cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Iron K Line Profile of IRAS 18325-5926
Creators: name: Lobban, Andrew
name: Vaughan, Simon
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: IRAS 18325-5926 is an X-ray bright, Compton-thin, type-2 Seyfert galaxy and it was the first Seyfert 2 in which the presence of a broad Fe K-alpha emission line was claimed. However, although the structure of the Fe line appears broad, there is tentative evidence that it may comprise multiple lines. Nevertheless, previous analyses have only consisted of fitting standalone broad components to the Fe K band. Here, we have analyzed all available X-ray CCD data from Suzaku, XMM-Newton and ASCA to fully investigate the nature of the emission complex by testing broad-band physical models and alternative hypotheses. We find that both a model consisting of broad, blurred reflection from an ionized accretion disc and a model consisting of cold, neutral reflection plus narrow emission lines from highly-ionized photoionized gas (log ξ= 3.5) offer statistically comparable fits to the data although the true reality of the Fe line cannot currently be determined with existing data. However, it is hoped that better quality data and improved photon statistics in the Fe K band will allow a more robust distinction between models to be made.
description: Accepted by MNRAS; 13 pages; 10 figures; 2 tables
Quality-aware Approach for Engineering Self-adaptive Software Systems
Creators: name: Abufouda, Mohammed
Publisher: name: arXiv
Year: 2014
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Self-adaptivity allows software systems to autonomously adjust their behavior during run-time to reduce the cost complexities caused by manual maintenance. In this paper, an approach for building an external adaptation engine for self-adaptive software systems is proposed. In order to improve the quality of self-adaptive software systems, this research addresses two challenges in self-adaptive software systems. The first challenge is managing the complexity of the adaptation space efficiently and the second is handling the run-time uncertainty that hinders the adaptation process. This research utilizes Case-based Reasoning as an adaptation engine along with utility functions for realizing the managed system's requirements and handling uncertainty.
description: Third International Conference on Information Technology Convergence and Services (ITCS 2014), January 2 ~ 4, 2014, Zurich, Switzerland. arXiv admin note: substantial text overlap with arXiv:1402.2144
Unpacking the Potential Influence of Life Satisfaction on Network Heterogeneity, Emotional Exhaustion and Mobile App Fatigue: A Stressor–Strain–Outcome Approach
Creators: name: Pang, Hua
name: Shao, Qinglong
Publisher: name: Freie Universität Berlin
Year: 2023
Subjects: subject: life satisfaction
subject: upward comparison
subject: self-presentation
subject: emotional exhaustion
subject: mobile app fatigue
subject: 100 Philosophie und Psychologie::150 Psychologie::150 Psychologie
subject: 000 Informatik, Informationswissenschaft, allgemeine Werke::000 Informatik, Wissen, Systeme::005 Computerprogrammierung, Programme, Daten

description: The ramifications of mobile apps’ detrimental aspect on users’ life satisfaction have garnered increased attention from academics. To probe the underlying association between life satisfaction and mobile app fatigue, this article builds a research model based on a stressor–strain–outcome approach. In addition, the study investigates the relationships between different dimensions of network heterogeneity, emotional exhaustion, and mobile app fatigue among users. Furthermore, the study uncovers the moderating influence of upward comparison, self-presentation, and privacy invasion on the association between life satisfaction and emotional exhaustion in the mobile app context. The study collected data in mainland China using a cross-sectional approach and analyzed the data using structural equation modeling. The findings demonstrate that life satisfaction is positively associated with self-presentation and negatively associated with upward comparison. Moreover, privacy invasion and upward comparison are positively correlated with emotional exhaustion, whilst self-presentation exerts no correlation with emotional exhaustion. Furthermore, upward comparison could mediate the association between life satisfaction and emotional exhaustion. The results provide fresh light on the mechanisms through which the life satisfaction of mobile app users and network heterogeneity might lead to emotional exhaustion and mobile app fatigue, highlighting important theoretical and practical implications.
Establishing the characteristics of learning-sensitive architectural design using a bespoke digital participatory tool: a study informed by an evolutionary perspective
Creators: name: Szynalska McAleavey, Karolina
Publisher: name: University of Lincoln
Year: 2023
Subjects: C820 - Developmental psychology
K100 - Architecture
K120 - Interior architecture
K190 - Architecture not elsewhere classified
X330 - Academic studies in secondary education
X990 - Education not elsewhere classified

description: Our understanding of school building design in relation to its effects on learning is surprisingly underdeveloped. This is due to the complex nature of the environments, the lack of consensus about the criteria for their pedagogical assessment, and attendant methodological challenges. By using theoretical concepts from developmental psychology and evolutionary approaches to both education and the perception of the physical environment, this study explored how the design of secondary school buildings affects pupils’ appetites for learning and promotes innovative pedagogical practices. The principal purpose of this research was to establish the characteristics of a learning-sensitive architectural design. The research tool employed the Experience Sampling Method (ESM) conducted through a digital app. It collected images of the pupil participants’ surroundings and information about their school related experience in situ – by sampling the participants’ thoughts and feelings as they occurred and in the environment within which they occurred. Over a course of a week in each case study, a total of 79 Year 7 and 8 pupil participants in four urban secondary schools in England recorded 1091 momentary responses reporting their experience of their motivation, school activity, and their immediate physical environment. The procedure collected both quantitative and qualitative data recording the effect of the pupils' perception of the school environment on their momentary motivation, as well as an assessment of the congruence between the buildings and the pedagogies they host. The study found that the perceived quality of the school environment has a lasting impact on pupils' momentary motivation and that a significant amount of variation in intrinsic motivation is momentary and context specific. These findings have potential implications for architects and educators concerned with enhancing and supporting learning through the design of school buildings.
An integrable model with parafermion zero energy modes
Creators: name: Tsvelik, A. M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Parafermion zero energy modes are a vital element of fault-tolerant topological quantum computation. Although it is believed that such modes form on the border between topological and normal phases, this has been demonstrated only for Z$_2$ (Majorana) and Z$_3$ parafermions. I consider an integrable model where such demonstration is possible for Z$_N$ parafermions with any $N$. The procedure is easely generalizable for more complicated symmetry groups.
description: 4 pages
Academic Freedom in Saudi Arabia: a comparative analysis
Creators: name: Author, Unknown
Publisher: name: University of Lincoln
Year: 2023

description: Saudi Arabia has recently sought to transform its economy from an existing extractive economy, based on oil as a single source of income, to a knowledge-based economy, based on highly skilled minds and creative human resources. A knowledge-based economy focuses on the production, generation, dissemination, and application of information. This is what the Vision 2030 government strategy confirmed. Vision 2030 was designed and promoted by Crown Prince Mohammed bin Salman and published on 25 April 2016, puts education at the forefront of the national transformation projects and programs of the Kingdom of Saudi Arabia. It also aims to make at least five of Saudi Arabia’s universities achieve ranking positions in the top 200 international universities 2030. The purpose of this research project was to evaluate academic freedom in Saudi Arabia in comparison to the EU nations by investigating faculty members’ understanding of academic freedom, as well as exploring the extent or degree to which academic freedom is available to faculty members, and by investigating the barriers faculty members face with respect to academic freedom in Saudi Arabian universities. The study employed a quantitative, mixed methods research design to explore factors surrounding the experiences of the faculty concerning academic freedom. This study seeks to answer the research question: To what extent is academic freedom possible in Saudi Arabia? The researcher compared the responses gathered from the academic staff selected within two cohorts of interest, SA and EU. Generally, the results indicated that respondents had positive views regarding the level of protection for academic freedom within their institutions. The study outcomes also revealed a significant number of faculty members had no idea of the existence of a policy guiding academic freedom in their workplaces, or in the Saudi constitution. IIFaculty members have faced some barriers for instance : The conservative nature of Saudi society, bureaucracy, and relying on the government as the main source of funding for universities.
The Lick-Carnegie Exoplanet Survey: Gliese 687b: A Neptune-Mass Planet Orbiting a Nearby Red Dwarf
Creators: name: Burt, Jennifer
name: Vogt, Steven S.
name: Butler, R. Paul
name: Hanson, Russell
name: Meschiari, Stefano
name: Rivera, Eugenio J.
name: Henry, Gregory W.
name: Laughlin, Gregory
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Precision radial velocities from the Automated Planet Finder and Keck/HIRES reveal an M*sin(i) =18 +/- 2 Earth mass planet orbiting the nearby M3V star GJ 687. This planet has an orbital period, P = 38.14 days, and a low orbital eccentricity. Our Stromgren b and y photometry of the host star suggests a stellar rotation signature with a period of P = 60 days. The star is somewhat chromospherically active, with a spot filling factor estimated to be several percent. The rotationally{induced 60-day signal, however, is well-separated from the period of the radial velocity variations, instilling confidence in the interpretation of a Keplerian origin for the observed velocity variations. Although GJ 687b produces relatively little specific interest in connection with its individual properties, a compelling case can be argued that it is worthy of remark as an eminently typical, yet at a distance of 4.52 pc, a very nearby representative of the galactic planetary census. The detection of GJ 687b indicates that the APF telescope is well suited to the discovery of low-mass planets orbiting low-mass stars in the as-yet relatively un-surveyed region of the sky near the north celestial pole.
description: 16 pages, 18 figures, accepted to ApJ
title: Weirding Winona: iDMAa 2022 Weird Media Exhibition
Creators: name: White, Melinda M.
Publisher: name: Electronic Book Review
Year: 2022

description: Melinda M. White's itinerary through the iDMA 2022 Weird Media Exhibition in Winona consider the various forms of weirdness or strangeness evoked by the exhibited works. She explores how strangeness characterises human relationship to constantly transforming technologies, how it manifests itself in our difficult pasts, and how it points to alternative of unexpected futures. While the weird encounters with the exhibition works in no way point to a single, unifying thread or approach to the theme, White's account reveals shared concerns, tendencies, and connections among them. Temporal distance and experiences of loss render familiar technologies, objects, or places unfamiliar; the borders between human and non-human entities and perspectives is blurred or even discarded; humor and surreal irreverence are employed to raise urgent questions on ecology, ethics, and individual or collective narratives and subjectivities.
Stochastic Stability of Event-triggered Anytime Control
Creators: name: Quevedo, Daniel E.
name: Gupta, Vijay
name: Ma, Wann-Jiun
name: Yuksel, Serdar
Publisher: name: arXiv
Year: 2013
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 93C10, 93E15

description: We investigate control of a non-linear process when communication and processing capabilities are limited. The sensor communicates with a controller node through an erasure channel which introduces i.i.d. packet dropouts. Processor availability for control is random and, at times, insufficient to calculate plant inputs. To make efficient use of communication and processing resources, the sensor only transmits when the plant state lies outside a bounded target set. Control calculations are triggered by the received data. If a plant state measurement is successfully received and while the processor is available for control, the algorithm recursively calculates a sequence of tentative plant inputs, which are stored in a buffer for potential future use. This safeguards for time-steps when the processor is unavailable for control. We derive sufficient conditions on system parameters for stochastic stability of the closed loop and illustrate performance gains through numerical studies.
description: IEEE Transactions on Automatic Control, under review
Youth Political Participation Under Neoliberal Hegemony
Creators: name: Allsop, Bradley
Publisher: name: University of Lincoln
Year: 2023
Subjects: L380 - Political sociology

description: This thesis seeks to develop an in-depth analysis of how neoliberal thought and policies have impacted on youth political engagement in the UK, specifically by attempting to understand how macro-economic and other public policies can influence the individual psychology of citizens and their subsequent behaviour. The thesis introduces the concept of political engagement and its importance, before moving on to chart the trends in youth political engagement over the past few decades, as well as common explanations for youth engagement, or its lack thereof. The thesis thensets out a clear definition and explanation of neoliberalism and summarises six key neoliberalimpacts particularly pertinent to political engagement: marketisation and the tension this brings with democratic norms; responsibilisation narratives; increased inequality; the changing character of the state through privatisation and deregulation; the preference among policy-makers for ‘expert rule’; and repression of labour. It argues that the main psychological effects that result, and which underpin and define the personal experience of neoliberal policy, are declines in political efficacy and increases in individualism. The argument presented in the early chapters of the thesis is that neoliberalism harms political engagement through this reduction of political efficacy and an increase in individualism, an argument then tested with empirical research detailed in later chapters.The methods and results of the primary research undertaken are then discussed - a sequential explanatory mixed methods approach, involving first a quantitative survey measuring political engagement, individualism and political efficacy, followed by in-depth interviews exploring these concepts and their relationships. The findings indicate that individualism does not seem to have an overall effect on political engagement, but political efficacy has a moderately positive, significant correlation with political engagement. There are interesting findings when individualism is divided along the lines of ‘Vertical’ and ‘Horizontal’ (following the theory of Triandis & Gelfand, 1998), whereby Vertical Individualism is found to have a negative relationship with political consumerism specifically. The interview stage is analysed using thematic analysis, and highlights several key themes, including a deep sense of concern over the future of the planet and the state of politics, a perceived connection between knowledge and the right or ability to engage politically, and the socially embedded nature of politics. These findings are collated and discussed along with the literature in the final chapter, where the future of neoliberalism and youth political engagement are also considered.
Συν-ανταγωνισμός ως στρατηγική της επιχείρησης : μελέτες περίπτωσης
Creators: name: Πετρίδης, Ιωάννης
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Συν-ανταγωνισμός
subject: Συν-ανταγωνισμός και δημιουργία αξίας
subject: Ανταγωνιστικό πλεονέκτημα με συν-ανταγωνισμό

description: Ο σκοπός αυτής της διπλωματικής εργασίας, είναι να αναπτύξει μία επιχειρηματική στρατηγική που δεν είναι τόσο διαδεδομένη. Πολλές φορές, ακόμα και φοιτητές μεταπτυχιακών προγραμμάτων μπορεί απλώς να έχουν ακούσει για αυτή, αλλά να μην γνωρίζουν πως θα χρησιμοποιήσουν μία τέτοια στρατηγική. Αυτό συμβαίνει πρωτίστως, επειδή η στρατηγική αυτή είναι μια σχετικά νέα μορφή, με την οποία οι επιχειρήσεις θα μπορούν να έχουν καλύτερη ανταγωνιστική θέση εντός του κλάδου που δραστηριοποιούνται, όταν συνεργάζονται με τους ανταγωνιστές τους. Κάτι που φυσικά έρχεται σε αντίθεση με την επι δεκαετιών άποψη μεγάλων συγγραφέων, όπως ο Porter (1985) και ο Aveni (1994), που έχουν δημιουργήσει διαχρονικά ανταγωνιστικά μοντέλα. Φυσικά, τα μοντέλα αυτά είναι αναγκαία στο κόσμο των επιχειρήσεων, όμως η παρούσα διπλωματική εργασία έρχεται να δώσει μια διαφορετική εικόνα, πως μπορεί να υπάρξει και η συνεργασία ταυτόχρονα. Συνεπώς, δεν είναι τυχαία η έκφραση που χρησιμοποίησαν οι Adam M. Brandenburger & Barry J. Nalebuff (1996) που αναφέρει: “πόλεμος και ειρήνη μαζί; Και όμως Ναι”.
Volatiles in protoplanetary disks
Creators: name: Pontoppidan, Klaus M.
name: Salyk, Colette
name: Bergin, Edwin A.
name: Brittain, Sean
name: Marty, Bernard
name: Mousis, Olvier
name: Oberg, Karin L.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped, snow lines are directly seen and quantified, and distinct chemical regions within protoplanetary disks are being identified, characterized and modeled. Theoretical processes invoked to explain the solar system record are now being observationally constrained in protoplanetary disks, including transport of icy bodies and concentration of bulk condensibles. The balance between chemical reset - processing of inner disk material strong enough to destroy its memory of past chemistry, and inheritance - the chemically gentle accretion of pristine material from the interstellar medium in the outer disk, ultimately determines the final composition of pre-planetary matter. This chapter focuses on making the first steps toward understanding whether the planet formation processes that led to our solar system are universal.
description: Accepted for publication as a chapter in Protostars and Planets VI, University of Arizona Press (2014), eds. H. Beuther, R. Klessen, C. Dullemond, Th. Henning
Desynchronization in an ensemble of globally coupled chaotic bursting neuronal oscillators by dynamic delayed feedback control
Creators: name: Che, Yanqiu
name: Yang, Tingting
name: Li, Ruixue
name: Li, Huiyan
name: Han, Chunxiao
name: Wang, Jiang
name: Wei, Xile
Publisher: name: arXiv
Year: 2014
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Biological Physics (physics.bio-ph)
subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: In this paper, we propose a dynamic delayed feedback control approach for desynchronization of chaotic-bursting synchronous activities in an ensemble of globally coupled neuronal oscillators. We demonstrate that the difference signal between an ensemble's mean field and its time delayed state, filtered and fed back to the ensemble, can suppress the self-synchronization in the ensemble. These individual units are decoupled and stabilized at the desired desynchronized states while the stimulation signal reduces to the noise level. The effectiveness of the method is illustrated by examples of two different populations of globally coupled chaotic-bursting neurons. The proposed method has potential for mild, effective and demand-controlled therapy of neurological diseases characterized by pathological synchronization.
description: This paper has been withdrawn by the author due to a crucial sign error in equation 3
Perceived Barriers and Challenges to Autistic Students in Higher Education
Creators: name: Gibbs, Kathryn
Publisher: name: University of Lincoln
Year: 2023

description: Autistic students in higher education face more barriers than those who are non-autistic (Dillenburger, McKerr, Jordan & Keenan, 2016) due to stigma and misconceptions held by the public (Zerbo, Massolo, Qian & Croen, 2015) and the ineffective supports in place (Ward & Webster, 2017). These difficulties may also overlap with difficulties faced by autistic people in other areas of life due to having autism-specific difficulties. Universities are particularly difficult for autistic people to access, with adaptations in higher education often overlooked (Lambe et al., 2018). To find out what sort of barriers people are aware of in higher education, 11 staff and students were invited to take part in focus groups to discuss what they saw as key barriers to autistic students in higher education. Thematic analysis revealed six key themes that showed areas in which staff and students perceived significant barriers to higher education. Results show that the difficulties perceived overlap with existing known difficulties in areas such as accessing healthcare and primary and secondary education. This research is not generalisable to large populations due to the limited sample size and purely qualitative approach however it does highlight key issues that are perceived as barriers to higher education for autistic students, and could form the basis of research conducting further investigation, or looking to trial improvements aimed at tackling barriers to access of higher education.
Chicken or Egg? Does Awareness Precede or Follow Long-Term Learning by Repeated Exposure?
Creators: name: Musfeld, Philipp
name: Krasnoff, Julia
name: Souza, Alessandra
name: Oberauer, Klaus
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Psychology
subject: FOS: Psychology
subject: Social and Behavioral Sciences

description: The aim of this project is to investigate the relation between long-term learning of repeatedly presented stimuli and the awareness of this repetition. The study aimes to determine whether awareness is preceded or followed by becoming aware of the repetition.
Τάσεις και προκλήσεις των διαδικτυακών ταξιδιωτικών πρακτορείων
Creators: name: Παρασκευόπουλος, Δημήτριος
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2023
Subjects: subject: Πανδημία
subject: Τουριστικός κλάδος
subject: COVID-19
subject: Ταξιδιωτικά πρακτορεία
subject: Διαδίκτυο

description: Η πανδημία αποτέλεσε ένα θέμα θεμελιώδους σημασίας καθώς επηρέασε και συνεχίζει να επηρεάζει πολιτικά, γεωγραφικά, κοινωνικά και οικονομικά την υφήλιο. Ο τομέας που επλήγη περισσότερο είναι αυτός του τουρισμού με ζημίες πολλών δισεκατομμυρίων. Τα «τραύματα» της πανδημίας είναι δεδομένο πως θα αργήσουν να επουλωθούν στον τουριστικό κλάδο. Πτήσεις, ακτοπλοϊκές γραμμές, ομαδικά ταξίδια και κρατήσεις ξενοδοχείων ακυρώνονταν όσο τα κρούσματα του κορονοϊού αυξάνονταν. Οι κυβερνήσεις όλων των κρατών παγκοσμίως έθεσαν σε λειτουργία, αυστηρά περιοριστικά μέτρα ως προς τις μετακινήσεις, με αποτέλεσμα την μεγεθυμένη τουριστική αδράνεια. Ειδικότερα, τα Διαδικτυακά Ταξιδιωτικά Πρακτορεία κλονίστηκαν ανεπανόρθωτα κατά την πανδημική κρίση με επακόλουθο την αναβολή της λειτουργίας τους. Η κατάρρευση αυτή ήταν αλληλένδετη με την αποδυνάμωση του εποχικού εργατικού δυναμικού και την ερήμωση τουριστικών προορισμών. Επιπλέον, τα κυβερνητικά συστήματα οικονομικής στήριξης δεν συνέβαλλαν επαρκώς στην συντήρηση του τουρισμού. Τα Διαδικτυακά Ταξιδιωτικά Πρακτορεία, όπου και είναι το κύριο θέμα της παρούσας διπλωματικής, κατευθύνθηκαν μετά το πέρας της χαλάρωσης των ταξιδιωτικών μέτρων σε μία ανέλπιστα θετική πορεία και αυτή η πορεία φαίνεται να συνεχίζεται αφού προωθεί την ταχύτητα στις συναλλαγές, την αναβάθμιση των τουριστικών υπηρεσιών ψηφιακά και την διευκόλυνση.
Antiferromagnetic Order in a Semiconductor Quantum Well with Spin-Orbit Coupling
Creators: name: Marinescu, D. C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: An argument is made on the existence of a low-temperature itinerant antiferromagnetic (AF) spin alignment, rather than persistent helical (PH), in the ground state of a two dimensional electron gas in a semiconductor quantum well with linear spin-orbit Rashba-Dresselhaus interaction at equal coupling strengths, $α$. This result is obtained on account of the opposite-spin single-particle state degeneracy at $\mb k = 0$ that makes the spin instability possible. A theory of the resulting magnetic phase is formulated within the Hartree-Fock approximation of the Coulomb interaction. In the AF state the direction of the fractional polarization is obtained to be aligned along the displacement vector of the single-particle states.
Inverse boundary value problem for the Stokes and the Navier-Stokes equations in the plane
Creators: name: Lai, Ru-Yu
name: Uhlmann, Gunther
name: Wang, Jenn-Nan
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we prove in two dimensions global identifiability of the viscosity in an incompressible fluid by making boundary measurements. The main contribution of this work is to use more natural boundary measurements, the Cauchy forces, than the Dirichlet-to-Neumann map previously considered in \cite{IY} to prove the uniqueness of the viscosity for the Stokes equations and for the Navier-Stokes equations.
Structure and Dynamics of the Accretion Process and Wind in TW Hya
Creators: name: Dupree, A. K.
name: Brickhouse, N. S.
name: Cranmer, S. R.
name: Berlind, P.
name: Strader, J.
name: Smith, G. H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Time-domain spectroscopy of the classical accreting T Tauri star, TW Hya, covering a decade and spanning the far UV to the near-infrared spectral regions can identify the radiation sources, the atmospheric structure produced by accretion,and properties of the stellar wind. On time scales from days to years, substantial changes occur in emission line profiles and line strengths. Our extensive time-domain spectroscopy suggests that the broad near-IR, optical, and far-uv emission lines, centered on the star, originate in a turbulent post-shock region and can undergo scattering by the overlying stellar wind as well as some absorption from infalling material. Stable absorption features appear in H-alpha, apparently caused by an accreting column silhouetted in the stellar wind. Inflow of material onto the star is revealed by the near-IR He I 10830A line, and its free-fall velocity correlates inversely with the strength of the post-shock emission, consistent with a dipole accretion model. However, the predictions of hydrogen line profiles based on accretion stream models are not well-matched by these observations. Evidence of an accelerating warm to hot stellar wind is shown by the near-IR He I line, and emission profiles of C II, C III, C IV, N V, and O VI. The outflow of material changes substantially in both speed and opacity in the yearly sampling of the near-IR He I line over a decade. Terminal outflow velocities that range from 200 km/s to almost 400 km/s in He I appear to be directly related to the amount of post- shock emission, giving evidence for an accretion-driven stellar wind. Calculations of the emission from realistic post- shock regions are needed.
description: Accepted by The Astrophysical Journal; 44 pages; 18 figures
Simplified Bond Hyperpolarizability Model of Second Harmonic Generation, Group Theory and Neumann's Principle
Creators: name: Alejo-Molina, Adalberto
name: Hardhienata, Hendradi
name: Hingerl, Kurt
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We discuss the susceptibility third-rank tensor for second harmonic and sumfrequency generation, associated with low index surfaces of silicon (Si(001), Si(011) and Si(111)) from two different approaches: the Simplified Bond-Hyperpolarizablility Model(SBHM) and Group Theory (GT). We show that SBHM agrees very well with the experimental results for simple surfaces because the definitions of the bond vectors implicitly include the geometry of the crystal and therefore the symmetry group. However, for more complex surfaces it is shown that one can derive from GT the SBHM tensor, if Kleinman symmetry is allowed.
description: 18 pages, 3 Figures, in review to be considered for publication in JOSA B
Magnetic structure of the conductive triangular-lattice antiferromagnet PdCrO2
Creators: name: Takatsu, Hiroshi
name: Nénert, Gwilherm
name: Kadowaki, Hiroaki
name: Yoshizawa, Hideki
name: Enderle, Mechthild
name: Yonezawa, Shingo
name: Maeno, Yoshiteru
name: Kim, Jungeun
name: Tsuji, Naruki
name: Takata, Masaki
name: Zhao, Yang
name: Green, Mark
name: Broholm, Collin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We performed neutron single crystal and synchrotron X-ray powder diffraction experiments in order to investigate the magnetic and crystal structures of the conductive layered triangular-lattice antiferromagnet PdCrO2 with a putative spin chirality, which contributes to an unconventional anomalous Hall effect. We revealed that the ground-state magnetic structure is a commensurate and nearly-coplanar 120-degrees spin structure. The 120-degrees plane in different Cr layers seem to tilt with one another, leading to a small noncoplanarity. Such a small but finite non-coplanar stacking of the 120-degrees planes gives rise to a finite scalar spin chirality, which may be responsible for the unconventional nature of the Hall effect of PdCrO2.
description: Phys. Rev. B 89, 104408 (2014)
Apodized phase mask coronagraphs for arbitrary apertures. II. Comprehensive review of solutions for the vortex coronagraph
Creators: name: Carlotti, Alexis
name: Pueyo, Laurent
name: Mawet, Dimitri
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: With a clear circular aperture, the vortex coronagraph perfectly cancels an on-axis point source and offers a 0.9 or 1.75 lambda/D inner working angle for topological charge 2 or 4, respectively. Current and near-future large telescopes are on-axis, however, and the diffraction effects of the central obscuration, and the secondary supports are strong enough to prevent the detection of companions 1e-3 - 1e-5 as bright as, or fainter than, their host star. Recent advances show that a ring apodizer can restore the performance of this coronagraph by compensating for the diffraction effects of a circular central obscuration in a 1D modeling of the pupil. We extend this work and optimize apodizers for arbitrary apertures in 2D in order to tackle the diffraction effects of the spiders and other noncircular artefacts in the pupil. We use a numerical optimization scheme to compute hybrid coronagraph designs that combine the advantages of the vortex coronagraph (small in IWA) and of shaped pupils coronagraphs (robustness to central obscuration and pupil asymmetric structures). We maximize the apodizer transmission, while constraints are set on the extremum values of the electric field that is computed in chosen regions of the Lyot plane through closed form expressions. Optimal apodizers are computed for topological charges 2 and 4 vortex coronagraphs and for telescope apertures with 10-30% central obscurations and 0-1% thick spiders. We characterize the impacts of the obscuration ratio and the thickness of the spiders on the throughput and the IWA for the two topological charges.
description: 23 pages, 12 figures, 2 tables
d+Au Hadron Correlation Measurements at PHENIX
Creators: name: Sickles, Anne M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In these proceedings, we discuss recent results from d+Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v2 at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v2 in d+Au to that in p+Pb, Au+Au and Pb+Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.
description: talk given at International Conference on the Initial Stages of High Energy Nuclear Collisions
Chern band insulators in magnetic field
Creators: name: Araújo, Miguel A. N.
name: Castro, Eduardo V.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The effect of a magnetic field on a two-dimensional Chern band insulator is discussed. It is shown that, unlike the trivial insulator, an anomalous Hall insulator with Chern number $C$ becomes a metal when a magnetic field is applied at constant particle density, for any $C>0$. For a time reversal invariant topological insulator with a spin Chern resolved number, $C_\uparrow= - C_\downarrow=C$, the magnetic field induces a spin polarized spin Hall insulator. We consider also the effect of a superlattice potential and extend previous results for the quantization of the Hall conductance of filled Hofstadter bands to this problem.
description: 7 pages, 5 figures
Acute and chronic effects of rotating shift work on running wheel activity, energy balance, and molecular alterations
Creators: name: Shabrish, Vasavi
Publisher: name: The University of Texas at Austin
Year: 2022
Subjects: Circadian rhythms
Shift work
Metabolism

description: Endogenous molecular clocks influence physiology, metabolism, and behavior. Shift workers are exposed to repeated changes in the timing of light, feeding, and activity and, consequently, are at increased risk for development of chronic disease associated with disruptions of circadian rhythms. The objectives of this research were to determine the behavioral, physiological, and molecular effects of acute and chronic exposure to rotating shift work (RSW) using murine models and evaluate the effects of timed exercise and timed feeding independently and in combination, within the context of high and low-fat diets, in a model of chronic rotating shift work (CRSW). To simulate human RSW, mice were housed in either normal or RSW conditions, consisting of 12-hour shifts in the light/dark cycle every 3 or 4 days for either 3- or 14-day in the acute experiment (RSW) or 10 weeks in the chronic experiment (CRSW). Under CRSW, six groups of mice were examined for metabolic and behavioral outcomes, including control (C), shift work control (SC), shift work chronic exercise (S-RW), shift work timed exercise (S-TE), shift work timed feeding (S-TF), and shift work timed exercise and feeding (S-TFEX). We report disrupted wheel running activity patterns in acute and chronic exposure to RSW. Differential effects of low- and high-fat diet were observed in wheel running activity in CRSW. Substantial alterations in the diurnal expression of core clock and metabolic genes were observed in a tissue-specific manner. After 14 days of RSW exposure, most tissues lost complete clock rhythmicity and resulted in impaired fasting glucose. CRSW resulted in significantly greater weight gain and lower glucose tolerance in S-TF and S-TFEX mice. The S-TE mice weighed lower and displayed higher glucose tolerance on low-fat diet compared to S-TF condition. Acute exposure to RSW disrupts molecular functions in a tissue-specific manner, which may precede the metabolic consequences of chronic exposure to RSW. The present study provides evidence that the variable food intake patterns associated with shift work may result in deleterious metabolic outcomes. A short intense voluntary bout of exercise every 24 hours may serve as a behavioral cue for eating behavior.
title: Μέθοδοι τεχνητής νοημοσύνης - βαθιάς μάθησης για την διάγνωση της νόσου Alzheimer με απεικονιστικές μεθόδους
title: Μέθοδοι τεχνητής νοημοσύνης - βαθιάς μάθησης για την διάγνωση της νόσου Alzheimer με απεικονιστικές μεθόδους
titleType: AlternativeTitle
Creators: name: Μαγιάκου, Βασιλική
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2023
Subjects: Νόσος Ατσχάιμερ
Λειτουργική μαγνητική τομογραφία
Τομογραφία εκπομπής ποζιτρονίων
Νευροαπεικόνιση
Βαθιά μάθηση
Νευρωνικά δίκτυα
Τεχνητή νοημοσύνη
Μαγνητική τομογραφία

description: Η ανίχνευση εγκεφαλικών ασθενειών σε πρώιμο στάδιο μπορεί να κάνει τεράστια διαφορά στην προσπάθεια ίασής τους. Τα τελευταία χρόνια, η χρήση της τεχνητής νοημοσύνης (ΤΝ) αυξάνεται σε όλους τους τομείς της επιστήμης και αναμφίβολα φέρνει επανάσταση στον τομέα της νευρολογίας. Η εφαρμογή της τεχνητής νοημοσύνης στην ιατρική επιστήμη έχει κάνει την πρόβλεψη και την ανίχνευση εγκεφαλικών ασθενειών πιο ακριβή και αποτελεσματική. Ταυτόχρονα, δεκαετίες πειραματικής και κλινικής έρευνας συνέβαλαν στην αποκάλυψη πολλών μηχανισμών παθογένεση της νόσου Αλτσχάιμερ (NA), αλλά η λύση είναι ακόμα απροσδιόριστη. Η πρόσφατη ανάπτυξη πρωτοβουλιών ανοιχτής ανταλλαγής πολυτροπικών δεδομένων που συλλέγουν δεδομένα τρόπου ζωής, κλινικών και βιολογικών δεδομένων από ασθενείς με ΝΑ έχει παράσχει έναν δυνητικά απεριόριστο όγκο πληροφοριών για τη νόσο, που υπερβαίνει κατά πολύ την ανθρώπινη ικανότητα αντίληψης. Επιπλέον, η ενσωμάτωση Μεγάλων Δεδομένων (Big Data) από μελέτες πολλαπλών ομικών δεδομένων παρέχει τη δυνατότητα διερεύνησης των παθοφυσιολογικών μηχανισμών ολόκληρου του βιολογικού συνεχούς της ΝΑ. Σε αυτή τη μελέτη, παρουσιάζουμε μια ανασκόπηση σχετικά με τις πρόσφατες προσεγγίσεις βαθιάς μάθησης (ΒΜ) στην ανίχνευση της ΝΑ, τις διάφορες τεχνικές εξαγωγής χαρακτηριστικών στη διάγνωση της, τα πρόσφατα ευρήματα και τις μελλοντικές προκλήσεις για την τεχνητή νοημοσύνη στην έρευνα κατά της νόσου. Πιο συγκεκριμένα, μελετάμε τη χρήση εργαλείων διάγνωσης με τη βοήθεια υπολογιστή στη διάγνωση της ΝΑ και τη χρήση της τεχνητής νοημοσύνης στη πιθανή υποστήριξη κλινικών πρακτικών για την πρόβλεψη του ατομικού κινδύνου εξέλιξης της ΝΑ, καθώς και τη διαστρωμάτωση των ασθενών, προκειμένου να αναπτυχθούν τελικά αποτελεσματικές και εξατομικευμένες θεραπείες. Η έρευνα βασίζεται σε πρόσφατη βιβλιογραφία, δίνοντας έμφαση σε 36 άρθρα σχετικά με την νόσο. Τέλος, συνοψίζονται τα βασικά ευρήματα από τα αναθεωρημένα άρθρα και συζητούνται ορισμένα σημαντικά ζητήματα που σχετίζονται με τις διαγνωστικές προσεγγίσεις της ΝΑ που βασίζονται στη ΒΜ.
Effects of domestic freezing temperature (-20?C) and blanching on the functional properties and constituents of three common culinary herbs of Lamiaceae family
Creators: name: Iheozor-Ejiofor, Pamela
Publisher: name: University of Lincoln
Year: 2023
Subjects: D690 - Food & beverage studies not elsewhere classified

description: The effects of blanching prior to freezing on the functional constituents (ascorbic acid, selenium, phytic acid and phenolic content) and properties (total antioxidant activity, enzyme inhibition activity and prebiotic functions) of 3 well known Lamiceae herbs (mint/Mentha piperita, thyme/Thymus vulgaris and basil/Ocmium basicilla) were investigated. Comparisons were made between herbs and across different treatments (fresh, un-blanched frozen (-20?C) and blanched frozen). Due to the complexity of antioxidant and phenolic compounds/components of plants, extracts for total phenolics and antioxidant activities were made in methanol and water.Generally, among all assayed herbs, mint showed superiority compared to other herbs in terms of functional constituents and properties. However, results of antioxidant capacity/content (DPPH, ORAC, FRAP and CUPRAC) and TPC varied inconsistently across herbs, treatments and assays.Results also showed that frozen herbs have lower selenium, ascorbic (total, and reduced) and phytic acid content compared to fresh herbs. Furthermore, results of ascorbic acid content showed a significantly lower dehydroascorbic acid (DHA) content in frozen herbs than fresh herbs.Results of enzyme inhibition showed a moderate to very low ?-amylase inhibition ability by all herbs which further reduced on freezing and blanching. Furthermore, compared to other herbs, mint showed the highest ?-glucosidase inhibition which reduced on freezing and blanching. Lineweaver-Burke plot showed that fresh and un-balnched frozen mint displayed un-competetive mode of inhibition while blanched frozen mint showed mixed inhibition. Freezing tended to improve the ?-glucosidase inhibition effects of thyme and basil which was not evident in fresh extracts. None of the herbs showed inhibitory effects against ACE.All herbs showed significant prebiotic effects on probiotic bacteria L. rhamnosus and B.bifidum. However, effects of freezing and blanching varied inconsistently among herbsResults of the functional properties correlated with individual phenolic acid content of herbs. This therefore shows that the product of the hydrolysis of these individual phenolic compounds play significant role in the functional properties of the assayed herbs.The findings from this research have therefore shown that freezing (blanching or without blanching) can positively or negatively affect the assayed functional constituents and properties of assayed lamiceae herbs. However, in some instances, there is no difference between the functional constituents of fresh and frozen (un-blanched and blanched).
Higgs CAT
Creators: name: Passarino, Giampiero
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Higgs Computed Axial Tomography, an excerpt. Taking a closer look at the camel-shaped tail of the light Higgs boson resonance and looking to the transformation of the (camel-shaped) signal into a square-root--shaped signal + interference with particular emphasis on residual theoretical uncertainties.
description: 29 pages, 11 figures
A Stable Higher Order Space-Time Galerkin Scheme for Time Domain Integral Equations
Creators: name: Pray, A. J.
name: Beghein, Y.
name: Nair, N. V.
name: Cools, K.
name: Bağcı, H.
name: Shanker, B.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Stability of time domain integral equation (TDIE) solvers has remained an elusive goal for many years. Advancement of this research has largely progressed on four fronts: (1) Exact integration, (2) Lubich quadrature, (3) smooth temporal basis functions, and (4) Space-time separation of convolutions with the retarded potential. The latter method was explored in [Pray et al. IEEE TAP 2012]. This method's efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was demonstrated on first order surface descriptions (flat elements) in tandem with 0th order functions as the temporal basis. In this work, we develop the methodology necessary to extend to higher order surface descriptions as well as to enable its use with higher order temporal basis functions. These higher order temporal basis functions are used in a Galerkin framework. A number of results that demonstrate convergence, stability, and applicability are presented.
description: 8 pages, 12 figures
Design and Development of a Bioinspired Gliding-optimised Tandem Wings for Micro Aerial Robots
Creators: name: Isakhani, Hamid
Publisher: name: University of Lincoln
Year: 2023
Subjects: G900 - Others in mathematical sciences

description: Research on aerial robotics particularly the articulated/flapping wing robots have gained aremarkable attention during the recent years due to their agility and stealthiness in surveillance and reconnaissance missions. However, wing flapping is highly energy-intensive thatcan be complemented by gliding to conserve energy for long-range flights as demonstratedby desert locusts (Schistocerca gregaria). Therefore, inspired by this insect we explorenovel solutions in this thesis to address some of the challenging problems of aeronauticsconcerning development, fabrication, and aerodynamic optimisation of a bio-inspired glid?ing wing for micro aerial vehicle (MAV) applications. Initially, we investigate the aerofoilgeometries (2D wings) of a locust by performing a pseudo-microscopic scanning of itswings in gliding posture. Using numerical analysis and a novel optimisation methodologybased on Nash-Genetic Algorithms, we study and enhance the aerodynamic performanceof the digitally reconstructed aerofoils. The optimised as well as the original aerofoils areintegrated using Computer-Aided Design (CAD) to form 3D wings that are subjected to aComputational Fluid Dynamics (CFD) modelling, and a Finite Element Analysis (FEA) tovalidate their aerodynamic performance and manufacturing-worthiness, respectively. Having established the required performance criteria numerically, a novel combination of fabrication techniques involving 3D printing, vacuum thermoforming, and laser trimming isproposed to realise the digital wings as artificial wing prototypes. Furthermore, we explorethe novel Computer-Associated Design (CAsD) based on machine learning technology toobtain computer-generated wings for a detailed comparative study of the mechanical properties associated with each wing prototype designed by an engineer, a computer, and thenature.