904 results on '"Ortega Ramírez, Juan Antonio"'
Search Results
2. Data Mining Techniques for Endometriosis Detection in a Data-Scarce Medical Dataset
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Universidad de Sevilla. Departamento de Estomatología, Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia e Innovación (MICIN). España, Caballero, Pablo, González Abril, Luis, Ortega Ramírez, Juan Antonio, Simón-Soro, Aúrea, Universidad de Sevilla. Departamento de Estomatología, Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia e Innovación (MICIN). España, Caballero, Pablo, González Abril, Luis, Ortega Ramírez, Juan Antonio, and Simón-Soro, Aúrea
- Abstract
Endometriosis (EM) is a chronic inflammatory estrogen-dependent disorder that affects 10% of women worldwide. It affects the female reproductive tract and its resident microbiota, as well as distal body sites that can serve as surrogate markers of EM. Currently, no single definitive biomarker can diagnose EM. For this pilot study, we analyzed a cohort of 21 patients with endometriosis and infertility-associated conditions. A microbiome dataset was created using five sample types taken from the reproductive and gastrointestinal tracts of each patient. We evaluated several machine learning algorithms for EM detection using these features. The characteristics of the dataset were derived from endometrial biopsy, endometrial fluid, vaginal, oral, and fecal samples. Despite limited data, the algorithms demonstrated high performance with respect to the F1 score. In addition, they suggested that disease diagnosis could potentially be improved by using less medically invasive procedures. Overall, the results indicate that machine learning algorithms can be useful tools for diagnosing endometriosis in low-resource settings where data availability and availability are limited. We recommend that future studies explore the complexities of the EM disorder using artificial intelligence and prediction modeling to further define the characteristics of the endometriosis phenotype.
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- 2024
3. Influence of Stress in Driving Behaviour
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Yay, Emre, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Kyriacou, Efthyvoulos, editor, Christofides, Stelios, editor, and Pattichis, Constantinos S., editor
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- 2016
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4. Performance of Algorithms for Interval Discretization of Biomedical Signals
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Soria Morillo, Luis Miguel, Gonzalez-Abril, Luis, Ortega Ramírez, Juan Antonio, Magjarevic, Ratko, Editor-in-chief, Ładyżyński, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Kyriacou, Efthyvoulos, editor, Christofides, Stelios, editor, and Pattichis, Constantinos S., editor
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- 2016
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5. Evaluating Wearable Activity Recognition and Fall Detection Systems
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Álvarez-García, Juan Antonio, Soria Morillo, Luis Miguel, de La Concepción, Miguel Ángel Álvarez, Fernández-Montes, Alejandro, Ortega Ramírez, Juan Antonio, MAGJAREVIC, Ratko, Editor-in-chief, Ładyzynsk, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, and Vasic, Darko, editor
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- 2015
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6. Detecting the adherence of driving rules in an energy-efficient, safe and adaptive driving system
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Yay, Emre, Martínez Madrid, Natividad, and Ortega Ramírez, Juan Antonio
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- 2016
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7. Design and development of comprehensive digital solutions with application in the medical field: Human sleep analysis
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Ortega Ramírez, Juan Antonio, Seepold, Ralf, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Ortega Ramírez, Juan Antonio, Seepold, Ralf, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Gaiduk, Maksym
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The influence of sleep on human life, including physiological, psychological, and mental aspects, is remarkable. Therefore, it is essential to apply appropriate therapy in the case of sleep disorders. For this, however, the irregularities must first be recognised, preferably conveniently for the person concerned. This dissertation, structured as a composition of research articles, presents the development of mathematically based algorithmic principles for a sleep analysis system. The particular focus is on the classification of sleep stages with a minimal set of physiological parameters. In addition, the aspects of using the sleep analysis system as part of the more complex healthcare systems are explored. Design of hardware for non-obtrusive measurement of relevant physiological parameters and the use of such systems to detect other sleep disorders, such as sleep apnoea, are also referred to. Multinomial logistic regression was selected as the basis for development resulting from the investigations carried out. By following a methodical procedure, the number of physiological parameters necessary for the classification of sleep stages was successively reduced to two: Respiratory and Movement signals. These signals might be measured in a contactless way. A prototype implementation of the developed algorithms was performed to validate the proposed method, and the evaluation of 19324 sleep epochs was carried out. The results, with the achieved accuracy of 73% in the classification of Wake/NREM/REM stages and Cohen's kappa of 0.44, outperform the state of the art and demonstrate the appropriateness of the selected approach. In the future, this method could enable convenient, cost-effective, and accurate sleep analysis, leading to the detection of sleep disorders at an early stage so that therapy can be initiated as soon as possible, thus improving the general population's health status and quality of life., La influencia del sueño en la vida humana, incluidos los aspectos fisiológicos, psicológicos y mentales, es notable. Por tanto, es fundamental aplicar la terapia adecuada para los trastornos del sueño. Para conseguirlo, es necesario en primer término reconocer los trastornos que presenta la persona afectada. En esta tesis, estructurada como un compendio de artículos de investigación, se presenta el desarrollo de los principios algorítmicos con base matemática para un sistema de análisis del sueño. Se hace especial hincapié en la clasificación de las etapas del sueño con un conjunto mínimo de parámetros fisiológicos. Además, se exploran los aspectos de la utilización del sistema de análisis del sueño como parte de sistemas sanitarios más complejos. También se hace referencia al diseño de hardware para la medición no intrusiva de los parámetros fisiológicos relevantes en el análisis del sueño y el uso de estos sistemas para detectar otros trastornos, como el de la apnea del sueño. Se ha seleccionado la regresión logística multinomial como base del desarrollo en las investigaciones realizadas. Siguiendo un procedimiento metódico, el número de parámetros fisiológicos necesarios para la clasificación de las etapas del sueño se ha ido reduciendo hasta conseguirlo con tan sólo dos: señales respiratorias y de movimiento. Estas señales pueden medirse de manera no invasiva, esto es, sin contacto. La validar del método propuesto en la tesis se ha conseguido implementando un prototipo con los algoritmos desarrollados y se han probado evaluando 19324 épocas de sueño. Los resultados obtenidos han conseguido una precisión del 73% en la clasificación de las etapas de vigilia/NREM/REM y un kappa de Cohen de 0,44, mejorando a los existentes en el estado del arte y demostrando la idoneidad del enfoque realizado. En el futuro, este método podría permitir un análisis del sueño cómodo, rentable y preciso, lo que permitiría detectar los trastornos del sueño en una fase temprana para poder
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- 2022
8. Statistical validation of synthetic data for lung cancer patients generated by using generative adversarial networks
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Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, González Abril, Luis, Angulo, Cecilio, Ortega Ramírez, Juan Antonio, Lopez-Guerra, José-Luis, Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, González Abril, Luis, Angulo, Cecilio, Ortega Ramírez, Juan Antonio, and Lopez-Guerra, José-Luis
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The development of healthcare patient digital twins in combination with machine learning technologies helps doctors in therapeutic prescription and in minimally invasive intervention procedures. The confidentiality of medical records or limited data availability in many health domains are drawbacks that can be overcome with the generation of synthetic data conformed to real data. The use of generative adversarial networks (GAN) for the generation of synthetic data of lung cancer patients has been previously introduced as a tool to solve this problem in the form of anonymized synthetic patients. However, generated synthetic data are mainly validated from the machine learning domain (loss functions) or expert domain (oncologists). In this paper, we propose statistical decision making as a validation tool: Is the model good enough to be used? Does the model pass rigorous hypothesis testing criteria? We show for the case at hand how loss functions and hypothesis validation are not always well aligned.
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- 2022
9. Initial evaluation of substituting a sleep diary by smartwatch measurement
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, Orcioni, Simone, Conti, Massimo, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, Orcioni, Simone, Conti, Massimo, and Ortega Ramírez, Juan Antonio
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Healthy sleep is required for sufficient restoration of the human body and brain. Therefore, in the case of sleep disorders, appropriate therapy should be applied timely, which requires a prompt diagnosis. Traditionally, a sleep diary is a part of diagnosis and therapy monitoring for some sleep disorders, such as cognitive behaviour therapy for insomnia. To automatise sleep monitoring and make it more comfortable for users, substituting a sleep diary with a smartwatch measurement could be considered. With the aim of providing accurate results, a study with a total of 30 night recordings was conducted. Objective sleep measurement with a Samsung Galaxy Watch 4 was compared with a subjective approach (sleep diary), evaluating the four relevant sleep characteristics: time of getting asleep, wake up time, sleep efficiency (SE), and total sleep time (TST). The performed analysis has demonstrated that the median difference between both measurement approaches was equal to 7 and 3 minutes for a time of getting asleep and wake up time correspondingly, which allows substituting a subjective measurement with a smartwatch. The SE was determined with a median difference between the two measurement methods of 5.22%. This result also implicates a possibility of substitution. Some single recordings have indicated a higher variance between the two approaches. Therefore, the conclusion can be made that a substitution provides reliable results primarily in the case of long-term monitoring. The results of the evaluation of the TST measurement do not allow to recommend substitution of the measurement method.
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- 2022
10. Influence of Stress in Driving Behaviour
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Yay, Emre, primary, Martínez Madrid, Natividad, additional, and Ortega Ramírez, Juan Antonio, additional
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- 2016
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11. Performance of Algorithms for Interval Discretization of Biomedical Signals
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Soria Morillo, Luis Miguel, primary, Gonzalez-Abril, Luis, additional, and Ortega Ramírez, Juan Antonio, additional
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- 2016
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12. Extrapolation of weight from smart scale data
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Caballero, Pablo, Ortega Ramírez, Juan Antonio, González Abril, Luis, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, and Ministerio de Ciencia, Innovación y Universidades (MICINN). España
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Algorithm ,Digital-Twin ,Signal Processing ,Extrapolation ,Weight ,Digital- Twin - Abstract
25th International Conference on Knowledge-Based and Intelligent Information and Engineering Systems In the area of human digital twins, the designed model should be as close as possible to the reality. The weight variable is one of the interested parameters of these mathematical models, as well as its interaction with other vital signals. The aim of this paper is including the information gathered from weight sensors of a person in its digital twin. To do this it is described an algorithm that filters and forecasts the human weight to use it in indexes such as BMI. It has been applied to a real sample and the results obtained are good. Ministerio de Ciencia, Innovación y Universidades PGC2018-102145-B-C21 Ministerio de Ciencia, Innovación y Universidades C22 (AEI/FEDER, UE)
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- 2021
13. Extrapolation of weight from smart scale data
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Caballero, Pablo, Ortega Ramírez, Juan Antonio, González Abril, Luis, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Caballero, Pablo, Ortega Ramírez, Juan Antonio, and González Abril, Luis
- Abstract
In the area of human digital twins, the designed model should be as close as possible to the reality. The weight variable is one of the interested parameters of these mathematical models, as well as its interaction with other vital signals. The aim of this paper is including the information gathered from weight sensors of a person in its digital twin. To do this it is described an algorithm that filters and forecasts the human weight to use it in indexes such as BMI. It has been applied to a real sample and the results obtained are good
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- 2021
14. Non-invasive devices for respiratory sound monitoring
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC-223: Investigación, Desarrollo e Innovación en Informática, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Troncoso, Ángela, Ortega Ramírez, Juan Antonio, Seepold, Ralf, Martínez Madrid, Natividad, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC-223: Investigación, Desarrollo e Innovación en Informática, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Troncoso, Ángela, Ortega Ramírez, Juan Antonio, Seepold, Ralf, and Martínez Madrid, Natividad
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Respiratory diseases are leading causes of death and disability in the world. The recent COVID-19 pandemic is also affecting the respiratory system. Detecting and diagnosing respiratory diseases requires both medical professionals and the clinical environment. Most of the techniques used up to date were also invasive or expensive. Some research groups are developing hardware devices and techniques to make possible a non-invasive or even remote respiratory sound acquisition. These sounds are then processed and analysed for clinical, scientific, or educational purposes. We present the literature review of non-invasive sound acquisition devices and techniques. The results are about a huge number of digital tools, like microphones, wearables, or Internet of Thing devices, that can be used in this scope. Some interesting applications have been found. Some devices make easier the sound acquisition in a clinic environment, but others make possible daily monitoring outside that ambient. We aim to use some of these devices and include the non-invasive recorded respiratory sounds in a Digital Twin system for personalized health.
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- 2021
15. Digital health and care study on elderly monitoring
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC-223: Investigación, Desarrollo e Innovación en Informática, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC-223: Investigación, Desarrollo e Innovación en Informática, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, and Ortega Ramírez, Juan Antonio
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Sustainable technologies are being increasingly used in various areas of human life. While they have a multitude of benefits, they are especially useful in health monitoring, especially for certain groups of people, such as the elderly. However, there are still several issues that need to be addressed before its use becomes widespread. This work aims to clarify the aspects that are of great importance for increasing the acceptance of the use of this type of technology in the elderly. In addition, we aim to clarify whether the technologies that are already available are able to ensure acceptable accuracy and whether they could replace some of the manual approaches that are currently being used. A two-week study with people 65 years of age and over was conducted to address the questions posed here, and the results were evaluated. It was demonstrated that simplicity of use and automatic functioning play a crucial role. It was also concluded that technology cannot yet completely replace traditional methods such as questionnaires in some areas. Although the technologies that were tested were classified as being “easy to use”, the elderly population in the current study indicated that they were not sure that they would use these technologies regularly in the long term because the added value is not always clear, among other issues. Therefore, awareness-raising must take place in parallel with the development of technologies and service
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- 2021
16. Generative adversarial networks for anonymized healthcare of lung cancer patients
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Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia, Innovación y Universidades, Unión Europea, González Abril, Luis, Angulo, Cecilio, Ortega Ramírez, Juan Antonio, López Guerra, José Luis, Universidad de Sevilla. Departamento de Economía Aplicada I, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Ciencia, Innovación y Universidades, Unión Europea, González Abril, Luis, Angulo, Cecilio, Ortega Ramírez, Juan Antonio, and López Guerra, José Luis
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The digital twin in health care is the dynamic digital representation of the patient’s anatomy and physiology through computational models which are continuously updated from clinical data. Furthermore, used in combination with machine learning technologies, it should help doctors in therapeutic path and in minimally invasive intervention procedures. Confidentiality of medical records is a very delicate issue, therefore some anonymization process is mandatory in order to maintain patients privacy. Moreover, data availability is very limited in some health domains like lung cancer treatment. Hence, generation of synthetic data conformed to real data would solve this issue. In this paper, the use of generative adversarial networks (GAN) for the generation of synthetic data of lung cancer patients is introduced as a tool to solve this problem in the form of anonymized synthetic patients. Generated synthetic patients are validated using both statistical methods, as well as by oncologists using the indirect mortality rate obtained for patients in different stages.
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- 2021
17. Generative adversarial networks for anonymized healthcare of lung cancer patients
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Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement, González Abril, Luis, Angulo Bahón, Cecilio, Ortega Ramírez, Juan Antonio, López Guerra, José Luis, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement, González Abril, Luis, Angulo Bahón, Cecilio, Ortega Ramírez, Juan Antonio, and López Guerra, José Luis
- Abstract
The digital twin in health care is the dynamic digital representation of the patient’s anatomy and physiology through computational models which are continuously updated from clinical data. Furthermore, used in combination with machine learning technologies, it should help doctors in therapeutic path and in minimally invasive intervention procedures. Confidentiality of medical records is a very delicate issue, therefore some anonymization process is mandatory in order to maintain patients privacy. Moreover, data availability is very limited in some health domains like lung cancer treatment. Hence, generation of synthetic data conformed to real data would solve this issue. In this paper, the use of generative adversarial networks (GAN) for the generation of synthetic data of lung cancer patients is introduced as a tool to solve this problem in the form of anonymized synthetic patients. Generated synthetic patients are validated using both statistical methods, as well as by oncologists using the indirect mortality rate obtained for patients in different stages., Peer Reviewed, Postprint (published version)
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- 2021
18. Estimation of Sleep Stages Analyzing Respiratory and Movement Signals
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Universidad de Sevilla. Departamento de lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Perea Rodríguez, Juan José, Seepold, Ralf, Martínez Madrid, Natividad, Penzel, Thomas, Glos, Martin, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Perea Rodríguez, Juan José, Seepold, Ralf, Martínez Madrid, Natividad, Penzel, Thomas, Glos, Martin, and Ortega Ramírez, Juan Antonio
- Abstract
The scoring of sleep stages is an essential part of sleep studies. The main objective of this research is to provide an algorithm for the automatic classification of sleep stages using signals that may be obtained in a non-obtrusive way. After reviewing the relevant research, the authors selected a multinomial logistic regression as the basis for their approach. Several parameters were derived from movement and breathing signals, and their combinations were investigated to develop an accurate and stable algorithm. The algorithm was implemented to produce successful results: the accuracy of the recognition of Wake/NREM/REM stages is equal to 73%, with Cohen's kappa of 0.44 for the analyzed 19324 sleep epochs of 30 seconds each. This approach has the advantage of using the only movement and breathing signals, which can be recorded with less effort than heart or brainwave signals, and requiring only four derived parameters for the calculations. Therefore, the new system is a significant improvement for non-obtrusive sleep stage identification compared to existing approaches.
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- 2021
19. Embedded system for non-obtrusive sleep apnea detection
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Orcioni, Simone, Conti, Massimo, Seepold, Ralf, Penzel, Thomas, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Orcioni, Simone, Conti, Massimo, Seepold, Ralf, Penzel, Thomas, Martínez Madrid, Natividad, and Ortega Ramírez, Juan Antonio
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This document presents a new complete standalone system for a recognition of sleep apnea using signals from the pressure sensors placed under the mattress. The developed hardware part of the system is tuned to filter and to amplify the signal. Its software part performs more accurate signal filtering and identification of apnea events. The overall achieved accuracy of the recognition of apnea occurrence is 91%, with the average measured recognition delay of about 15 seconds, which confirms the suitability of the proposed method for future employment. The main aim of the presented approach is the support of the healthcare system with the cost-efficient tool for recognition of sleep apnea in the home environment.
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- 2020
20. A Proposal to Evolving Towards Digital Twins in Healthcare
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Angulo, Cecilio, González Abril, Luis, Raya, Cristóbal, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Ciencia, Innovación y Universidades (MICINN). España, Angulo, Cecilio, González Abril, Luis, Raya, Cristóbal, and Ortega Ramírez, Juan Antonio
- Abstract
The main objective in this proposal is to orchestrate an ecosystem of manipulation of reliable and safe data, applied to the field of health, specifically lung cancer, by introducing the creation of digital twins for personalised healthcare about the behaviour of this disease on patients. Digital twins is a very popular and novel approach in digitisation units in industry which will be used by both kind of experts: (i) data analysts, who will design expert recommender systems and extract knowledge – explainable Artificial Intelligence (AI); and (ii) professionals in medicine, who will consume that knowledge generated with their research for better diagnosis. This knowledge generation/extraction process will work in the form of a lifelong learning system by iterative and continuous use. The produced software platform will be abstracted so it can be applied like a general purpose service tool in other domains of knowledge, specially health and industry. Furthermore, a rule extraction module will be made available for explainability issues.
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- 2020
21. A portable ECG for recording and flexible development of algorithms and stress detection
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Baun, Jannik, Seepold, Ralf, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Baun, Jannik, Seepold, Ralf, Martínez Madrid, Natividad, and Ortega Ramírez, Juan Antonio
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Cardiovascular diseases are directly or indirectly responsible for up to 38.5% of all deaths in Germany and thus represent the most frequent cause of death. At present, heart diseases are mainly discovered by chance during routine visits to the doctor or when acute symptoms occur. However, there is no practical method to proactively detect diseases or abnormalities of the heart in the daily environment and to take preventive measures for the person concerned. Long-term ECG devices, as currently used by physicians, are simply too expensive, impractical, and not widely available for everyday use. This work aims to develop an ECG device suitable for everyday use that can be worn directly on the body. For this purpose, an already existing hardware platform will be analyzed, and the corresponding potential for improvement will be identified. A precise picture of the existing data quality is obtained by metrological examination, and corresponding requirements are defined. Based on these identified optimization potentials, a new ECG device is developed. The revised ECG device is characterized by a high integration density and combines all components directly on one board except the battery and the ECG electrodes. The compact design allows the device to be attached directly to the chest. An integrated microcontroller allows digital signal processing without the need for an additional computer. Central features of the evaluation are a peak detection for detecting R-peaks and a calculation of the current heart rate based on the RR interval. To ensure the validity of the detected R-peaks, a model of the anatomical conditions is used. Thus, unrealistic RR-intervals can be excluded. The wireless interface allows continuous transmission of the calculated heart rate. Following the development of hardware and software, the results are verified, and appropriate conclusions about the data quality are drawn. As a result, a very compact and wearable ECG device with different wireless t
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- 2020
22. Can Virtual Reality be used as a significant stressor for studies using ECG?
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Corcoba Magaña, Víctor, Seepold, Ralf, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Corcoba Magaña, Víctor, Seepold, Ralf, Martínez Madrid, Natividad, and Ortega Ramírez, Juan Antonio
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In previous studies, we used a method for detecting stress that was based exclusively on heart rate and ECG for differentiation between such situations as mental stress, physical activity, relaxation, and rest. As a response of the heart to these situations, we observed different behavior in the Root Mean Square of the Successive differences heartbeats (RMSSD). This study aims to analyze Virtual Reality via a virtual reality headset as an effective stressor for future works. The value of the Root Mean Square of the Successive Differences is an important marker for the parasympathetic effector on the heart and can provide information about stress. For these measurements, the RR interval was collected using a breast belt. In these studies, we can observe the Root Mean Square of the successive differences heartbeats. Additional sensors for the analysis were not used. We conducted experiments with ten subjects that had to drive a simulator for 25 minutes using monitors and 25 minutes using virtual reality headset. Before starting and after finishing each simulation, the subjects had to complete a survey in which they had to describe their mental state. The experiment results show that driving using virtual reality headset has some influence on the heart rate and RMSSD, but it does not significantly increase the stress of driving.
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- 2020
23. Non-obtrusive system for overnight respiration and heartbeat tracking
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Wehrle, Dennis, Seepold, Ralf, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Wehrle, Dennis, Seepold, Ralf, and Ortega Ramírez, Juan Antonio
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Polysomnography is a gold standard for a sleep study, and it provides very accurate results, but its cost (both personnel and material) are quite high. Therefore, the development of a low-cost system for overnight breathing and heartbeat monitoring, which provides more comfort while recording the data, is a well-motivated challenge. The system proposed in this manuscript is based on the usage of resistive pressure sensors installed under the mattress. These sensors can measure slight pressure changes provoked during breathing and heartbeat. The captured signal requires advanced processing, like applying filters and amplifiers before the analog signal is ready for the next step. Then, the output signal is digitalized and further processed by an algorithm that performs a custom filtering before it can recognize breathing and heart rate in real-time. The result can be directly visualized. Furthermore, a CSV file is created containing the raw data, timestamps, and unique IDs to facilitate further processing. The achieved results are promising, and the average deviation from a reference device is about 4bpm.
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- 2020
24. Comparison of sleep characteristics measurements: a case study with a population aged 65 and above
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Ortega Ramírez, Juan Antonio, Martínez Madrid, Natividad, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Ortega Ramírez, Juan Antonio, and Martínez Madrid, Natividad
- Abstract
Good sleep is crucial for a healthy life of every person. Unfortunately, its quality often decreases with aging. A common approach to measuring the sleep characteristics is based on interviews with the subjects or letting them fill in a daily questionnaire and afterward evaluating the obtained data. However, this method has time and personal costs for the interviewer and evaluator of responses. Therefore, it would be important to execute the collection and evaluation of sleep characteristics automatically. To do that, it is necessary to investigate the level of agreement between measurements performed in a traditional way using questionnaires and measurements obtained using electronic monitoring devices. The study presented in this manuscript performs this investigation, comparing such sleep characteristics as "time going to bed", "total time in bed", "total sleep time" and "sleep efficiency". A total number of 106 night records of elderly persons (aged 65+) were analyzed. The results achieved so far reveal the fact that the degree of agreement between the two measurement methods varies substantially for different characteristics, from 31 minutes of mean difference for "time going to bed" to 77 minutes for "total sleep time". For this reason, a direct exchange of objective and subjective measuring methods is currently not possible.
- Published
- 2020
25. A Comparison of Objective and Subjective Sleep Quality Measurement in a Group of Elderly Persons in a Home Environment
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Conti, Massimo, Orcioni, Simone, Penzel, Thomas, Scherz, Wilhelm Daniel, Perea, Juan José, Serrano Alarcón, Ángel, Weiss, Gerald, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Martínez Madrid, Natividad, Ortega Ramírez, Juan Antonio, Conti, Massimo, Orcioni, Simone, Penzel, Thomas, Scherz, Wilhelm Daniel, Perea, Juan José, Serrano Alarcón, Ángel, and Weiss, Gerald
- Abstract
The main aim of presented in this manuscript research is to compare the results of objective and subjective measurement of sleep quality for older adults (65+) in the home environment. A total amount of 73 nights was evaluated in this study. Placing under the mattress devicewas used to obtain objective measurement data, and a common question on perceived sleep quality was asked to collect the subjective sleep quality level. The achieved results confirm the correlation between objective and subjective measurement of sleep quality with the average standard deviation equal to 2 of 10 possible quality points.
- Published
- 2020
26. RR interval analysis for the distinction between stress, physical activity and no activity using a portable ECG
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Seepold, Ralf, Martínez Madrid, Natividad, Crippa, Paolo, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Seepold, Ralf, Martínez Madrid, Natividad, Crippa, Paolo, and Ortega Ramírez, Juan Antonio
- Abstract
Methods based exclusively on heart rate hardly allow to differentiate between physical activity, stress, relaxation, and rest, that is why an additional sensor like activity/movement sensor added for detection and classification. The response of the heart to physical activity, stress, relaxation, and no activity can be very similar. In this study, we can observe the influence of induced stress and analyze which metrics could be considered for its detection. The changes in the Root Mean Square of the Successive Differences provide us with information about physiological changes. A set of measurements collecting the RR intervals was taken. The intervals are used as a parameter to distinguish four different stages. Parameters like skin conductivity or skin temperature were not used because the main aim is to maintain a minimum number of sensors and devices and thereby to increase the wearability in the future.
- Published
- 2020
27. La COVID-19 y los desafíos de la vigilancia digital para los derechos humanos: a propósito de la app DataCOVID prevista en la Orden Ministerial SND/29/2020, de 27 de marzo
- Author
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Márquez Carrasco, Carmen, primary and Ortega Ramírez, Juan Antonio, additional
- Published
- 2020
- Full Text
- View/download PDF
28. Towards a healthcare digital twin
- Author
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Angulo Bahón, Cecilio, Ortega Ramírez, Juan Antonio, Gonzalez Abril, Luis, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, and Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement
- Subjects
Information theory ,Medical care ,Informàtica::Automàtica i control [Àrees temàtiques de la UPC] ,Computer security ,Informació, Teoria de la ,Healthcare ,Anonymization ,Assistència mèdica ,Seguretat informàtica ,Medical innovations ,Digital twin ,Decision support system ,Medicina -- Innovacions - Abstract
The main aim of this short position paper is to introduce a proposal to orchestrate an ecosystem of manipulation of reliable and safe data, applied to the field of health, proposing the creation of digital twins for personalised healthcare. These will be used by both kind of experts: (i) data analysts, who will design expert recommender systems and extract knowledge (explainable AI); and (ii) professionals in medicine, who will consume that knowledge generated with their research for better diagnosis. Knowledge generation / extraction processes will work in the form of a lifelong learning system by iterative and continuous use. The produced platform would be abstracted so it can be applied like a general purpose service tool in other domains. A rule extraction module would be also made available.
- Published
- 2019
29. Recognition of Sleep/Wake States analyzing Heart Rate, Breathing and Movement Signals
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Penzel, Thomas, Ortega Ramírez, Juan Antonio, Glos, Martin, Martínez Madrid, Natividad, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Seepold, Ralf, Penzel, Thomas, Ortega Ramírez, Juan Antonio, Glos, Martin, and Martínez Madrid, Natividad
- Abstract
This document presents an algorithm for a nonobtrusive recognition of Sleep/Wake states using signals derived from ECG, respiration, and body movement captured while lying in a bed. As a core mathematical base of system data analytics, multinomial logistic regression techniques were chosen. Derived parameters of the three signals are used as the input for the proposed method. The overall achieved accuracy rate is 84% for Wake/Sleep stages, with Cohen’s kappa value 0.46. The presented algorithm should support experts in analyzing sleep quality in more detail. The results confirm the potential of this method and disclose several ways for its improvement.
- Published
- 2019
30. Home Hospital e-Health Centers for Barrier-Free and Cross-Border Telemedicine
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Seepold, Ralf, Gaiduk, Maksym, Ortega Ramírez, Juan Antonio, Conti, Massimo, Orcioni, Simone, Martínez Madrid, Natividad, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Seepold, Ralf, Gaiduk, Maksym, Ortega Ramírez, Juan Antonio, Conti, Massimo, Orcioni, Simone, and Martínez Madrid, Natividad
- Abstract
The goal of the presented project is to develop the concept of home ehealth centers for barrier-free and cross-border telemedicine. AAL technologies are already present on the market but there is still a gap to close until they can be used for ordinary patient needs. The general idea needs to be accompanied by new services, which should be brought together in order to provide a full coverage of service for the users. Sleep and stress were chosen as predominant diseases for a detailed study within this project because of their widespread influence in the population. The executed scientific study of available home devices analyzing sleep has provided the necessary to select appropriate devices. The first choice for the project implementation is the device EMFIT QS+. This equipment provides a part of a complete system that a home telemedical hospital can provide at a level of precision and communication with internal and/or external health services.
- Published
- 2019
31. Towards a healthcare digital twin
- Author
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Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement, Angulo Bahón, Cecilio, Ortega Ramírez, Juan Antonio, Gonzalez Abril, Luis, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Universitat Politècnica de Catalunya. GREC - Grup de Recerca en Enginyeria del Coneixement, Angulo Bahón, Cecilio, Ortega Ramírez, Juan Antonio, and Gonzalez Abril, Luis
- Abstract
The main aim of this short position paper is to introduce a proposal to orchestrate an ecosystem of manipulation of reliable and safe data, applied to the field of health, proposing the creation of digital twins for personalised healthcare. These will be used by both kind of experts: (i) data analysts, who will design expert recommender systems and extract knowledge (explainable AI); and (ii) professionals in medicine, who will consume that knowledge generated with their research for better diagnosis. Knowledge generation / extraction processes will work in the form of a lifelong learning system by iterative and continuous use. The produced platform would be abstracted so it can be applied like a general purpose service tool in other domains. A rule extraction module would be also made available., Peer Reviewed, Postprint (published version)
- Published
- 2019
32. Patrones de comportamiento temporal en modelos semicualitativos con restricciones
- Author
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Ortega Ramírez, Juan Antonio, Toro Bonilla, Miguel, and Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos
- Subjects
Dinámica diferenciable ,Turismo Viajeros ,Turismo ,Andalucía ,Sistemas, Análisis de ,Siglo XIX ,Razonamiento cualitativo académicas - Abstract
En esta tesis se propone una nueva metodología para automatizar el análisis y el estudio de modelos con restricciones que integran conocimiento cuantitativo y cualitativo construidos para sistemas que evolucionan en el tiempo. El tipo de conocimiento cualitativo que puede incorporarse a los modelos puede estar compuesto por operadores cualitativos, funciones de banda, etiquetas cualitativas y funciones cualitativas continuas con restricciones. Se describe un formalismo para incorporar esta información cualitativa a los modelos. La metodología propuesta permite estudiar tanto el régimen estacionario como el régimen transitorio de los sistemas que evolucionan en el tiempo. La principal idea de la metodología es: "cuando un modelo semicualitativo se transforma en una familia de modelos cuantitativos, cada uno de estos modelos tiene un comportamiento cuantitativo diferente, si bien entre si pueden responder a comportamientos cualitativos similares". La metodología permite razonar sobre los modelos semicualitativos con restricciones. Para conseguirlo, combina de cierta manera y en un cierto orden: reglas de transformación, técnicas estocásticas, simulación cuantitativa, generación de bases de datos, lenguajes de consulta/clasificación sobre bases de datos, minería de datos, técnicas de clasificación y agrupamiento o clustering y algoritmos para obtención de patrones de comportamiento. El detalle sobre la manera y el orden de aplicar estos pasos se describe conforme se avanza en los capítulos de la memoria. También se ha realizado un estudio teórico sobre la validez de las conclusiones obtenidas con la metodología, demostrándose el grado de fiabilidad con el que estas conclusiones son aplicables al sistema real. La metodología propuesta se ha aplicado a diferentes ejemplos. Entre ellos, destacar su aplicación a un modelo semicualitativo de crecimiento logístico con retraso. La evolución de las baterias, la extracción de minerales, el crecimiento de la población, las epidemias, los rumores, los desarrollos económicos o las curvas de aprendizaje son sistemas reales cuyos patrones de comportamiento están relacionados con un crecimiento logístico. Los resultados obtenidos con esta metodología concuerdan con otros aparecidos en la bibliografía, obtenidos por medio de razonamientos matemáticos.
- Published
- 2018
33. Energy policies for data-center monolithic schedulers
- Author
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Fernández Cerero, Damián, Fernández Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Universidad de Sevilla. TIC134: Sistemas Informáticos
- Subjects
Data centre ,Energy policies ,Decision Making ,Simulation software ,Efficiency - Abstract
Cloud computing and data centers that support this paradigm are rapidly evolving in order to satisfy new demands. These ever-growing needs represent an energy-related challenge to achieve sustainability and cost reduction. In this paper, we define an expert and intelligent system that applies various en ergy policies. These policies are employed to maximize the energy-efficiency of data-center resources by simulating a realistic environment and heterogeneous workload in a trustworthy tool. An environmental and economic impact of around 20% of energy consumption can be saved in high-utilization scenarios without exerting any noticeable impact on data-center performance if an adequate policy is applied.
- Published
- 2018
34. Energy and performance-aware scheduling and shut-down models for efficient cloud-computing data centers.
- Author
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Fernández-Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Fernández Cerero, Damián, Fernández-Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Fernández Cerero, Damián
- Abstract
This Doctoral Dissertation, presented as a set of research contributions, focuses on resource efficiency in data centers. This topic has been faced mainly by the development of several energy-efficiency, resource managing and scheduling policies, as well as the simulation tools required to test them in realistic cloud computing environments. Several models have been implemented in order to minimize energy consumption in Cloud Computing environments. Among them: a) Fifteen probabilistic and deterministic energy-policies which shut-down idle machines; b) Five energy-aware scheduling algorithms, including several genetic algorithm models; c) A Stackelberg game-based strategy which models the concurrency between opposite requirements of Cloud-Computing systems in order to dynamically apply the most optimal scheduling algorithms and energy-efficiency policies depending on the environment; and d) A productive analysis on the resource efficiency of several realistic cloud–computing environments. A novel simulation tool called SCORE, able to simulate several data-center sizes, machine heterogeneity, security levels, workload composition and patterns, scheduling strategies and energy-efficiency strategies, was developed in order to test these strategies in large-scale cloud-computing clusters. As results, more than fifty Key Performance Indicators (KPI) show that more than 20% of energy consumption can be reduced in realistic high-utilization environments when proper policies are employed., Esta Tesis Doctoral, que se presenta como compendio de artículos de investigación, se centra en la eficiencia en la utilización de los recursos en centros de datos de internet. Este problema ha sido abordado esencialmente desarrollando diferentes estrategias de eficiencia energética, gestión y distribución de recursos, así como todas las herramientas de simulación y análisis necesarias para su validación en entornos realistas de Cloud Computing. Numerosas estrategias han sido desarrolladas para minimizar el consumo energético en entornos de Cloud Computing. Entre ellos: 1. Quince políticas de eficiencia energética, tanto probabilísticas como deterministas, que apagan máquinas en estado de espera siempre que sea posible; 2. Cinco algoritmos de distribución de tareas que tienen en cuenta el consumo energético, incluyendo varios modelos de algoritmos genéticos; 3. Una estrategia basada en la teoría de juegos de Stackelberg que modela la competición entre diferentes partes de los centros de datos que tienen objetivos encontrados. Este modelo aplica dinámicamente las estrategias de distribución de tareas y las políticas de eficiencia energética dependiendo de las características del entorno; y 4. Un análisis productivo sobre la eficiencia en la utilización de recursos en numerosos escenarios de Cloud Computing. Una nueva herramienta de simulación llamada SCORE se ha desarrollado para analizar las estrategias antes mencionadas en clústers de Cloud Computing de grandes dimensiones. Los resultados obtenidos muestran que se puede conseguir un ahorro de energía superior al 20% en entornos realistas de alta utilización si se emplean las estrategias de eficiencia energética adecuadas. SCORE es open source y puede simular diferentes centros de datos con, entre otros muchos, los siguientes parámetros: Tamaño del centro de datos; heterogeneidad de los servidores; tipo, composición y patrones de carga de trabajo, estrategias de distribución de tareas y políticas de eficiencia energ
- Published
- 2018
35. Energy policies for data-center monolithic schedulers
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC134: Sistemas Informáticos, Fernández Cerero, Damián, Fernández Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. TIC134: Sistemas Informáticos, Fernández Cerero, Damián, Fernández Montes González, Alejandro, and Ortega Ramírez, Juan Antonio
- Abstract
Cloud computing and data centers that support this paradigm are rapidly evolving in order to satisfy new demands. These ever-growing needs represent an energy-related challenge to achieve sustainability and cost reduction. In this paper, we define an expert and intelligent system that applies various en ergy policies. These policies are employed to maximize the energy-efficiency of data-center resources by simulating a realistic environment and heterogeneous workload in a trustworthy tool. An environmental and economic impact of around 20% of energy consumption can be saved in high-utilization scenarios without exerting any noticeable impact on data-center performance if an adequate policy is applied.
- Published
- 2018
36. Sensor-mesh-based system with application on sleep study
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Vunderl, Bruno, Seepold, Ralf, Ortega Ramírez, Juan Antonio, Penzel, Thomas, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Vunderl, Bruno, Seepold, Ralf, Ortega Ramírez, Juan Antonio, and Penzel, Thomas
- Abstract
The process of restoring our body and brain from fatigue is directly depending on the quality of sleep. It can be determined from the report of the sleep study results. Classification of sleep stages is the first step of this study and this includes the measurement of biovital data and its further processing. In this work, the sleep analysis system is based on a hardware sensor net, namely a grid of 24 pressure sensors, supporting sleep phase recognition. In com-parison to the leading standard, which is polysomnography, the proposed ap-proach is a non-invasive system. It recognises respiration and body movement with only one type of low-cost pressure sensors forming a mesh architecture. The nodes implement as a series of pressure sensors connected to a low-power and performant microcontroller. All nodes are connected via a system wide bus with address arbitration. The embedded processor is the mesh network endpoint that enables network configuration, storing and pre-processing of the data, external data access and visualization. The system was tested by executing experiments recording the sleep of differ-ent healthy young subjects. The results obtained have indicated the potential to detect breathing rate and body movement. A major difference of this system in comparison to other approaches is the innovative way to place the sensors under the mattress. This characteristic facilitates the continuous using of the system without any influence on the common sleep process.
- Published
- 2018
37. Automatic sleep stages classification using respiratory, heart rate and movement signals
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Penzel, Thomas, Ortega Ramírez, Juan Antonio, Seepold, Ralf, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Penzel, Thomas, Ortega Ramírez, Juan Antonio, and Seepold, Ralf
- Abstract
This paper presents an algorithm for non-invasive sleep stage identification using respiratory, heart rate and movement signals. The algorithm is part of a system suitable for longterm monitoring in a home environment, which should support experts analysing sleep. Approach: As there is a strong correlation between bio-vital signals and sleep stages, multinomial logistic regression was chosen for categorical distribution of sleep stages. Several derived parameters of three signals (respiratory, heart rate and movement) are input for the proposed method. Sleep recordings of five subjects were used for the training of a machine learning model and 30 overnight recordings collected from 30 individuals with about 27 000 epochs of 30 s intervals each were evaluated. Main results: The achieved rate of accuracy is 72% for Wake, NREM, REM (with Cohen’s kappa value 0.67) and 58% for Wake, Light (N1 and N2), Deep (N3) and REM stages (Cohen’s kappa is 0.50). Our approach has confirmed the potential of this method and disclosed several ways for its improvement. Significance: The results indicate that respiratory, heart rate and movement signals can be used for sleep studies with a reasonable level of accuracy. These inputs can be obtained in a non-invasive way applying it in a home environment. The proposed system introduces a convenient approach for a long-term monitoring system which could support sleep laboratories. The algorithm which was developed allows for an easy adjustment of input parameters that depend on available signals and for this reason could also be used with various hardware systems.
- Published
- 2018
38. Energy and performance-aware scheduling and shut-down models for efficient cloud-computing data centers.
- Author
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Fernández Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Fernández Cerero, Damián, Fernández Montes González, Alejandro, Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Fernández Cerero, Damián
- Abstract
This Doctoral Dissertation, presented as a set of research contributions, focuses on resource efficiency in data centers. This topic has been faced mainly by the development of several energy-efficiency, resource managing and scheduling policies, as well as the simulation tools required to test them in realistic cloud computing environments. Several models have been implemented in order to minimize energy consumption in Cloud Computing environments. Among them: a) Fifteen probabilistic and deterministic energy-policies which shut-down idle machines; b) Five energy-aware scheduling algorithms, including several genetic algorithm models; c) A Stackelberg game-based strategy which models the concurrency between opposite requirements of Cloud-Computing systems in order to dynamically apply the most optimal scheduling algorithms and energy-efficiency policies depending on the environment; and d) A productive analysis on the resource efficiency of several realistic cloud–computing environments. A novel simulation tool called SCORE, able to simulate several data-center sizes, machine heterogeneity, security levels, workload composition and patterns, scheduling strategies and energy-efficiency strategies, was developed in order to test these strategies in large-scale cloud-computing clusters. As results, more than fifty Key Performance Indicators (KPI) show that more than 20% of energy consumption can be reduced in realistic high-utilization environments when proper policies are employed., Esta Tesis Doctoral, que se presenta como compendio de artículos de investigación, se centra en la eficiencia en la utilización de los recursos en centros de datos de internet. Este problema ha sido abordado esencialmente desarrollando diferentes estrategias de eficiencia energética, gestión y distribución de recursos, así como todas las herramientas de simulación y análisis necesarias para su validación en entornos realistas de Cloud Computing. Numerosas estrategias han sido desarrolladas para minimizar el consumo energético en entornos de Cloud Computing. Entre ellos: 1. Quince políticas de eficiencia energética, tanto probabilísticas como deterministas, que apagan máquinas en estado de espera siempre que sea posible; 2. Cinco algoritmos de distribución de tareas que tienen en cuenta el consumo energético, incluyendo varios modelos de algoritmos genéticos; 3. Una estrategia basada en la teoría de juegos de Stackelberg que modela la competición entre diferentes partes de los centros de datos que tienen objetivos encontrados. Este modelo aplica dinámicamente las estrategias de distribución de tareas y las políticas de eficiencia energética dependiendo de las características del entorno; y 4. Un análisis productivo sobre la eficiencia en la utilización de recursos en numerosos escenarios de Cloud Computing. Una nueva herramienta de simulación llamada SCORE se ha desarrollado para analizar las estrategias antes mencionadas en clústers de Cloud Computing de grandes dimensiones. Los resultados obtenidos muestran que se puede conseguir un ahorro de energía superior al 20% en entornos realistas de alta utilización si se emplean las estrategias de eficiencia energética adecuadas. SCORE es open source y puede simular diferentes centros de datos con, entre otros muchos, los siguientes parámetros: Tamaño del centro de datos; heterogeneidad de los servidores; tipo, composición y patrones de carga de trabajo, estrategias de distribución de tareas y políticas de eficiencia energ
- Published
- 2018
39. Energy Efficient Resource Usage in Data Centers: GreenDoop
- Author
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Fernández Cerero, Damián, Fernández Montes, Alejandro, Ortega Ramírez, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, and Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos
- Abstract
The spread of cloud computing has increased recent data center size and usage. Because of this, the optimization of data centers is becoming the focus of most important companies in this sector. In order to improve data cenler energy efficiency, we propose a software infrastructure for minimizing power usage of data centers based on policies for switching on/off servers, load balancing and data organization; keeping the mínimum number of machines on, while affecting as little as possible performance and reliability.
- Published
- 2013
40. ARTEMISA: Architecture of an eco-driving assistant based on the anticipation
- Author
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Corcoba Magaña, Víctor, Muñoz Organero, Mario, Fernández Montes, A., Ortega Ramírez, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Ministerio de Ciencia e Innovación (MICIN). España
- Abstract
This paper presents the architecture of an ecodriving assistant. The assistant evaluates the fulfilment of classic eco-driving advices such as: maintain a constant speed, driving at high gear, slow down smoothly and so on. In addition, the assistant issues advices based on the anticipation. Anticipation is the key of eco-driving. The assistant is capable of detecting traffic signs beforehand and it checks if the speed is suitable for not having to slow down sharply. In addition, the system proposes an optimal average speed according to the conditions of the road. To model the environment where the vehicle is moving, we use an Android mobile device. These devices are ideal due to to their multiple network connections (Bluetooth, UTMS and WIFI) and sensors (camera, acceleration sensor, GPS and so on). To obtain the vehicle’s parameters (speed, fuel consumption, RPM, etc.), we use the diagnostic port (OBD2). The proposed system can improve fuel consumption and safety. In addition, it is independent of the type of vehicle. Ministerio de Ciencia e Innovación TIN2009-14378-C02-02
- Published
- 2012
41. An extended chronicle discovery approach to find temporal patterns between sequences
- Author
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Álvarez, M.A., Subias, A., Travé-Massuyès, L., González Abril, Luis, Ortega Ramírez, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Economía y Competitividad (MINECO). España, and Junta de Andalucía. Consejería de Economía, Innovación y Ciencia
- Abstract
Sequences of events describing the behavior and actions of users or systems can be collected in several domains. An episode is a collection of events that occurs relatively close to each other in a given partial order. Also, chronicles are a special type of temporal patterns, where temporal orders of events are quantified with numerical bounds and reflect the temporal evolution of the system over the time. In this paper, the problem of finding rules for describing or predicting the behavior of the sequences with the intention of characterizing some interesting tasks is considered. Obtaining these patterns is the main objective of this work, where an automatic method to learn relevant and discriminating chronicles is proposed. The method extends existing algorithms that have been proposed to find frequent episodes/chronicles in a single event sequence to the case of multiple sequences. Ministerio de Economía y Competitividad TIN2009-14378-C02-01 Junta de Andalucía. Consejería de Economía, Innovación y Ciencia TIC8052
- Published
- 2012
42. A Sensor Grid for Pressure and Movement Detection Supporting Sleep Phase Analysis
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Kuhn, Ina, Seepold, Ralf, Ortega Ramírez, Juan Antonio, Martínez Madrid, Natividad, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Gaiduk, Maksym, Kuhn, Ina, Seepold, Ralf, Ortega Ramírez, Juan Antonio, and Martínez Madrid, Natividad
- Abstract
Sleep quality and in general, behavior in bed can be detected using a sleep state analysis. These results can help a subject to regulate sleep and recognize different sleeping disorders. In this work, a sensor grid for pressure and movement detection supporting sleep phase analysis is proposed. In comparison to the leading standard measuring system, which is Polysomnography (PSG), the system proposed in this project is a non-invasive sleep monitoring device. For continuous analysis or home use, the PSG or wearable Actigraphy devices tends to be uncomfortable. Besides this fact, they are also very expensive. The system represented in this work classifies respiration and body movement with only one type of sensor and also in a non-invasive way. The sensor used is a pressure sensor. This sensor is low cost and can be used for commercial proposes. The system was tested by carrying out an experiment that recorded the sleep process of a subject. These recordings showed the potential for classification of breathing rate and body movements. Although previous researches show the use of pressure sensors in recognizing posture and breathing, they have been mostly used by positioning the sensors between the mattress and bedsheet. This project however, shows an innovative way to position the sensors under the mattress.
- Published
- 2017
43. Pattern recognition techniques and classification sets supporting behavioural tagging when using a limited number of body sensors
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Ortega Ramírez, Juan Antonio, Seepold, Ralf, Conti, Massimo, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Scherz, Wilhelm Daniel, Ortega Ramírez, Juan Antonio, Seepold, Ralf, and Conti, Massimo
- Abstract
Stress and physical activities are important aspects of life of people. Body reactions on stress and on physical activities can be very similar but long-term stress leads to diseases and damages the body [1]. Currently there is no method to differentiate easily and clearly between these two aspects in a time slot. We have confronted this problem while developing a mobile system for detection and analysis of stress. This paper presents an approach, which uses a long-term monitor with ECG/EKG capabilities and analysis of the heart rate data that is extracted from the device. The focus of the work is to find characteristics that are useful for differentiation between physical activity and stress.
- Published
- 2017
44. Thematic issue on human-centred ambient intelligence: Cognitive approaches, reasoning and learning
- Author
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Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Falomir, Zoe, Ortega Ramírez, Juan Antonio, Martínez Madrid, Natividad, Guesguen, Hans, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Falomir, Zoe, Ortega Ramírez, Juan Antonio, Martínez Madrid, Natividad, and Guesguen, Hans
- Abstract
This editorial presents advances on Human-centred Ambient Intelligence applications which take into account cognitive issues when modelling users (i.e. stress, attention disorders), and learn users’ activities/preferences and adapt to them (i.e. at home, driving a car). These papers also show AmI applications in health and education, which make them even more valuable for the general society.
- Published
- 2017
45. Predicción de destinos geográficos mediante Modelos de Markov Ocultos
- Author
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Álvarez García, Juan Antonio, González Abril, Luis, Ortega Ramírez, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Educación y Cultura (MEC). España, and Junta de Andalucía
- Abstract
En este artículo se propone una metodología basada en los modelos de Markov Ocultos para realizar predicciones del futuro lugar geográfico hacia el que nos dirigimos cuando comenzamos un nuevo recorrido. En primer lugar recogemos datos suficientes como para poder generar una estructura de rutas basadas en similitudes entre recorridos. Una vez que conseguimos las rutas, detectamos automáticamente los cruces entre éstas y utilizamos los datos para entrenar al modelo. Una vez entrenado, a partir de una serie de observaciones predecimos el destino más probable hacia el que nos dirigimos basándonos en el recorrido real del usuario utilizando el algoritmo de Viterbi. Ministerio de Educación y Cultura TSI2006-I 3390-C02-02 Junta de Andalucía P06- TIC-02 I 41
- Published
- 2008
46. Modelado de características para itinerarios formativos adaptativos
- Author
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Márquez, J.M., Cetina, Carlos, Velasco Morente, Francisco, González Abril, Luis, Ortega Ramírez, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de lenguajes y Sistemas Informáticos, and Universidad de Sevilla. Departamento de Economía Aplicada I
- Abstract
Este trabajo presenta una forma de combinar dos técnicas diferentes de la inteligencia artificial para aplicarlas en la adaptación de itinerarios formativos usando plataformas de e-Leaming. La utilización de las técnicas descritas en este trabajo, a diferencia de otras técnicas más "intrusivas", no afecta al formato de empaquetado de los contenidos y mantiene la compatibilidad de éstos con las especificaciones existentes en la actualidad, permitiendo la adaptación del currículo en tiempo de ejecución, y adaptándolo a las necesidades específicas de los alumnos.
- Published
- 2008
47. Experimental environment to learn user preferences
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Fernández Montes, Alejandro, Ortega Ramírez, Juan Antonio, González Abril, Luis, Álvarez García, Juan Antonio, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, Ministerio de Educación y Ciencia (MEC). España, and Junta de Andalucía
- Abstract
Tne automation of smart environment systems is one of the main goals of smart home researching. Tui paper focus on learning user lighting preference, considering a working field like a standard office. A review of the smart environment and de\;ces setup is done, showing a real configuration for test purposes. Suitable learning machine techniques are exposed in order to leam these preferences, and suggest the actions the smart environment should execute to satisfy the user preferences. Leaming machine techniques proposed are fed with a database, so a proposal for the vectorization of data is described and analyzed. Ministerio de Educación y Ciencia TSI2006-13390-C02-02 Junta de Andalucía TIC2141
- Published
- 2008
48. A location of robots proposal in collaborative environments
- Author
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Álvarez, M. A., Fernández Montes, A., Ortega Ramírez, Juan Antonio, Velasco Morente, Francisco, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, and Universidad de Sevilla. Departamento de Economía Aplicada I
- Abstract
This paper proposes a method to localize a robot in a collaborative enviroment when it can not do itself. In a enviroment is possible that a robot crashes with an object and breaks any of its sensors or something works wrong. In this case, this robot will use the others to find its location. Distances and power signals will be used to locate the robot inside the environment. In this way, a robot may be triangulate from the position of other robots to achieve the objective of this paper.
- Published
- 2008
49. Estudio de troyanos en dispositivos móviles
- Author
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Fuentes, D., Álvarez García, Juan Antonio, Ortega Ramírez, Juan Antonio, Torres Valderrama, Jesús, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Ministerio de Educación y Cultura (MEC). España, and Junta de Andalucía
- Abstract
A finales de 2007 había en el mundo 3.300 millones de móviles según un estudio de la Unión Internacional de Telecomunicaciones (UTI), lo que supone aproximadamente un teléfono móvil cada dos personas. Si a esto unimos el incremento de capacidades de sensorización de dichos dispositivos, hace que hoy en día la mayoría de las personas se encuentren comunicadas y puedan aprovechar la potencia de sus terminales para conseguir funcionalidades avanzadas: navegación vía GPS, comunicación a Internet, realizar fotografías,... Según Gartner Inc., en 2009 un 29% de los dispositivos móviles en el mundo serán PDAs y Smartphones, con un 90% de predominio de los sistemas operativos Symbian y Microsoft Windows Mobile. Además, actualmente 33 millones de usuarios ya usan los dispositivos móviles para realizar compras y se prevé que en 2010 llega a 103.8 millones. Por otra parte el spam, el número de SMS con intenciones fraudulentas, las numerosas descargas de melodías, fondos para móviles, etc, están aumentando de una manera increíble. Según los datos proporcionados de la firma Ferris Research, se estima que los estadounidenses propietarios de teléfonos móviles reciban unos 1.500 millones de SMS no solicitados a lo largo de 2008. Dicha cifra es el doble de lo que se recibió en 2006. Y eso no es lo peor, sino las posibles infecciones que todos estos mensajes pueden contener en su interior. En los dispositivos móviles, cada servicio que permita conectar con otro dispositivo puede ser fuente para la intrusión de un virus u otra amenaza. Pueden existir otros caminos que den lugar a la intrusión de un software malicioso, como son las tarjetas de memoria extraíble o la sincronización de una PDA con un PC. La mayoría de los usuarios pueden acceder con sus dispositivos móviles a Internet y debido a ello, también son posible blanco de estas amenazas. Nuestro estudio analizará con detalle todas estas posibles fuentes de infección, advertencias o consejos de prevención y software actual de protección para nuestros dispositivos móviles. En este artículo nos centraremos en los ataques con troyanos, cuyo objetivo fundamental (además de su propia propagación) es la obtención de información de un usuario de forma maliciosa sin que este pueda percibir el robo. Para ello, se analizará la seguridad en estos dispositivos móviles mediante una experiencia práctica en la que se introducirá un troyano en el terminal de un usuario para conseguir la información de los contactos almacenados en el terminal. El troyano se instalará en la máquina del usuario atacado sin que este pueda ser consciente de ello puesto que irá camuflado dentro de una imagen (aunque también podría ir junto a un archivo de audio o vídeo). El programa una vez instalado, quedará de forma permanente ejecutándose en la PDA atacada a la espera de que un segundo usuario malicioso envíe un mensaje SMS con una estructura predeterminada cuyo contenido será procesado a través de un parser programado dentro del troyano, que devolverá todos los contactos dentro de tantos mensajes SMS como sean necesarios. Una vez analizado el problema, se propondrá una solución que tratará de solventar las posibles consecuencias del ataque a la privacidad del usuario. Por último como conclusión se realizará una reflexión sobre los resultados obtenidos en el estudio, aconsejando al lector sobre la importancia de la seguridad en los dispositivos móviles en una sociedad en la que los más diversos adelantos tecnológicos ocupan un lugar cada vez más cotidiano y habitual. Ministerio de Educación y Cultura TSI2006-13390-C02-02 Junta de Andalucía P06--TIC-02141
- Published
- 2008
50. Bifurcaciones locales en el mercado actual y potencial: El mercado cervecero español
- Author
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Velasco Morente, Francisco, Nadal, P., González Abril, Luis, Ortega Ramírez, Juan Antonio, Vilchez Lobato, María Luisa, Cuberos, Francisco Javier, Ortega Ramírez, Juan Antonio (Coordinador), Ortega Ramírez, Juan Antonio, Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos, Universidad de Sevilla. Departamento de Economía Aplicada I, and Junta de Andalucía
- Abstract
En este trabajo establecemos las condiciones necesarias para la existencia de bifurcaciones de codimensión 1 y 2 de un modelo dinámico discreto en el mercado actual y potencial de las organizaciones. Tal y como ocurre con el estudio de la estabilidad, los resultados están ligado a determinadas regiones del plano paramétrico. Posteriormente, sobre el modelo aplicado al mercado cervecero español, aplicamos los resultados obtenidos para analizar si las cuotas de mercado para los mercados potenciales y actuales de un determinado producto tenderán a estabilizarse, o si por el contrario sufrirán aumentos y/o disminuciones periódicas, es decir, una vez encontrado el punto de equilibrio para el mercado cervecero, estudiamos como cambia el comportamiento de los mercados, en un entorno de dicho equilibrio, al variar los valores de los parámetros de ajuste encontrados. Junta de Andalucía ACC-944-SEJ-2002 Junta de Andalucía CC-944-SEJ-2003
- Published
- 2005
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