A Bayesian Ensemble Regression Framework on the Angry Birds Game

An ensemble inference mechanism is proposed on the Angry Birds domain. It is based on an efficient tree structure for encoding and representing game screenshots, where it exploits its enhanced modeling capability. This has the advantage to establish an informative feature space and modify the task of game playing to a regression analysis problem. To this direction, we assume that each type of object material and bird pair has its own Bayesian linear regression model. In this way, a multi-model regression framework is designed that simultaneously calculates the conditional expectations of several objects and makes a target decision through an ensemble of regression models. Learning procedure is performed according to an online estimation strategy for the model parameters. We provide comparative experimental results on several game levels that empirically illustrate the efficiency of the proposed methodology.Comment: Angry Birds AI Symposium, ECAI 201

Measurement of efficiency in Greek banking industries in the light of the financial crisis

The main purpose of the present paper is to investigate the impact of the global financial crisis on the efficiency of Greek banks during the period 2008-2010. The DEA model is applied according to input oriented approach in order to measure the technical and the scale efficiency scores of 20 Greek banks. Generally, the results indicate that the global financial crisis did not affect adversely the efficiency of Greek banks during the examined period. The findings suggest a slight increase in technical and scale efficiency scores in 2009 and a decline in technical and scale efficiency scores in 2010.peer-reviewe

Imitation Learning with Sinkhorn Distances

Imitation learning algorithms have been interpreted as variants of divergence minimization problems. The ability to compare occupancy measures between experts and learners is crucial in their effectiveness in learning from demonstrations. In this paper, we present tractable solutions by formulating imitation learning as minimization of the Sinkhorn distance between occupancy measures. The formulation combines the valuable properties of optimal transport metrics in comparing non-overlapping distributions with a cosine distance cost defined in an adversarially learned feature space. This leads to a highly discriminative critic network and optimal transport plan that subsequently guide imitation learning. We evaluate the proposed approach using both the reward metric and the Sinkhorn distance metric on a number of MuJoCo experiments

Οι μηχανισμοί διαχείρισης κρίσεων στην ΕΕ και τον ΟΗΕ. Ο ρόλος της Ηγεσίας στην αντιμετώπιση κρίσεων.

Οι πάσης φύσεως καταστροφές αποτελούσαν ανέκαθεν παραμέτρους αποσταθεροποίησης των κοινωνικών δομών, που προκαλούσαν ποικίλες δυσλειτουργίες. Στις μέρες μας, η συχνότητα εμφάνισής τους αυξάνεται με ραγδαίους ρυθμούς, εξαιτίας των σημαντικών αλλαγών που συντελούνται σε κάθε επίπεδο. Σκοπός της διπλωματικής εργασίας, είναι η ενδελεχής παρουσίαση των μηχανισμών διαχείρισης κρίσεων της Ευρωπαϊκής Ένωσης (ΕΕ) και του Οργανισμού Ηνωμένων Εθνών (ΟΗΕ), καθώς και η ανάλυση του ρόλου της Ηγεσίας στην αντιμετώπιση κρίσεων. Για την επίτευξη του σκοπού αυτού θα μελετηθούν οι δομές, τα θεσμικά όργανα, η σκοπιμότητα ύπαρξης ενός αποτελεσματικού πλαισίου διαχείρισης των κρίσεων και οι μηχανισμοί διαχείρισης κρίσεων στην ΕΕ και τον ΟΗΕ. Παράλληλα κάθε καταστροφικό γεγονός, αποτελεί και μία κρίση ηγεσίας για τους θεσμικούς ηγέτες. Η έγκαιρη διάγνωση και η εκτίμηση των κρίσιμων καταστάσεων οφείλουν να συντελούν στην προετοιμασία, το σχεδιασμό στρατηγικής και την άμεση απόκριση που αποτελούν καθοριστικά στοιχεία για τη διαχείριση των κρίσεων. Με βάση τα προαναφερθέντα, θα καταλήξουμε σε κάποια χρήσιμα συμπεράσματα όσον αφορά τη δυναμική της ΕΕ και του ΟΗΕ σε θέματα διαχείρισης κρίσεων και θα σχηματίσουμε μία ολοκληρωμένη εικόνα για τα απαραίτητα εκείνα ηγετικά χαρακτηρηστικά τα οποία θα οδηγήσουν τους μηχανισμούς στην έγκαιρη ανταπόκριση στις δύσκολες καταστάσεις.All types of disasters have always constituted destabilizing parameters of social structures, which caused a variety of dysfunctions. Nowadays, their incidence rates are rising rapidly, due to the significant changes taking place at each level. The aim of this diploma thesis is to present a thorough presentation of the European Union (EU) and United Nations (UN) crisis management mechanisms, as well as to analyze the role of Leadership in crisis management. In order to achieve this aim, the structures, the institutions, the feasibility of an effective crisis management framework and the crisis management mechanisms in the EU and the UN will be studied. At the same time, every disastrous event is also a crisis of leadership for institutional leaders. Timely diagnosis and assessment of critical situations should contribute to the preparation, strategic planning and immediate response that are critical to crisis management. Based on the above, we will come up with some useful conclusions on the EU's and UN's momentum in crisis management and we will form a comprehensive picture of the necessary leadership characteristics that will lead the mechanisms to timely respond to difficult situations

End-To-End Semi-supervised Learning for Differentiable Particle Filters

Recent advances in incorporating neural networks into particle filters provide the desired flexibility to apply particle filters in large-scale real-world applications. The dynamic and measurement models in this framework are learnable through the differentiable implementation of particle filters. Past efforts in optimising such models often require the knowledge of true states which can be expensive to obtain or even unavailable in practice. In this paper, in order to reduce the demand for annotated data, we present an end-to-end learning objective based upon the maximisation of a pseudo-likelihood function which can improve the estimation of states when large portion of true states are unknown. We assess performance of the proposed method in state estimation tasks in robotics with simulated and real-world datasets.Comment: Accepted in ICRA 202

Deep learning techniques for in-core perturbation identification and localization of time-series nuclear plant measurements

The research conducted has been made possible through funding from the Euratom research and training programme 2014-2018 under grant agreement No 754316 for the “CORe Monitoring Techniques And EXperimental Validation And Demonstration (CORTEX)” Horizon 2020 project, 2017-2021.Peer reviewedPublisher PD

Neurological and neurourological complications of electrical injuries

Electrical injury can affect any system and organ. Central nervous system (CNS) complications are especially well recognised, causing an increased risk of morbidity, while peripheral nervous system (PNS) complications, neurourological and cognitive and psychological abnormalities are less predictable after electrical injuries.PubMed was searched for English language clinical observational, retrospective, review and case studies published in the last 30 years using the key words: electrical injury, electrocution, complications, sequelae, neurological, cognitive, psychological, urological, neuropsychological, neurourological, neurogenic, and bladder.In this review, the broad spectrum of neurological, cognitive, psychological and neurourological consequences of electrical trauma are discussed, and clinical features characteristic of an underlying neurological, psychological or neurourological disorder are identified. The latest information about the most recently discovered forms of nervous system disorders secondary to electrical trauma, such as the presentation of neurological sequelae years after electrocution, in other words long-term sequelae, are presented. Unexpected central nervous system or muscular complications such as hydrocephalus, brain venous thrombosis, and amyotrophic lateral sclerosis are described. Common and uncommon neuropsychological syndromes after electrical trauma are defined. Neurourological sequelae secondary to spinal cord or brain trauma or as independent consequences of electrical shock are also highlighted