Visual Data Mining : Real Applications and New Approaches

En los últimos años, la visualización de datos se ha convertido en un área muy activa y vital de la investigación. Es una manera eficaz de analizar grandes cantidades de datos para identificar correlaciones, tendencias, valores extremos, patrones, entre otra mucha información. Los datos sin procesar a menudo carecen de sentido, pero representar dichos datos visualmente ofrece al público un contexto importante para entender la información contenida en ellos. Debido a la importancia de esta área de investigación, y a su novedad, esta tesis se centra en esta temática y pretende descubrir nuevos hallazgos, extraer conclusiones y legar contribuciones relevantes a la comunidad científica en dicho campo. Para alcanzar dicho propósito, este trabajo trata de abordar dos objetivos principales. El primer objetivo de la presente tesis es tratar de desarrollar nuevos métodos de visualización para interpretar los resultados de varios algoritmos de minería de datos. Por ejemplo, el análisis de clusters o técnicas de agrupamiento es un gran desafío en la visualización de datos; por esta razón, ambos van a menudo de la mano. Sin embargo, hay una falta de técnicas de visualización asociadas al clustering y clustering jerárquico que proporcionen información sobre los valores de los atributos de los centroides y de las relaciones entre ellos. Por lo tanto, esta tesis investiga nuevas aproximaciones que hagan posible incluir esta información visualmente, además de encontrar nuevos métodos para visualizar los resultados de varios algoritmos de minería de datos, aparte de los anteriormente mencionados, con el fin de ayudar a simplificar su interpretación y para obtener una mejor comprensión. Otro de los objetivos de esta tesis se centra en abordar diferentes problemas reales de diversa índole, algunos de ellos enmarcados en proyectos de investigación financiados. La solución de estos problemas se aborda a través de la visualización de datos y minería de datos visual con el fin de obtener una perspectiva sobre el problema, lo que hace posible la extracción de conocimiento, el descubrimiento de información oculta y encontrar patrones y relaciones entre los datos. En particular, la presente tesis se centra en el uso de los conocidos Self-Organizing Maps (SOMs) para resolver problemas reales en diversos campos de investigación, proporcionando soluciones a problemas complejos que de otra manera habría sido muy difícil de resolver.Data visualization has in recent years become a very active and vital area of research. It is an effective way to analyze large amounts of data to identify correlations, trends, outliers, patterns, among many other information. Raw data are often meaningless, but representing visually such data offers audiences important context for understanding the information contained in them. Due to the importance of this area of research, and its novelty, this thesis aims to discover new findings, draw conclusions and bequeath significant contributions to the scientific community in this field. To achieve this purpose, this work attempts to address two main objectives. The first objective of this thesis is to try to develop new visualization methods for interpreting the results of several data mining algorithms. For example, cluster analysis is a big challenge in data visualization; for this reason, they both often go hand in hand. Nonetheless, there is a lack of visualization techniques associated with clustering and hierarchical clustering that provide information about the values of the centroids’ attributes and the relationships among them. Thus, this thesis researches new approaches that make possible to include this information visually, as well as to find new methods for visualizing the results of several data mining algorithms, apart from those above mentioned, in order to help simplify their interpretation and to obtain a better understanding. Another objective of the present thesis is focused on addressing different real problems of diverse nature, some of them framed in funded research projects. The solution of these problems are approached through data visualization and visual data mining in order to gain insight about the problem making possible the knowledge extraction, the discovery of hidden information, and finding patterns and relationships in data. Particularly, the present thesis focuses on the use of the well-known Self- Organizing Maps (SOMs) to solve real problems in several different fields of research, providing solutions to complex problems that would otherwise have been very difficult to solve

On the design and evaluation of adjustable footwear for the prevention of diabetic foot ulcers

Worldwide there are over 422 million people with diabetes. Up to 34% of them will develop a diabetic foot ulcer. These ulcers are extremely dangerous and can result in amputation of the affected leg. Elevated pressures at the plantar surface of the foot are a major cause of diabetic foot ulcerations. Diabetic foot ulcers can be prevented by reducing plantar pressures that are too high. Special footwear such as custom-made insoles and rocker profile shoes are commonly used to reduce plantar pressure. However, the design of this footwear is mainly based on the experience of the prescribing specialist and orthopaedic shoe technician. This leads to a large variety of results and sometimes to insufficient offloading of the foot. Even when the insole or rocker profile shoe initially is effective, over time the location of the pressure spots can shift, resulting in poor offloading and putting the person at risk again of developing an ulcer. The work in this thesis aimed to overcome the problems with the current offloading footwear and includes the design and evaluation of an adjustable rocker profile and a self-adjusting insole

The acute effects of pre-fabricated insoles on running mechanics and perceived footwear comfort of endurance runners

Tibial acceleration is a prominent biomechanical consideration associated with common running-related injuries, such as tibial stress injuries. Cushioning insoles are proposed to be capable of reducing tibial acceleration, though there is conflicting evidence. Perceived comfort, primarily through enhanced cushioning, has shown some association with peak axial tibial acceleration, however the magnitude of this correlation has been found to be low. Changes in footwear cushioning have been associated with adjustments in running mechanics that may mask the effect of the cushioning material or potentially increase the risk of injury by altering the biomechanical variables associated with running-related injuries. The majority of research related to running mechanics has historically occurred in laboratory environments, thus compromising ecological validity. The purpose of this study was to investigate the effects of pre-fabricated insoles on running mechanics and footwear comfort in a field setting. Twenty-nine recreational runners (age: 31.8 ± 6.5 y) completed four separate laps of an athletics track while wearing running shoes containing either the ordinary sock liner (CON), or pre-fabricated insoles namely Sofsole Athlete (AT), Spenco Arch Cushioned (AC), and Spenco Walker Runner (WR) (Implus LLC, Durham, North Carolina, USA). Participants were fitted with seven inertial measurement units (IMUs) (Noraxon, Scottsdale, Arizona, USA). Each IMU included a tri-axial accelerometer, gyroscope, and magnetometer in order to capture segment and joint kinematics in all three planes of motion. Spatiotemporal data was collected using a 10 m length of an optical measurement system (OptoJump by Microgate, Bolzaho, Italy). Subsequent to each lap, the participant completed the Footwear Comfort Assessment Tool comprising of nine 100 mm visual analogue scales. Biomechanical and perceived comfort variables were compared in R using a linear mixed model with main effect for condition. Pairwise comparison between condition was conducted post-hoc with Tukey adjustments for the p-values. No significant differences for spatiotemporal parameters, tibial acceleration, shock attenuation, knee flexion, hip flexion, or shin inclination were observed. Foot pitch angle was significantly greater between WR versus AC, AT versus CON, and WR versus CON (p < 0.001), as was ankle dorsiflexion at touchdown between WR versus AC and WR versus CON (p < 0.001). Peak ankle dorsiflexion was significantly greater between WR versus AC and WR versus CON (p = 0.006), while ankle dorsiflexion ROM was significantly reduced between WR versus CON and AC versus CON (p = 0.007). Overall comfort was significantly greater for AT versus AC, AT versus WR, and AC versus CON (p = 0.002), and shoe length comfort was significantly less for WR versus CON (p = 0.33). The pre-fabricated insoles investigated in this study did not result in any significant acute changes to peak acceleration or shock attenuation, however significant and clinically relevant changes regarding ankle dorsiflexion, foot inclination, and overall footwear comfort did occur. Runners should be aware that enhanced cushioning of pre-fabricated insoles may be negated by adjustments to ankle dorsiflexion and foot strike pattern during touchdown. Runners may therefore be advised to select pre-fabricated insoles based on their perceived comfort.Dissertation (MSc (Sports Science (Biomechanics)))--University of Pretoria, 2022.PhysiologyMSc (Sports Science (Biomechanics))Unrestricte

Space Station medical sciences concepts

Current life sciences concepts relating to Space Station are presented including the following: research, extravehicular activity, biobehavioral considerations, medical care, maintenance of dental health, maintaining health through physical conditioning and countermeasures, protection from radiation, atmospheric contamination control, atmospheric composition, noise pollution, food supply and service, clothing and furnishings, and educational program possibilities. Information on the current status of Soviet Space Stations is contained

Análisis de la respuesta biomecánica, percepción del esfuerzo y confort en función del soporte plantar: termoconformable vs control durante un test de carrera prolongada en atletas recreativos

En las últimas décadas se ha incrementado el número de corredores/as recreativos/as y competitivos/as en todo el mundo debido a los numerosos beneficios que conlleva la carrera a nivel físico, psicológico y social. Sin embargo, este incremento también ha supuesto en un aumento en la incidencia de lesiones en las extremidades inferiores. Entre las estrategias empleadas por los corredores/as para reducir la incidencia de lesiones durante la carrera está la utilización de soportes plantares. Además de los soportes prefabricados genéricos y los personalizados, surgen nuevos soportes como los termoconformables, los cuales pueden adaptarse a la ergonomía del pie calentándose por el propio usuario con un microondas convencional. No obstante, la evidencia científica sobre sus efectos en determinados parámetros biomecánicos durante la carrera prolongada es escasa. En consecuencia, el objetivo del presente estudio fue evaluar el efecto de un soporte plantar termoconformable en la biomecánica de la carrera durante 30 minutos de carrera. Treinta corredores/as recreativos sanos (20 hombres y 10 mujeres) participaron en tres pruebas: un test de campo para determinar la velocidad aérobica máxima (VAM) e individualizar la velocidad para las dos siguientes pruebas y, dos pruebas de laboratorio: con el soporte plantar original de las zapatillas y con el soporte plantar termoconformable. Ambas pruebas, consistieron en una carrera de 30 minutos en cinta ergométrica al 80% de su VAM, con un calentamiento previo y progresivo de 6 minutos. Los participantes realizaron un periodo de adaptación de tres semanas con el soporte termoconformable. Se analizaron diferentes parámetros biomecánicos en relación a la percepción del esfuerzo, parámetros espacio-temporales, impactos de aceleración, temperatura superficial plantar, presión plantar y percepción del confort. Las conclusiones más relevantes de la presente investigación muestran que la percepción del esfuerzo, los parámetros espacio-temporales y los impactos de aceleración no se alteraron por el uso del soporte termoconformable, aumentándo la presión plantar (42%) en la zona medial del pie. Además, con el soporte termoconformable la temperatura superficial plantar obtuvo menores incrementos de temperatura (23%) y, la percepción de confort mostró valores más altos (9%) en la temperatura y humedad. El efecto de la carrera prolongada permitió un incremento de la percepción del esfuerzo (19%) de manera similar en ambas condiciones de soporte plantar y de la temperatura superficial plantar (25%), aunque con mejores resultados con el uso del soporte termoconformable

The effectiveness of foot orthoses as a treatment for plantar ulceration in leprosy : a study of the efficacy, acceptability, appropriateness and implantation of a podiatric regimen

This was a holistic study. Four themes were investigated to demonstrate the effectiveness of orthotic intervention for plantar ulceration affecting leprosy impaired subjects in India. 1. Efficacy Efficacy was demonstrated, primarily, through analysis of data pertaining to a controlled trial. Thirty-seven subjects, presenting with leprosy impairments including anaesthesia and plantar ulceration, were fitted with orthoses and allocated to an experimental group. Thirty-four similar subjects, were not offered orthoses and were allocated to a control group. After 8 months 52% of the ulcers presented by Experimental group and 12% of the ulcers presented by the Control group had healed. The rationale supporting the prescription of orthoses was investigated using the EMED system. It was demonstrated that intervention with orthoses resulted in significantly lower sub pedal peak pressures than intervention with leprosy sandals. 2. Implementation and Sustain ability Ulcer assessment data from March 1994 to January 1995 were used to compare the effects of orthoses supplied by the investigator with orthoses supplied by an Indian technician. The service, evaluated on the strength of these findings, was considered to have been successfully implemented. The analysis of data, collected from January 1995 to December 1995, was used to explain why the service was not sustained at an acceptable level. 3. Acceptability Interview data were analysed to describe the attitudes of the subjects to the intervention (n = 46). Indications from the analysis were that neither ulcer status (healed or unresolved) nor group allocation (Experimental or Control) affected attitudes towards the intervention. A general indication was that the intervention was favourably endorsed. 4. Appropriateness Using the Delphi technique (n = 10), a consensus on indicators of "appropriate" impairment control measures was sought. Differences of opinion were not resolved, but group priorities were ranked and a polled response was recorded. The results of the study were similar to the criteria suggested by the Delphi contributors

Sport@Future: Valoración biomecánica de un soporte plantar termoconformable durante la carrera en fatiga

La carrera es una de las actividades físico-recreativas más populares, que sigue creciendo en participación año a año por el gran número de beneficios que reporta a la salud. Sin embargo, la incidencia anual de lesiones en sus practicantes también es elevada. En este sentido, los soportes plantares son una de las estrategias más utilizadas por los corredores/as como sistema de prevención y tratamiento de lesiones, pero también como mecanismo para la mejora del rendimiento. Con el auge de las nuevas tecnologías y de la industria del calzado y del equipamiento deportivo, se ha desarrollado un nuevo soporte plantar prefabricado con materiales termoconformables que permite al propio usuario adaptárselo a la ergonomía de su pie mediante el calor de un microondas doméstico. No obstante, sus beneficios están aún por investigar, siendo la fatiga y el género dos factores determinantes en su uso. Por ello, el objetivo del presente estudio fue evaluar el efecto de un soporte plantar prefabricado termoconformable en la biomecánica de carrera durante 30 minutos de carrera intensa, en comparación con un soporte prefabricado genérico, centrándose en el desarrollo de fatiga y en las diferencias asociadas al género de los participantes. Para ello, se analizaron 30 corredores/as populares sanos (15 hombres y 15 mujeres) que realizaron un total de tres test. El primero consistió en una prueba de esfuerzo máxima con el objetivo de determinar el consumo máximo de oxígeno (VO2máx), para individualizar la velocidad de las siguientes pruebas. Los siguientes dos test consistieron en realizar 6 minutos de carrera progresivos como calentamiento, más 30 minutos de carrera continua en cinta al 70-75% del VO2máx individual, cada uno con un soporte plantar prefabricado, previamente aleatorizados. Los participantes llevaron a cabo un periodo de adaptación progresivo de 2 semanas con cada soporte. Se analizaron diferentes parámetros biomecánicos en relación a la percepción del esfuerzo y el confort, la transmisión de impactos, la presión plantar, la cinemática espacio-temporal y angular y la temperatura superficial plantar. Las conclusiones más relevantes obtenidas en la presente tesis indican que tanto los parámetros de la transmisión de impactos como la eversión máxima del retropié se incrementaron con el uso del soporte termoconformable (15% y 13%), mientras que la presión en dedos y arco aumentó (15% y 23%) aliviando cargas en los metatarsos y el talón (11% y 12%). Sin embargo, el resto de parámetros estudiados no se vio alterado. El desarrollo de fatiga únicamente incrementó la percepción del esfuerzo (22%), la transmisión de impactos (10%) y la presión y temperatura plantar (15% y 29%); con efectos similares en ambos soportes, pero con una ligera tendencia más positiva a favor del termoconformable. Finalmente, de forma general, el soporte termoconformable favoreció en mayor medida a las mujeres, en comparación con los hombres.Running is one of the most popular physical-recreational activities, which continues growing in participation year by year due to the large number of health benefits that generates. However, the annual injury incidence in its practitioners is also high. In this sense, foot orthoses are one of the most used strategies by runners as an injury prevention and treatment system, but also as a mechanism for improving performance. With the rise of new technologies and footwear and sports equipment industry, a new prefabricated foot orthosis with thermoformable materials has been developed that allows the user to adapt it to foot ergonomics by heating it in a domestic microwave. Nevertheless, its benefits are still to be investigated, being fatigue and gender two determining factors in its use. Therefore, the aim of the present study was to evaluate the effect of a thermoformable prefabricated foot orthosis on running biomechanics during 30 minutes of intense running, compared to a generic prefabricated foot orthosis, focusing on the development of fatigue and the differences associated with the gender of the participants. 30 healthy popular runners (15 men and 15 women) performed three tests and were analysed. The first test was a maximum incremental test with the objective of determining the maximum oxygen consumption (VO2max) to individualize the speed of the following tests. The next two tests consisted of 6 minutes progressive warming up, plus 30 minutes of continuous running on a treadmill at 70-75% of individual VO2max, each one with a different prefabricated foot orthosis condition, previously randomized. Participants carried out a progressive adaptation period of 2 weeks with each foot orthosis. Different biomechanical parameters were analysed in relation to effort and comfort perception, impact transmission, plantar pressure, spatio-temporal and angular kinematics and plantar surface temperature. The most relevant conclusions obtained on this work were that both impact transmission parameters and maximum rearfoot eversion were increased with the use of the thermoformable foot orthosis (15% and 13%), while pressure on toes and arch increased (15% and 23%), relieving loads on metatarsals and heel (11% and 12%). However, the rest of parameters studied was not altered. The development of fatigue only increased effort perception (22%), impact transmission (10%) and plantar pressure and temperature (15% and 29%); with similar effects on both foot orthoses, but with a slightly more positive tendency in favour of the thermoformable foot orthosis. Finally, in general, the thermoformable foot orthosis favoured women to a greater extent, compared to men