A Primer on Bayesian Neural Networks: Review and Debates

Neural networks have achieved remarkable performance across various problem domains, but their widespread applicability is hindered by inherent limitations such as overconfidence in predictions, lack of interpretability, and vulnerability to adversarial attacks. To address these challenges, Bayesian neural networks (BNNs) have emerged as a compelling extension of conventional neural networks, integrating uncertainty estimation into their predictive capabilities. This comprehensive primer presents a systematic introduction to the fundamental concepts of neural networks and Bayesian inference, elucidating their synergistic integration for the development of BNNs. The target audience comprises statisticians with a potential background in Bayesian methods but lacking deep learning expertise, as well as machine learners proficient in deep neural networks but with limited exposure to Bayesian statistics. We provide an overview of commonly employed priors, examining their impact on model behavior and performance. Additionally, we delve into the practical considerations associated with training and inference in BNNs. Furthermore, we explore advanced topics within the realm of BNN research, acknowledging the existence of ongoing debates and controversies. By offering insights into cutting-edge developments, this primer not only equips researchers and practitioners with a solid foundation in BNNs, but also illuminates the potential applications of this dynamic field. As a valuable resource, it fosters an understanding of BNNs and their promising prospects, facilitating further advancements in the pursuit of knowledge and innovation.Comment: 65 page

PREDICTING INTERNET TRAFFIC BURSTS USING EXTREME VALUE THEORY

Computer networks play an important role in today’s organization and people life. These interconnected devices share a common medium and they tend to compete for it. Quality of Service (QoS) comes into play as to define what level of services users get. Accurately defining the QoS metrics is thus important. Bursts and serious deteriorations are omnipresent in Internet and considered as an important aspects of it. This thesis examines bursts and serious deteriorations in Internet traffic and applies Extreme Value Theory (EVT) to their prediction and modelling. EVT itself is a field of statistics that has been in application in fields like hydrology and finance, with only a recent introduction to the field of telecommunications. Model fitting is based on real traces from Belcore laboratory along with some simulated traces based on fractional Gaussian noise and linear fractional alpha stable motion. QoS traces from University of Napoli are also used in the prediction stage. Three methods from EVT are successfully used for the bursts prediction problem. They are Block Maxima (BM) method, Peaks Over Threshold (POT) method, and RLargest Order Statistics (RLOS) method. Bursts in internet traffic are predicted using the above three methods. A clear methodology was developed for the bursts prediction problem. New metrics for QoS are suggested based on Return Level and Return Period. Thus, robust QoS metrics can be defined. In turn, a superior QoS will be obtained that would support mission critical applications

Simulation Modeling

The book presents some recent specialized works of a theoretical and practical nature in the field of simulation modeling, which is being addressed to a large number of specialists, mathematicians, doctors, engineers, economists, professors, and students. The book comprises 11 chapters that promote modern mathematical algorithms and simulation modeling techniques, in practical applications, in the following thematic areas: mathematics, biomedicine, systems of systems, materials science and engineering, energy systems, and economics. This project presents scientific papers and applications that emphasize the capabilities of simulation modeling methods, helping readers to understand the phenomena that take place in the real world, the conditions of their development, and their effects, at a high scientific and technical level. The authors have published work examples and case studies that resulted from their researches in the field. The readers get new solutions and answers to questions related to the emerging applications of simulation modeling and their advantages

Behavioral Economics

Behavioral economics uses evidence from psychology and other disciplines to create models of limits on rationality, willpower and self-interest, and explore their implications in economic aggregates. This paper reviews the basic themes of behavioral economics: Sensitivity of revealed preferences to descriptions of goods and procedures; generalizations of models of choice over risk, ambiguity, and time; fairness and reciprocity; non-Bayesian judgment; and stochastic equilibrium and learning. A central issue is what happens in equilibrium when agents are imperfect but heterogeneous; sometimes firms “repair” limits through sorting, but profit-maximizing firms can also exploit limits of consumers. Frontiers of research are careful formal theorizing about psychology and studies with field data. Neuroeconomics extends the psychological data use to inform theorizing to include details of neural circuitry. It is likely to support rational choice theory in some cases, to buttress behavioral economics in some cases, and to suggest different constructs as well

Assessment of chronic pain in companion animals : development and concurrent validation of neurophysiological methods

La douleur est une expérience complexe impliquant des composantes sensorielles et de perception (émotionnelle, affective, cognitive). Elle est associée au stress, de la souffrance et une dégradation de la qualité de la vie. Les affections douloureuses chroniques telles que l'arthrose et le cancer des os touchent les chats et les chiens. La douleur dans ces conditions implique de nombreux mécanismes affectant les systèmes nerveux périphérique et central, qui génèrent et entretiennent une douleur pathologique. Les tests sensoriels quantitatifs (TSQ) sont des outils pour quantifier la composante sensorielle de la douleur, qui peuvent aussi être utilisés pour éluder les mécanismes de la douleur impliquée. Les travaux initiaux sur les chats et les chiens souffrant d'arthrose ont permis de développer et de valider certaines méthodes de TSQ; cependant, quelques questions sont restées sans réponse chez les chats souffrant de l'arthrose, et cette méthodologie n'a pas été encore explorée chez les chiens atteints d’ostéosarcome. Nos hypothèses de recherche étaient: 1) les chats arthrosiques sont affectés par des modifications neurophysiologiques caractéristiques de la sensibilisation centrale, pouvant être détectées par les TSQ et répondant à l'administration d'analgésiques à action centrale; et 2) l’ostéosarcome provoque une sensibilisation périphérique et centrale avec des mécanismes descendants d’inhibition de la douleur déficients chez le chien. Nos objectifs étaient : 1) chez les chats souffrant d'arthrose, de fournir des évidences sur la thérapie basée sur les mécanismes neurophysiologiques à l'aide de TSQ; et 2) de tester la capacité d'un protocole TSQ à démontrer la sensibilisation périphérique et centrale chez les chiens atteints de cancer des os, y compris un test de modulation de la douleur conditionnée, et de tester l’efficacité d’un protocole d’analgésique palliatif par paliers chez ces patients. En utilisant les TSQ statiques et dynamiques chez les chats arthrosiques, nous avons démontré que les analgésiques à action centrale tels que le tramadol peuvent renverser la sensibilisation centrale mesurée par la sommation temporelle de la douleur. Cet effet n’a pas été observé après l’administration d’analgésique à action périphérique tel que les antiinflammatoires non stéroïdiens comme le meloxicam. Ces résultats 3 soulignent l’importance d’une approche de traitement fondée sur les mécanismes de la douleur chronique. Le protocole TSQ développé pour les chiens a révélé que ceux atteints de cancer des os manifestaient de l'hyperalgésie primaire et secondaire et de l’allodynie dynamique au brossage par rapport aux chiens en bonne santé. Un test de modulation de la douleur conditionnée pouvant être facilement appliqué a été mis au point et a démontré la capacité de différencier les chiens sains des chiens cancéreux. En utilisant cette méthodologie, il s’est avéré que cette dernière population démontrait un système descendant d’inhibition de la douleur déficient. Ces études ont fourni des preuves des similitudes dans le profil sensoriel entre les malades humains et les animaux de compagnie affectés par l'arthrose, ainsi que les ostéosarcomiques. Les TSQ sont utiles dans la recherche vétérinaire sur la douleur et doivent être accompagnés des normes les plus strictes en matière de soins des animaux et de conception, de conduite et de compte-rendu des études.Pain is a complex experience involving sensory and perceptual components. It causes stress, suffering and decreased quality of life. Chronic painful conditions such as osteoarthritis (OA) and bone cancer affect cats and dogs. Pain in these conditions results from numerous mechanisms affecting the peripheral and central nervous systems which generate and maintain pathological pain in affected individuals. Quantitative sensory testing (QST) are means to quantify the sensory component of pain. In combination with observed analgesic efficacy, they can be used to study mechanisms of pain. Initial work on cats and dogs with OA has helped to develop and validate some QST methods; however, questions remained unanswered in cats with OA, and this methodology was not yet explored in dogs with bone cancer. Our main hypotheses were: 1) osteoarthritic cats are affected by neurophysiological changes characteristic of central sensitization which can be detected by QST and the concomitant administration of centrally-acting analgesics; and 2) bone cancer in dogs causes peripheral and central sensitization with deficient descending modulating mechanisms. Our main objectives were: 1) to provide evidence of mechanism-based therapy in cats with OA using QST; and 2) to test the ability of a QST protocol to provide evidence of peripheral and central sensitization in dogs with bone cancer including the development and validation of a conditioned pain modulation test, and to test the efficacy of a step-wise palliative analgesic protocol in these patients. Using static and dynamic QST in osteoarthritic cats, we demonstrated that centrally-acting analgesics such as tramadol can reverse central sensitization as measured by facilitated temporal summation of pain, while the same is not observed when a peripherally-acting analgesic such as non-steroidal anti-inflammatory drug, meloxicam, is administered. These findings highlight the importance of mechanism-based approach for the treatment of chronic pain. The QST protocol developed for use in dogs revealed that dogs with bone cancer are affected by primary and secondary hyperalgesia and brush allodynia when compared 5 with healthy dogs. A conditioned pain modulation test which can be easily applied into clinical practice was developed and demonstrated ability to differentiate between healthy and cancerous dogs. Using this methodology, the latter population was found to be affected by deficient descending modulating systems. These studies provided evidence of the similarities in sensory profile between people and companion animals affected by OA- and bone cancer-related pain. The use of QST is valuable in veterinary pain research and should be accompanied by the highest standards of animal care and study design, conduct and reporting

PREDICTING INTERNET TRAFFIC BURSTS USING EXTREME VALUE THEORY

Computer networks play an important role in today’s organization and people life. These interconnected devices share a common medium and they tend to compete for it. Quality of Service (QoS) comes into play as to define what level of services users get. Accurately defining the QoS metrics is thus important. Bursts and serious deteriorations are omnipresent in Internet and considered as an important aspects of it. This thesis examines bursts and serious deteriorations in Internet traffic and applies Extreme Value Theory (EVT) to their prediction and modelling. EVT itself is a field of statistics that has been in application in fields like hydrology and finance, with only a recent introduction to the field of telecommunications. Model fitting is based on real traces from Belcore laboratory along with some simulated traces based on fractional Gaussian noise and linear fractional alpha stable motion. QoS traces from University of Napoli are also used in the prediction stage. Three methods from EVT are successfully used for the bursts prediction problem. They are Block Maxima (BM) method, Peaks Over Threshold (POT) method, and RLargest Order Statistics (RLOS) method. Bursts in internet traffic are predicted using the above three methods. A clear methodology was developed for the bursts prediction problem. New metrics for QoS are suggested based on Return Level and Return Period. Thus, robust QoS metrics can be defined. In turn, a superior QoS will be obtained that would support mission critical applications

Attitudes towards old age and age of retirement across the world: findings from the future of retirement survey

The 21st century has been described as the first era in human history when the world will no longer be young and there will be drastic changes in many aspects of our lives including socio-demographics, financial and attitudes towards the old age and retirement. This talk will introduce briefly about the Global Ageing Survey (GLAS) 2004 and 2005 which is also popularly known as “The Future of Retirement”. These surveys provide us a unique data source collected in 21 countries and territories that allow researchers for better understanding the individual as well as societal changes as we age with regard to savings, retirement and healthcare. In 2004, approximately 10,000 people aged 18+ were surveyed in nine counties and one territory (Brazil, Canada, China, France, Hong Kong, India, Japan, Mexico, UK and USA). In 2005, the number was increased to twenty-one by adding Egypt, Germany, Indonesia, Malaysia, Poland, Russia, Saudi Arabia, Singapore, Sweden, Turkey and South Korea). Moreover, an additional 6320 private sector employers was surveyed in 2005, some 300 in each country with a view to elucidating the attitudes of employers to issues relating to older workers. The paper aims to examine the attitudes towards the old age and retirement across the world and will indicate some policy implications