cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A framework for qualitative and semi-quantitative analysis in engineering design and evaluation
Creators: name: Gedig, Michael H.
Publisher: name: University of British Columbia
Year: 2009

description: A framework is presented which is used to support engineering decision-making in the presence of incomplete and imprecise information. A number of sound reasoning techniques which utilize this framework are described. These techniques include qualitative reasoning, a branch of study in the field of artificial intelligence, and semi-quantitative reasoning, which draws inferences from partially-specified numeric values. The constraint-satisfaction paradigm plays an important role in the implementation of these reasoning strategies. The notion of the constraint is well-suited to engineering planning and design, where projects are generally formulated in terms of a set of functional specifications. A computer program was developed based on the framework presented here. The program implements several complementary qualitative and semi-quantitative reasoning strategies. The specific techniques used in the program include constraint-satisfaction algorithms for both qualitative and numeric domains, interval arithmetic, and constraint inference methods. It was intended that the computer program developed as a part of this research serve as a practical tool which could provide logical justification for engineering decisions. For this reason, the program was developed on a platform which is both accessible and familiar. As part of the program, a convenient method of systematically specifying constraints was created, which mirrors the way in which engineering problems are normally specified. Examples are given which illustrate the application of the techniques presented here. These examples show that the techniques discussed in this thesis have significant potential for justifying engineering decisions made under conditions of uncertainty.
Modeling coupled spin and lattice dynamics
Creators: name: Strungaru, Mara
name: Ellis, Matthew O A
name: Ruta, Sergiu
name: Chubykalo-Fesenko, Oksana
name: Evans, Richard F L
name: Chantrell, Roy W
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A unified model of molecular and atomistic spin dynamics is presented enabling simulations both in microcanonical and canonical ensembles without the necessity of additional phenomenological spin damping. Transfer of energy and angular momentum between the lattice and the spin systems is achieved by a coupling term based upon the spin-orbit interaction. The characteristic spectra of the spin and phonon systems are analyzed for different coupling strength and temperatures. The spin spectral density shows magnon modes together with the uncorrelated noise induced by the coupling to the lattice. The effective damping parameter is investigated showing an increase with both coupling strength and temperature. The model paves the way to understanding magnetic relaxation processes beyond the phenomenological approach of the Gilbert damping and the dynamics of the energy transfer between lattice and spins.
description: 12 pages, 9 figures
Η σχέση τοπικού και παγκοσμίου στη συγκριτική έρευνα στο χώρο της Συνεχιζόμενης Εκπαίδευσης
Creators: name: Ζαρίφης, Γεώργιος
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: In this paper I look at the whys and the how’s or legitimizing comparative research in Continuing Education that focuses on the study of the local and the specific, as part of a micro-social research paradigm that emphasizes the importance of contextualized experience. My basic argument is that the study of the local -although bouncing and non-general sable- can east new light on the interpretation of the global. In continuing education, an area in which personal experience – as a locality- is valued greatly, the study of the local can help us understand the global and relate it to our own experience. I support my argument by suggesting that legitimating of comparison between different personal experiences (localities) is possible through Leotard’s assumption of production of ideas as part of his more general approach to 'language games' rather than generalizations. To emphasize the practical side of my argument 1 present a research model for case-oriented comparison that I used to study different learning experiences based on personal biographies.
description: Παιδαγωγική Επιθεώρηση, Vol. 37 (2004)
$k$-Inflation-corrected Einstein-Gauss-Bonnet Gravity with Massless Primordial Gravitons
Creators: name: Odintsov, S. D.
name: Oikonomou, V. K.
name: Fronimos, F. P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the present paper, we study the inflationary phenomenology of a $k$-inflation corrected Einstein-Gauss-Bonnet theory. Non-canonical kinetic terms are known for producing Jean instabilities or superluminal sound wave velocities in the aforementioned era, but we demonstrate in this work that by adding Gauss-Bonnet string corrections and assuming that the non-canonical kinetic term $ωX^γ$ is in quadratic, one can obtain a ghost free description. Demanding compatibility with the recent GW170817 event forces one to accept that the relation $\ddotξ=H\dotξ$ for the scalar coupling function $ξ(ϕ)$. As a result, the scalar functions of the theory are revealed to be interconnected and by assuming a specific form for one of them, specifies immediately the other. Here, we shall assume that the scalar potential is directly derivable from the equations of motion, once the Gauss-Bonnet coupling is appropriately chosen, but obviously the opposite is feasible as well. As a result, each term entering the equations of motion, can be written in terms of the scalar field and a relatively tractable phenomenology is produced. For quadratic kinetic terms, the resulting scalar potential is quite elegant functionally. Different exponents, which lead to either a more perplexed solution for the scalar potential, are still a possibility which was not further studied. We also discuss in brief the non-Gaussianities issue under the slow-roll and constant-roll conditions holding true, and we demonstrate that the predicted amount of non-Gaussianities is significantly enhanced in comparison to the $k$-inflation free Einstein-Gauss-Bonnet theory.
description: NPB Accepted
Weak Lensing of the Primary CMB Bispectrum
Creators: name: Cooray, Asantha
name: Sarkar, Devdeep
name: Serra, Paolo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The cosmic microwave background (CMB) bispectrum is a well-known probe of the non-Gaussianity of primordial perturbations. Just as the intervening large-scale structure modifies the CMB angular power spectrum through weak gravitational lensing, the CMB primary bispectrum generated at the last scattering surface is also modified by lensing. We discuss the lensing modification to the CMB bispectrum and show that lensing leads to an overall decrease in the amplitude of the primary bispectrum at multipoles of interest between 100 and 2000 through additional smoothing introduced by lensing. Since weak lensing is not accounted for in current estimators of the primordial non-Gaussianity parameter, the existing measurements of $f_{\rm NL}$ of the local model with WMAP out to $l_{\rm max} \sim 750$ is biased low by about 6%. For a high resolution experiment such as Planck, the lensing modification to the bispectrum must be properly included when attempting to estimate the primordial non-Gaussianity or the bias will be at the level of 30%. For Planck, weak lensing increases the minimum detectable value for the non-Gaussianity parameter of the local type $f_{\rm NL}$ to 7 from the previous estimate of about 5 without lensing. The minimum detectable value of $f_{\rm NL}$ for a cosmic variance limited experiment is also increased from less than 3 to $\sim$ 5.
description: 9 Pages, 9 Figures, Submitted to PRD
Η ποινική προβληματική της ευθανασίας
Creators: name: Τραχαλιού, Αννα Νικολάου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: ευθανασία
Βιοηθική
ενεργητική ευθανασία
παθητική ευθανασία
δικαίωμα στο θάνατο
αξιοπρέπεια
euthanasia
Bioethics
active euthanasia
passive euthanasia
right to die
dignity

description: Σκοπός της παρούσας εργασίας είναι να εξεταστεί εις βάθος ένα από τα πλέον αμφιλεγόμενα και φλέγοντα ζητήματα, αυτό της ευθανασίας. Στο πρώτο κεφάλαιο, επιχειρείται μια σύντομη παρουσίαση της πορείας της έννοιας αλλά και της πρακτικής της ευθανασίας ανά τους αιώνες, ξεκινώντας από την αρχαιότητα και καταλήγοντας στη σύγχρονη εποχή. Στο δεύτερο κεφάλαιο γίνεται μια εκτενής ανάλυση του εννόμου αγαθού της ζωής, της εγχώριας και διεθνούς προστασίας του και εξετάζεται η βασιμότητα της ύπαρξης ενός δικαιώματος που έχει προκαλέσει ποικίλες αντιδράσεις στην επιστήμη, αυτό του δικαιώματος στο θάνατο. Τον εννοιολογικό προσδιορισμό της ευθανασίας καθώς και τις επιμέρους διακρίσεις της σε ενεργητική, παθητική και υποβοηθούμενη αυτοκτονία, με γνώμονα τον τρόπο διενέργειάς της, πραγματεύεται το τρίτο κεφάλαιο. Στο τέταρτο κεφάλαιο αναλύονται δυο επιμέρους περιπτώσεις ευθανασίας αυτές της πρόωρης ευθανασίας ελαττωματικών νεογνών και του θανάτου στη Μονάδα Εντατικής Θεραπείας (ΜΕΘ) με τον ταυτόχρονο προβληματισμό για τις κοινωνικές τους διαστάσεις. Στο πέμπτο και τελευταίο κεφάλαιο πραγματοποιείται μία ενδελεχής παράθεση των νομοθεσιών σε ζητήματα ευθανασίας τόσο των ευρωπαϊκών κρατών με έμφαση την Ολλανδία, το Βέλγιο και το Λουξεμβούργο, χώρες στις οποίες είναι επιτρεπτή, όσο και των Ηνωμένων Πολιτείων Αμερικής και των υπολοίπων κρατών του κόσμου. Η εργασία ολοκληρώνεται με τα συμπεράσματα και τον κριτικό προβληματισμό επί του θέματος με την παράθεση προσωπικών απόψεων.
description: The purpose of this work is to examine in depth one of the most controversial issues, that of euthanasia. In the first chapter, there is a brief presentation of the concept of euthanasia and the direction it has taken through the ages, from antiquity to modern times. The second chapter includes a comprehensive analysis of the legal interest of life and its domestic and international protection. The existence of a right to die, which has caused intense debate and controversy in legal literature, is further examined. The conceptual definition of euthanasia and its classification in active and passive euthanasia and assisted suicide, depending on the manner of conduct, are presented in the third chapter. The fourth chapter analyses two individual euthanasia cases, these of premature euthanasia of defective neonates and those of death in Intensive Care Unit, while simultaneously reflecting on their social dimensions. The fifth and last chapter includes a thorough exposition of pertinent legislation both of the European countries and particularly the Netherlands, Belgium and Luxemburg, where this practice is permissible, and of the United States of America and other countries of the world. The work concludes with the findings and critical input on the subject with the inclusion of some personal views.
Interferometric Observations of Explosive Variables: V838 Mon, Nova Aql 2005, and RS Oph
Creators: name: Lane, Benjamin F.
name: Retter, Alon
name: Eisner, Joshua A.
name: Thompson, Robert R.
name: Muterspaugh, Matthew W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: During the last two years we have used the Palomar Testbed Interferometer to observe several explosive variable stars, including V838 Monocerotis, V1663 Aquilae and recently RS Ophiuchi. We observed V838 Monocerotis approximately 34 months after its eruption, and were able to resolve the ejecta. Observations of V1663 Aql were obtained starting 9 days after peak brightness and continued for 10 days. We were able to resolve the milliarcsecond-scale emission and follow the expansion of the nova photosphere. When combined with radial-velocity information, these observations can be used to infer the distance to the nova. Finally we have resolved the recurrent nova RS Oph and can draw some preliminary conclusions regarding the emission morphology.
description: 8 Pages, SPIE Astronomical Telescopes and Instrumentation 2006, Advances in Stellar Interferometery, 6268-161
Οι επιπτώσεις των γραφειοκρατικών διαδικασιών στην αποτελεσματική λειτουργία ενός δημόσιου οργανισμού. Η περίπτωση του ελληνικού νοσοκομείου.
Creators: name: Μήτρεντσε, Δέσποινα Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Γραφειοκρατία
Αποτελεσματική λειτουργία
Νοσοκομείο
Bureaucracy
Effective functioning
Hospital

description: Σκοπός της παρούσας εργασίας είναι η διερεύνηση των γραφειοκρατικών διαδικασιών που ακολουθούνται στα νοσηλευτικά ιδρύματα και οι συνέπειες που αυτές έχουν στην αποτελεσματική λειτουργία των ιδρυμάτων αυτών. Για τη διερεύνηση του στόχου αυτού, η μελέτη μας διαρθρώνεται σε δύο επίπεδα το θεωρητικό και το εμπειρικό. Το εμπειρικό μέρος πραγματοποιήθηκε σε συγκεκριμένο νοσηλευτικό ίδρυμα της Θεσσαλονίκης. Η ερευνητική μέθοδος που ακολουθείται στην παρούσα εργασία είναι η ποσοτική έρευνα με τη χρήση ενός δομημένου κλειστού τύπου ερωτηματολογίου, το οποίο που διανεμήθηκε σε όλα τα στελέχη του νοσοκομείου. Με τη στατιστική και παραγοντική ανάλυση των δεδομένων που συλλέχθηκαν με βάση το εργαλείο αυτό, δόθηκαν απαντήσεις σχετικά με το εάν υπάρχουν γραφειοκρατικές διαδικασίες και πως αυτές επηρεάζουν τη λειτουργία του νοσοκομείου. Τα συμπεράσματα στα οποία κατέληξε η έρευνά μας είναι ότι η γραφειοκρατία ενδημεί στο πλαίσιο του νοσηλευτικού ιδρύματος προκαλώντας τη δυσλειτουργία, την οικονομική του αποδυνάμωση και την αναποτελεσματικότητά του. Τέλος, η μελέτη ολοκληρώθηκε με τη διατύπωση συγκεκριμένων μέτρων που πρέπει να ληφθούν ώστε να αντιμετωπιστούν οι επιπτώσεις του γραφειοκρατικού φαινομένου.
description: The purpose of this paper is the investigation of the bureaucratic procedures used in hospitals and the effects these have on the effective functioning of these institutions. To investigate this goal, or study is structured in two levels theoretical and empirical. The empirical part was implemented in a hospital of Thessaloniki. The research method this paper follows, is the quantitative research using a structured closed-ended questionnaire, which was distributed to all the members of the hospital. Statistical and factor analysis of the data collected, by this tool, gave answers about the existence of bureaucratic procedures and how they affect the operation of the hospital. Statistical and factor analysis of the data collected by this tool, gave answers about the existence of all bureaucratic procedures used and how these affect the operation of the hospital. The conclusions drawn from our research is that the bureaucracy is endemic within the hospital, causing malfunction, financial weakening and ineffectiveness. Finally, the study concluded with concrete measures to be taken, to address the impact of bureaucratic phenomenon.
Light and Slow-Neutron Diffraction by Nanodiamond-Dispersed Nanocomposite Holographic Gratings
Creators: name: Tomita, Y.
name: Kageyama, A.
name: Iso, Y.
name: Umemoto, K.
name: Kume, A.
name: Liu, M.
name: Pruner, C.
name: Jenke, T.
name: Roccia, S.
name: Geltenbort, P.
name: Fally, M.
name: Klepp, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: We demonstrate the use of nanodiamond in constructing holographic nanoparticle-polymer composite transmission gratings with large saturated refractive index modulation amplitudes at both optical and slow-neutron wavelengths, resulting in efficient control of light and slow-neutron beams. Nanodiamond possesses a high refractive index at optical wavelengths and large coherent and small incoherent scattering cross sections with low absorption at slow-neutron wavelengths. We describe the synthesis of nanodiamond, the preparation of photopolymerizable nanodiamond-polymer composite films, the construction of transmission gratings in nanodiamond-polymer composite films and light optical diffraction experiments. Results of slow-neutron diffraction from such gratings are also presented.
description: Accepted for publication in Phys. Rev. Applied (2020)
Biquotient actions on unipotent Lie groups
Creators: name: Puettmann, Annett
Publisher: name: arXiv
Year: 2007
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 22F05, 14R20

description: We consider pairs (V,H) of subgroups of a connected unipotent complex Lie group G for which the induced VxH-action on G by multiplication from the left and from the right is free. We prove that this action is proper if the Lie algebra g of G is 3-step nilpotent. If g is 2-step nilpotent then there is a global slice of the action that is isomorphic to C^n. Furthermore, a global slice isomorphic to C^n exists if dim V = 1 = dim H or dim V = 1 and g is 3-step nilpotent. We give an explicit example of a 3-step nilpotent Lie group and a pair of 2-dimensional subgroups such that the induced action is proper but the corresponding geometric quotient is not affine.
A non-Hermitian analysis of strongly correlated quantum systems
Creators: name: Nakamura, Yuichi
name: Hatano, Naomichi
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study a non-Hermitian generalization of strongly correlated quantum systems in which the transfer energy of electrons is asymmetric. It is known that a non-Hermitian critical point is equal to the inverse localization length of a Hermitian non-interacting random electron system. We here conjecture that we can obtain in the same way the correlation length of a Hermitian interacting non-random system. We confirm the conjecture using exact solutions and numerical finite-size data of the Hubbard model and the antiferromagnetic XXZ model in one dimension.
Οι ουγγρο-βυζαντινοί ανταγωνισμοί στα μέσα του 12ου αιώνα και η επίδραση τους στη δυτική πολιτική του Μανουήλ Α’ Κομνηνού (1143-1180)
Creators: name: Λαπαρίδης, Γεώργιος Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Ουγγρο-βυζαντινοί ανταγωνισμοί
Μανουήλ Α’ Κομνηνός
12ος αιώνας
Hungaro-byzantine rivalries
Manuel A’ Comnenus
12th century

description: Σκοπός της παρούσας κύριας μεταπτυχιακής εργασίας ήταν η διεξοδική μελέτη των ουγγρο-βυζαντινών συγκρούσεων στα μέσα του 12ου αιώνα (1150-1156, 1161-1167) και η ανάλυση των επιδράσεων τους στη δυτική πολιτική του Μανουήλ Α’ Κομνηνού (1143-1180). Αρχικά, εξετάστηκαν τα σημαντικά γεγονότα της ουγγρικής ιστορίας έως τις αρχές του 12ου αιώνα και στη συνέχεια ακολούθησε η λεπτομερής περιγραφή των ουγγρο-βυζαντινών συγκρούσεων. Ιδιαίτερη σημασία δόθηκε στη γεωστρατηγική και γεωπολιτική σημασία της Ουγγαρίας, στην ουγγρική πολιτική του Μανουήλ Α΄ Κομνηνού, καθώς και στον κομβικό ρόλο που διαδραμάτισε ο Ούγγρος πρίγκιπας Vela. Τέλος, παρουσιάστηκαν αναλυτικά οι επιδράσεις που είχαν οι συγκρούσεις στην πολιτική του Μανουήλ προς τους δυτικούς αντιπάλους του (Νορμανδοί Κ. Ιταλίας, Δυτική Αυτοκρατορία, Βενετία, Ούγγροι, παπικό κράτος, Σέρβοι) και προέκυψαν σημαντικές διαπιστώσεις σχετικά με τα αποτελέσματα των συγκρούσεων αναφορικά με τους Νορμανδούς της Κ. Ιταλίας και ιδιαίτερα με τη Βενετία.
description: The aim of the present ΜSc thesis was the detailed study of the conflicts between Hungary and Byzantium in the middle of the 12th century (1150-1156, 1161-1167) and the analysis of their impact on the western policy of Manuel A’ Comnenus (1143-1180). Initially, the most important events of the Hungarian history were examined up to the very beginning of the 12th century followed by the analytical description of the hungaro-byzantine conflicts. Particular attention was given to the geostrategic and geopolitical importance of Hungary, the hungarian policy of Manuel and the crucial role played by the Hungarian prince, Vela. Finally, the impact of the hungaro-byzantine conflicts on the policy of Manuel towards his western adversaries (Normans of S. Italy, Western Empire, Venice, Hungarians, papal state, Serbs) was presented thoroughly and important conclusions were drawn regarding the outcome of the conflicts concerning the Norman kingdom of S. Italy, and particularly Venice.
Energy-Efficient Power Control in Impulse Radio UWB Wireless Networks
Creators: name: Bacci, Giacomo
name: Luise, Marco
name: Poor, H. Vincent
name: Tulino, Antonia M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this paper, a game-theoretic model for studying power control for wireless data networks in frequency-selective multipath environments is analyzed. The uplink of an impulse-radio ultrawideband system is considered. The effects of self-interference and multiple-access interference on the performance of generic Rake receivers are investigated for synchronous systems. Focusing on energy efficiency, a noncooperative game is proposed in which users in the network are allowed to choose their transmit powers to maximize their own utilities, and the Nash equilibrium for the proposed game is derived. It is shown that, due to the frequency selective multipath, the noncooperative solution is achieved at different signal-to-interference-plus-noise ratios, depending on the channel realization and the type of Rake receiver employed. A large-system analysis is performed to derive explicit expressions for the achieved utilities. The Pareto-optimal (cooperative) solution is also discussed and compared with the noncooperative approach.
description: Submitted to the IEEE Journal on Selected Topics in Signal Processing - Special issue on Performance Limits of Ultra-Wideband Systems
Studying the all-but-dissertation phenomenon
Creators: name: Grosjean, Garnet
Publisher: name: University of British Columbia
Year: 2009

description: When doctoral students complete all required coursework, pass the comprehensive examinations, and develop a proposal for an original piece of research which demonstrates their competence, they are admitted to candidacy. Because at this stage the execution and defence of the dissertation still remain, students become classified as ABD or All But Dissertation. Some never complete their dissertation, and never progress beyond ABD status. University administrators, the graduate programs they provide, the supervisors of doctoral students, and the doctoral students themselves, are all vested in the outcomes of doctoral education. Doctoral education is one of the primary functions of research universities. Yet studies indicate that only 50 percent of students who start a doctoral program manage to complete it. The reasons for this high level of doctoral student attrition are relatively unexamined: how and why doctoral students arrive at the decision to withdraw isn't fully understood. The current study addresses the issue by developing and pilot testing an instrument to begin investigating the All But Dissertation (ABD) phenomenon. When an extensive search of the literature on dropouts revealed little information on post-graduate attrition, theory-based research on undergraduate dropout was examined to determine its applicability at the doctoral level. Based on two major theories of undergraduate dropout, (Tinto, 1975 ; Bean, 1982) a conceptual model was developed to provide the theoretical framework for the current study. Five constructs - - Background, Environment, Organization, Attitude, and Intent - - were incorporated into the model in order to guide the investigation of the personal and contextual factors affecting doctoral students' completion of their programs. In-depth interviews, used in the context of the multiple case study method, were employed with six current doctoral students at the ABD stage to pilot test an instrument designed specifically for this study. A self-report measure of procrastination (Tuckman, 1991) was used in conjunction with the interview schedule to address psychological characteristics missing from earlier studies. The interview schedule and procrastination scale were not tested with any TABDs (Terminal All But Dissertation). Findings indicate that the instrument developed for this study is adequate for collecting data on ABD students enrolled in an adult education doctoral program. As such, it could prove useful to future researchers collecting data on the ABD phenomenon.
HI 21cm absorption at $z \sim 3.39$ towards PKS 0201+113
Creators: name: Kanekar, N.
name: Chengalur, J. N.
name: Lane, W. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the GMRT detection of HI 21cm absorption from the $z \sim 3.39$ damped Lyman-$α$ absorber (DLA) towards PKS 0201+113, the highest redshift at which 21cm absorption has been detected in a DLA. The absorption is spread over $\sim 115$ km s$^{-1}$ and has two components, at $z = 3.387144 (17)$ and $z = 3.386141 (45)$. The stronger component has a redshift and velocity width in agreement with the tentative detection of Briggs et al. (1997), but a significantly lower optical depth. The core size and DLA covering factor are estimated to be $\lesssim 100$ pc and $f \sim 0.69$, respectively, from a VLBA 328 MHz image. If one makes the conventional assumption that the HI column densities towards the optical and radio cores are the same, this optical depth corresponds to a spin temperature of $\ts \sim [(955 \pm 160) \times (f/0.69)] $ K. However, this assumption may not be correct, given that no metal-line absorption is seen at the redshift of the stronger 21cm component, indicating that this component does not arise along the line of sight to the optical QSO, and that there is structure in the 21cm absorbing gas on scales smaller than the size of the radio core. We model the 21cm absorbing gas as having a two-phase structure with cold dense gas randomly distributed within a diffuse envelope of warm gas. For such a model, our radio data indicate that, even if the optical QSO lies along a line-of-sight with a fortuitously high ($\sim 50$%) cold gas fraction, the average cold gas fraction is low, ($\lesssim 17%$), when averaged over the the spatial extent of the radio core. Finally, the large mismatch between peak 21cm and optical redshifts and the complexity of both profiles makes it unlikely that the $z \sim 3.39$ DLA will be useful in tests of fundamental constant evolution.
description: 9 pages, 10 figures; accepted for publication in MNRAS. Missing reference added
Role of electromagnetic dipole operator in the electroweak penguin dominated vector meson decays of $B$ meson
Creators: name: Lü, Cai-Dian
name: Shen, Yue-Long
name: Wang, Wei
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The pure annihilation type decays $B^0_d\toϕγ$ and $B_s\toργ$ receive only color suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected electromagnetic dipole operator, the branching ratios can be enhanced one order magnitude larger than previous study using QCD factorization approach. That is ${\cal BR}(\bar B^0_d\toϕγ)\simeq 1 \times 10^{-11}$ and ${\cal BR}(B_s\toργ) \sim (6-16)\times 10^{-10}$. The new effect can also give a large contribution, of order $10^{-9}$, to transverse polarization of $B\toϕρ$ and $B\to ωϕ$ which is comparable to the longitudinal part. These effects can be detected in the LHCb experiment and the Super-B factories.
description: Revised extensively. 8 pages, 4 figures
Energy-Optimal Motion Planning for Agents: Barycentric Motion and Collision Avoidance Constraints
Creators: name: Beaver, Logan E.
name: Dorothy, Michael
name: Kroninger, Christopher
name: Malikopoulos, Andreas A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optimization and Control (math.OC)
subject: Multiagent Systems (cs.MA)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: As robotic swarm systems emerge, it is increasingly important to provide strong guarantees on energy consumption and safety to maximize system performance. One approach to achieve these guarantees is through constraint-driven control, where agents seek to minimize energy consumption subject to a set of safety and task constraints. In this paper, we provide a sufficient and necessary condition for an energy-minimizing agent with integrator dynamics to have a continuous control input at the transition between unconstrained and constrained trajectories. In addition, we present and analyze barycentric motion and collision avoidance constraints to be used in constraint-driven control of swarms.
description: 6 pages, no figures
Train Tracks with Gaps: Applying the Probabilistic Method to Trains
Creators: name: Kuszmaul, William
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Data Structures and Algorithms (cs.DS)
subject: Combinatorics (math.CO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We identify a tradeoff curve between the number of wheels on a train car, and the amount of track that must be installed in order to ensure that the train car is supported by the track at all times. The goal is to build an elevated track that covers some large distance $\ell$, but that consists primarily of gaps, so that the total amount of feet of train track that is actually installed is only a small fraction of $\ell$. In order so that the train track can support the train at all points, the requirement is that as the train drives across the track, at least one set of wheels from the rear quarter and at least one set of wheels from the front quarter of the train must be touching the track at all times. We show that, if a train car has $n$ sets of wheels evenly spaced apart in its rear and $n$ sets of wheels evenly spaced apart in its front, then it is possible to build a train track that supports the train car but uses only $Θ( \ell / n )$ feet of track. We then consider what happens if the wheels on the train car are not evenly spaced (and may even be configured adversarially). We show that for any configuration of the train car, with $n$ wheels in each of the front and rear quarters of the car, it is possible to build a track that supports the car for distance $\ell$ and uses only $O\left(\frac{\ell \log n}{n}\right)$ feet of track. Additionally, we show that there exist configurations of the train car for which this tradeoff curve is asymptotically optimal. Both the upper and lower bounds are achieved via applications of the probabilistic method.
Supercritical Coulomb Impurities in Gapped Graphene
Creators: name: Pereira, Vitor M.
name: Kotov, Valeri N.
name: Neto, A. H. Castro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We study the problem of Coulomb field-induced charging of the ground state in a system of 2D massive Dirac particles (gapped graphene). As in its 3D QED counterpart, the critical Coulomb coupling is renormalized to higher values, compared to the massless case. We find that in gapped graphene a novel supercritical regime is possible, where the screening charge is comparable to the impurity charge, thus leading to suppression of the Coulomb field at nanometer scales. We corroborate this with numerical solution of the tight-binding problem in the honeycomb lattice.
description: Revised and extended version
Schwinger functions and light-quark bound states
Creators: name: Bhagwat, M. S.
name: Hoell, A.
name: Krassnigg, A.
name: Roberts, C. D.
name: Wright, S. V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We examine the applicability and viability of methods to obtain knowledge about bound-states from information provided solely in Euclidean space. Rudimentary methods can be adequate if one only requires information about the ground and first excited state and assumptions made about analytic properties are valid. However, to obtain information from Schwinger functions about higher mass states, something more sophisticated is necessary. A method based on the correlator matrix can be dependable when operators are carefully tuned and errors are small. This method is nevertheless not competitive when an unambiguous analytic continuation of even a single Schwinger function to complex momenta is available.
description: 27 pages, 14 figures
Μια τεχνική αντιμετώπισης των προβλημάτων συμπεριφοράς: η ανάλυση των κρίσιμων περιστατικών με παραδείγματα από τα σχολεία της Κύπρου
Creators: name: Αγγελίδης, Παναγιώτης
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: The purpose of this paper is to propose a technique for enabling schools to deal with behavioral difficulties through an analysis of critical incidents. First, the article examines definitions of behavior difficulties, briefly explores the causes of misbehavior and summarizes the different theories and methods that have been used for behavior management. It, then, defines the proposing technique by providing, its theoretical background and illustrates how this method has been used. Using evidence from schools in Cyprus, this article provides illustrative examples which demonstrate how certain events that happen in the classroom can be analyzed in order to provide schools with useful information for developing new ways of facing behavioral difficulties.
description: Παιδαγωγική Επιθεώρηση, Vol. 37 (2004)
Weakly Supervised Multi-Object Tracking and Segmentation
Creators: name: Ruiz, Idoia
name: Porzi, Lorenzo
name: Bulò, Samuel Rota
name: Kontschieder, Peter
name: Serrat, Joan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: We introduce the problem of weakly supervised Multi-Object Tracking and Segmentation, i.e. joint weakly supervised instance segmentation and multi-object tracking, in which we do not provide any kind of mask annotation. To address it, we design a novel synergistic training strategy by taking advantage of multi-task learning, i.e. classification and tracking tasks guide the training of the unsupervised instance segmentation. For that purpose, we extract weak foreground localization information, provided by Grad-CAM heatmaps, to generate a partial ground truth to learn from. Additionally, RGB image level information is employed to refine the mask prediction at the edges of the objects. We evaluate our method on KITTI MOTS, the most representative benchmark for this task, reducing the performance gap on the MOTSP metric between the fully supervised and weakly supervised approach to just 12% and 12.7% for cars and pedestrians, respectively.
description: Accepted at Autonomous Vehicle Vision WACV 2021 Workshop
A Survey of Weak MgII Absorbers at 0.4 < z < 2.4
Creators: name: Narayanan, Anand
name: Misawa, Toru
name: Charlton, Jane C.
name: Kim, Tae-Sun
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results from a survey of weak MgII absorbers in the VLT/UVES spectra of 81 QSOs obtained from the ESO archive. In this survey, we identified 112 weak MgII systems within the redshift interval 0.4 < z < 2.4 with 86% completeness down to a rest-frame equivalent width of W_r(2796) = 0.02A, covering a cumulative redshift path length of deltaZ=77.3. From this sample, we estimate that the number of weak absorbers per unit redshift dN/dz increases from 1.06 +/- 0.04 at =1.9 to 1.76 +/- 0.08 at =1.2 and thereafter decreases to 1.51 +/- 0.09 at =0.9 and 1.06 +/- 0.10 at =0.6. Thus we find evidence for an evolution in the population of weak MgII absorbers, with their number density peaking at z=1.2. We also determine the equivalent width distribution of weak systems at =0.9 and =1.9. At 0.4 < z < 1.4, there is evidence for a turnover from a powerlaw of the form n(W_r) \propto W_r^{-1.04} at W_r(2796) < 0.1A. This turnover is more extreme at 1.4 < z < 2.4, where the equivalent width distribution is close to an extrapolation of the exponential distribution function found for strong MgII absorbers. Based on these results, we discuss the possibility that some fraction of weak MgII absorbers, particularly single cloud systems, are related to satellite clouds surrounding strong MgII systems. These structures could also be analogs to Milky Way high velocity clouds. In this context, the paucity of high redshift weak MgII absorbers is caused by a lack of isolated accreting clouds on to galaxies during that epoch.
description: 14 pages, 11 figures, ApJ accepted
Geodesics on the Ellipsoid and Monodromy
Creators: name: Davison, Chris M.
name: Dullin, Holger R.
name: Bolsinov, Alexey V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 37J15, 37J35, 53D25, 70H06, 70H33

description: The equations for geodesic flow on the ellipsoid are well known, and were first solved by Jacobi in 1838 by separating the variables of the Hamilton-Jacobi equation. In 1979 Moser investigated the case of the general ellipsoid with distinct semi-axes and described a set of integrals which weren't know classically. After reviewing the properties of geodesic flow on the three dimensional ellipsoid with distinct semi-axes, we investigate the three dimensional ellipsoid with the two middle semi-axes being equal, corresponding to a Hamiltonian invariant under rotations. The system is Liouville-integrable and thus the invariant manifolds corresponding to regular points of the energy momentum map are 3-dimensional tori. An analysis of the critical points of the energy momentum maps gives the bifurcation diagram. We find the fibres of the critical values of the energy momentum map, and carry out an analysis of the action variables. We show that the obstruction to the existence of single valued globally smooth action variables is monodromy.
description: 24 pages, 7 figures
Multipole vector solitons in nonlocal nonlinear media
Creators: name: Kartashov, Yaroslav V.
name: Vysloukh, Victor A.
name: Mihalache, D.
name: Torner, Lluis
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We show that multipole solitons can be made stable via vectorial coupling in bulk nonlocal nonlinear media. Such vector solitons are composed of mutually incoherent nodeless and multipole components jointly inducing a nonlinear refractive index profile. We found that stabilization of the otherwise highly unstable multipoles occurs below a maximum energy flow. Such threshold is determined by the nonlocality degree.
description: 13 pages, 3 figures, to appear in Optics Letters
Tensor model and dynamical generation of commutative nonassociative fuzzy spaces
Creators: name: Sasakura, Naoki
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: Rank-three tensor model may be regarded as theory of dynamical fuzzy spaces, because a fuzzy space is defined by a three-index coefficient of the product between functions on it, f_a*f_b=C_ab^cf_c. In this paper, this previous proposal is applied to dynamical generation of commutative nonassociative fuzzy spaces. It is numerically shown that fuzzy flat torus and fuzzy spheres of various dimensions are classical solutions of the rank-three tensor model. Since these solutions are obtained for the same coupling constants of the tensor model, the cosmological constant and the dimensions are not fundamental but can be regarded as dynamical quantities. The symmetry of the model under the general linear transformation can be identified with a fuzzy analog of the general coordinate transformation symmetry in general relativity. This symmetry of the tensor model is broken at the classical solutions. This feature may make the model to be a concrete finite setting for applying the old idea of obtaining gravity as Nambu-Goldstone fields of the spontaneous breaking of the local translational symmetry.
description: Adding discussions on effective geometry, a note added, four references added, other minor changes, 27 pages, 17 figures
Παιδιά με εκλεκτική αλαλία: η σιωπηλή μειονότητα της σχολικής τάξης
Creators: name: Ψάλτη, Αναστασία
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: Selective Mutism is a rather rare out complex childhood anxiety disorder characterized by a child's inability to speak in selected social settings -usually in the school classroom. Although it is a rare disorder, there are many teachers who come across students with Selective Mutism and are familiar with the frustration caused by these students' silence and resistance against any form of treatment. This article aims at providing information about Selective Mutism on one hand, and on the other, at presenting the steps that teachers can follow to handle a selectively mute student and at suggesting several interventions that can be applied in class.
description: Παιδαγωγική Επιθεώρηση, Vol. 37 (2004)
Thermocapillary valve for droplet production and sorting
Creators: name: Baroud, C. N.
name: Delville, J. -P.
name: Gallaire, F.
name: Wunenburger, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Droplets are natural candidates for use as microfluidic reactors, if active control of their formation and transport can be achieved. We show here that localized heating from a laser can block the motion of a water-oil interface, acting as a microfluidic valve for two-phase flows. A theoretical model is developed to explain the forces acting on a drop due to thermocapillary flow, predicting a scaling law which favors miniaturization. Finally, we show how the laser forcing can be applied to sorting drops, thus demonstrating how it may be integrated in complex droplet microfluidic systems.
description: Five pages, four figures
Revisiting the progenitor of the low-luminosity type II-plateau supernova, SN 2008bk
Creators: name: O'Neill, D.
name: Kotak, R.
name: Fraser, M.
name: Mattila, S.
name: Pietrzyński, G.
name: Prieto, J. L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The availability of updated model atmospheres for red supergiants and improvements in single and binary stellar evolution models, as well as previously unpublished data prompted us to revisit the progenitor of low-luminosity type II-Plateau supernova, SN 2008bk. Using mid-IR data in combination with dust models, we find that high temperature (4250-4500 K), high extinction (E(B-V)>0.7) solutions are incompatible with the data. We therefore favour a cool (~3500-3700 K) progenitor with a luminosity of log(L/Lsun)~4.53. Comparing with evolutionary tracks, we infer progenitor masses in the 8-10 Msun range in agreement with some previous studies. This mass is consistent with the observed pattern of low-luminosity Type IIP SNe coming from the explosion of RSGs at the lower extremum for core-collapse. We also present multi-epoch data of the progenitor, but do not find clear evidence of variability.
description: 9 pages, 6 figures
Chow points of C-orbits
Creators: name: Puettmann, Annett
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 14R20, 32C25, 14C05

description: We consider free algebraic actions of the additive group of complex numbers on a complex vector space X embedded in the complex projective space. We find an explicit formula for the map p that assigns to a generic point x in X the Chow point of the closure of the orbit through x. The properties Hausdorff quotient topology and proper action are equivalently characterized by the closure of the image of p in the closed Chow variety.
A Phase Prediction Method for Pattern Formation in Time-Dependent Ginzburg-Landau Dynamics for Kinetic Ising Model without a priori Assumptions on Domain Patterns
Creators: name: Anzaki, Ryoji
name: Ito, Shin-ichi
name: Nagao, Hiromichi
name: Mizumaki, Masaichiro
name: Okada, Masato
name: Akai, Ichiro
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We propose a phase prediction method for the pattern formation in the uniaxial two-dimensional kinetic Ising model with the dipole-dipole interactions under the time-dependent Ginzburg-Landau dynamics. Taking the effects of the material thickness into account by assuming the uniformness along the magnetization axis, the model corresponds to thin magnetic materials with long-range repulsive interactions. We propose a new theoretical basis to understand the effects of the material parameters on the formation of the magnetic domain patterns in terms of the equation of balance governing the balance between the linear- and nonlinear forces in the equilibrium state. Based on this theoretical basis, we propose a new method to predict the phase in the equilibrium state reached after the time-evolution under the dynamics with a given set of parameters, by approximating the third-order term using the restricted phase-space approximation [R. Anzaki, K. Fukushima, Y. Hidaka, and T. Oka, Ann. Phys. 353, 107 (2015)] for the $ϕ^4$-models. Although the proposed method does not have the perfect concordance with the actual numerical results, it has no arbitrary parameters and functions to tune the prediction. In other words, it is a method with no a priori assumptions on domain patterns.
The WIMPless Miracle: Dark Matter Particles without Weak-scale Masses or Weak Interactions
Creators: name: Feng, Jonathan L.
name: Kumar, Jason
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose that dark matter is composed of particles that naturally have the correct thermal relic density, but have neither weak-scale masses nor weak interactions. These WIMPless models emerge naturally from gauge-mediated supersymmetry breaking, where they elegantly solve the dark matter problem. The framework accommodates single or multiple component dark matter, dark matter masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to strong. These candidates enhance many direct and indirect signals relative to WIMPs and have qualitatively new implications for dark matter searches and cosmological implications for colliders.
description: 4 pages; v2: references added; v3: published version