cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sample-Efficient Learning for a Surrogate Model of Three-Phase Distribution System
Creators: name: Nguyen, Hoang Tien
name: Kim, Young-Jin
name: Choi, Dae-Hyun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: A surrogate model that accurately predicts distribution system voltages is crucial for reliable smart grid planning and operation. This letter proposes a fixed-point data-driven surrogate modeling method that employs a limited dataset to learn the power-voltage relationship of an unbalanced three-phase distribution system. The proposed surrogate model is designed using a fixed-point load-flow equation, and the stochastic gradient descent method with an automatic differentiation technique is employed to update the parameters of the surrogate model using complex power and voltage samples. Numerical examples in IEEE 13-bus, 37-bus, and 123-bus systems demonstrate that the proposed surrogate model can outperform surrogate models based on the deep neural network and Gaussian process regarding prediction accuracy and sample efficiency
Gravitational Perturbations of Higher Dimensional Rotating Black Holes: Tensor Perturbations
Creators: name: Kunduri, Hari K.
name: Lucietti, James
name: Reall, Harvey S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Assessing the stability of higher-dimensional rotating black holes requires a study of linearized gravitational perturbations around such backgrounds. We study perturbations of Myers-Perry black holes with equal angular momenta in an odd number of dimensions (greater than five), allowing for a cosmological constant. We find a class of perturbations for which the equations of motion reduce to a single radial equation. In the asymptotically flat case we find no evidence of any instability. In the asymptotically anti-de Sitter case, we demonstrate the existence of a superradiant instability that sets in precisely when the angular velocity of the black hole exceeds the speed of light from the point of view of the conformal boundary. We suggest that the endpoint of the instability may be a stationary, nonaxisymmetric black hole.
description: latex, 29 pages, 5 figures. v2 reference added. v3 title changed, note added on classification of perturbations (this paper deals with the most general tensor perturbations)
Isolated vs. Common Envelope Dynamos in Planetary Nebula Progenitors
Creators: name: Nordhaus, J.
name: Blackman, E. G.
name: Frank, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The origin, evolution and role of magnetic fields in the production and shaping of proto-planetary and planetary nebulae (PPNe, PNe) is a subject of active research. Most PNe and PPNe are axisymmetric with many exhibiting highly collimated outflows, however, it is important to understand whether such structures can be generated by isolated stars or require the presence of a binary companion. Toward this end we study a dynamical, large-scale alpha-Omega interface dynamo operating in a 3.0 M_sun Asymptotic Giant Branch star (AGB) in both an isolated setting and one in which a low-mass companion is embedded inside the envelope. The back reaction of the fields on the shear is included and differential rotation and rotation deplete via turbulent dissipation and Poynting flux. For the isolated star, the shear must be resupplied in order to sufficiently sustain the dynamo. Furthermore, we investigate the energy requirements that convection must satisfy to accomplish this by analogy to the sun. For the common envelope case, a robust dynamo results, unbinding the envelope under a broad range of conditions. Two qualitatively different types of explosion may arise: (i) magnetically dominated, possibly resulting in collimated bipolar outflows and (ii) thermally induced from turbulent dissipation, possibly resulting in quasi-spherical outflows. A range of models is presented for a variety of companion masses.
description: 25 pages, 7 figures, submitted to MNRAS; revised to fix Fig. 5
Analysis of growth and mortality from daily growth increments in the otoliths of dagaa (Rastrineobola argentea) in Nyanza Gulf, Lake Victoria, Kenya
Creators: name: Njiru, Murithi
Publisher: name: University of British Columbia
Year: 2009

description: Prior to 1960, Rastrineobola argentea was of little economic importance in terms of catches in Lake Victoria. Catches have increased in the last 15-20 years and it is now become the second most important commercially targeted fish species. Growth and mortality parameters of R. argentea, a tropical cyprinid, were estimated using growth increments in otoliths and length-frequency analysis to gather more biological data on the species. The Gompertz growth curve yielded the best fit for the juvenile population. Growth and population parameters for the commercial catch show a growth rate coefficient (K) of 1.8 yr⁻¹ with L∞ of 5.0 cm standard length (SL) in Nyanza Gulf and K of 1.5 yr⁻¹ with L∞ of 6.5 cm SL in the open waters site. Instantaneous growth rates decreased with age, with fish from open waters showing a more gradual decline. The weight (g)-length (mm) relationship is W = 5.562L³⁻³. Fish immersed in 600 mg/L of tetracycline hydrochloride showed its incorporation within 12 hours and increments were likely formed daily. Juvenile fish mortality ranged from 11.3 to 29.9 yr⁻¹. Total mortality (Z) for adults estimated from length-converted catch curves was 4.0 and 4.8 yr"1 for Nyanza Gulf and the open waters respectively. Fishing mortality (F) estimated from catch and biomass was 0.98 yr⁻¹ for Nyanza Gulf, while that of open waters from length-converted catch curve was 1.4 yr⁻¹. The exploitation rate is 0.25 and 0.29 for Nyanza Gulf and open waters respectively. Two annual breeding peaks were observed in both Nyanza Gulf (May/ October) and open waters (May/November). Length and age at recruitment for L50% for Nyanza Gulf was 11.6 mm and 34.5 mm in open waters, corresponding to age of 44 and 175 days respectively. In comparison with published data on the growth and mortality of some small pelagics of African waters, R. argentea had low values of L∞, K, M and Z.
Differentiable Earth Mover's Distance for Data Compression at the High-Luminosity LHC
Creators: name: Shenoy, Rohan
name: Duarte, Javier
name: Herwig, Christian
name: Hirschauer, James
name: Noonan, Daniel
name: Pierini, Maurizio
name: Tran, Nhan
name: Suarez, Cristina Mantilla
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Machine Learning (cs.LG)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The Earth mover's distance (EMD) is a useful metric for image recognition and classification, but its usual implementations are not differentiable or too slow to be used as a loss function for training other algorithms via gradient descent. In this paper, we train a convolutional neural network (CNN) to learn a differentiable, fast approximation of the EMD and demonstrate that it can be used as a substitute for computing-intensive EMD implementations. We apply this differentiable approximation in the training of an autoencoder-inspired neural network (encoder NN) for data compression at the high-luminosity LHC at CERN. The goal of this encoder NN is to compress the data while preserving the information related to the distribution of energy deposits in particle detectors. We demonstrate that the performance of our encoder NN trained using the differentiable EMD CNN surpasses that of training with loss functions based on mean squared error.
description: 16 pages, 7 figures
The Design Principles of the Elixir Type System
Creators: name: Castagna, Giuseppe
name: Duboc, Guillaume
name: Valim, José
Publisher: name: arXiv
Year: 2023
Subjects: subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: Elixir is a dynamically-typed functional language running on the Erlang Virtual Machine, designed for building scalable and maintainable applications. Its characteristics have earned it a surging adoption by hundreds of industrial actors and tens of thousands of developers. Static typing seems nowadays to be the most important request coming from the Elixir community. We present a gradual type system we plan to include in the Elixir compiler, outline its characteristics and design principles, and show by some short examples how to use it in practice.
Developing a static type system suitable for Erlang's family of languages has been an open research problem for almost two decades. Our system transposes to this family of languages a polymorphic type system with set-theoretic types and semantic subtyping. To do that, we had to improve and extend both semantic subtyping and the typing techniques thereof, to account for several characteristics of these languages -- and of Elixir in particular -- such as the arity of functions, the use of guards, a uniform treatment of records and dictionaries, the need for a new sound gradual typing discipline that does not rely on the insertion at compile time of specific run-time type-tests but, rather, takes into account both the type tests performed by the virtual machine and those explicitly added by the programmer.
The system presented here is "gradually" being implemented and integrated in Elixir, but a prototype implementation is already available.
The aim of this work is to serve as a longstanding reference that will be used to introduce types to Elixir programmers, as well as to hint at some future directions and possible evolutions of the Elixir language.
Εκπαιδευτικοί και περιβαλλοντική εκπαίδευση
Creators: name: Παπαδημητρίου, Βάσω
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 1995

description: This paper deals with an attempt to investigate factors that motivate in the active participation of some secondary teachers in environmental education. Through a questionnaire and some interviews, their concept of environmental education, as well as their perception about the relation of EE and schooling has been assessed. Also through the same questionnaire they were asked to say what kind of factors had motivated them to become involved in EE. From the analysis of the data it is evident that they do have a good grasp of the concept of EE, and also that they do have a positive attitude to the field. It was also found that the main factor that motivates them to get involved in EE, despite the difficulties they face, is the educationally innovative character of EE and their dissatisfaction with the educational system.
description: Παιδαγωγική Επιθεώρηση, Vol. 22 (1995)
Variation of atmospheric depth profile on different time scales
Creators: name: Wilczynska, B.
name: Gora, D.
name: Homola, P.
name: Pekala, J.
name: Risse, M.
name: Wilczynski, H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The vertical profile of atmospheric depth is an important element in extensive air shower studies. The depth of shower maximum is one of the most important characteristics of the shower. In the fluorescence technique of shower detection, the geometrical reconstruction provides the altitude of shower maximum, so that an accurate profile of atmospheric depth is needed to convert this altitude to the depth of shower maximum. In this paper the temporal variation of experimentally measured profiles of atmospheric depth at different sites is studied and implications for shower reconstruction are shown. The atmospheric profiles vary on time scales from hours to years. It is shown that the daily variation of the profile is as important as its seasonal variation and should be accounted for in air shower studies. For precise shower reconstruction, the daily profiles determined locally at the site of the air shower detector are recommended.
description: 23 pages, including 15 figures and 2 tables
URAT: astrometric requirements and design history
Creators: name: Zacharias, N.
name: Laux, U.
name: Rakich, A.
name: Epps, H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The U.S. Naval Observatory Robotic Astrometric Telescope (URAT) project aims at a highly accurate (5 mas), ground-based, all-sky survey. Requirements are presented for the optics and telescope for this 0.85 m aperture, 4.5 degree diameter field-of-view, specialized instrument, which are close to the capability of the industry. The history of the design process is presented as well as astrometric performance evaluations of the toleranced, optical design, with expected wavefront errors included.
description: 12 pages, 7 figures, SPIE 2006 Orlando conf. proc. Vol. 6267
New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
Creators: name: Riess, Adam G.
name: Strolger, Louis-Gregory
name: Casertano, Stefano
name: Ferguson, Henry C.
name: Mobasher, Bahram
name: Gold, Ben
name: Challis, Peter J.
name: Filippenko, Alexei V.
name: Jha, Saurabh
name: Li, Weidong
name: Tonry, John
name: Foley, Ryan
name: Kirshner, Robert P.
name: Dickinson, Mark
name: MacDonald, Emily
name: Eisenstein, Daniel
name: Livio, Mario
name: Younger, Josh
name: Xu, Chun
name: Dahlen, Tomas
name: Stern, Daniel
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have discovered 21 new Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to trace the history of cosmic expansion over the last 10 billion years. These objects, which include 13 spectroscopically confirmed SNe Ia at z > 1, were discovered during 14 epochs of reimaging of the GOODS fields North and South over two years with the Advanced Camera for Surveys on HST. Together with a recalibration of our previous HST-discovered SNe Ia, the full sample of 23 SNe Ia at z > 1 provides the highest-redshift sample known. Combined with previous SN Ia datasets, we measured H(z) at discrete, uncorrelated epochs, reducing the uncertainty of H(z>1) from 50% to under 20%, strengthening the evidence for a cosmic jerk--the transition from deceleration in the past to acceleration in the present. The unique leverage of the HST high-redshift SNe Ia provides the first meaningful constraint on the dark energy equation-of-state parameter at z >1. The result remains consistent with a cosmological constant (w(z)=-1), and rules out rapidly evolving dark energy (dw/dz >>1). The defining property of dark energy, its negative pressure, appears to be present at z>1, in the epoch preceding acceleration, with ~98% confidence in our primary fit. Moreover, the z>1 sample-averaged spectral energy distribution is consistent with that of the typical SN Ia over the last 10 Gyr, indicating that any spectral evolution of the properties of SNe Ia with redshift is still below our detection threshold.
description: typos, references corrected, minor additions to exposition 82 pages, 17 figures, 6 tables. Data also available at: http://braeburn.pha.jhu.edu/~ariess/R06. Accepted, Astrophysical Journal vol. 656 for March 10, 2007
Resource-efficient fault-tolerant one-way quantum repeater with code concatenation
Creators: name: Wo, Kah Jen
name: Avis, Guus
name: Rozpędek, Filip
name: Mor-Ruiz, Maria Flors
name: Pieplow, Gregor
name: Schröder, Tim
name: Jiang, Liang
name: Sørensen, Anders Søndberg
name: Borregaard, Johannes
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One-way quantum repeaters where loss and operational errors are counteracted by quantum error correcting codes can ensure fast and reliable qubit transmission in quantum networks. It is crucial that the resource requirements of such repeaters, for example, the number of qubits per repeater node and the complexity of the quantum error correcting operations are kept to a minimum to allow for near-future implementations. To this end, we propose a one-way quantum repeater that targets both the loss and operational error rates in a communication channel in a resource-efficient manner using code concatenation. Specifically, we consider a tree-cluster code as an inner loss-tolerant code concatenated with an outer 5-qubit code for protection against Pauli errors. Adopting flag-based stabilizer measurements, we show that intercontinental distances of up to 10,000 km can be bridged with a minimal resource overhead by interspersing repeater nodes that each specializes in suppressing either loss or operational errors. Our work demonstrates how tailored error-correcting codes can significantly lower the experimental requirements for long-distance quantum communication.
description: 25 pages, 16 figures, 4 tables
XMM-Newton and Chandra Spectroscopy of the Variable High-Energy Absorption of PG 1115+080: Refined Outflow Constraints
Creators: name: Chartas, G.
name: Brandt, W. N.
name: Gallagher, S. C.
name: Proga, D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the mini broad absorption line (BAL) quasar PG 1115+080. This is one of the few X-ray detected mini-BAL quasars to date that is bright enough in the X-ray band, mostly due to large gravitational-lensing magnifications, to allow in-depth spectral analysis. The present XMM-Newton observations of PG 1115+080 have provided the highest signal-to-noise X-ray spectra of a mini-BAL quasar obtained to date. By modeling the spectra of PG 1115+080 we have obtained constraints on the column density and ionization state of its outflowing absorbing gas. A comparison between these constraints over several epochs indicates significant variability in the properties of the outflowing absorbers in PG 1115+080. The depths of the high-energy broad absorption features in PG 1115+080 show a significant decrease between the first two observation epochs separated by a rest-frame timescale of ~ 1 year. This variability supports the intrinsic nature of these absorbers. Assuming the interpretation that the high-energy absorption features arise from highly ionized Fe XXV we constrain the fraction of the total bolometric energy released by quasars PG 1115+080 and APM 08279+5225 into the IGM in the form of kinetic energy to be epsilon_k = 0.64(-0.40,+0.52) (68% confidence), and epsilon_k =0.09(-0.05,+0.07), respectively. According to recent theoretical studies this range of efficiencies is large enough to influence significantly the formation of the host galaxy and to regulate the growth of the central black hole.
description: 20 pages, includes 5 figures, Accepted for publication in AJ
Διερεύνηση του πόνου σε ασθενείς με αυχεναλγία μέσω αγωγιμότητας δέρματος και αισθητόμετρουυ
Creators: name: Αναγνωστοπούλου, Αλεξάνδρα Νικολάου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Αυχεναλγία
Αγωγιμότητα Δέρματος
Αισθητόμετρο
Neck Pain
Skin Conductivity
Algometer

description: Στην παρούσα εργασία πραγματοποιήθηκαν μετρήσεις σε ασθενείς με αυχεναλγία με την μέθοδο εφαρμογής πίεσης σε έξι σημεία «αναφοράς» στον αυχένα. Σκοπός της ήταν ο προσδιορισμός της ουδού του πόνου καθώς και η καταγραφή σωματομετρικών παραμέτρων. Οι μετρήσεις έγιναν με τη χρήση σταθμισμένου ερωτηματολογίου καθώς και με τη χρήση ειδικού εξοπλισμού βιοϊατρικής τεχνολογίας. Ελέγχθηκε κατά πόσο το κατώφλι του πόνου επηρεάζεται απο παράγοντες όπως : φύλο, ηλικία, είδος εργασίας, κάπνισμα, άσκηση, συνοδά προβλήματα υγείας, παρουσία άλγους κατά την διαδικασία των μετρήσεων, βάρος, ύψος, υγρασία δέρματος και παλμοί ανά λεπτό. Από την επεξεργασία των αποτελεσμάτων προκύπτει ότι όλοι οι μελετηθέντες παράμετροι φαίνεται να επηρεάζουν και να διαμορφώνουν το κατώφλι του πόνου πλήν του ύψους, της υγρασίας δέρματος και των παλμών.
description: In this work, were conducted measurements in patients with neck pain through pressure methods, in six trigger neck points. The purpose was to measure the threshold of pain and also some other physiological parameters. The measurements were made using a suitable questionnaire and using special medical technology equipment. Is being examined whether the threshold of pain is influenced by the factors: gender, age group, type of work, smoking, exercise, other health problems, pain existence at the time of measurement, weight, height, skin moisture and beats per minute. The results show all factors to influence and shape the threshold of pain, apart from the amount of skin moisture and pulses.
Deep HST Photometry of NGC 6388: Age and Horizontal Branch Luminosity
Creators: name: Catelan, M.
name: Stetson, P. B.
name: Pritzl, B. J.
name: Smith, H. A.
name: Kinemuchi, K.
name: Layden, A. C.
name: Sweigart, A. V.
name: Rich, R. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using the Hubble Space Telescope, we have obtained the first color-magnitude diagram (CMD) to reach the main-sequence turnoff of the Galactic globular cluster NGC 6388. From a comparison between the cluster CMD and 47 Tucanae's, we find that the bulk of the stars in these two clusters have nearly the same age and chemical composition. On the other hand, our results indicate that the blue horizontal branch and RR Lyrae components in NGC 6388 are intrinsically overluminous, which must be due to one or more, still undetermined, non-canonical second parameter(s) affecting a relatively minor fraction of the stars in NGC 6388.
description: 4 pages, 3 colored figures. LOW-RESOLUTION VERSION. The interested reader is strongly encouraged to download the full-resolution preprint from http://www.astro.puc.cl/~mcatelan/N6388-HST.pdf
Existence results for cyclotomic orthomorphisms
Creators: name: Fear, David
name: Wanless, Ian M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 11T06

description: An {\em orthomorphism} over a finite field $\mathbb{F}$ is a permutation $θ:\mathbb{F}\mapsto\mathbb{F}$ such that the map $x\mapstoθ(x)-x$ is also a permutation of $\mathbb{F}$. The orthomorphism $θ$ is {\em cyclotomic of index $k$} if $θ(0)=0$ and $θ(x)/x$ is constant on the cosets of a subgroup of index $k$ in the multiplicative group $\mathbb{F}^*$. We say that $θ$ has {\em least index} $k$ if it is cyclotomic of index $k$ and not of any smaller index. We answer an open problem due to Evans by establishing for which pairs $(q,k)$ there exists an orthomorphism over $\mathbb{F}_q$ that is cyclotomic of least index $k$. Two orthomorphisms over $\mathbb{F}_q$ are orthogonal if their difference is a permutation of $\mathbb{F}_q$. For any list $[b_1,\dots,b_n]$ of indices we show that if $q$ is large enough then $\mathbb{F}_q$ has pairwise orthogonal orthomorphisms of least indices $b_1,\dots,b_n$. This provides a partial answer to another open problem due to Evans. For some pairs of small indices we establish exactly which fields have orthogonal orthomorphisms of those indices. We also find the number of linear orthomorphisms that are orthogonal to certain cyclotomic orthomorphisms of higher index.
Η κατανόηση εννοιών και φράσεων χρόνου από παιδιά ηλικίας 8-11 ετών
Creators: name: Μπονίδης, Κυριάκος Θ.
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 1995

description: Die vorliegende Untersuchung beabsichtigte die Wahrnehmung der Zeitbegriffen "Jahrzehnt", "Jahrhundert", "Erste und Zweite halb Jahrhunderts", "v.Chr." und "n.Chr.", bei 8-11 jährigen Kinder zu erforschen. 120 Volkschulkinder, die sich hinsichtlich des Alters, der sozialer Herkunft und des Geschlecht unterschieden, wurden ausgewählt und im einzeln-durch einen strukturierten Fragebogenbefragt. Die ausgestellte Hypothesen wurden unterstützt. Folgende Ergebnisse sind herausgekommen:1. Die Korrelationen zwischen dem Alter und der Leistungen im Fragebogen sind relativ hoch. 8jährige Kinder erreichen nidrigen Leistungen als 9-10jährige Kinder. 2. 8-11hähriger Kinder wahrnehmen die Begriffe "Jahrzehnt" und "Jahrhundert" genauer als die Begriffe "Erste und Zweite Jahr-hunders" "v.Chr." und "n.Chr.". 3. 8-11hähriger Kinder können die Begriffe definieren, in denen sie gefragt wurden, ohne manchemal diesen Begriffe zu wahrnehmen. 4. Die Korrelationen zwischen der Herkunft und den Leistungen im Fragebogen sind relativ hoch. 5. Nennenwerte geschlechtspezifische Differenzen sind nicht festzustellen.
description: Παιδαγωγική Επιθεώρηση, Vol. 22 (1995)
Διαχείριση και επεξεργασία αστικών λυμάτων μικρών οικισμών με φυσικά συστήματα επεξεργασίας. Δυνατότητα εφαρμογής τεχνητών υγροβιοτόπων στο Νομό Ημαθίας
Creators: name: Λαπαβίτσας, Αργύριος Φίλιππου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Φυσικά συστήματα επεξεργασίας
Τεχνητοί Υγροβιότοποι
Διαχείριση και επεξεργασία λυμάτων
Natural treatment systems
Artficial Wetlands
Management and treatment of urban wastewater

description: Σκοπός της παρούσας μεταπτυχιακής διατριβής είναι, αρχικά, η παρουσίαση των φυσικών συστημάτων επεξεργασίας και ιδιαίτερα, των τεχνητών υγροβιότοπων, ως εναλλακτική εφικτή λύση για την επεξεργασία των αστικών λυμάτων μικρών πόλεων και κοινοτήτων, με ισοδύναμο πληθυσμό μικρότερο των 2000 ι.κ., αναπτύσσοντας μεθόδους, οι οποίες απαιτούν χαμηλό κόστος κατασκευής, λειτουργίας και συντήρησης και οι οποίες είναι φιλικότερες προς το περιβάλλον. Επιπλέον, διερευνάται η δυνατότητα κατασκευής τεχνητού υγροβιότοπου οριζόντιας υπόγειας ροής για την επεξεργασία των λυμάτων Κοινοτήτων του Νομού Ημαθίας. Για τις επιλεγμένες περιοχές και τους επιλεγμένους εξυπηρετούμενους οικισμούς γίνεται χωροθέτηση και διαστασιολόγηση του τεχνητού υγροβιότοπου. Τέλος, ορίζονται οι φυσικοί αποδέκτες των επεξεργασμένων λυμάτων στις υπό έρευνα περιοχές, ενώ, παράλληλα, ερευνάται η δυνατότητα επαναχρησιμοποίησης των εκροών.
description: The purpose of this master thesis is, firstly, the presentation of natural systems for wastewater treatment and in particular, of artificial wetlands, as an alternative possible solution for urban wastewater treatment of small towns and communities, with an equivalent population of less than 2000, developing methods, which require low manufacturing, operation and maintenance costs and which are more environmentally friendly. Additionally, the possibility of constructing a horizontal subsurface flow artificial wetland, for processing sewage of Communities of the Prefecture of Imathia, is investigated. For the selected regions and the respective populations, the siting and sizing of the constructed wetlands are presented. Finally, the natural recipients of the treated wastewater are defined, while, at the same time, the reusability of the outflows is investigated.
Secure Short-Packet Communications via UAV-Enabled Mobile Relaying: Joint Resource Optimization and 3D Trajectory Design
Creators: name: Mamaghani, Milad Tatar
name: Zhou, Xiangyun
name: Yang, Nan
name: Swindlehurst, A. Lee
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Theory (cs.IT)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Short-packet communication (SPC) and unmanned aerial vehicles (UAVs) are anticipated to play crucial roles in the development of 5G-and-beyond wireless networks and the Internet of Things (IoT). In this paper, we propose a secure SPC system, where a UAV serves as a mobile decode-and-forward (DF) relay, periodically receiving and relaying small data packets from a remote IoT device to its receiver in two hops with strict latency requirements, in the presence of an eavesdropper. This system requires careful optimization of important design parameters, such as the coding blocklengths of both hops, transmit powers, and the UAV's trajectory. While the overall optimization problem is nonconvex, we tackle it by applying a block successive convex approximation (BSCA) approach to divide the original problem into three subproblems and solve them separately. Then, an overall iterative algorithm is proposed to obtain the final design with guaranteed convergence. Our proposed low-complexity algorithm incorporates robust trajectory design and resource management to optimize the effective average secrecy throughput of the communication system over the course of the UAV-relay's mission. Simulation results demonstrate significant performance improvements compared to various benchmark schemes and provide useful design insights on the coding blocklengths and transmit powers along the trajectory of the UAV.
description: 14 double-column pages, 8 figures. To appear in IEEE Transactions on Wireless Communications. This is an extended version of our work presented at the 2023 IEEE GlobeCom arXiv:2310.05142
On the Common Structure of Bohmian Mechanics and the Ghirardi-Rimini-Weber Theory
Creators: name: Allori, Valia
name: Goldstein, Sheldon
name: Tumulka, Roderich
name: Zanghi, Nino
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Bohmian mechanics and the Ghirardi-Rimini-Weber theory provide opposite resolutions of the quantum measurement problem: the former postulates additional variables (the particle positions) besides the wave function, whereas the latter implements spontaneous collapses of the wave function by a nonlinear and stochastic modification of Schrödinger's equation. Still, both theories, when understood appropriately, share the following structure: They are ultimately not about wave functions but about ``matter'' moving in space, represented by either particle trajectories, fields on space-time, or a discrete set of space-time points. The role of the wave function then is to govern the motion of the matter.
description: 35 pages LaTeX, 1 figure; v4 minor additions, v2 major revision
dHybrid: a massively parallel code for hybrid simulations of space plasmas
Creators: name: Gargaté, L.
name: Bingham, R.
name: Fonseca, R. A.
name: Silva, L. O.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A massively parallel simulation code, called \textit{dHybrid}, has been developed to perform global scale studies of space plasma interactions. This code is based on an explicit hybrid model; the numerical stability and parallel scalability of the code are studied. A stabilization method for the explicit algorithm, for regions of near zero density, is proposed. Three-dimensional hybrid simulations of the interaction of the solar wind with unmagnetized artificial objects are presented, with a focus on the expansion of a plasma cloud into the solar wind, which creates a diamagnetic cavity and drives the Interplanetary Magnetic Field out of the expansion region. The dynamics of this system can provide insights into other similar scenarios, such as the interaction of the solar wind with unmagnetized planets.
description: 15 pages, 6 figures, accepted for publication in Computer Physics Communications
Subfield subcodes of projective Reed-Muller codes
Creators: name: Gimenez, Philippe
name: Ruano, Diego
name: San-José, Rodrigo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Theory (cs.IT)
subject: Commutative Algebra (math.AC)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 11T71 (Primary) 94B05, 14G50, 13P25 (Secondary)

description: Explicit bases for the subfield subcodes of projective Reed-Muller codes over the projective plane and their duals are obtained. In particular, we provide a formula for the dimension of these codes. For the general case over the projective space, we generalize the necessary tools to deal with this case as well: we obtain a universal Gröbner basis for the vanishing ideal of the set of standard representatives of the projective space and we show how to reduce any monomial with respect to this Gröbner basis. With respect to the parameters of these codes, by considering subfield subcodes of projective Reed-Muller codes we obtain long linear codes with good parameters over a small finite field.
The blue supergiant Sher 25 and its intriguing hourglass nebula
Creators: name: Hendry, M. A.
name: Smartt, S. J.
name: Skillman, E. D.
name: Evans, C. J.
name: Trundle, C.
name: Lennon, D. J.
name: Crowther, P. A.
name: Hunter, I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The blue supergiant Sher 25 is surrounded by an asymmetric, hourglass-shaped circumstellar nebula. Its structure and dynamics have been studied previously through high-resolution imaging and spectroscopy, and it appears dynamically similar to the ring structure around SN 1987A. Here we present long-slit spectroscopy of the circumstellar nebula around Sher 25, and of the background nebula of the host cluster NGC 3603. We perform a detailed nebular abundance analysis to measure the gas-phase abundances of oxygen, nitrogen, sulphur, neon and argon. The oxygen abundance in the circumstellar nebula (12 + log[O/H] = 8.61 +/- 0.13 dex) is similar to that in the background nebula (8.56 +/- 0.07), suggesting the composition of the host cluster is around solar. However, we confirm that the circumstellar nebula is very rich in nitrogen, with an abundance of 8.91 +/- 0.15, compared to the background value of 7.47 +/- 0.18. A new analysis of the stellar spectrum with the FASTWIND model atmosphere code suggests that the photospheric nitrogen and oxygen abundances in Sher 25 are consistent with the nebular results. While the nitrogen abundances are high, when compared to stellar evolutionary models they do not unambiguously confirm that the star has undergone convective dredge-up during a previous red supergiant phase. We suggest that the more likely scenario is that the nebula was ejected from the star while it was in the blue supergiant phase. The star's initial mass was around 50 M_sun, which is rather too high for it to have had a convective envelope stage as a red supergiant. Rotating stellar models that lead to mixing of core-processed material to the stellar surface during core H-burning can quantitatively match the stellar results with the nebula abundances.
description: Revised after initial referee report, to appear in MNRAS. 24 pages, some figures significantly degraded, high-res copy available at http://star.pst.qub.ac.uk/~sjs/papers/sher25/
A new proof of the expansion of iterated Ito stochastic integrals with respect to the components of a multidimensional Wiener process based on generalized multiple Fourier series and Hermite polynomials
Creators: name: Kuznetsov, Dmitriy F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: The article is devoted to a new proof of the expansion for iterated Ito stochastic integrals with respect to the components of a multidimensional Wiener process. The above expansion is based on Hermite polynomials and generalized multiple Fourier series in arbitrary complete orthonormal systems of functions in a Hilbert space. In 2006, the author obtained a similar expansion, but with a lesser degree of generality. Namely, for the case of continuous or piecewise continuous complete orthonornal systems of functions in a Hilbert space. In this article, the author generalizes the expansion of iterated Ito stochastic integrals obtained by him in 2006 to the case of an arbitrary complete orthonormal systems of functions in a Hilbert space using a new approach based on the Ito formula. The obtained expansion of iterated Ito stochastic integrals is useful for constructing of high-order strong numerical methods for systems of Ito stochastic differential equations with multidimensional non-commutative noise.
description: 58 pages. Some changes. arXiv admin note: substantial text overlap with arXiv:1712.09746, arXiv:1801.03195; text overlap with arXiv:2003.14184
Άσκηση της μη λεκτικής συμπεριφοράς του εκπαιδευτικού με μικροδιδασκαλία
Creators: name: Βρεττός, Γιάννης Ε.
name: Τσουπάκης, Λευτέρης Ε.
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 1995

description: Ziel der vorliegenden Untersuchung ist es zu zeigen, daß das nichtverbale Verhalten der Lehramtsstudierenden durch Microteaching trainierbar ist. Die Versuchsanordnung und die daraus gewonnenen Daten haben tatsachlich gezeigt, daß sich durch dieses Training die Expressivität und die Ausdrucksfähigkeit der Beteiligten betrachtlich erhoht haben. Die gewunschte Verhaltensanderung bleibt sogar lange Zeit nach der Übung erhalten, das Training also nachhaltige Auswirkungen hat, ein Ziel das man bei der Lehrerausbildung als hochsterw-ünscht anstrebt.
description: Παιδαγωγική Επιθεώρηση, Vol. 22 (1995)
Minimally modified gravity with an auxiliary constraint: a Hamiltonian construction
Creators: name: Yao, Zhi-Bang
name: Oliosi, Michele
name: Gao, Xian
name: Mukohyama, Shinji
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Working directly with a general Hamiltonian for the spacetime metric with the $3+1$ decomposition and keeping only the spatial covariance, we investigate the possibility of reducing the number of degrees of freedom by introducing an auxiliary constraint. The auxiliary constraint is considered as part of the definition of the theory. Through a general Hamiltonian analysis, we find the conditions for the Hamiltonian as well as for the auxiliary constraint, under which the theory propagates two tensorial degrees of freedom only. The class of theories satisfying these conditions can be viewed as a new construction for the type-II minimally modified gravity theories, which propagate the same degrees of freedom of but are not equivalent to general relativity in the vacuum. We also illustrate our formalism by a concrete example, and derive the dispersion relation for the gravitational waves, which can be constrained by observations.
description: 11 pages
Scalable Quantum Spin Networks from Unitary Construction
Creators: name: Alsulami, Abdulsalam H.
name: D'Amico, Irene
name: Estarellas, Marta P.
name: Spiller, Timothy P.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Spin network systems can be used to achieve quantum state transfer with high fidelity and to generate entanglement. A new approach to design spin-chain-based spin network systems, for shortrange quantum information processing and phase-sensing, has been proposed recently in [1]. In this paper, we investigate the scalability of such systems, by designing larger spin network systems that can be used for longer-range quantum information tasks, such as connecting together quantum processors. Furthermore, we present more complex spin network designs, which can produce different types of entangled states. Simulations of disorder effects show that even such larger spin network systems are robust against realistic levels of disorder.
description: 19 pages, 25 figures
The first Chern form on moduli of parabolic bundles
Creators: name: Takhtajan, Leon A.
name: Zograf, Peter G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: High Energy Physics - Theory (hep-th)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 14H60, 32G13, 58J52

description: For moduli space of stable parabolic bundles on a compact Riemann surface, we derive an explicit formula for the curvature of its canonical line bundle with respect to Quillen's metric and interpret it as a local index theorem for the family of dbar-operators in associated parabolic endomorphism bundles. The formula consists of two terms: one standard (proportional to the canonical Kaehler form on the moduli space), and one nonstandard, called a cuspidal defect, that is defined by means of special values of the Eisenstein-Maass series. The cuspidal defect is explicitly expressed through curvature forms of certain natural line bundles on the moduli space related to the parabolic structure. We also compare our result with Witten's volume computation.
description: 22 pages. references added. The final version, to appear in Mathematische Annalen
Quantitative study of the response of a single NV defect in diamond to magnetic noise
Creators: name: Rollo, M.
name: Finco, A.
name: Tanos, R.
name: Fabre, F.
name: Devolder, T.
name: Robert-Philip, I.
name: Jacques, V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The nitrogen-vacancy (NV) defect in diamond is an efficient quantum sensor of randomly fluctuating signals via relaxometry measurements. In particular, the longitudinal spin relaxation of the NV defect accelerates in the presence of magnetic noise with a spectral component at its electron spin resonance frequency. We look into this effect quantitatively by applying a calibrated and tunable magnetic noise on a single NV defect. We show that an increase of the longitudinal spin relaxation rate translates into a reduction of the photoluminescence (PL) signal emitted under continuous optical illumination, which can be explained using a simplified three-level model of the NV defect. This PL quenching mechanism offers a simple, all-optical method to detect magnetic noise sources at the nanoscale.
description: 5 pages, 3 figures
Μελέτη εκπαιδευτικών παρεμβάσεων στις διατροφικές συνήθειες Ελλήνων και αλλοδαπών μαθητών σε σχολεία του Νομού Θεσσαλονίκης : μια κριτική αποτίμηση
Creators: name: Ιακωβίδου, Αναστασία Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Διαπολιτισμική Εκπαίδευση
Αγωγή Υγείας
Δευτεροβάθμια Εκπαίδευση
Intercultural Education
Health Education
Secondary Education

description: Όσο ο πολιτισμός και οι γνώσεις του ανθρώπου αναπτύσσονται τόσο περισσότερο ο άνθρωπος κατανοεί τις ανάγκες που προσδιορίζουν την υγεία, την πνευματική και ψυχική του υπόσταση. Η παρούσα εργασία επιδιώκει την καταγραφή και την ανάδειξη του ρόλου της υγιεινής διατροφής και της σημασίας που μπορεί να προσφέρει η κατάλληλη εκπαίδευση και αγωγή των νέων στην πνευματική, ψυχική και σωματική τους ανάπτυξη. Η διερεύνηση των προσπαθειών μέσα από τα Προγράμματα Αγωγής Υγείας σε ευρωπαϊκό και ελληνικό επίπεδο επιτρέπει τη συλλογή συμπερασμάτων για τη θετική και πολύ απαραίτητη σχέση της υγιεινής διατροφής με την εκπαίδευση είτε αυτή προκύπτει μέσα από παρεμβατικές εκπαιδευτικές επιδιώξεις είτε συντελείται άμεσα μέσα από τη διδασκαλία και την εκπαιδευτική παρέμβαση. Οι παραπάνω βασικές διαπιστώσεις παρέμβασης επιβεβαιώνονται περαιτέρω στο παράδειγμα της εφαρμογής Προγραμμάτων Αγωγής Υγείας σε σχολεία του Νομού Θεσσαλονίκης κατά το σχολικό έτος 2012 – 2013.
description: The more the human knowledge and culture develops and evolves, the deeper the understanding of the need for health, as well as for mental and psychological well-being becomes. This dissertation seeks to record and highlight the role of healthy nutrition, and the importance of the appropriate training and education of youngsters in their mental, psychological, and physical development. The exploration of efforts made in this direction, through Health Education Programs at Greek and European level, enables the collection of findings attesting to the positive and much needed for the man relationship between healthy eating habits and education. The existence of such a relationship is caused both through interventionist educational objectives and through teaching and educational interventions. The aforementioned fundamental intervention findings are being further confirmed by the implementation of Health Education Programs in schools within the Prefecture of Thessaloniki during the school year 2012 – 2013.
Corner reflectors: fractal analysis and integrated single-photon sources
Creators: name: Chamorro-Posada, Pedro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this work, the properties of the radiation emitted by a corner reflector with an electric dipole feeder are analyzed in the optical domain where the distance between the dipole and the corner apex can be large in terms of the optical wavelength. A comprehensive study of the fractal properties of the radiated intensity patterns is presented. The use of this setup for the realization of single-photon sources in photonic integrated circuits is also put forward and a detailed study of the emission properties of the device and its optimal configurations is presented.
description: Final published version
Ο Κανόνας Taylor σε περιόδους κρίσεις: Αντιδρά η ΕΚΤ στη χρηματοοικονομική αβεβαιότητα;
Creators: name: Βίδρα, Αριστέα Αιμιλιανού
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Κανόνας Taylor
Χρηματοοικονομική αβεβαιότητα
ΕΚΤ
Taylor Rule
Financial Uncertainty
ECB

description: Η πρόσφατη παγκόσμια οικονομική κρίση έχει κλονίσει την ευρεία συναίνεση που επικράτησε παλαιότερα γύρω από τους στόχους που πρέπει να έχει μια Κεντρική Τράπεζα. Η άποψη πως οι ιθύνοντες της Νομισματικής Πολιτικής όφειλαν να αγνοούν τη χρηματοοικονομική σταθερότητα έχει αρχίζει να κλονίζεται. Η εργασία αυτή εξετάζει σε ποιο βαθμό οι αποφάσεις Νομισματικής Πολιτικής της ΕΚΤ, καθοδηγούνται με γνώμονα τα σήματα της χρηματοοικονομικής σφαίρας. Ο σκοπός αυτός επιτυγχάνεται χρησιμοποιώντας τον κανόνα Taylor επαυξημένο με μεταβλητές που μπορούν να αποδώσουν το χρηματοοικονομικό στοιχείο προκειμένου να περιγραφεί η συμπεριφορά της ΕΚΤ. Ο τρόπος αυτός μας δίνει τη δυνατότητα να συγκριθούν τα επιτόκια που προτείνει ο κανόνας Taylor με αυτά που τελικά παρατηρήθηκαν τόσο για την Ευρωζώνη όσο και για κάποιες μεμονωμένες χώρες της. Οι εκτιμήσεις που έγιναν με τη μέθοδο GMM ,για τα διαστήματα πριν και κατά τη διάρκεια της κρίσης, παρέχουν ενδείξεις για την επίδραση της χρηματοοικονομικής σφαίρας στην άσκηση της Νομισματικής Πολιτικής της ΕΚΤ και για τη μη ορθή λειτουργία της Ευρωζώνης. Ωστόσο, απαιτείται περαιτέρω και πιο σύνθετη έρευνα προκειμένου να παγιοποιηθεί η ισχύς των συμπερασμάτων
description: The recent global financial crisis has unsettled the broad acquiescence that has predominated about the goals of a CB for years. The viewpoint that the monetary policy makers have to ignore financial stability has started to decay. This paper examines to what extent the the ECB's monetary policy decisions are driven by the signals of financial sphere. This goal is achieved by using using the Taylor Rule augmented by variables that can attribute the financial element in order for the behavior of the ECB to be described. This way gives us the opportunity to compare the rates proposed by the Taylor Rule with those that were finally observed not only for the Eurozone in total, but also for some of its member countries individually. The estimations that come from the GMM for the periods before and during the financial crisis provide us with indications concerning the effects of the financial sector over the conduct of the ECB's Monetary Policy as well as the defective operation of the Eurozone. However, more research is needed to be conducted in order for the validity of the results to be consolidated.