265 research outputs found

    Remote monitoring of repository integrity using passive seismic arrays

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    Once radioactive waste is emplaced in the repository, the challenge of monitoring the continued integrity of the excavated openings (e.g., emplacement drifts) escalates tremendously. We envision a seismic monitoring array installed on the surface at Yucca Mountain, which operates automatically to monitor repository opening stability in the long term. The objective is to monitor and validate the structural integrity of the emplacement drifts through identifying and localizing rock falls that could compromise drift access, hinder waste retrievability, and potentially reduce the effective life of waste canisters. Collateral benefits of the system include the ability to address some outstanding uncertainties regarding seismic wave attenuation in the vicinity of the repository, and provision of a tool for security monitoring of the repository in guarding against unauthorized access and entry

    Federated K-Means Clustering via Dual Decomposition-based Distributed Optimization

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    The use of distributed optimization in machine learning can be motivated either by the resulting preservation of privacy or the increase in computational efficiency. On the one hand, training data might be stored across multiple devices. Training a global model within a network where each node only has access to its confidential data requires the use of distributed algorithms. Even if the data is not confidential, sharing it might be prohibitive due to bandwidth limitations. On the other hand, the ever-increasing amount of available data leads to large-scale machine learning problems. By splitting the training process across multiple nodes its efficiency can be significantly increased. This paper aims to demonstrate how dual decomposition can be applied for distributed training of K K -means clustering problems. After an overview of distributed and federated machine learning, the mixed-integer quadratically constrained programming-based formulation of the K K -means clustering training problem is presented. The training can be performed in a distributed manner by splitting the data across different nodes and linking these nodes through consensus constraints. Finally, the performance of the subgradient method, the bundle trust method, and the quasi-Newton dual ascent algorithm are evaluated on a set of benchmark problems. While the mixed-integer programming-based formulation of the clustering problems suffers from weak integer relaxations, the presented approach can potentially be used to enable an efficient solution in the future, both in a central and distributed setting

    Land use and transportation planning in urban areas collective needs and investigation of possibilities for combined application.

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    The object of this work is the examination of how urban planning is combined with the circulatory planning in Greece and the emergence of the importance of implementing integrated land use and transport planning to achieve sustainability in cities. The study examines the relationship between land use and locomotions and also studies how these two factors interact in creating the urban environment. Still, is examined the frame of application of planning and is appointed the weakness of completed approach in the emerging questions, by the decision-making centres and the responsible institutions of application and control. For this reason, proposed guidelines for the creation of that framework which will address land-use planning and transport as a single system, addressing more effectively the impact on urban space by the lack of coordinated urban and circulatory planning, creating a sustainable urban environment that respects the citizen - user

    The MaaS Dictionary

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    This dictionary provides the definition of the Mobility as a Service (MaaS) concept, as well as the definitions of the actors involved in MaaS

    Το μαντείο του Τροφωνίου στη Λεβάδεια

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    Αντικείμενο της παρούσης διπλωματικής εργασίας είναι η πολύπλευρη επισκόπηση μιας από τις μεγάλες μυθικο-θρησκευτικές μορφές της Βοιωτίας, του Τροφωνίου, και του χρηστηρίου του στην αρχαία Λεβάδεια. Στο πρώτο μέρος, μετά από μια σύντομη επισκόπηση των σχετικών γραμματειακών πηγών, αναλύεται η τοπογραφία του Τροφωνίου και της ευρύτερης περιοχής του, όπως προκύπτει από τις πρωτογενείς πηγές και τα ανασκαφικά δεδομένα, ενώ συζητούνται και οι εορτές των Βασιλείων και των Τροφων(ε)ίων. Το επόμενο τμήμα είναι αφιερωμένο στην τροφώνεια μυθολογία. Από τις φαινομενικά ασύνδετες μεταξύ τους μυθικές εκδοχές μέχρι τις επίμονες συσχετίσεις του Τροφωνίου με συγγενικές μορφές στα κείμενα ελληνιστικών και μεταγενεστέρων συγγραφέων, επιχειρείται η κατανόηση της μυθολογικής φυσιογνωμίας του και η αποσαφήνιση της αμφίσημης οντολογικής φύσης του. Στο τρίτο μέρος αναλύονται τα επιμέρους στάδια του ιδιόμορφου και περίπλοκου τελετουργικού του Τροφωνίου, από τους προπαρασκευαστικούς καθαρμούς και τις αποχές μέχρι την πόση των υδάτων της Λήθης και της Μνημοσύνης και την αυτοπρόσωπη υποχθόνια συνάντηση του προσκυνητή με τον Τροφώνιο. Με οδηγούς τα κείμενα του Παυσανία και του Πλουτάρχου, και αξιοποιώντας τα ευρήματα και συμπεράσματα των συγχρόνων νευροεπιστημών, επιχειρείται μια διεπιστημονική προσέγγιση και ερμηνεία της εμπειρίας του χρηστηριαζομένου κατά την κατάβασίν του στο μαντικό χάσμα γῆς. Το τέταρτο μέρος πραγματεύεται ποικίλες όψεις της λεβαδειακής λατρείας, από τις μυστηριακές και χθόνιες πτυχές της έως τον εντοπισμό ορφικών και πυθαγορείων αντιλήψεων, ακόμη και σαμανιστικών ιχνών στο μυθικό – λατρευτικό σύμπλεγμα του Τροφωνίου. Στο τελευταίο μέρος μελετάται το πάνθεον του ιερού, αποτελούμενο από τις διάφορες θεότητες που δορυφορούνται γύρω από τον πυρήνα της λατρείας, σε στενότερη ή χαλαρότερη σχέση με αυτήν. Απώτερος σκοπός του γράφοντος είναι η παροχή μιας συνεχούς και κατατοπιστικής εικόνας σχετικά με το φαινόμενο του Τροφωνίου της Λεβαδείας, από τα μυθολογικά παρακλάδια της ιστορίας του μέχρι το προσεκτικά ενορχηστρωμένο, «εξωτικό» τελετουργικό του ιερού του: ποιες ιδέες αντιπροσώπευε στον ελληνικό νου, με ποιες πραγματικότητες συνδεόταν το όνομά του, ποιος ήταν ο χαρακτήρας της λατρείας του και – το μεγαλύτερο μυστήριο όλων – τι εκτυλισσόταν στα βάθη του σπηλαιώδους αδύτου του.The subject of this thesis is the multifaceted survey of one of the great mythical – religious figures of Boeotia, Trophonios, and his chrēstērion (oracle) in ancient Lebadeia. In part one, after a brief overview of the literature, the topography of the Trophonion and its broader area is analyzed, as it emerges from the primary sources and excavation data; the festivals of the Basileia and the Trophon(e)ia are also discussed. The next part is dedicated to the trophoneian mythology. From the seemingly unrelated mythical versions to the persistent associations of Trophonios with related figures in the writings of Hellenistic and later authors, an attempt is made to comprehend his mythological character and to elucidate his elusive ontological nature. In the third part, the individual stages of the peculiar and complicated ritual of the Trophonion are analyzed, from the preliminary purifications and abstinences to the drinking of the waters of Lēthē and Mnēmosynē and the in-person subterranean meeting of the pilgrim with Trophonios. Guided by the texts of Pausanias and Plutarch, and utilizing the findings and conclusions of modern neuroscience, a multidisciplinary approach and interpretation of the consultant’s experience during his katabasis in the oracular earthly chasm is attempted. Part four discusses several aspects of the Lebadean cult, from its mysteric and chthonic facets to the detection of Orphic and Pythagorean views, and even shamanistic traces in the mythic – cultic complex of the Trophonion. In the final part, the sanctuary’s pantheon is discussed, comprised of the various deities orbiting the core of the cult, loosely or more closely connected to it. The writer’s ultimate goal is to provide a cohesive and comprehensive picture of the phenomenon of Trophonios of Lebadeia, from the mythological branches of his story to the carefully orchestrated, ‘exotic’ ritual of his sanctuary: which ideas he represented in the Greek mind, with what realities was his name connected, what was the character of his cult and – the greatest mystery of them all – what was taking place in the depths of his cavernous shrine
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