894 resultados para work-related assessment


Relevância:

40.00% 40.00%

Publicador:

Resumo:

The feature of this paper is a critical assessment of the current discourses about quality of life (QoL) and their implications for Social Work. At first it pictures some major historical backgrounds of the discussion on the improvement of life quality as an aim of societal development. In particular three crucial shifts in the politics of QoL - its 'individualisation', its 'informalisation' and its 'culturalisation' - and their implications for Social Work are critically examined theoretically and empirically referring to the results of an own community-study. The paper concludes with an alternative suggestion reflecting the idea of an 'autonomy-based' approach of democratic equality.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Purpose Recovery is a critical link between acute reactions to work-stressors and the development of health-impairments in the long run. Even though recovery is particularly necessary when recovery opportunities during work are insufficient, research on recovery during weekends, is still scarce. To fill this gap we tested, whether the inability to psychologically detach from work mediates the effect of social stressors at work on sleep quality on Sunday night. Design/Methodology Sixty full-time employees participated in the study. Daily assessment included diaries on psychological detachment and ambulatory actigraphy to assess psychophysiological indicators of sleep quality. Results Hierarchical regression analyses revealed social stressors at work to be related with psychological detachment and with several sleep quality parameters on Sunday night. Furthermore, psychological detachment from work mediated the effect of social stressors at work on sleep quality. Limitations Methodological considerations regarding the use of actigraphy data should be taken into account. Research/Practical Implications Our results show that social stressors at work may lower resources just before people get started into the new working week. Originality/Value This is the first study to show that social stressors at work are an antecedent of psychological detachment on Sunday evening and of objective sleep quality on Sunday.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Social stressors at work may result in long-term health impairments if recovery is insufficient. In the present psychophysiological field study, we tested whether the inability to psychologically detach from work issues mediates the negative effect of social stressors at work on sleep during weekends. Sixty full-time employees participated in the study. Daily assessment included diaries on psychological detachment and continuous ambulatory actigraphy to assess psychophysiological indicators of sleep. Hierarchical regression analyses revealed that enduring social stressors at work were negatively related with psychological detachment on Sunday evening and negatively related with various sleep indicators on Sunday night. Furthermore, psychological detachment from work on Sunday evening partially mediated the effect of social stressors at work on two sleep indicators. Social stressors at work may threaten recovery processes just before the working week starts.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Material Safety Data Sheets (MSDSs) are an integral component of occupational hazard communication systems. These documents are used to disseminate hazard information to workers on chemical substances. The primary purpose of this study was to investigate the comprehensibility of MSDSs by workers at an international level. ^ A total of 117 employees of a multi-national petrochemical company participated; thirty-nine (39) each in the United States, Canada and the United Kingdom. Overall participation rate of those approached to participate was 82%. These countries were selected as they each utilize one of the three major existing hazard communication systems for fixed workplaces. The systems are comprised of the Occupational Safety and Health Administration's Hazard Communication Standard in the United States, the Workplace Hazardous Materials Information System (WHMIS) in Canada, and the compilation of several European Union directives addressing classification, labeling of substances and preparations, and MSDSs in Europe. ^ A pretest posttest randomized study design was used, with the posttest being comparable to an open book test. The results of this research indicated that only about two-thirds of the information on the MSDSs was comprehended by the workers with a significant difference identified among study participants based on country comparisons. This data was fairly consistent with the results of previous MSDS comprehensibility studies conducted in the United States. There was no significant difference in the comprehension level among study participants when taking into account the international hazard communication standard that the MSDS complied with. Marginally, age, education level and experience level did not have a significant impact on the comprehension level. ^ Participants did find MSDSs to be satisfactory in providing the information needed to protect them regardless of their views on the readability and formatting of MSDSs. The health-related information was the least comprehended as less than half of it was comprehended on the basis of the responses. The findings from this research suggest that there is much work needed yet to make MSDSs more comprehensible on a global basis, particularly regarding health-related information. ^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Background. Over half of children in the United States under age five spend 32 hours a week in child care, facilities, where they consume approximately 33-50% of their food intake. ^ Objectives. The aim of this research was to identify the effects of state nutrition policies on provision of food in child care centers. ^ Subjects. Eleven directors or their designee from ten randomly selected licensed child care centers in Travis County, Texas were interviewed. Centers included both nonprofit and for-profit centers, with enrollments ranging from 19 to 82. ^ Methods. Centers were selected using a web-based list of licensed child care providers in the Austin area. One-on-one interviews were conducted in person with center directors using a standard set of questions developed from previous pilot work. Interview items included demographic data, questions about state policies regarding provision of foods in centers, effects of policies on child care center budgets and foods offered, and changes in the provision of food. All interviews were audiotaped and transcribed, and themes were identified using standard qualitative techniques. ^ Results. Four of the centers provided both meals and snacks, four provided snacks only, and two did not provide any food. Directors of centers that provided food were more likely to report adherence to the Minimum Standards than directors of centers that did not. In general, center directors reported that the regulations were loosely enforced. In contrast, center directors were more concerned about a local city-county regulation that required food permits and new standards for kitchens. Most of these local regulations were cost prohibitive and, as a result, centers had changed the types of foods provided, which included providing less fresh produce and more prepackaged items. Although implementation of local regulations had reduced provision of fruits and vegetables to children, no adjustments were reported for allocation of resources, tuition costs or care of the children. ^ Conclusions. Qualitative data from a small sample of child care directors indicate that the implementation and accountability of food- and nutrition-related guidelines for centers is sporadic, uncoordinated, and can have unforeseen effects on the provision of food. A quantitative survey and dietary assessment methods should be conducted to verify these findings in a larger and more representative sample.^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Project MYTRI (Mobilizing Youth for Tobacco-Related Initiatives in India) was a large 2-year randomized school-based trial with a goal to reduce and prevent tobacco use among students in 6th and 8th grades in Delhi and Chennai in India (n=32 schools). Baseline analyses in 2004 showed that 6th grade students reported more tobacco use than 8 th grade students, opposite of what is typically observed in developed countries like the US. The present study aims to study differences in tobacco use and psychosocial risk factors between the 6th grade cohort and 8th grade cohort, in a compliant sub-sample of control students that were present at all 3 surveys from 2004-06. Both in 2004 and 2005, 6th grade cohort reported significantly greater prevalence of ever use of all tobacco products (cigarettes, bidis, chewing tobacco, any tobacco). These significant differences in ever use of any tobacco between cohorts were maintained by gender, city and socioeconomic status. The 6th grade cohort also reported significantly greater prevalence of current use of tobacco products (cigarettes, chewing tobacco, any tobacco) in 2004. Similar findings were observed for psychosocial risk factors for tobacco use, where the 6th grade cohort scored higher risk than 8th grade cohort on scales for intentions to smoke or chew tobacco and susceptibility to smoke or chew tobacco in 2004 and 2005, and for knowledge of health effects of tobacco in all three years.^ The evidence of early initiation of tobacco use in our 6th grade cohort in India indicates the need to target prevention programs and other tobacco control measures from a younger age in this setting. With increasing proportions of total deaths and lost DALYs in India being attributable to chronic diseases, addressing tobacco use among younger cohorts is even more critical. Increase in tobacco use among youth is a cause for concern with respect to future burden of chronic disease and tobacco-related mortality in many developing countries. Similarly, epidemiological studies that aim to predict future death and disease burden due to tobacco should address the early age at initiation and increasing prevalence rates among younger populations. ^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

This study examined barriers that cancer patients experience in obtaining treatment. The principal aim of the study was to conduct a comprehensive quantitative and qualitative assessment of barriers to cancer treatment for Texas cancer patients. The three specific aims of the study were to: (1) conduct a review and critique of published and unpublished research on barriers to cancer treatment; (2) conduct focus groups for the qualitative assessment of cancer patients' perceived barriers to cancer treatment; and (3) survey a representative sample of cancer patients regarding perceived barriers to treatment. The study was guided by the Aday and Andersen access framework of predisposing, enabling, and need determinants of care-seeking.^ To address the first specific aim, a total of 732 abstracts were examined, from which 154 articles were selected for review. Of these 154 articles, 57 that related directly to research on barriers to cancer treatment were chosen for subsequent analysis. Criteria were applied to each article to evaluate the strength of the study design, sampling and measurement procedures. The major barriers that were consistently documented to influence whether or not cancer patients sought or continued required treatment included problems with communication between the patient and provider, lack of information on side effects, the cost of treatment and associated difficulties in obtaining and maintaining insurance coverage, and the absence of formal and informal networks of social support. Access barriers were generally greater for older, minority women, and patients of lower socioeconomic status.^ To address the second specific aim, a total of eight focus groups (n = 44) were conducted across the State of Texas with cancer patients identified by the Texas Community Oncology Network, American Cancer Society, and community health centers. One important finding was that cost is the greatest hurdle that patients face. Another finding was that with the health care/insurance crisis, an increasing number of physicians are working with their patients to develop individually-tailored payment plans. For people in rural areas, travel to treatment sites is a major barrier due to the travel costs as well as work time forfeited by patients and their family members. A third major finding was the patients' family and church play important roles in providing social and emotional support for cancer patients.^ To address the third aim, a total of 910 cancer patients were surveyed during October and November, 1993. Approximately 65% of the cancer patients responded to the survey. The findings showed that the major barriers to treatment included costs of medications and diagnostic tests, transportation, lack of social support, problems understanding the written information regarding their disease as well as losing coverage or having higher premiums or copayments once they were diagnosed (particularly among blacks).^ Significant differences in reported barriers were found between racial groups. The minority respondents (i.e., blacks and Hispanics) tended to experience more barriers to treatment compared to the white respondents. More specifically, Hispanics were more likely to report transportation as a barrier to treatment than both white and blacks. Future research is needed to better understand the problems that minority cancer patients experience in receiving treatment. (Abstract shortened by UMI.) ^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Personnel involved in natural or man-made disaster response and recovery efforts may be exposed to a wide variety of physical and mental stressors that can exhibit long-lasting and detrimental psychopathological outcomes. In a disaster situation, huge numbers of "secondary" responders can be involved in contaminant clean-up and debris removal and can be at risk of developing stress-related mental health outcomes. The Occupational Safety and Health Administration (OSHA) worker training hierarchy typically required for response workers, known as "Hazardous Waste Operations and Emergency Response" (HAZWOPER), does not address the mental health and safety concerns of workers. This study focused on the prevalence of traumatic stress experienced by secondary responders that had received or expressed interest in receiving HAZWOPER training through the National Institute of Environmental Health Sciences Worker Education and Training Program (NIEHS WETP). ^ The study involved the modification of two preexisting and validated survey tools to assess secondary responder awareness of physical, mental, and traumatic stressors on mental health and sought to determine if a need existed to include traumatic stress-related mental health education in the current HAZWOPER training regimen. The study evaluated post-traumatic stress disorder (PTSD), resiliency, mental distress, and negative effects within a secondary responder population of 176 respondents. Elevated PTSD levels were seen in the study population as compared to a general responder population (32.9% positive vs. 8%-22.5% positive). Results indicated that HAZWOPER-trained disaster responders were likely to test positive for PTSD, whereas, untrained responders with no disaster experience and responders who possessed either training or disaster experience only were likely to test PTSD negative. A majority (68.75%) of the population tested below the mean resiliency to cope score (80.4) of the average worker population. Results indicated that those who were trained only or who possessed both training and disaster work experience were more likely to have lower resiliency scores than those with no training or experience. There were direct correlations between being PTSD positive and having worked at a disaster site and experiencing mental distress and negative effects. However, HAZWOPER training status does not significantly correlate with mental distress or negative effect. ^ The survey indicated clear support (91% of respondents) for mental health education. The development of a pre- and post-deployment training module is recommended. Such training could provide responders with the necessary knowledge and skills to recognize the symptomology of PTSD, mental stressors, and physical and traumatic stressors, thus empowering them to employ protective strategies or seek professional help if needed. It is further recommended that pre-deployment mental health education be included in the current HAZWOPER 24- and 40-hour course curriculums, as well as, consideration be given towards integrating a stand-alone post-deployment mental health education training course into the current HAZWOPER hierarchy.^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Despite the popularity of the positron emitting glucose analog, ($\sp{18}$F) -2-deoxy-2-fluoro-D-glucose (2FDG), for the noninvasive "metabolic imaging" of organs with positron emission tomography (PET), the physiological basis for the tracer has not been tested, and the potential of 2FDG for the rapid kinetic analysis of altered glucose metabolism in the intact heart has not been fully exploited. We, therefore, developed a quantitative method to characterize metabolic changes of myocardial glucose metabolism noninvasively and with high temporal resolution.^ The first objective of the work was to provide direct evidence that the initial steps in the metabolism of 2FDG are the same as for glucose and that 2FDG is retained by the tissue in proportion to the rate of glucose utilization. The second objective was to characterize the kinetic changes in myocardial glucose transport and phosphorylation in response to changes in work load, competing substrates, acute ischemia and reperfusion, and the addition of insulin. To assess changes in myocardial glucose metabolism isolated working rat hearts were perfused with glucose and 2FDG. Tissue uptake of 2FDG and the input function were measured on-line by external detection. The steady state rate of 2FDG phosphorylation was determined by graphical analysis of 2FDG time-activity curves.^ The rate of 2FDG uptake was linear with time and the tracer was retained in its phosphorylated form. Tissue accumulation of 2FDG decreased within seconds with a reduction in work load, in the presence of competing substrates, and during reperfusion after global ischemia. Thus, most interventions known to alter glucose metabolism induced rapid parallel changes in 2FDG uptake. By contrast, insulin caused a significant increase in 2FDG accumulation only in hearts from fasted animals when perfused at a sub-physiological work load. The mechanism for this phenomenon is not known but may be related to the existence of two different glucose transporter systems and/or glycogen metabolism in the myocardial cell.^ It is concluded that (1) 2FDG traces glucose uptake and phosphorylation in the isolated working rat heart; and (2) early and transient kinetic changes in glucose metabolism can be monitored with high temporal resolution with 2FDG and a simple positron coincidence counting system. The new method has revealed transients of myocardial glucose metabolism, which would have remained unnoticed with conventional methods. These transients are not only important for the interpretation of glucose metabolic PET scans, but also provide insights into mechanisms of glucose transport and phosphorylation in heart muscle. ^

Relevância:

40.00% 40.00%

Publicador:

Resumo:

“Teamwork” is one of the abilities most valued by employers. In [16] we describe the process of adapting to the ECTS methodologies (for ongoing assessment), a course in computer programming for students in a technical degree (Marine Engineering, UPM) not specifically dedicated to computing. As a further step in this process we have emphasized cooperative learning. For this, the students were paired and the work of each pair was evaluated via surprise tests taken and graded jointly, and constituting a substantial part of the final grade. Here we document this experience, discussing methodological aspects, describing indicators for measuring the impact of these methodologies on the educational experience, and reporting on the students’ opinion of it.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The crop diseases sometimes are related to the irradiance that the crop receives. When an experiment requires the measurement of the irradiance, usually it results in an expensive data acquisition system. If it is necessary to check many test points, the use of traditional sensors will increase the cost of the experiment. By using low cost sensors based in the photovoltaic effect, it is possible to perform a precise test of irradiance with a reduced price. This work presents an experiment performed in Ademuz (Valencia, Spain) during September of 2011 to check the validity of low cost sensors based on solar cells.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

La presente Tesis analiza las posibilidades que ofrecen en la actualidad las tecnologías del habla para la detección de patologías clínicas asociadas a la vía aérea superior. El estudio del habla que tradicionalmente cubre tanto la producción como el proceso de transformación del mensaje y las señales involucradas, desde el emisor hasta alcanzar al receptor, ofrece una vía de estudio alternativa para estas patologías. El hecho de que la señal emitida no solo contiene este mensaje, sino también información acerca del locutor, ha motivado el desarrollo de sistemas orientados a la identificación y verificación de la identidad de los locutores. Estos trabajos han recibido recientemente un nuevo impulso, orientándose tanto hacia la caracterización de rasgos que son comunes a varios locutores, como a las diferencias existentes entre grabaciones de un mismo locutor. Los primeros resultan especialmente relevantes para esta Tesis dado que estos rasgos podrían evidenciar la presencia de características relacionadas con una cierta condición común a varios locutores, independiente de su identidad. Tal es el caso que se enfrenta en esta Tesis, donde los rasgos identificados se relacionarían con una de la patología particular y directamente vinculada con el sistema de físico de conformación del habla. El caso del Síndrome de Apneas Hipopneas durante el Sueno (SAHS) resulta paradigmático. Se trata de una patología con una elevada prevalencia mundo, que aumenta con la edad. Los pacientes de esta patología experimentan episodios de cese involuntario de la respiración durante el sueño, que se prolongan durante varios segundos y que se reproducen a lo largo de la noche impidiendo el correcto descanso. En el caso de la apnea obstructiva, estos episodios se deben a la imposibilidad de mantener un camino abierto a través de la vía aérea, de forma que el flujo de aire se ve interrumpido. En la actualidad, el diagnostico de estos pacientes se realiza a través de un estudio polisomnográfico, que se centra en el análisis de los episodios de apnea durante el sueño, requiriendo que el paciente permanezca en el hospital durante una noche. La complejidad y el elevado coste de estos procedimientos, unidos a las crecientes listas de espera, han evidenciado la necesidad de contar con técnicas rápidas de detección, que si bien podrían no obtener tasas tan elevadas, permitirían reorganizar las listas de espera en función del grado de severidad de la patología en cada paciente. Entre otros, los sistemas de diagnostico por imagen, así como la caracterización antropométrica de los pacientes, han evidenciado la existencia de patrones anatómicos que tendrían influencia directa sobre el habla. Los trabajos dedicados al estudio del SAHS en lo relativo a como esta afecta al habla han sido escasos y algunos de ellos incluso contradictorios. Sin embargo, desde finales de la década de 1980 se conoce la existencia de patrones específicos relativos a la articulación, la fonación y la resonancia. Sin embargo, su descripción resultaba difícilmente aprovechable a través de un sistema de reconocimiento automático, pero apuntaba la existencia de un nexo entre voz y SAHS. En los últimos anos las técnicas de procesado automático han permitido el desarrollo de sistemas automáticos que ya son capaces de identificar diferencias significativas en el habla de los pacientes del SAHS, y que los distinguen de los locutores sanos. Por contra, poco se conoce acerca de la conexión entre estos nuevos resultados, los sé que habían obtenido en el pasado y la patogénesis del SAHS. Esta Tesis continua la labor desarrollada en este ámbito considerando específicamente: el estudio de la forma en que el SAHS afecta el habla de los pacientes, la mejora en las tasas de clasificación automática y la combinación de la información obtenida con los predictores utilizados por los especialistas clínicos en sus evaluaciones preliminares. Las dos primeras tareas plantean problemas simbióticos, pero diferentes. Mientras el estudio de la conexión entre el SAHS y el habla requiere de modelos acotados que puedan ser interpretados con facilidad, los sistemas de reconocimiento se sirven de un elevado número de dimensiones para la caracterización y posterior identificación de patrones. Así, la primera tarea debe permitirnos avanzar en la segunda, al igual que la incorporación de los predictores utilizados por los especialistas clínicos. La Tesis aborda el estudio tanto del habla continua como del habla sostenida, con el fin de aprovechar las sinergias y diferencias existentes entre ambas. En el análisis del habla continua se tomo como punto de partida un esquema que ya fue evaluado con anterioridad, y sobre el cual se ha tratado la evaluación y optimización de la representación del habla, así como la caracterización de los patrones específicos asociados al SAHS. Ello ha evidenciado la conexión entre el SAHS y los elementos fundamentales de la señal de voz: los formantes. Los resultados obtenidos demuestran que el éxito de estos sistemas se debe, fundamentalmente, a la capacidad de estas representaciones para describir dichas componentes, obviando las dimensiones ruidosas o con poca capacidad discriminativa. El esquema resultante ofrece una tasa de error por debajo del 18%, sirviéndose de clasificadores notablemente menos complejos que los descritos en el estado del arte y de una única grabación de voz de corta duración. En relación a la conexión entre el SAHS y los patrones observados, fue necesario considerar las diferencias inter- e intra-grupo, centrándonos en la articulación característica del locutor, sustituyendo los complejos modelos de clasificación por el estudio de los promedios espectrales. El resultado apunta con claridad hacia ciertas regiones del eje de frecuencias, sugiriendo la existencia de un estrechamiento sistemático en la sección del tracto en la región de la orofaringe, ya prevista en la patogénesis de este síndrome. En cuanto al habla sostenida, se han reproducido los estudios realizados sobre el habla continua en grabaciones de la vocal /a/ sostenida. Los resultados son cualitativamente análogos a los anteriores, si bien en este caso las tasas de clasificación resultan ser más bajas. Con el objetivo de identificar el sentido de este resultado se reprodujo el estudio de los promedios espectrales y de la variabilidad inter e intra-grupo. Ambos estudios mostraron importantes diferencias con los anteriores que podrían explicar estos resultados. Sin embargo, el habla sostenida ofrece otras oportunidades al establecer un entorno controlado para el estudio de la fonación, que también había sido identificada como una fuente de información para la detección del SAHS. De su estudio se pudo observar que, en el conjunto de datos disponibles, no existen variaciones que pudieran asociarse fácilmente con la fonación. Únicamente aquellas dimensiones que describen la distribución de energía a lo largo del eje de frecuencia evidenciaron diferencias significativas, apuntando, una vez más, en la dirección de las resonancias espectrales. Analizados los resultados anteriores, la Tesis afronta la fusión de ambas fuentes de información en un único sistema de clasificación. Con ello es posible mejorar las tasas de clasificación, bajo la hipótesis de que la información presente en el habla continua y el habla sostenida es fundamentalmente distinta. Esta tarea se realizo a través de un sencillo esquema de fusión que obtuvo un 88.6% de aciertos en clasificación (tasa de error del 11.4%), lo que representa una mejora significativa respecto al estado del arte. Finalmente, la combinación de este clasificador con los predictores utilizados por los especialistas clínicos ofreció una tasa del 91.3% (tasa de error de 8.7%), que se encuentra dentro del margen ofrecido por esquemas más costosos e intrusivos, y que a diferencia del propuesto, no pueden ser utilizados en la evaluación previa de los pacientes. Con todo, la Tesis ofrece una visión clara sobre la relación entre el SAHS y el habla, evidenciando el grado de madurez alcanzado por la tecnología del habla en la caracterización y detección del SAHS, poniendo de manifiesto que su uso para la evaluación de los pacientes ya sería posible, y dejando la puerta abierta a futuras investigaciones que continúen el trabajo aquí iniciado. ABSTRACT This Thesis explores the potential of speech technologies for the detection of clinical disorders connected to the upper airway. The study of speech traditionally covers both the production process and post processing of the signals involved, from the speaker up to the listener, offering an alternative path to study these pathologies. The fact that utterances embed not just the encoded message but also information about the speaker, has motivated the development of automatic systems oriented to the identification and verificaton the speaker’s identity. These have recently been boosted and reoriented either towards the characterization of traits that are common to several speakers, or to the differences between records of the same speaker collected under different conditions. The first are particularly relevant to this Thesis as these patterns could reveal the presence of features that are related to a common condition shared among different speakers, regardless of their identity. Such is the case faced in this Thesis, where the traits identified would relate to a particular pathology, directly connected to the speech production system. The Obstructive Sleep Apnea syndrome (OSA) is a paradigmatic case for analysis. It is a disorder with high prevalence among adults and affecting a larger number of them as they grow older. Patients suffering from this disorder experience episodes of involuntary cessation of breath during sleep that may last a few seconds and reproduce throughout the night, preventing proper rest. In the case of obstructive apnea, these episodes are related to the collapse of the pharynx, which interrupts the air flow. Currently, OSA diagnosis is done through a polysomnographic study, which focuses on the analysis of apnea episodes during sleep, requiring the patient to stay at the hospital for the whole night. The complexity and high cost of the procedures involved, combined with the waiting lists, have evidenced the need for screening techniques, which perhaps would not achieve outstanding performance rates but would allow clinicians to reorganize these lists ranking patients according to the severity of their condition. Among others, imaging diagnosis and anthropometric characterization of patients have evidenced the existence of anatomical patterns related to OSA that have direct influence on speech. Contributions devoted to the study of how this disorder affects scpeech are scarce and somehow contradictory. However, since the late 1980s the existence of specific patterns related to articulation, phonation and resonance is known. By that time these descriptions were virtually useless when coming to the development of an automatic system, but pointed out the existence of a link between speech and OSA. In recent years automatic processing techniques have evolved and are now able to identify significant differences in the speech of OSAS patients when compared to records from healthy subjects. Nevertheless, little is known about the connection between these new results with those published in the past and the pathogenesis of the OSA syndrome. This Thesis is aimed to progress beyond the previous research done in this area by addressing: the study of how OSA affects patients’ speech, the enhancement of automatic OSA classification based on speech analysis, and its integration with the information embedded in the predictors generally used by clinicians in preliminary patients’ examination. The first two tasks, though may appear symbiotic at first, are quite different. While studying the connection between speech and OSA requires simple narrow models that can be easily interpreted, classification requires larger models including a large number dimensions for the characterization and posterior identification of the observed patterns. Anyhow, it is clear that any progress made in the first task should allow us to improve our performance on the second one, and that the incorporation of the predictors used by clinicians shall contribute in this same direction. The Thesis considers both continuous and sustained speech analysis, to exploit the synergies and differences between them. On continuous speech analysis, a conventional speech processing scheme, designed and evaluated before this Thesis, was taken as a baseline. Over this initial system several alternative representations of the speech information were proposed, optimized and tested to select those more suitable for the characterization of OSA-specific patterns. Evidences were found on the existence of a connection between OSA and the fundamental constituents of the speech: the formants. Experimental results proved that the success of the proposed solution is well explained by the ability of speech representations to describe these specific OSA-related components, ignoring the noisy ones as well those presenting low discrimination capabilities. The resulting scheme obtained a 18% error rate, on a classification scheme significantly less complex than those described in the literature and operating on a single speech record. Regarding the connection between OSA and the observed patterns, it was necessary to consider inter-and intra-group differences for this analysis, and to focus on the articulation, replacing the complex classification models by the long-term average spectra. Results clearly point to certain regions on the frequency axis, suggesting the existence of a systematic narrowing in the vocal tract section at the oropharynx. This was already described in the pathogenesis of this syndrome. Regarding sustained speech, similar experiments as those conducted on continuous speech were reproduced on sustained phonations of vowel / a /. Results were qualitatively similar to the previous ones, though in this case perfomance rates were found to be noticeably lower. Trying to derive further knowledge from this result, experiments on the long-term average spectra and intraand inter-group variability ratios were also reproduced on sustained speech records. Results on both experiments showed significant differences from the previous ones obtained from continuous speech which could explain the differences observed on peformance. However, sustained speech also provided the opportunity to study phonation within the controlled framework it provides. This was also identified in the literature as a source of information for the detection of OSA. In this study it was found that, for the available dataset, no sistematic differences related to phonation could be found between the two groups of speakers. Only those dimensions which relate energy distribution along the frequency axis provided significant differences, pointing once again towards the direction of resonant components. Once classification schemes on both continuous and sustained speech were developed, the Thesis addressed their combination into a single classification system. Under the assumption that the information in continuous and sustained speech is fundamentally different, it should be possible to successfully merge the two of them. This was tested through a simple fusion scheme which obtained a 88.6% correct classification (11.4% error rate), which represents a significant improvement over the state of the art. Finally, the combination of this classifier with the variables used by clinicians obtained a 91.3% accuracy (8.7% error rate). This is within the range of alternative, but costly and intrusive schemes, which unlike the one proposed can not be used in the preliminary assessment of patients’ condition. In the end, this Thesis has shed new light on the underlying connection between OSA and speech, and evidenced the degree of maturity reached by speech technology on OSA characterization and detection, leaving the door open for future research which shall continue in the multiple directions that have been pointed out and left as future work.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

An extension of guarantees related to rainfall-related risks in the insurance of processing tomato crops has been accompanied with a large increase in claims in Western Spain, suggesting that damages may have been underestimated in previous years. A database was built by linking agricultural insurance records, meteorological data from local weather stations, and topographic data. The risk of rainfall-related damages in processing tomato in the Extremenian Guadiana river basin (W Spain) was studied using a logistic model. Risks during the growth of the crop and at harvesting were modelled separately. First, the risk related to rainfall was modelled as a function of meteorological, terrain and management variables. The resulting models were used to identify the variables responsible for rainfall-related damages, with a view to assess the potential impact of extending insurance coverage, and to develop an index to express the suitability of the cropping system for insurance. The analyses reveal that damages at different stages of crop development correspond to different hazards. The geographic dependence of the risk influences the scale at which the model might have validity, which together with the year dependency, the possibility of implementing index based insurances is questioned.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Automating the assessment of programming assignments brings benefits for both students and teachers, since it helps the formers to gain a timely feedback and releases the latter from tedious tasks. The related literature in the domain has usually focused on the assessment process and the tools required for it, proposing libraries and systems that teachers can use in this process. However, few of them have work rowards reducing the effort and time teacher require to properly set up new assessente processes. This paper describes our experience with the analysis and design of a new tool to support teachers in visually developing automatic grades of programming assignments, introducing the underlying concepts and technologies and presenting the system architecture.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The achievement of the limit values established in the European legislation pose an important handicap for large urban areas with intense road traffic, such as Madrid (Spain). Despite permanent measures included in air quality plans it is important to assess additional measures that may be temporally applied under unfavourable conditions. This paper reports on the simulation of different traffic restriction strategies in Madrid for high-pollution episodes.