cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Collective dynamics in a laser-pumped mixture of two atomic ensembles
Creators: name: Jin, Luling
name: Evers, Jörg
name: Macovei, Mihai
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the quantum dynamics of an atomic mixture composed of two multi-atom ensembles. Each ensemble is driven separately by a coherent laser field, respectively, and dampens via the interactions with the environmental vacuum electromagnetic field reservoir. We find that, due to the photon exchange among the two components, long-time excitation oscillations appear, which may be significantly longer than the inverse lifetime of a single emitter. Furthermore, few-atom "jumps" to the excited state occur as a function of the parameter characterizing the inter-component interactions around a certain working point.
description: 6 pages, 5 figures
Tracing the electronic pairing glue in unconventional superconductors via inelastic Scanning Tunneling Spectroscopy
Creators: name: Hlobil, Patrik
name: Jandke, Jasmin
name: Wulfhekel, Wulf
name: Schmalian, Jörg
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The origin of Cooper pairing in high-temperature superconductors, such as the copper-oxide and iron-based system, is still under debate. High transition temperatures together with unconventional pairing states support the picture of an electronic pairing glue in the cuprates, where superconductivity is mediated by collective bosonic excitations of the electron fluid. In other materials, most importantly iron based systems with only hole or only electron pockets, the microscopic origin is hotly debated. Scanning tunneling microscopy (STM) has been shown to be a powerful experimental probe to detect electronic excitations and further allows to deduce some fingerprints of bosonic collective modes. Here, we demonstrate that the inclusion of inelastic tunnel events is crucial for the interpretation of tunneling spectra and allows to directly probe bosonic excitations via STM. We develop a model describing both the elastic tunneling current, which displays the electronic spectral function, and the inelastic current, that contains the information about the bosonic spectrum, in the superconducting state. Adopting this extended tunneling formalism we can naturally reproduce the tunneling spectra of various unconventional superconductors and trace the occurring features back to an opening of a spin gap in the superconducting state. More generally, our approach is a strong argument in favour of a collective mode mediating the pairing state in particular in iron-based systems. In particular, we conclude that the debated pairing mechanism in LiFeSe is also of electronic origin with sign-changing pairing symmetry.
description: 7 pages, 4 figures, +Suppl. Mat
A^1-connectedness in reductive algebraic groups
Creators: name: Balwe, Chetan
name: Sawant, Anand
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Geometry (math.AG)
subject: Group Theory (math.GR)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 14F42

description: Using sheaves of A^1-connected components, we prove that the Morel-Voevodsky singular construction on a reductive algebraic group fails to be A^1-local if the group does not satisfy suitable isotropy hypotheses. As a consequence, we show the failure of A^1-invariance of torsors for such groups on smooth affine schemes over infinite perfect fields. We also characterize A^1-connected reductive algebraic groups over a field of characteristic 0.
description: 19 pages; v3: Minor changes and corrections. Corrected a typographical error in the statement of the main theorem in v2
A generalized Michaelis-Menten equation in protein synthesis: effects of mis-charged cognate tRNA and mis-reading of codon
Creators: name: Dutta, Annwesha
name: Chowdhury, Debashish
Publisher: name: arXiv
Year: 2015
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Quantitative Methods (q-bio.QM)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The sequence of amino acid monomers in the primary structure of a protein is decided by the corresponding sequence of codons (triplets of nucleic acid monomers) on the template messenger RNA (mRNA). The polymerization of a protein, by incorporation of the successive amino acid monomers, is carried out by a molecular machine called ribosome. We develop a stochastic kinetic model that captures the possibilities of mis-reading of mRNA codon and prior mis-charging of a tRNA. By a combination of analytical and numerical methods we obtain the distribution of the times taken for incorporation of the successive amino acids in the growing protein in this mathematical model. The corresponding exact analytical expression for the average rate of elongation of a nascent protein is a `biologically motivated' generalization of the {\it Michaelis-Menten formula} for the average rate of enzymatic reactions. This generalized Michaelis-Menten-like formula (and the exact analytical expressions for a few other quantities) that we report here display the interplay of four different branched pathways corresponding to selection of four different types of tRNA.
description: This is an author-created, un-copyedited version of an article published in BULLETIN OF MATHEMATICAL BIOLOGY (Official Journal of The Society for Mathematical Biology)
Design and Optimization of Pulsed Chemical Exchange Saturation Transfer MRI Using a Multiobjective Genetic Algorithm: A Matlab Code
Creators: name: Cárdenas-Rodríguez, Julio
name: Yoshimaru, Eriko
name: Randtke, Edward
Publisher: name: Open Science Framework
Year: 2022

description: This collection of matlab scripts and functions was used to design and optimize shaped pulses for CEST MRI
A. pusilla and P. colorata leaf margin data
Creators: name: Yager, Karl
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Alseuosmia pusilla
subject: Pseudowintera colorata

description: Cartesian coordinates (based on the middle of each leaf) of Alseuosmia pusilla and Pseudowintera colorata leaf margins. Other species file contains leaf margin data for other species growing near A. pusilla and P. colorata. Leaves collected from Field Hut Track, Otaki Forks, Otaki, NEW ZEALAND
title: Εφαρμογή Next Generation Sequencing σε γαλακτοκομικά προϊόντα
title: Application of Next Generation Sequencing in dairy products
titleType: AlternativeTitle
Creators: name: Παύλου, Άγγελος
name: Κομνηνός, Ιωάννης
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: NGS
Anthotyros
Genetic fingerprint

description: Η εφαρμογή των τεχνολογιών αλληλούχισης επόμενης γενιάς (NGS) έχει αναδειχθεί ως ένα ισχυρό εργαλείο για την ανάλυση δειγμάτων τυριού, φέρνοντας επανάσταση στον τομέα της μικροβιολογίας και της γονιδιωματικής του τυριού. Το τυρί, ένα σύνθετο και ποικιλόμορφο γαλακτοκομικό προϊόν, επηρεάζεται από μυριάδες μικροοργανισμούς που διαδραματίζουν κρίσιμο ρόλο στην παραγωγή, την ανάπτυξη της γεύσης και την ποιότητά του. Οι παραδοσιακές μέθοδοι που βασίζονται σε καλλιέργειες έχουν προσφέρει πολύτιμες γνώσεις, αλλά είναι περιορισμένες ως προς την ικανότητά τους να καταγράφουν την πλήρη μικροβιακή ποικιλομορφία που υπάρχει στο τυρί. Η NGS επιτρέπει την ολοκληρωμένη και υψηλής απόδοσης ανάλυση των μικροβιακών κοινοτήτων του τυριού με την αλληλουχία του γενετικού υλικού που εξάγεται από τα δείγματα. Οι μεταγονιδιωματικές προσεγγίσεις παρέχουν μια ολιστική εικόνα της μικροβιακής ποικιλότητας, επιτρέποντας την ταυτοποίηση και τον χαρακτηρισμό βακτηρίων, ζυμών, μούχλας και των λειτουργικών γονιδίων τους, καθώς και την ανίχνευση LAB (Lactic Acid Bacteria) βακτηρίων και προβιοτικών πολύτιμων για την ανθρώπινη υγεία. Μέσω της NGS, οι ερευνητές μπορούν να διερευνήσουν τη σύνθεση, τη δυναμική και τις αλληλεπιδράσεις αυτών των μικροβιακών πληθυσμών, ρίχνοντας φως στο ρόλο τους στην παραγωγή τυριού, την ωρίμανση και τα οργανοληπτικά χαρακτηριστικά. Στην παρούσα μελέτη θα χρησιμοποιήσουμε την τεχνολογία NGS προκειμένου να καταγράψουμε την εικόνα του μικρβιώματος διαφορετικών δειγμάτων ανθότυρου Ελληνικής παραγωγής. Στόχος μας είναι να κατανοήσουμε το βακτηριακό αποτύπωμα ενός προϊόντος το οποίο θεωρείται χαρακτηριστικά ευαλλοίωτο και να μελετήσουμε τη συμπεριφορά των μικροοργανισμών που συνυπάρχουν στο περιβάλλον του ανθότυρου και το πώς οι μεταξύ τους αλληλεπιδράσεις επηρεάζουν την τελική μορφή του προϊόντος, αλλά και τα οργανοληπτικά του χαρακτηριστικά.
title: Διαδικτυακό εκπαιδευτικό λογισμικό εκμάθησης πληροφορικής με ενσωματωμένο chatbot
title: Online educational IT learning software with built-in chatbot
titleType: AlternativeTitle
Creators: name: Νομικός, Ιάκωβος
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Εκπαιδευτικό σύστημα
Σύστημα elearning
Εκπαιδευτικό λογισμικό
Elearning chatbot
Εκμάθηση πληροφορικής
Λογισμικό εκμάθησης πληροφορικής
ITtlearning

description: Η παρούσα διπλωματική εργασία επικεντρώνεται στην ανάπτυξη ενός Διαδικτυακού εκπαιδευτικού λογισμικού εκμάθησης Πληροφορικής, με ενσωματωμένο chatbot. Σε μια εποχή που το e-learning έχει αναδειχθεί ως ένα αποτελεσματικό εργαλείο για την απόκτηση γνώσεων και την εκπαίδευση από απόσταση, η ύπαρξη διαδικτυακού εκπαιδευτικού λογισμικού είναι απαραίτητη. Το συγκεκριμένο λογισμικό προσφέρει τη δυνατότητα στους μαθητές να αποκτήσουν πρόσβαση σε πλούσιο εκπαιδευτικό υλικό από οπουδήποτε και αν βρίσκονται, χωρίς την ανάγκη να παραβρεθούν σε παραδοσιακά μαθήματα. Αυτό προσφέρει ευελιξία και αυτονομία στη μάθηση, καθώς οι μαθητές μπορούν να προσαρμόσουν το ρυθμό και τον τρόπο μάθησης σύμφωνα με τις ατομικές τους ανάγκες. Η εφαρμογή αυτή προσφέρει μια σειρά λειτουργιών που βοηθούν στην αποτελεσματική μάθηση των χρηστών. Παρέχει εκπαιδευτικό υλικό με χρήση εικόνων, βίντεο, κειμένου και άλλων μέσων, το οποίο παρουσιάζεται σε ένα φιλικό περιβάλλον μάθησης. Το υλικό οργανώνεται σε κεφάλαια για ευκολότερη περιήγηση και κατανόηση. Επιπλέον, η εφαρμογή προσφέρει αξιολόγηση των μαθητών μέσω διαγωνισμάτων που περιλαμβάνουν ερωτήσεις διαφορετικών τύπων, όπως πολλαπλής επιλογής, αντιστοίχισης και άλλων. Στο τέλος, υπάρχει ένα επαναληπτικό διαγώνισμα που καλύπτει το υλικό όλων των κεφαλαίων, προκειμένου να αξιολογηθεί ο μαθητής. Επιπλέον, η εφαρμογή διατηρεί στατιστικά για την πρόοδο του μαθητή, καθώς ο ίδιος έχει τη δυνατότητα να παρακολουθεί τους βαθμούς του στα διαγωνίσματα και το επαναληπτικό διαγώνισμα, αλλά και άλλες πληροφορίες σχετικά με την πρόοδό του. Το σύστημα επίσης εμφανίζει μηνύματα στον μαθητή κατά τη διάρκεια της αλληλεπίδρασης του, με σκοπό να του δοθούν κίνητρα μάθησης ή συμβουλές. Για παράδειγμα, μπορεί να εμφανίζει ένα μήνυμα που ενθαρρύνει τον μαθητή να βελτιώσει την απόδοσή του ή να προσφέρει συμβουλές σχετικά με συγκεκριμένες δραστηριότητες. Τέλος, το ενσωματωμένο chatbot αποτελεί ένα χρήσιμο εργαλείο για τον μαθητή. Ο μαθητής μπορεί να αναζητήσει οδηγίες για τον εντοπισμό στατιστικών του ή να εισάγει λέξεις-κλειδιά από ένα κεφάλαιο για να λάβει σχετικές πληροφορίες κλπ. Συνολικά, η εφαρμογή παρέχει ένα πλούσιο περιβάλλον μάθησης με εκπαιδευτικό υλικό, αξιολόγηση, στατιστικά, εμφάνιση μηνυμάτων και τη δυνατότητα επικοινωνίας με το chatbot για την υποστήριξη του μαθητή. Αυτό το σύστημα συνδυάζει την τεχνολογία με την εκπαίδευση, προσφέροντας έναν εύχρηστο και αποτελεσματικό τρόπο εκμάθησης της Πληροφορικής.
A systematic study of magnetodynamic properties at finite temperatures in doped permalloy from first principles calculations
Creators: name: Pan, Fan
name: Chico, Jonathan
name: Hellsvik, Johan
name: Delin, Anna
name: Bergman, Anders
name: Bergqvist, Lars
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: By means of first principles calculations, we have systematically investigated how the magnetodynamic properties Gilbert damping, magnetization and exchange stiffness are affected when permalloy (Py) (Fe$_{0.19}$Ni$_{0.81}$) is doped with 4d or 5d transition metal impurities. We find that the trends in the Gilbert damping can be understood from relatively few basic parameters such as the density of states at the Fermi level, the spin-orbit coupling and the impurity concentration. % The temperature dependence of the Gilbert damping is found to be very weak which we relate to the lack of intraband transitions in alloys. % Doping with $4d$ elements has no major impact on the studied Gilbert damping, apart from diluting the host. However, the $5d$ elements have a profound effect on the damping and allows it to be tuned over a large interval while maintaining the magnetization and exchange stiffness. % As regards spin stiffness, doping with early transition metals results in considerable softening, whereas late transition metals have a minor impact. % Our result agree well with earlier calculations where available. In comparison to experiments, the computed Gilbert damping appears slightly underestimated while the spin stiffness show good general agreement.
description: 8 pages, 9 figures
Dataset: Effect of LXR/RXR agonism on brain and CSF Aβ40 levels in rats
Creators: name: Wang, Songli
name: Wen, Paul
name: Wood, Stephen
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Alzheimer’s
subject: Apolipoprotein E
subject: Aβ
subject: Bexarotene
subject: liver X receptor
subject: retinoid X receptor

description: Dataset for Wang et al. (2016).
Proposals for gain cascading in single-pass of a free-electron laser oscillator
Creators: name: Li, Kai
name: Deng, Haixiao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The low-gain free-electron laser (FEL) oscillators are cutting-edge tools to produce fully coherent radiation in the spectral region from terahertz to vacuum ultraviolet, and potentially in hard X-ray. In this paper, it is proposed to utilize an FEL oscillator with multi-stage undulators to enable gain cascading in a single-pass, making it possible to achieve shorter single pulse lengths, higher peak power, and even higher pulse energy than classical FEL oscillator. Theoretical analysis and numerical simulations in the infrared and hard X-ray regions show that our proposal is effective.
description: 12 pages, 7 figures
Study Reporting in Predatory Journal Articles
Creators: name: Cobey, Kelly
name: Galipeau, James
name: Avey, Marc
name: Moher, David
name: Shamseer, Larissa
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Beall's List
subject: Completeness of Reporting
subject: Predatory Journals
subject: Reporting Guidelines
subject: Reporting Quality

description: An assessment of the epidemiological characteristics and the reporting quality of predatory journals.
The DART Project: using data management plans as a research tool
Creators: name: Whitmire, Amanda
name: Carlson, Jacob
name: Westra, Brian
name: Hswe, Patricia
name: Parham, Susan
Publisher: name: Open Science Framework
Year: 2022

description: This is a two-year National Leadership Grant for Libraries Demonstration Project to facilitate a multi-university study of faculty data management plans (DMPs). The primary outputs of this project will be an analytic rubric to standardize the review of data management plans as a means to inform targeted expansion or development of research data services at academic libraries; and a study utilizing the rubric that presents the results of data management plan analyses at five universities. This project was made possible in part by the Institute of Museum and Library Services grant number LG-07-13-0328.
Tight continuity bounds for the quantum conditional mutual information, for the Holevo quantity and for capacities of quantum channels
Creators: name: Shirokov, M. E.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We start with Fannes' type and Winter's type tight continuity bounds for the quantum conditional mutual information and their specifications for states of special types. Then we analyse continuity of the Holevo quantity with respect to nonequivalent metrics on the set of discrete ensembles of quantum states. We show that the Holevo quantity is continuous on the set of all ensembles of m states with respect to all the metrics if either m or the dimension of underlying Hilbert space is finite and obtain Fannes' type tight continuity bounds for the Holevo quantity in this case. In general case conditions for local continuity of the Holevo quantity for discrete and continuous ensembles are found. Winter's type tight continuity bound for the Holevo quantity under constraint on the average energy of ensembles is obtained and applied to the system of quantum oscillators. The above results are used to obtain tight and close-to-tight continuity bounds for basic capacities of finite-dimensional channels (refining the Leung-Smith continuity bounds).
description: 39 pages, significantly extended version, in v.2 tight and close-to-tight continuity bounds for capacities of finite-dimensional quantum channels are added, in v.3 the section devoted to the Holevo capacity is revised, in v.4 applications to the multi-mode quantum oscillator are revised and extended, in v.5,6 minor corrections and modifications are made, in v.7 Proposition 3 is strengthened
Dataset: Does inactivation of USP14 enhance degradation of proteasomal substrates that are associated with neurodegenerative diseases?
Creators: name: Ortuno, Daniel
name: Carlisle, Holly
name: Miller, Silke
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Deubiquitinating enzyme
subject: Neurodegeneration
subject: Proteasome
subject: Protein clearance
subject: tau
subject: TDP-43
subject: Ubiquitin
subject: Ubiquitin-specific peptidase 14

description: Dataset for Ortuno et al. (2016).
Accretion onto a Kiselev black hole
Creators: name: Jiao, Lei
name: Yang, Rong-Jia
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider accretion onto a Kiselev black hole. We obtain the fundamental equations for accretion without the back-reaction. We determine the general analytic expressions for the critical points and the mass accretion rate and find the physical conditions the critical points should fulfill. The case of polytropic gas are discussed in detail. It turns out that the quintessence parameter plays an important role in the accretion process.
description: 7 pages
Dataset: GPR21 KO mice demonstrate no resistance to high fat diet induced obesity or improved glucose tolerance
Creators: name: Wang, Jinghong
name: Pan, Zheng
name: Baribault, Helene
name: Chui, Danny
name: Gundel, Caroline
name: Véniant, Murielle
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Diabetes
subject: Drug target
subject: GPCR
subject: Rabgap1
subject: TALENS technology

description: Dataset for Wang et al. (2016).
Strong solidity of free Araki-Woods factors
Creators: name: Boutonnet, Rémi
name: Houdayer, Cyril
name: Vaes, Stefaan
Publisher: name: arXiv
Year: 2015
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics

description: We show that Shlyakhtenko's free Araki-Woods factors are strongly solid, meaning that for any diffuse amenable von Neumann subalgebra that is the range of a normal conditional expectation, the normalizer remains amenable. This provides the first class of nonamenable strongly solid type III factors.
description: v2: minor changes, final version, to appear in American Journal of Mathematics
Χτίζοντας την ιδιαιτερότητα ενός ανεξερεύνητου τουριστικού προορισμού : η περίπτωση της Σαλαμίνας
Creators: name: Δημητριάδη, Σοφία
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Τουριστικά κίνητρα
subject: Τουριστική τυπολογία
subject: Σαλαμίνα
subject: Push & pull factors
subject: Παράγοντες έλξης
subject: Παράγοντες ώθησης
subject: Λόγοι πραγματοποίησης ταξιδιού
subject: Παράγοντες επιλογής προορισμού
subject: Τυπολογία Plog
subject: Τυπολογία Cohen
subject: Τουριστικό μάρκετινγκ
subject: Τουριστική συμπεριφορά

description: Η παρούσα μελέτη πραγματεύεται την καταγραφή των τουριστικών κινήτρων και της τουριστικής τυπολογίας των επισκεπτών της Σαλαμίνας. Πιο συγκεκριμένα, μέσω της πρωτογενούς έρευνας γίνεται η μελέτη και η καταγραφή των ψυχο-κοινωνικών παραγόντων που επηρεάζουν τον τουρίστα να επισκεφθεί το νησί της Σαλαμίνας αλλά και τον ρόλο που παίζουν αυτοί οι παράγοντες στην ικανοποίησή του, στην απόφασή του να επιστρέψει στο μέλλον και στην πρόθεση να συστήσει τη Σαλαμίνα και σε άλλους. Ακόμη, μέσω της τουριστικής τυπολογίας επιχειρείται η κατηγοριοποίηση των τουριστών σε ομάδες προκειμένου να σκιαγραφήσουμε το προφίλ, τις ανάγκες και τις προσδοκίες των τουριστών που επισκέπτονται το νησί της Σαλαμίνας έτσι ώστε να τους προφέρουμε μια πιο ολοκληρωμένη τουριστική εμπειρία. Η έρευνα διεξήχθη μέσω ερωτηματολογίου το οποίο στο λιμάνι της Σαλαμίνας και σε δύο πολυσύχναστα σημεία του νησιού από τις 20 Ιουνίου 2020 έως τις 20 Οκτωβρίου 2020. Το ερωτηματολόγιο είναι χωρισμένο σε τέσσερις ενότητες. Στην πρώτη ενότητα οι ερωτήσεις αφορούν τα κίνητρα ώθησης και έλξης (Push & Pull Factors) όπου ο ερωτώμενος απαντά για ποιους λόγους πραγματοποιεί ένα ταξίδι και με ποια κριτήρια επιλέγει προορισμό για διακοπές. Η δεύτερη ενότητα περιλαμβάνει ερωτήσεις σχετικά με τις δραστηριότητες που επιλέγει να κάνει στις διακοπές του με σκοπό να κατηγοριοποιηθεί με βάση την ταξιδιωτική του συμπεριφορά σε συγκεκριμένες τυπολογίες. Στην τρίτη ενότητα, οι ερωτήσεις αφορούν την εμπειρία των τουριστών στη Σαλαμίνα, τα επίπεδα ικανοποίησης τους, καθώς και την πρόθεση τους να επιστρέψουν στο νησί, αλλά και να το συστήσουν και σε άλλους. Τέλος, η τέταρτη ενότητα περιλαμβάνει ερωτήσεις που αφορούν τα δημογραφικά χαρακτηριστικά των ερωτηθέντων. Τα πορίσματα της παρούσας μελέτης θα βοηθήσουν τους ερευνητές και τους επαγγελματίες στο κλάδο του τουρισμού να μάθουν περισσότερα στοιχεία για τα κίνητρα, τους λόγους, τις τυπολογίες των τουριστών που επιλέγουν το νησί της Σαλαμίνας για τις διακοπές τους, ώστε να καταστήσουν τις ενέργειες στο πεδίο του μάρκετινγκ πιο αποτελεσματικές.
Stellar Tidal Disruption Events by Direct Collapse Black Holes
Creators: name: Kashiyama, Kazumi
name: Inayoshi, Kohei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We analyze the early growth stage of direct-collapse black holes (DCBHs) with $\sim 10^{5} \ \rm M_\odot$, which are formed by collapse of supermassive stars in atomic-cooling halos at $z \gtrsim 10$. A nuclear accretion disk around a newborn DCBH is gravitationally unstable and fragments into clumps with a few $10 \ \rm M_\odot$ at $\sim 0.01-0.1 \ \rm pc$ from the center. Such clumps evolve into massive population III stars with a few $10-100 \ \rm M_\odot$ via successive gas accretion and a nuclear star cluster is formed. Radiative and mechanical feedback from an inner slim disk and the star cluster will significantly reduce the gas accretion rate onto the DCBH within $\sim 10^6 \ \rm yr$. Some of the nuclear stars can be scattered onto the loss cone orbits also within $\lesssim 10^6 \ \rm yr$ and tidally disrupted by the central DCBH. The jet luminosity powered by such tidal disruption events can be $L_{\rm j} \gtrsim 10^{50} \ \rm erg \ s^{-1}$. The prompt emission will be observed in X-ray bands with a peak duration of $δt_{\rm obs} \sim 10^{5-6} \ (1+z) \ \rm s$ followed by a tail $\propto t_{\rm obs}^{-5/3}$, which can be detectable by Swift BAT and eROSITA even from $z \sim 20$. Follow-up observations of the radio afterglows with, e.g., eVLA and the host halos with JWST could probe the earliest AGN feedback from DCBHs.
description: 8 pages, 1 figure, accepted for publication in ApJ
Bayesian Analysis for Fluorescence Lifetime Imaging
Creators: name: Rowley, Mark
Publisher: name: Open Science Framework
Year: 2022

description: This project includes data used for demonstration of the effectiveness of developed Bayesian analysis algorithms for fluorescence decay parameter estimation, decay model selection, and instrument response determination. The data in this project comprises the time-domain FLIM images and the results from the application of Bayesian analysis algorithms (and for comparison, of least-squares and maximum-likelihood estimation) to this data. The Bayesian theory and software implementation of the time-domain FLIM analysis algorithms, which have produced the data/results included in this project, is a consequence of the work of Paul R Barber, Anthonius CC Coolen, Mark I Rowley, and Borivoj Vojnovic.
title: Ταυτοποίηση γουνοφόρων ζώων με χρήση συνελικτικού νευρωνικού δικτύου βαθιάς μάθησης
title: Identification of fur animals using a deep convolutional neural network
titleType: AlternativeTitle
Creators: name: Ντίμο, Έλιος
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Μηχανική μάθηση
Βαθιά μάθηση
Συνελικτικά νευρωνικά δίκτυα
Ταυτοποίηση
Μάθηση μεταφοράς

description: Η βαθιά μάθηση αποτελεί υποκατηγορία της μηχανικής μάθησης και μέρος της είναι η εκπαίδευση και χρήση συνελικτικών νευρωνικών δικτύων (CNN) για την αναγνώριση και ταυτοποίηση εικόνων. Αναγνωρίζουν μοτίβα και χαρακτηριστικά σε εικόνες με την εφαρμογή πολλαπλών στρωμάτων φίλτρων μεταβιβάζοντας κάθε φορά της πληροφορίες στο επόμενο επίπεδο. Ο στόχος της παρούσας διπλωματικής εργασίας είναι η δημιουργία ενός μοντέλου που θα αναγνωρίζει μοτίβα γουνοφόρων ζώων σύμφωνα με τα δεδομένα που του δώσαμε για την εκπαίδευση. Συγκεκριμένα έχουμε 30 κλάσεις γουνοφόρων και το μοντέλο θα πρέπει να αναγνωρίζει ζώα που ανήκουν μέσα σε αυτές τις 30 κλάσεις. Ένα δίκτυο βαθιάς μάθησης έχει την ικανότητα να λαμβάνει αποφάσεις με βάση τα δεδομένα στα οπαία εκπαιδεύεται. Γι’ αυτό λοιπόν η συλλογή και ομοιόμορφη κατανομή των δεδομένων αποτελεί ένα απο τα πιο σημαντικά κομμάτια της όλης διαδικασίας. Κάθε κλάση χωρίζεται σε 3 πεδία train, validation και test set με 800, 100 και 100 εικόνες κατά αντιστοιχία. Για να καταλήξουμε στο τελικό μοντέλο έγιναν πολλοί πειραματισμοί. Δημιουργήθηκαν διάφορα CNN μοντέλα ποικίλων επιπέδων τα οποία χτίστηκαν απο το μηδέν χωρίς όμως να δίνουν τα επιθυμητά αποτελέσματα. Χάρις σε αυτό όμως έγινε καλύτερη κατανόηση του προβλήματος οδηγώντας στην εφαρμογή μια τεχνικής που ονομάζεται μάθηση μεταφοράς που αξιοποιεί τις αρχιτεκτονικές και χαρακτηριστικά που έχουν εξαχθεί από άλλα μοντέλα. Στην προκειμένου περίπτωση έγινε χρήση του VGG16 που μας έδωσε ικανοποιητικά αποτελέσματα.
Open string T-duality in a weakly curved background
Creators: name: Davidović, Ljubica
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a theory of an open string moving in a weakly curved background, composed of a constant metric and a linearly coordinate dependent Kalb-Ramond field with an infinitesimal field strength. We find its T-dual using the generalized Buscher procedure developed for the closed string moving in a weakly curved background, and the fact that solving the boundary conditions, the open string theory transforms to the effective closed string theory. So, T-dualizing the effective theory along all effective directions we obtain its T-dual theory and resume the open sting theory which has such an effective theory. In this way we obtain the open string theory T-dual.
Flood and landslide fatalities in Italy
Creators: name: Salvati, Paola
name: Petrucci, Olga
name: Rossi, Mauro
name: Bianchi, Cinzia
name: Guzzetti, Fausto
name: Pasqua, Aurora
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: flood fatalities
subject: geo-hydrological hazards
subject: landslide fatalities

description: Causes and circumstances of flood and landslide fatalities in Italy
Solving the Equity Risk Premium Puzzle and Inching Towards a Theory of Everything
Creators: name: Kashyap, Ravi
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Finance (q-fin.GN)
subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: The equity risk premium puzzle is that the return on equities has far exceeded the average return on short-term risk-free debt and cannot be explained by conventional representative-agent consumption based equilibrium models. We review a few attempts done over the years to explain this anomaly: 1. Inclusion of highly unlikely events with low probability (Ugly state along with Good and Bad), or market crashes / Black Swans. 2. Slow moving habit, or time-varying subsistence level, added to the basic power utility function. 3. A separation of the inter-temporal elasticity of substitution and risk aversion, combined with long run risks which captures time varying economic uncertainty. We explore whether a fusion of the above approaches supplemented with better methods to handle the below reservations would provide a more realistic and yet tractable framework to tackle the various conundrums in the social sciences: 1. Unlimited ability of individuals to invest as compared to their ability to consume. 2. Lack of an objective measuring stick of value 3. Unintended consequences due to the dynamic nature of social systems 4. Relaxation of the transversality condition to avoid the formation of asset price bubbles 5. How durable is durable? Accounting for durable goods since nothing lasts forever The world we live in produces fascinating phenomenon despite (or perhaps, due to) being a hotchpotch of varying doses of the above elements. The rationale for a unified theory is that beauty can emerge from chaos since the best test for a stew is its taste. Many long standing puzzles seem to have been resolved using different techniques. The various explanations need to stand the test of time before acceptance; but then unexpected outcomes set in and new puzzles emerge. As real analysis and limits tell us: We are getting Closer and Closer; Yet it seems we are still Far Far Away...
Stiffening Thermal Membranes by Cutting
Creators: name: Russell, Emily
name: Sknepnek, Rastko
name: Bowick, Mark J.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional crystalline membranes have recently been realized experimentally in such systems as graphene and molybdenum disulfide, sparking a resurgence in interest in their statistical properties. Thermal fluctuations can significantly affect the effective mechanical properties of properly thermalized membranes, renormalizing both bending rigidity and elastic moduli so that in particular they become stiffer to bending than their bare bending rigidity would suggest. We use molecular dynamics simulations to examine how the mechanical behavior of thermalized two-dimensional clamped ribbons (cantilevers) depends on their precise topology and geometry. We find that a simple slit smooths roughness as measured by the variance of height fluctuations. This counterintuitive effect may be due to the counter-posed coupling of the lips of the slit to twist in the intact regions of the ribbon.
description: 7 pages
Exploring inductive reasoning, scientifc reasoning and science motivation, and their role in predicting STEM achievement across grade levels
Creators: name: Vo, De Van
name: Csapó, Benő
Publisher: name: University of Limerick
Year: 2023
Subjects: classificationCode: 39
subject: Education

description: This study aims to investigate the patterns of students’ performance in inductive reasoning, scientifc reasoning and science motivation at diferent grade levels. We also examined the interaction of these variables with parental factors in predicting students’ STEM achievement. A cross-sectional study assessed 726 participants from the 6th, 8th, 10th and 11th grades in 6 secondary schools. The fndings showed that students in the upper grades achieved higher scores on reasoning tests than their counterparts in the lower-grade cohorts, but their motivation toward learning science decreased slightly across the grade cohorts. Although the students performed better on an inductive reasoning test, the developmental patterns were comparable for the results on 2 cognitive tests across grade levels. Generally, we found that inductive reasoning and scientifc reasoning were closely tied and that both had a signifcant efect on STEM achievement, while parents’ education impacted positively on both STEM performance and parental involvement in their children’s schooling. However, parental involvement and science motivation had a minor—and diferent—infuence on students’ STEM achievement in the individual grade cohorts. The implications for enhancing students’ STEM performance are further discussed accordingly.
Breaking a "poor man" RG approach in the Luttinger liquid with one impurity
Creators: name: Afonin, V.
name: Petrov, V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using derived previously effective theory we explore conductance in the Luttinger model with one impurity. A new approach to the renormalization group (RG) analysis of this model is developed. It is based on the original Gell-Mann-Low formulation of RG. We sum up infrared logarithmic contibutions to conductance in the leading and few subsequent approximations. We analyze the validity of widely used ``poor man's'' scaling approach and find that it is applicable only in the leading approximation. Our results for corrections to this approximation are different from results obtained in other papers. It should be expected beforehand, as Gell-Mann-Low function of the model is not regularization scheme invariant. For this reason the observed quantity (e.g., conductance) can not satisfy the Gell-Mann-Low equation beyond the "leading-log"\ approximation as it is supposed in the "poor man's" approach. We formulate the method to calculate the conductance from renormalized hamiltonian in the post-leading approximations and match results to the case of weak impurity where the answer is known in any order in electron-electron interaction.
description: 28 pages, 4 figures. Corrections and extensions as compared to previous version. This is a version published in journal
Aerodynamic Ground Effect in Fruitfly Sized Insect Takeoff: Source Codes and Datasets
Creators: name: Kolomenskiy, Dmitry
name: Maeda, Masateru
name: Engels, Thomas
name: Liu, Hao
name: Schneider, Kai
name: Nave, Jean-Christophe
Publisher: name: Open Science Framework
Year: 2022

description: Supplementary materials for the numerical simulations of fruitfly takeoff described in [http://arxiv.org/abs/1504.04484].
Coleman-Weinberg symmetry breaking in $SU(8)$ induced by a third rank antisymmetric tensor scalar field
Creators: name: Adler, Stephen L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study $SU(8)$ symmetry breaking induced by minimizing the Coleman-Weinberg effective potential for a third rank antisymmetric tensor scalar field in the 56 representation. Instead of breaking $SU(8) \supset SU(3) \times SU(5)$, we find that the stable minimum of the potential breaks the original symmetry according to $SU(8) \supset SU(3) \times Sp(4)$. Using both numerical and analytical methods, we present results for the potential minimum, the corresponding Goldstone boson structure and BEH mechanism, and the group-theoretic classification of the residual states after symmetry breaking.
description: Latex, 15 pages. v3 to appear in Journal of Physics A: Mathematical and Theoretical
C-di-GMP signalling in Pseudomonas aeruginosa: connecting the dots in a multi modal network
Creators: name: Glatzel, Kira
Publisher: name: Imperial College London
Year: 2022

description: Bacteria rely on complex regulatory networks to control their cellular programme in order to respond to extracellular factors in an environment or host setting. Bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) is a signalling molecule used by several bacterial species to facilitate some of those important lifestyle decisions. One of the most complex and elaborated c-di-GMP signalling networks is found in the human opportunistic pathogen Pseudomonas aeruginosa, which is a major cause of chronic infection in cystic fibrosis patients. The genome of P. aeruginosa alone encodes 41 proteins harbouring the potential to make or break c-di-GMP. Using a methodical deletion approach, single and multiple c-di-GMP metabolizing genes were knocked out and their role in attachment, biofilm, motility, virulence and antimicrobial resistance systematically assessed, providing a comprehensive pool of data for the c-di-GMP research community. Interestingly, a very large number of c-di-GMP deletion mutants showed an altered biofilm/attachment profile, indicating that the network is of great importance for motile to sessile transition. We further uncovered that among all c-di-GMP regulating enzymes, PA0285 is one of the most potent phosphodiesterases regulating intracellular c-di-GMP levels leading to the most pronounced biofilm attachment phenotype. It is uniquely controlled by its dual domain structure containing both an EAL domain responsible for breaking c-di-GMP as well as a regulatory GGDEF domain characteristic of c-di-GMP synthesis. Both domains have been shown to be essential for the PA0285 mediated phenotypes in biofilm attachment and intracellular c-di-GMP. Further, targeted protein-protein interaction analysis revealed the molecular mechanisms of DgcP (PA5487), a c-di-GMP synthesising cyclase. involved in the convergence of c-di-GMP and cyclic adenosine monophosphate (cAMP) signalling pathways facilitating touch-down and attachment behaviour of P. aeruginosa.
Kondo screening in two-dimensional $p$-type transition-metal dichalcogenides
Creators: name: Phillips, Michael
name: Aji, Vivek
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Systems with strong spin orbit coupling support a number of new phases of matter and novel phenomena. This work focuses on the interplay of spin orbit coupling and interactions in yielding correlated phenomena in two dimensional transition metal dichalcogenides. In particular we explore the physics of Kondo screening resulting from the lack of centro-symmetry, large spin splitting and spin valley locking in hole doped systems. The key ingredients are i) valley dependent spin-momentum locking perpendicular to the two dimensional crystal; ii) single nondegenerate Fermi surface per valley, and iii) nontrivial Berry curvature associated with the low energy bands. The resulting Kondo resonance has a finite triplet component and nontrivial momentum space structure which facilitates new approaches to both probe and manipulate the correlated state. Using a variational wave function and the numerical renormalization group approaches we study the nature of the Kondo resonance both in the absence and presence of circularly polarized light. The latter induces an imbalance in the population of the two valleys leading to novel magnetic phenomena in the correlated state.
description: 16 pages, 14 figures
Petrinetze zum Entwurf selbststabilisierender Algorithmen
Creators: name: Vesper, Tobias
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II
Year: 2000
Subjects: subject: Selbststabilisierung
subject: verteiltes System
subject: verteilter Algorithmus
subject: Petrinetz
subject: self-stabiilization
subject: distributed system
subject: distributed algorithm
subject: Petri net
subject: 004 Informatik
subject: 28 Informatik, Datenverarbeitung
subject: ST 130

description: Edsger W. Dijkstra prägte im Jahr 1974 den Begriff Selbststabilisierung (self-stabilization) in der Informatik. Ein System ist selbststabilisierend, wenn es von jedem denkbaren Zustand aus nach einer endlichen Anzahl von Aktionen ein stabiles Verhalten erreicht. Im Mittelpunkt dieser Arbeit steht der Entwurf selbststabilisierender Algorithmen. Wir stellen eine Petrinetz-basierte Methode zum Entwurf selbststabilisierender Algorithmen vor. Wir validieren unsere Methode an mehreren Fallstudien: Ausgehend von algorithmischen Ideen existierender Algorithmen beschreiben wir jeweils die die schrittweise Entwicklung eines neuen Algorithmus. Dazu gehört ein neuer randomisierter selbststabilisierender Algorithmus zur Leader Election in einem Ring von Prozessoren. Dieser Algorithmus ist abgeleitet aus einem publizierten Algorithmus, von dem wir hier erstmals zeigen, daß er fehlerhaft arbeitet. Wir weisen die Speicherminimalität unseres Algorithmus nach. Ein weiteres Ergebnis ist der erste Algorithmus, der ohne Time-Out-Aktionen selbststabilisierenden Tokenaustausch in asynchronen Systemen realisiert. Petrinetze bilden einen einheitlichen formalen Rahmen für die Modellierung und Verifikation dieser Algorithmen.
description: In 1974, Edsger W. Dijkstra suggested the notion of self-stabilization. A system is self-stabilizing if regardless of the initial state it eventually reaches a stable behaviour. This thesis focuses on the design of self-stabilizing algorithms. We introduce a new Petri net based method for the design of self-stabilizing algorithms. We validate our method on several case studies. In each of the case studies, our stepwise design starts from an algorithmic idea and leads to a new self-stabilizing algorithm. One of these algorithms is a new randomized self-stabilizing algorithm for leader election in a ring of processors. This algorithm is derived from a published algorithm which we show to be incorrect. We prove that our algorithm is space-minimal. A further result is the first algorithm for token-passing in a asynchronous environment which works without time-out actions. Petri nets form a unique framework for modelling and verification of these algorithms.
Ultra-low-noise room-temperature quantum memory for polarization qubits
Creators: name: Namazi, Mehdi
name: Kupchak, Connor
name: Jordaan, Bertus
name: Shahrokhshahi, Reihaneh
name: Figueroa, Eden
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Here we show an ultra-low noise regime of operation in a simple quantum memory in warm Rb atomic vapor. By modelling the quantum dynamics of four-level room temperature atoms, we achieve fidelities >90% for single-photon level polarization qubits, clearly surpassing any classical strategy exploiting the non-unitary memory efficiency. This is the first time such important threshold has been crossed with a room temperature device. Additionally we also show novel experimental techniques capable of producing fidelities close to unity. Our results demonstrate the potential of simple, resource-moderate experimental room temperature quantum devices.
description: 5 pages, 5 figures
Exact short-time height distribution in 1D KPZ equation and edge fermions at high temperature
Creators: name: Doussal, Pierre Le
name: Majumdar, Satya N.
name: Rosso, Alberto
name: Schehr, Gregory
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider the early time regime of the Kardar-Parisi-Zhang (KPZ) equation in $1+1$ dimensions in curved (or droplet) geometry. We show that for short time $t$, the probability distribution $P(H,t)$ of the height $H$ at a given point $x$ takes the scaling form $P(H,t) \sim \exp{\left(-Φ_{\rm drop}(H)/\sqrt{t} \right)}$ where the rate function $Φ_{\rm drop}(H)$ is computed exactly. While it is Gaussian in the center, i.e., for small $H$, the PDF has highly asymmetric non-Gaussian tails which we characterize in detail. This function $Φ_{\rm drop}(H)$ is surprisingly reminiscent of the large deviation function describing the stationary fluctuations of finite size models belonging to the KPZ universality class. Thanks to a recently discovered connection between KPZ and free fermions, our results have interesting implications for the fluctuations of the rightmost fermion in a harmonic trap at high temperature and the full couting statistics at the edge.
description: 5 pages + 7 pages of supplemental material, 3 figures, typos corrected
Measurement and optimisation of beam quality from laser wakefield accelerators
Creators: name: Backhouse, Michael
Publisher: name: Imperial College London
Year: 2022

description: This thesis concerns experimental work in the field of laser wakefield acceleration, with a focus on the diagnosis and optimisation of the electron beam quality. The density length parameter space of a 5TW, 0.25J laser driven wakefield accelerator was characterised. Measurements of the electron beams and x-ray pulses were reported, and optimal parameters for various metrics were found. Beam-driven acceleration was identified as the mechanism that produced energies above 211MeV, and the peak x-ray brilliance was 4.2+/-0.8E20 ph/s/mm^2/mrad^2/0.1%BW^-1. Both the electron energy and the x-ray brilliance are significantly higher than literature values using comparable laser powers. Separately, the parameter scans were used to measure an extended dephasing length of the laser-accelerated beam, attributable to semi-localised depletion of the driving laser pulse, and measure the pulse evolution rate and injection length as a function of plasma density, which was found to be slower than would be expected when only considering the longitudinal evolution. An emittance diagnostic was developed using a beam mask and electron spectrometer. This was used to measure the spectrally resolved normalised emittance of GeV beams, produced by ionisation injection in a gas jet using a 165TW, 7.4J laser. Average emittance values as low as 4um were measured, which are the lowest emittances recorded using a beam mask technique in the literature, at energies that are close to an order of magnitude higher than other beam mask methods. The effect of density ramps and plasma mirrors on electron beam divergence was measured in the context of staged wakefield acceleration, using a 242TW, 11J laser. Termination of an acceleration stage with a plasma mirror was found to increase total beam divergence from 3.38+/-0.07mrad to 6.13+/-0.13mrad, and the effect was observed to persist at high energies, up to 2.2GeV. Using simulations and numerical models, the presence of the density ramp was shown to have a divergence-reducing effect with a magnitude that matched the experiment. The 10^3 tesla magnetic fields generated in plasma mirrors were investigated using simulations, and the effect of these fields on the electron beam was quantified. Compared to normal incidence, a 45 degree angle of the plasma mirror to the beam axis was found to reduce the integrated magnetic fields inside the mirror, with beneficial effects on electron beam emittance.