertas antecipados. / Construction project management: risk management oriented to time management with emphasis on the identification of early warnings.

Silvana Sugano Navarro 01 August 2007 (has links)
O aprimoramento de processos de gerenciamento de empreendimentos é um fator condicionante para que uma empresa mantenha sua competitividade no mercado de empreendimentos imobiliários de edifícios de apartamentos. O gerenciamento de prazos está entre os processos que concentra maiores esforços durante as fases de planejamento e implantação de um empreendimento, pois desvios de prazo geralmente afetam sensivelmente sua rentabilidade. O objetivo desta pesquisa é apresentar uma abordagem de gerenciamento de riscos orientada ao gerenciamento de prazos com ênfase na identificação de alertas antecipados a condições de risco de cumprimento de prazos. A partir do reconhecimento do estado da arte sobre o tema, um estudo de caso foi conduzido em empresas que atuam no mercado de empreendimentos imobiliários de edifícios de apartamentos na cidade de São Paulo. Este estudo permitiu a exploração do conjunto de práticas de gerenciamento de prazos e riscos e dos alertas utilizados por estas empresas no gerenciamento de seus empreendimentos. A abordagem proposta se baseia na integração entre os processos de gerenciamento de prazos e riscos, possibilitando a utilização de alertas antecipados como suporte ao processo de tomada de decisões, permitindo reagir rapidamente, tão logo um alerta seja identificado. / The improvement of the project management process is a key factor for a company to keep its competitiveness in the real estate market. Time management demands great efforts during the planning and implementation phases of a project, since schedule delays usually affect the project profits in a significant way. The objective of this research is to present an approach to risk management oriented to time management processes with emphasis on the identification of early warnings about risk conditions to time of conclusion. Based on the recognition of the state-of-the-art of this subject, a case study was conducted in companies that act in the apartment building real estate market in the city of São Paulo. This case study enabled us to exploit a set of time and risk management practices and early warnings used by these companies while managing their projects. The approach proposed is based on the integration of time and risk management processes, making possible for us the use of early warning as a support to decision making process, allowing us to react quickly, as soon as a warning is identified.
148

Previsão hidrometeorológica visando sistema de alerta antecipado de cheias em bacias urbanas / Hidrometeorological precipitation forecast for flood early warning systems in urban areas

Juliana Pontes Machado de Andrade 13 September 2006 (has links)
Freqüentemente, a população das áreas metropolitanas é surpreendida pela ocorrência de inundações muito rápidas que causam danos diversos. O sistema de alerta antecipado contra inundações é uma ferramenta que visa minimizar tais impactos. O componente de previsão do sistema será abordado neste trabalho. Tal previsão é feita através de um modelo conceitual de previsão hidrometeorológica de precipitação baseado em equações termodinâmicas e modelo simplificado de física das nuvens seguido de um modelo chuva-vazão. A antecedência proporcionada pelo modelo hidrometeorológico aplicado é de 30 minutos para variáveis de entrada observadas. Este tempo pode ser estendido com a inclusão de estimativas futuras das variáveis de entrada. A calibração do modelo foi feita manualmente com o uso de duas medidas de desempenho, esta etapa pode ser aprimorada em pesquisas futuras. Apesar da simplicidade do modelo hidrometeorológico apresentou-se satisfatório em algumas simulações, conseguindo prever o início das precipitações. / Urban population are often surprised by flash floods which cause several kinds of damages. An early warning system is a tool which aims to minimize such impacts. This work will approach the forecast component of this system. A conceptual hydrometeorological precipitation forecasting model, based on thermodynamics equations and simplified cloud physics, will be used to perform the forecast. Model lead time is 30 minutes for measured inputs, this time can be extended by the use of estimated inputs instead of the measured ones. Calibration was performed manually based on conservation of precipitation volume and its distribution in time. This step can be improved on future researches. In spite of model’s simplicity, some simulations presented satisfactory results, being able to forecast precipitation’s beginning.
149

The vulnerability of laser warning systems against guided weapons based on low power lasers

Al-Jaberi, Mubarak 28 April 2006 (has links)
Laser assisted weapons, such as laser guided bombs, laser guided missiles and laser beam-riding missiles pose a significant threat to military assets in the modern battlefield. Laser beam-riding missiles are particularly hard to detect because they use low power lasers. Most laser warning systems produced so far can not detect laser beam-riding missiles because of their weak emissions which have signals less than 1% of laser range finder power . They are even harder to defeat because current counter-measures are not designed to work against this threat. The aim of this project is to examine the vulnerability of laser warning systems against guided weapons, to build an evaluation tool for laser warning sensors (LWS) and seekers, and try to find suitable counter-measures for laser beam-riding missiles that use low power lasers in their guidance systems. The project comes about because of the unexpected results obtained from extensive field trials carried out on various LWRs in the United Arab Emirates desert, where severe weather conditions may be experienced. The objective was to help find a solution for these systems to do their job in protecting the tanks and armoured vehicles crews from such a threat. In order to approach the subject, a computer model has been developed to enable the assessment of all phases of a laser warning receiver and missile seeker. MATLAB & SIMULINK software have been used to build the model. During this process experimentation and field trials have been carried out to verify the reliability of the model. This project will enable both the evaluation and design of any generic laser warning receiver or missile seeker and specific systems if various parameters are known. Moreover, this model will be used as a guide to the development of reliable countermeasures for laser beam-riding missiles.
150

Modelling an RF Converter in Matlab / Modellering av en radarvarningsmottagare i Matlab

Hjorth, Mattias, Hvittfeldt, Björn January 2002 (has links)
Radar warning systems are life saving equipment in modern fighter aircraft. It is therefore vital that the system can tell the difference between a threat genuine frequency) and a false signal (spurious frequency). This thesis presents a model aimed at predicting the frequencies and other parameters in the RF converter of the radar warning system. The components of the RF converter have been studied, measured, and modelled. The modelling tool has been the Simulink toolbox for Matlab. Extreme accuracy has been sacrificed in order to make the model easy to use for the working engineer. Instead, this model presents a rough estimate of some of the most important properties of the radar warning system with just a few data sheet figures as input. The simulation results are satisfactory as a whole. Simulink is the limiting factor in the implementation of the model. Significantly improved results can probably be obtained by working in another software environment.

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