cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
QCD fixed points: Banks-Zaks scenario or dynamical gluon mass generation?
Creators: name: Gomez, J. D.
name: Natale, A. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Fixed points in QCD can appear when the number of quark flavors ($N_f$) is increased above a certain critical value as proposed by Banks and Zaks (BZ). There is also the possibility that QCD possess an effective charge indicating an infrared frozen coupling constant. In particular, an infrared frozen coupling associated to dynamical gluon mass generation (DGM) does lead to a fixed point even for a small number of quarks. We compare the BZ and DGM mechanisms, their $β$ functions and fixed points, and within the approximations of this work, which rely basically on extrapolations of the dynamical gluon masses at large $N_f$, we verify that near the so called QCD conformal window both cases exhibit fixed points at similar coupling constant values ($g^*$). We argue that the states of minimum vacuum energy, as a function of the coupling constant up to $g^*$ and for several $N_f$ values, are related to the dynamical gluon mass generation mechanism.
description: 9 pages, 9 figures, new references, improved discussion and small change in the title, to appear in IJMPA
Adaptive Analysis
Creators: name: Scott H.
Publisher: name: Zenodo
Year: 2024

description: I show how to quickly map relationships of complex system components using a scenario of a small town of 5,000 facing an Internet outage. Reporting, visualization, and data for the model takes up less space than a medium sized digital image of 2MB. The model does not require experts, servers or administrators to build, share and maintain.
Εντοπισμός και Αντιμετώπιση των Παγκόσμιων Παράνομων Ροών Πετρελαίου
Creators: name: Τσιούφης, Μάριος
Publisher: name: Πανεπιστήμιο Πελοποννήσου
Year: 2022
Subjects: subject: Maritime piracy; AHP; spatio-temporal data analysis; Time-varying Granger causality; oil tankers

description: Μ.Δ.Ε. 22
description: Despite maritime piracy is a major concern to international trade, there is no comprehensive study that considers the causing factors, spatio-temporal patters and association rules of pirates’ behaviour that influence the choice of attack areas that can be used as a decision support tool to enhance security in the most vulnerable areas. To solve this issue and contribute further on the literature, we apply multiple methods namely AHP, and spatio-temporal analysis by using data from the National Geospatial-Intelligence Agency. It is observed that territorial waters are preferable areas; thus, pirates prefer to attack the ships close to the coastline. Moreover, pirates in certain areas are influenced by the activity and the information from other pirates, which can be used as tool from the authorities e.g. derive information from pirates that have been arrested.
High-Energy Scatterings in Infinite-Derivative Field Theory and Ghost-Free Gravity
Creators: name: Talaganis, Spyridon
name: Mazumdar, Anupam
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper, we will consider scattering diagrams in the context of infinite-derivative theories. First, we examine a finite-order higher-derivative scalar field theory and find that we cannot eliminate the external momentum divergences of scattering diagrams in the regime of large external momenta. Then, we employ an infinite-derivative scalar toy model and obtain that the external momentum dependence of scattering diagrams is convergent as the external momenta become very large. In order to eliminate the external momentum divergences, one has to dress the bare vertices of the scattering diagrams by considering renormalised propagator and vertex loop corrections to the bare vertices. Finally, we investigate scattering diagrams in the context of a scalar toy model which is inspired by a $\mathit{ghost-free}$ and $\mathit{singularity-free}$ infinite-derivative theory of gravity, where we conclude that infinite derivatives can eliminate the external momentum divergences of scattering diagrams and make the scattering diagrams convergent in the ultraviolet.
description: 37 pages, 9 figures; v2: Accepted for publication in Classical and Quantum Gravity; v3: minor revisions
Minimizing couplings in renormalization by preserving short-range mutual information
Creators: name: Bertoni, Christian
name: Renes, Joseph M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The connections between renormalization in statistical mechanics and information theory are intuitively evident, but a satisfactory theoretical treatment remains elusive. Recently, Koch-Janusz and Ringel proposed selecting a real-space renormalization map for classical lattice systems by minimizing the loss of long-range mutual information [Nat. Phys. 14, 578 (2018)]. The success of this technique has been related in part to the minimization of long-range couplings in the renormalized Hamiltonian [Lenggenhager et al., Phys. Rev. X 10, 011037 (2020)]. We show that to minimize these couplings the renormalization map should, somewhat counterintuitively, instead be chosen to minimize the loss of short-range mutual information between a block and its boundary. Moreover, the previous minimization is a relaxation of this approach, which indicates that the aims of preserving long-range physics and eliminating short-range couplings are related in a nontrivial way.
description: 5 pages, 4 figures
Απαιτούμενες δεξιότητες στελεχών στην εποχή του ψηφιακού μετασχηματισμού
Creators: name: Σηφάκης, Μάριος Κωνσταντίνος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2022
Subjects: subject: Ψηφιακός μετασχηματισμός
subject: Στρατηγική
subject: Δεξιότητες
subject: Στελέχη
subject: Διεθνείς οργανισμοί

description: Το παρόν ερευνητικό έργο έρχεται να απαντήσει στο ερώτημα ποιες είναι εκείνες οι δεξιότητες που καλούνται να έχουν τα στελέχη την εποχή του ψηφιακού μετασχηματισμού. Για το σκοπό αυτό, αρχικά, επιδιώκεται η οριοθέτηση της έννοιας του ψηφιακού μετασχηματισμού καθώς και ανάδειξη της σημασίας της στρατηγικής παράλληλα με την τεχνολογία για την κατάστρωση του. Στη συνέχεια, εξετάζεται η έννοια των ψηφιακών δεξιοτήτων και οι ποικίλες κατηγοριοποιήσεις τους. Έπειτα, παρατίθενται οι θέσεις των διεθνών οργανισμών όσον αφορά τον κλάδο των επιχειρήσεων στην ψηφιακή εποχή και κατά συνέπεια ποιες είναι εκείνες οι δεξιότητες που απαιτούνται να έχουν τα υποψήφια στελέχη προκειμένου να ανταποκριθούν σε αυτή. Τέλος, λαμβάνοντας υπόψη τις θέσεις της διεθνούς κοινότητας, προτείνονται εκείνες οι δεξιότητες που κρίνονται απαραίτητες για τη στελέχωση της επιχείρησης του 21ου αιώνα και τρόποι απόκτησης τους.
Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes
Creators: name: Liu, Hang
name: Meng, Xin-he
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions $d\geq4$, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter $a_j$ = 0 in higher dimensions $d\geq5$, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge $δ=0$. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotating Kaluza-Klein black holes in asymptotically flat spacetime act the same way, it is found that the charge has no effect in the angular momentum-independence of entropy sum and product in asymptotically flat spactime.
description: Final version, accepted for publication by International Journal of Theoretical Physics
Isochronal annealing effects on local structure, crystalline fraction, and undamaged region size of radiation damage in Ga-stabilized $δ$-Pu
Creators: name: Olive, D. T.
name: Wang, D. L.
name: Booth, C. H.
name: Bauer, E. D.
name: Pugmire, A. L.
name: Freibert, F. J.
name: McCall, S. K.
name: Wall, M. A.
name: Allen, P. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The effects on the local structure due to self-irradiation damage of Ga stabilized $δ$-Pu stored at cryogenic temperatures have been examined using extended x-ray absorption fine structure (EXAFS) experiments. Extensive damage, seen as a loss of local order, was evident after 72 days of storage below 15 K. The effect was observed from both the Pu and Ga sites, although less pronounced around Ga. Isochronal annealing was performed on this sample to study the annealing processes that occur between cryogenic and room temperature storage conditions, where damage is mostly reversed. Damage fractions at various points along the annealing curve have been determined using an amplitude-ratio method, standard EXAFS fitting, and a spherical crystallite model, and provide information complementary to previous electrical resistivity- and susceptibility-based isochronal annealing studies. The use of a spherical crystallite model accounts for the changes in EXAFS spectra using just two parameters, namely, the crystalline fraction and the particle radius. Together, these results are discussed in terms of changes to the local structure around Ga and Pu throughout the annealing process and highlight the unusual role of Ga in the behavior of the lowest temperature anneals.
description: 13 pages, 10 figures
Charge transport in a multi-terminal DNA tetrahedron: Interplay among contact position, disorder, and base-pair mismatch
Creators: name: Hu, Pei-Jia
name: Wang, Si-Xian
name: Chen, Xiao-Feng
name: Gao, Xiao-Hui
name: Fang, Tie-Feng
name: Guo, Ai-Min
name: Sun, Qing-Feng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: As a secondary structure of DNA, DNA tetrahedra exhibit intriguing charge transport phenomena and provide a promising platform for wide applications like biosensors, as shown in recent electrochemical experiments. Here, we study charge transport in a multi-terminal DNA tetrahedron, finding that its charge transport properties strongly depend upon the interplay among contact position, on-site energy disorder, and base-pair mismatch. Our results indicate that the charge transport efficiency is nearly independent of contact position in the weak disorder regime, and is dramatically declined by the occurrence of a single base-pair mismatch between the source and the drain, in accordance with experimental results [J. Am. Chem. Soc. {\bf 134}, 13148 (2012); Chem. Sci. {\bf 9}, 979 (2018)]. By contrast, the charge transport efficiency could be enhanced monotonically by shifting the source toward the drain in the strong disorder regime, and be increased when the base-pair mismatch takes place exactly at the contact position. In particular, when the source moves successively from the top vertex to the drain, the charge transport through the tetrahedral DNA device can be separated into three regimes, ranging from disorder-induced linear decrement of charge transport to disorder-insensitive charge transport, and to disorder-enhanced charge transport. Finally, we predict that the DNA tetrahedron functions as a more efficient spin filter compared to double-stranded DNA and opposite spin polarization could be observed at different drains, which may be used to separate spin-unpolarized electrons into spin-up ones and spin-down ones. These results could be readily checked by electrochemical measurements and may help for designing novel DNA tetrahedron-based molecular nanodevices.
description: Comments are welcome; 10 pages; 6 figures
Constraints on Scalar Leptoquark from Kaon Sector
Creators: name: Kumar, Girish
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recently, several anomalies in flavor physics have been observed, and it was noticed that leptoquarks might account for the deviations from the Standard Model. In this work, we examine the effects of new physics originating from a scalar leptoquark model on the kaon sector. The leptoquark we consider is a TeV-scale particle and within the reach of the LHC. We use the existing experimental data on the several kaon processes including $K^{0}-\bar{K}^{0}$ mixing, rare decays $K^{+} \rightarrow π^{+} ν\barν$, $ K_L \rightarrow π^0 ν\barν$, short-distance part of $K_L\rightarrow μ^{+}μ^{-}$, and lepton-flavor-violating decay $K_L\rightarrow μ^{\pm} e^{\mp}$ to obtain useful constraints on the model.
description: 11 pages, 6 figures, new references added, matches published version
Tribological characterization of valve train ball/socket-contacts based on a tribometric model testing system
Creators: name: Denzel, Michael
Publisher: name: Zenodo
Year: 2024
Subjects: engine oil
wear
ZDDP
artificial oil aging
soot
abrasive particles
valvetrain

description: The demand for higher efficiency and less emissions in combustion engines requires the use of low-viscosity engine oils in order to reduce friction losses. In addition, certain oil additives must be reduced to meet novel environmental regulations. This leads to increased wear on engine components which were uncritical in the past. Especially at ball/socket-contacts in valvetrains, wear is critical because it affects the valve clearance and consequently the gas exchange, which can lead to efficiency losses, increase in emissions and engine damage. Currently, engine tests with a run time of several days are used to investigate the tribological performance of valvetrain components. To reduce costs and testing duration, a model testing system is demanded. Therefore, a test setup on a rotary tribometer was designed, where various ball and socket specimens cut out from engine valvetrain components can be tested within one day. With the test setup's modular structure it is possible to vary different specimens, their assembly positions, lubrication systems and motion. A suitable test program to simulate the running conditions was developed, which is based on a start-stop cycle, and an appropriate data evaluation was programmed. The results of an accompanying optical analysis and gravimetric wear measurements are compared with engine tests. Changing the axis of rotation due to machine settings requires an adjustment of speed and load to match the same mild abrasive wear mechanism as observed in engine parts. As tests with fresh oil did not cause significant wear to make meaningful statements in terms of oil effectiveness, an artificial oil aging process was performed by adding abrasive particles or a soot surrogate to fresh oil. It was shown that the geometric difference in sockets has a big influence on reproducibility as it supports the build-up of a potential load-bearing oil film. Tests with used engine oil proved that, with this test setup, causing significant wear in a moderate time is possible. Furthermore, it was shown that, depending on their concentration, abrasive particles increase the coefficient of friction, which can lead to seizure, but do not increase mild abrasive wear in the investigated components. Adding a soot surrogate significantly increases wear. According to literature, this is due to chemical interaction of the oil additive zinc dialkyldithiophoshpate with soot. For the purpose of validation, tests with various oils with well-known engine performance were conducted. It was shown that an oil with low wear in the engine also shows low wear in model tests using artificial oil aging. Consequently, the developed test procedure provides a good tool for gaining deeper understanding and tribosystem-screening of ball/socket-contacts.
Cut-and-paste restoration of entanglement transmission
Creators: name: Cuevas, Alvaro
name: Mari, Andrea
name: De Pasquale, Antonella
name: Orieux, Adeline
name: Massaro, Marcello
name: Sciarrino, Fabio
name: Mataloni, Paolo
name: Giovannetti, Vittorio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The distribution of entangled quantum systems among two or more nodes of a network is a key task at the basis of quantum communication, quantum computation and quantum cryptography. Unfortunately the transmission lines used in this procedure can introduce so much perturbations and noise in the transmitted signal that prevent the possibility of restoring quantum correlations in the received messages either by means of encoding optimization or by exploiting local operations and classical communication. In this work we present a procedure which allows one to improve the performance of some of these channels. The mechanism underpinning this result is a protocol which we dub cut-and-paste, as it consists in extracting and reshuffling the sub-components of these communication lines, which finally succeed in "correcting each other". The proof of this counterin- tuitive phenomenon, while improving our theoretical understanding of quantum entanglement, has also a direct application in the realization of quantum information networks based on imperfect and highly noisy communication lines. A quantum optics experiment, based on the transmission of single-photon polarization states, is also presented which provides a proof-of-principle test of the proposed protocol.
Comparing Information Literacy of Students from University of Graz (Austria) and Chungbuk National University (Republic of Korea)
Creators: name: Rust, Kathrin
name: Schlögl, Christian
name: DongBack, Seo
Publisher: name: Humboldt-Universität zu Berlin
Year: 2017
Subjects: subject: information literacy
subject: comparison
subject: questionnaire
subject: University of Graz
subject: Chungbuk National University
subject: cultural differences
subject: 020 Bibliotheks- und Informationswissenschaft

description: In this article, we present the results of a study in which we compared information literacy of master students from the University of Graz, Austria and Chungbuk National University (CBNU), Republic of Korea. Data were collected using a multiple-choice questionnaire which consisted of the following parts: demographic data, self-assessment of one’s information literacy, use of information sources, and knowledge test. The latter was designed on the basis of the Information Literacy Competency Standards for Higher Education (ALA, 2000). Data were collected in two classes of the Business Administration program at the University of Graz. At CBNU, the study participants were subscribed to the master programs of Business Administration, Management Information Systems, and Psychology. Usually, it took the students 20 minutes to fill out the questionnaire. The results reveal that students from the University of Graz have a higher level of information literacy than their colleagues from CBNU. To some degree, this might be due to cultural and social differences between the students. However, the test instrument might have had also some cultural (European) bias. Finally, it turned out that the Korean students were more exposed toward the use of modern information and communication technologies.
KK-like relations of $α^{\prime}$ corrections to disk amplitudes
Creators: name: Mafra, Carlos R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Inspired by the definition of color-dressed amplitudes in string theory, we define analogous {\it color-dressed permutations} replacing the color-ordered string amplitudes by their corresponding permutations. Decomposing the color traces into symmetrized traces and structure constants, the color-dressed permutations define {\it BRST-invariant permutations}, which we show are elements of the inverse Solomon descent algebra and we find a closed formula for them. We then present evidence that these permutations encode KK-like relations among the different $α'$ corrections to disk amplitudes refined by their motivic MZV content. In particular, the number of linearly independent amplitudes at a given ${α^{\prime}}$ order and motivic MZV content is given by (sums of) Stirling cycle numbers. In addition, we show how the superfield expansion of BRST invariants of the pure spinor formalism corresponding to ${α^{\prime}}^2 f_2$ corrections is encoded in the descent algebra.
description: 31 pages, v2: title and presentation changes, results the same. Published version, v3: use motivic version of amplitudes
title: Χρηματοοικονομικός αναλυτής - Full stack web εφαρμογή με React & Spring Boot
title: Financial assets analyst - Full stack application with React & Spring Boot
titleType: AlternativeTitle
Creators: name: Χατζηαθανασίου, Φανούριος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2022
Subjects: subject: React
subject: Spring Boot
subject: Web application
subject: Full stack

description: Τα χρηματοοικονομικά μέσα λόγω της ραγδαίας εξέλιξης της τεχνολογίας, αποτελόυν ένα πλέον προσβάσιμο τρόπο επένδυσης του χρήματος. Εξυπηρετεί στη ροή του χρήματος και με τη κατάλληλη έρευνα στις αγορές, μπορεί να αποφέρει κέρδη στους επενδυτές. Σκοπός αυτής της πτυχιακής εργασίας είναι η ανάπτυξη μιας Full Stack Web Application, με όνομα Financial Assets Analyst. Οι τεχνολογίες που αξιοποιήθηκαν στο backend περιλαμβάνουν Spring boot, MongoDB και στο frontend κυρίως Typescript (NextJS-React). Μέσω αυτής της εφαρμογής δίνεται η δυνατότητα στους χρήστες να έχουν πρόσβαση σε χρηματοοικονομικά γραφήματα και να χρησιμοποιούν δείκτες τεχνικής ανάλυσης, να κατεβάζουν σε μορφή CSV τα δεδομένα αυτά καθώς και να μπορούν να βρουν ευκαιρίες αγοράς-πώλησης χρηματοοικονομικών μέσων μέσα από ένα αυτοματοποιημένο σύστημα που παρέχει ο Web Server.
Superfluid flow past an obstacle in annular Bose--Einstein condensates
Creators: name: Syafwan, M.
name: Kevrekidis, P.
name: Paris-Mandoki, A.
name: Lesanovsky, I.
name: Kruger, P.
name: Hackermuller, L.
name: Susanto, H.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We investigate the flow of a one-dimensional nonlinear Schrodinger model with periodic boundary conditions past an obstacle, motivated by recent experiments with Bose--Einstein condensates in ring traps. Above certain rotation velocities, localized solutions with a nontrivial phase profile appear. In striking difference from the infinite domain, in this case there are many critical velocities. At each critical velocity, the steady flow solutions disappear in a saddle-center bifurcation. These interconnected branches of the bifurcation diagram lead to additions of circulation quanta to the phase of the associated solution. This, in turn, relates to the manifestation of persistent current in numerous recent experimental and theoretical works, the connections to which we touch upon. The complex dynamics of the identified waveforms and the instability of unstable solution branches are demonstrated.
description: Resubmitted (2016)
Complexity analysis of quantum teleportation via different entangled channels in the presence of noise
Creators: name: Singh, Deepak
name: Kumar, Sanjeev
name: Behera, Bikash K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum communication is one of the hot topics in quantum computing, where teleportation of a quantum state has a slight edge and gained significant attention from researchers. A large number of teleportation schemes have already been introduced so far. Here, we compare the teleportation of a single qubit message among different entangled channels such as the two-qubit Bell channel, three-qubit GHZ channel, two- and three-qubit cluster states, the highly entangled five-qubit Brown \emph{et al.} state and the six-qubit Borras \emph{et al.} state. We calculate and compare the quantum costs in each of the cases. Furthermore, we study the effects of six noise models, namely bit-flip noise, phase-flip noise, bit-phase flip noise, amplitude damping, phase damping and the depolarizing error that may affect the communication channel used for the teleportation. An investigation on the variation of the initial state's fidelity with respect to the teleported state in the presence of the noise model is performed. A visual representation of the variation of fidelity for various values of the noise parameter $η$ is done through a graph plot. It is observed that as the value of noise parameter in the range $η\in [0,0.5]$, the fidelity decreases in all the entangled channels under all the noise models. After that, in the Bell channel, GHZ channel and three-qubit cluster state channel, the fidelity shows an upward trend under all the noise models. However, in the other three channels, the fidelity substantially decreases in the case of amplitude damping, phase damping and depolarizing noise, and even it reaches zero for $η= 1$ in Brown \emph{et al.} and Borras \emph{et al.} channels.
description: 18 pages, 13 figures
VICI
Creators: name: Odoni, Fabian
name: Semar, Wolfgang
name: Mastrandrea, Elena
Publisher: name: Humboldt-Universität zu Berlin
Year: 2017
Subjects: subject: information retrieval
subject: knowledge management
subject: data visualisation
subject: software development
subject: 020 Bibliotheks- und Informationswissenschaft

description: This poster describes the relationship visualisation framework VICI. VICI was developed to extract co-author relationships found on an Atlassian Confluence installation and visualise them as network graphs. Therefore wikientries are extracted directly from the Confluence database using sql-queries. This data is used to calculate co-authorship bigrams and build a relationship graph. The graph is then visualised as force-directed network graph using D3.js in a web app. Node size and colour as well as path width and colour are used to encode relationship degrees and author activity. Additional relationship visualisations will be developed in the future.
Leveraging public mass spectrometry for molecular discovery from millions of mass spectra
Creators: name: Bittremieux, Wout
Publisher: name: Zenodo
Year: 2023

description: Despite an explosion of publicly available data in mass spectrometry repositories, mass spectra are typically still analyzed by each laboratory in isolation, treating each experiment as if it has no relationship to any others. This approach fails to exploit the wealth of existing, previously analyzed mass spectrometry data. Here I will present two approaches that harness repository-scale public mass spectrometry data to achieve a deeper understanding of the molecular composition of complex biological samples. First, I will describe a deep neural network approach, called "GLEAMS," which learns to embed spectra across an entire data repository into a low-dimensional space such that spectra generated by the same peptide are close to one another. This learned embedding captures latent properties of the spectra, and the low-dimensional space can be used for the efficient clustering and identification of hundreds of millions of spectra. We have used GLEAMS to process 31TB of human proteomics data belonging to the MassIVE Knowledge Base dataset, corresponding to 666 million spectra derived from 220 publicly available experiments. Using GLEAMS, we were able to investigate the "dark matter" of the human proteome by propagating peptide labels within high-quality clusters and open modification searching to annotate 73% additional mass spectra compared to the state of the art. Second, I will present the "nearest neighbor suspect spectral library" that can be used to identify molecules that are structurally related to previously known reference molecules. Based on spectral similarity, information can be propagated to neighboring mass spectra in a molecular network to increase the spectrum annotation rate. We have propagated annotations from molecular networks associated with 521 million mass spectra from 1335 compatible untargeted metabolomics datasets in various metabolomics data repositories, including GNPS/MassIVE, Metabolights, and Metabolomics Workbench, to create the GNPS nearest neighbor suspect spectral library. It consists of 87,916 novel reference spectra corresponding to modified molecules that are structurally related to known reference molecules. Using the suspect library for spectral library searching increases the spectrum annotation rate 2-fold on average, considerably boosting the interpretation rate of untargeted metabolomics beyond the state of the art. In conclusion, these two powerful computational approaches highlight the enormous value of open data, and provide significant breakthroughs in deriving biological insights from mass spectrometry proteomics and metabolomics experiments.
Η επίδραση της πανδημίας στο ηλεκτρονικό εμπόριο
Creators: name: Πράππα, Αθηνά
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2022
Subjects: subject: Πανδημία
subject: Ηλεκτρονικό εμπόριο

description: Η παρακάτω εργασία εξετάζει τον ρόλο του Ηλεκτρονικού Εμπορίου την εποχή της πανδημίας. Αναλύει τα προβλήματα και τις αλλαγές που προέκυψαν τα τελευταία χρόνια λόγω της εμφάνισης του κορονοϊού. Πραγματεύεται ένα επίκαιρο θέμα, που σχετίζεται με την αλματώδη και συνεχομένη εξέλιξη της τεχνολογίας, τη στιγμή που ένας απροσπέλαστος «εχθρός» ήρθε να «δοκιμάσει» τα όρια της ανθρωπότητας σε όλους τους τομείς της καθημερινής μας ζωής. Αυτός δεν είναι άλλος από τον επικίνδυνο ιό, που ήρθε για να αλλάζει ριζικά τον τρόπο που ζούμε. Μαζί με την αλματώδη αύξηση της τεχνολογίας, κορύφωση συναντά το ηλεκτρονικό εμπόριο και οι ηλεκτρονικές αγορές, ειδικότερα από το 2009 και έπειτα, όπου η οικονομική κρίση έπληξε τη χώρα μας. Ένα από τα πιο σημαντικά ζητήματα που επηρέασε σε ανυπέρβλητο βαθμό ο κορονοϊός είναι η οικονομία, όχι μόνο της χώρας, αλλά παγκοσμίως. Αξίζει να αναφερθεί πως η παρούσα εργασία είναι χωρισμένη σε 6 κεφάλαια. Πιο συγκεκριμένα αναλύει τον κλάδο του ηλεκτρονικού εμπορίου, περιγράφει θέματα ψηφιακού μετασχηματισμού και εξετάζει την υιοθέτηση του ηλεκτρονικού εμπορίου. Στο δεύτερο κεφάλαιο παρουσιάζεται μια ανάλυση που αναφέρεται στην συμπεριφορά του καταναλωτή απέναντι στο διαδίκτυο και πιο συγκεκριμένα στον ψηφιακό καταναλωτή. Στα επόμενα κεφάλαια γίνεται εκτενής αναφορά στην επίδραση της πανδημίας στο ηλεκτρονικό εμπόριο, καθώς και στις αλλαγές, προσαρμογές και δράσεις που υιοθετήθηκαν από τους οργανισμούς και τις επιχειρήσεις. Τα παραπάνω συμπεράσματα αποτυπώνονται και αναλύονται στο τελευταίο κεφάλαιο, το οποίο είναι αφιερωμένο στη μελέτη δυο επιχειρησιακών περιπτώσεων, της Amazon και της Skroutz.
Orbital engineering in nickelate heterostructures driven by anisotropic oxygen hybridization rather than orbital energy levels
Creators: name: Fabbris, G.
name: Meyers, D.
name: Okamoto, J.
name: Pelliciari, J.
name: Disa, A. S.
name: Huang, Y.
name: Chen, Z. -Y.
name: Wu, W. B.
name: Chen, C. T.
name: Ismail-Beigi, S.
name: Ahn, C. H.
name: Walker, F. J.
name: Huang, D. J.
name: Schmitt, T.
name: Dean, M. P. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking $\mathrm{LaTiO_3-LaNiO_3-3x(LaAlO_3)}$, a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni $3d$ orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O $K$-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.
description: Accepted for publication in Physical Review Letters. 6 pages, 4 figures
title: Αυτοδιαχειριζόμενες ταυτότητες με τη χρήση του οικοσυστήματος Hyperledger
title: Self-sovereign identities using the Hyperledger ecosystem
titleType: AlternativeTitle
Creators: name: Λοΐζος, Εμμανουήλ
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2022
Subjects: subject: Blockchain
subject: Ψηφιακή ταυτότητα
subject: Hyperledger
subject: Αυτοδιαχειριζόμενη ταυτότητα

description: Σε αντίθεση με τα συμβατικά δίκτυα που χρησιμοποιούνται ευρέως, η τεχνολογία Blockchain είναι ένα δίκτυο ομότιμων χρηστών που μπορεί να λειτουργεί χωρίς κεντρική αρχή. Αυτό υποδηλώνει ότι οι κόμβοι σε ένα τέτοιο δίκτυο δεν χρειάζεται να είναι επίσημα εξουσιοδοτημένοι ή επαληθευμένοι από μια κεντρική αρχή προκειμένου να συμμετέχουν σε αυτό. Δεδομένου ότι ολόκληρο το δίκτυο επικυρώνει κάθε συναλλαγή, το δίκτυο θεωρείται δεδομένο ότι είναι αξιόπιστο. Για να επιβάλει την εξουσία του στο δίκτυο, ένας χρήστης θα πρέπει να αποκτήσει τον έλεγχο της πλειοψηφίας των κόμβων, γεγονός που εξασφαλίζει και την εμπιστοσύνη με αυτό τον τρόπο. Η παρούσα μεταπτυχιακή διατριβή αποσκοπεί λοιπόν στην ανάπτυξη ενός συστήματος διαχείρισης αυτοδύναμων ταυτοτήτων (Self Sovereign Identity - SSI), αξιοποιώντας τις δυνατότητες του οικοσυστήματος Hyperledger. Οι χρήστες ενός τέτοιου συστήματος διαχείρισης θα μπορούσαν να επιλέξουν ποια από τα χαρακτηριστικά της ταυτότητάς τους θέλουν να μοιραστούν με συγκεκριμένους παρόχους υπηρεσιών προκειμένου να χρησιμοποιούν τις υπηρεσίες τους.
Orchard, Bernand und Riley, Harold: The Order of the Synoptics
Creators: name: Thiede, Carsten Peter
Publisher: name: Jahrbuch für evangelikale Theologie
Year: 2025

description: 182254825X
description: Jahrbuch für evangelikale Theologie, V. 4 (1990): Jahrbuch für evangelikale Theologie, Band 4
Continual Semi-Supervised Learning through Contrastive Interpolation Consistency
Creators: name: Boschini, Matteo
name: Buzzega, Pietro
name: Bonicelli, Lorenzo
name: Porrello, Angelo
name: Calderara, Simone
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Continual Learning (CL) investigates how to train Deep Networks on a stream of tasks without incurring forgetting. CL settings proposed in literature assume that every incoming example is paired with ground-truth annotations. However, this clashes with many real-world applications: gathering labeled data, which is in itself tedious and expensive, becomes infeasible when data flow as a stream. This work explores Continual Semi-Supervised Learning (CSSL): here, only a small fraction of labeled input examples are shown to the learner. We assess how current CL methods (e.g.: EWC, LwF, iCaRL, ER, GDumb, DER) perform in this novel and challenging scenario, where overfitting entangles forgetting. Subsequently, we design a novel CSSL method that exploits metric learning and consistency regularization to leverage unlabeled examples while learning. We show that our proposal exhibits higher resilience to diminishing supervision and, even more surprisingly, relying only on 25% supervision suffices to outperform SOTA methods trained under full supervision.
description: 7 pages, 2 figures, to appear in Pattern Recognition Letters, Volume 162, October 2022, Pages 9-14
Sparse Kalman Filtering Approaches to Covariance Estimation from High Frequency Data in the Presence of Jumps
Creators: name: Ho, Michael
name: Xin, Jack
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Finance (q-fin.ST)
subject: Methodology (stat.ME)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences
subject: 91B28, 65K10, 62F35, 62F40

description: Estimation of the covariance matrix of asset returns from high frequency data is complicated by asynchronous returns, market mi- crostructure noise and jumps. One technique for addressing both asynchronous returns and market microstructure is the Kalman-EM (KEM) algorithm. However the KEM approach assumes log-normal prices and does not address jumps in the return process which can corrupt estimation of the covariance matrix. In this paper we extend the KEM algorithm to price models that include jumps. We propose two sparse Kalman filtering approaches to this problem. In the first approach we develop a Kalman Expectation Conditional Maximization (KECM) algorithm to determine the un- known covariance as well as detecting the jumps. For this algorithm we consider Laplace and the spike and slab jump models, both of which promote sparse estimates of the jumps. In the second method we take a Bayesian approach and use Gibbs sampling to sample from the posterior distribution of the covariance matrix under the spike and slab jump model. Numerical results using simulated data show that each of these approaches provide for improved covariance estima- tion relative to the KEM method in a variety of settings where jumps occur.
A Reinforcement Learning Approach for GNSS Spoofing Attack Detection of Autonomous Vehicles
Creators: name: Dasgupta, Sagar
name: Ghosh, Tonmoy
name: Rahman, Mizanur
Publisher: name: arXiv
Year: 2021
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: A resilient and robust positioning, navigation, and timing (PNT) system is a necessity for the navigation of autonomous vehicles (AVs). Global Navigation Satelite System (GNSS) provides satellite-based PNT services. However, a spoofer can temper an authentic GNSS signal and could transmit wrong position information to an AV. Therefore, a GNSS must have the capability of real-time detection and feedback-correction of spoofing attacks related to PNT receivers, whereby it will help the end-user (autonomous vehicle in this case) to navigate safely if it falls into any compromises. This paper aims to develop a deep reinforcement learning (RL)-based turn-by-turn spoofing attack detection using low-cost in-vehicle sensor data. We have utilized Honda Driving Dataset to create attack and non-attack datasets, develop a deep RL model, and evaluate the performance of the RL-based attack detection model. We find that the accuracy of the RL model ranges from 99.99% to 100%, and the recall value is 100%. However, the precision ranges from 93.44% to 100%, and the f1 score ranges from 96.61% to 100%. Overall, the analyses reveal that the RL model is effective in turn-by-turn spoofing attack detection.
ROBERT RAMAGE - Bibliography from ROBERT RAMAGE. 4 October 1935 — 16 October 2019
Creators: name: Muir, Tom W.
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Organic Chemistry
subject: FOS: Chemical sciences

description: Robert (Bob) Ramage was an innovative and versatile organic chemist who made pioneering contributions to the fields of target-oriented synthesis and synthetic methodology. His research programme was initially focused on the (bio)synthesis of natural products, but later expanded to include peptides and proteins, where he became a key figure in the development of that field in the UK and beyond. As a PhD student in Glasgow, he developed a synthesis of the sesquiterpene cuparene, an achievement that earned him a Fulbright scholarship to Harvard, where he worked under the guidance of R. B. Woodward ForMemRS. With Woodward he participated in the now classic synthesis of the beta-lactam antibiotic cephalosporin C. His independent career began in Liverpool, where he continued his interests in sesquiterpene synthesis, devising several notable syntheses. This period also saw him forge important collaborations with Alan Battersby (FRS 1966) and George Kenner FRS, with whom he worked on the biosynthesis of the alkaloid colchicine and the chemical synthesis of several polypeptides, respectively. In Manchester, and later in Edinburgh, he continued his work in peptide synthesis methodology, a multi-pronged effort that culminated in the successful chemical synthesis of crystalline ubiquitin, widely considered a landmark achievement in the field. His scientific impact reached beyond academia through various consultancies with the pharmaceutical industry and the founding of a successful biotech company. He also assumed various academic leadership roles throughout his career. Bob will be remembered for his exacting standards and resolve to tackle big problems, attributes that he instilled in the many young scientists he mentored. He is dearly missed by all who knew him, by his colleagues around the world and most of all by his family.
Determining the large-scale environmental dependence of gas-phase metallicity in dwarf galaxies
Creators: name: Douglass, Kelly A.
name: Vogeley, Michael S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study how the cosmic environment affects galaxy evolution in the Universe by comparing the metallicities of dwarf galaxies in voids with dwarf galaxies in more dense regions. Ratios of the fluxes of emission lines, particularly those of the forbidden [O III] and [S II] transitions, provide estimates of a region's electron temperature and number density. From these two quantities and the emission line fluxes [O II] 3727, [O III] 4363, and [O III] 4959,5007, we estimate the abundance of oxygen with the Direct Te method. We estimate the metallicity of 42 blue, star-forming void dwarf galaxies and 89 blue, star-forming dwarf galaxies in more dense regions using spectroscopic observations from the Sloan Digital Sky Survey Data Release 7, as re-processed in the MPA-JHU value-added catalog. We find very little difference between the two sets of galaxies, indicating little influence from the large-scale environment on their chemical evolution. Of particular interest are a number of extremely metal-poor dwarf galaxies that are less prevalent in voids than in the denser regions.
description: 15 pages, 11 figures, published in ApJ; updated declination units
A Sensor Fusion-based GNSS Spoofing Attack Detection Framework for Autonomous Vehicles
Creators: name: Dasgupta, Sagar
name: Rahman, Mizanur
name: Islam, Mhafuzul
name: Chowdhury, Mashrur
Publisher: name: arXiv
Year: 2021
Subjects: subject: Signal Processing (eess.SP)
subject: Cryptography and Security (cs.CR)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: This paper presents a sensor fusion based Global Navigation Satellite System (GNSS) spoofing attack detection framework for autonomous vehicles (AV) that consists of two concurrent strategies: (i) detection of vehicle state using predicted location shift -- i.e., distance traveled between two consecutive timestamps -- and monitoring of vehicle motion state -- i.e., standstill/ in motion; and (ii) detection and classification of turns (i.e., left or right). Data from multiple low-cost in-vehicle sensors (i.e., accelerometer, steering angle sensor, speed sensor, and GNSS) are fused and fed into a recurrent neural network model, which is a long short-term memory (LSTM) network for predicting the location shift, i.e., the distance that an AV travels between two consecutive timestamps. This location shift is then compared with the GNSS-based location shift to detect an attack. We have then combined k-Nearest Neighbors (k-NN) and Dynamic Time Warping (DTW) algorithms to detect and classify left and right turns using data from the steering angle sensor. To prove the efficacy of the sensor fusion-based attack detection framework, attack datasets are created for four unique and sophisticated spoofing attacks-turn-by-turn, overshoot, wrong turn, and stop, using the publicly available real-world Honda Research Institute Driving Dataset (HDD). Our analysis reveals that the sensor fusion-based detection framework successfully detects all four types of spoofing attacks within the required computational latency threshold.
description: arXiv admin note: substantial text overlap with arXiv:2106.02982
The role of ionic sizes in inducing the cubic to tetragonal distortion in AV$_{2}$O$_{4}$ and ACr$_{2}$O$_{4}$ (A=Zn, Mg and Cd) compounds
Creators: name: Lal, Sohan
name: Pandey, Sudhir K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Cubic to tetragonal distortion in spinel compounds have been a contentious issue for last two decades. Different groups have proposed different mechanisms to understand such a distortion in these spinels, which are: (i) spin lattice coupling mechanism known as the spin driven Jahn-Teller (JT) effect, (ii) the strong relativistic spin-orbit coupling, a moderate JT distortion and weak V-V interactions and (iii) the JT effect. Now, in order to know the possible cause for such a distortion, we have avoided these complexities (various interactions among spin, electronic, orbital and lattice degrees of freedom) by carrying out spin unpolarized calculations. The calculated values of bulk moduli for ZnV$_{2}$O$_{4}$ (ZnCr$_{2}$O$_{4}$), MgV$_{2}$O$_{4}$ (MgCr$_{2}$O$_{4}$) and CdV$_{2}$O$_{4}$ (CdCr$_{2}$O$_{4}$) are found to be $\sim$289 ($\sim$254), $\sim$244 ($\sim$243) and $\sim$230 ($\sim$233) GPa, respectively. For vanadates and chromates, the order of calculated values of lattice parameter $a$ are found to CdV$_{2}$O$_{4}$$>$MgV$_{2}$O$_{4}$$>$ZnV$_{2}$O$_{4}$ and CdCr$_{2}$O$_{4}$$>$MgCr$_{2}$O$_{4}$$>$ZnCr$_{2}$O$_{4}$, respectively and are consistent with the experimental results. The calculated values of cubic to tetragonal distortion (c/a), with c/a$
description: 17 pages, 4 figures, 2 tables
Shape Entropy of a Reconfigurable Ising Surface
Creators: name: Katz, Benjamin N
name: Krainov, Lev
name: Crespi, Vincent H
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Disclinations in a 2D sheet create regions of Gaussian curvature whose inversion produces a reconfigurable surface with many distinct metastable shapes, as shown by molecular dynamics of a disclinated graphene monolayer. This material has a near-Gaussian "density of shapes" and an effectively antiferromagnetic interaction between adjacent cones. A $\sim10$ nm patch has hundreds of distinct metastable shapes with tunable stability and topography on the size scale of biomolecules. As every conical disclination provides an Ising-like degree of freedom, we call this technique "Isigami".
description: 6 Pages, 6 figures: Published in PRL August 26 2022. Supplementary is 15 pages, 12 figures. Ancillary files include simulation code and particle position files used by the code. Videos referenced in the paper are included with supplementary material published with PRL: they can also be reproduced by running included simulation code