cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: A theoretical and practical framework for managing complexity and its organizational and managerial implications
Creators: name: Rauter, Harald
Publisher: name: TU Wien
Year: 2017
Subjects: subject: organization of innovation
subject: ambidexterity
subject: complexity theorems for organizations
subject: network-based human system organization
subject: agile ambidexterity model

description: Both academic and practitioners' literature are highlighting the importance of open innovation or more generally the requirement for organizations to source and interact beyond their structural organizational boundaries. The merit of doing so is widely discussed and literature provides success stories that underpin why such initiatives can substantially pay off and translate into competitive advantage. Academic organizational-, strategic- and managerial literature does provide answers which barriers must be overcome for organization that want to transition their business from closed to open innovation collaborative formats. However, from the practitioners there is a lack of understanding how all these elements are interconnected in a coherent framework and how they can be overcome by systematic intervention. Using the opportunity of this MBA thesis for the MBA program of Entrepreneurship & Innovation I want to address this phenomenon of the collaborative imperative (=collaboration as the new competitive advantage) from the natural scientific perspective of understanding complexity, deriving organizational and managerial implications and finally benchmarking the learnings against the business model of my current employer Climate-KIC, a trans-European innovation platform driving innovation in climate-change mitigation and adaption. The major findings are that a) the collaborative imperative is a natural consequence of the increased inter-connectedness of agents within and beyond the traditional structural boundaries of organizations; b) the increased complexity results in three major theorems (complexity trap, shift in power-structure and identity crisis). These theorems constitute the framework that all managerial decisions need to account for; c) the increased environmental complexity requires from organizations within their organizational setup to be able to at least reflect the complexity of the environment they are exposed to; d) organizations must be able to organize around functional groups and challenge-related teams based on a simple rule concept; e) in order for the individual actor to be sufficiently effective in such an environment traditional performance management concepts are counterproductive and fundamentally new forms of behavioural performance management concepts are required. This work is intended to serve as a naturally imperfect but practical guide for managers and innovation practitioners that face the challenge of transforming structure-based organizations into network-based organizations that are aiming to collaborate beyond their traditional structural boundaries as part of larger, highly interconnected networks in collaborative platforms.
POLÍTICAS DE DESENVOLVIMENTO AGRÁRIO NA REALIDADE CAMPONESA: O CASO DO ASSENTAMENTO TRANSVAL EM CANINDÉ – CE.
Creators: name: OLIVEIRA FILHO, GERALDO SOARES DE
name: MOREIRA, A LÚCIA DE SOUSA
name: OLIVEIRA FILHO, GERALDO SOARES DE
name: MOREIRA, A LÚCIA DE SOUSA
Publisher: name: Unknown
Year: 2006
Subjects: subject: Agricultural and Food Policy
subject: Community/Rural/Urban Development
subject: Assentamento
subject: PRONAF
subject: Assistência Técnica
subject: Camponês

description: O trabalho analisou duas políticas públicas do desenvolvimento agrário, o PRONAF e o serviço de assistência técnica a partir da realidade dos assentados do Transval em Canindé-Ce. Participaram desse estudo 29 assentados e 2 técnicos do MST. A escolha da pesquisa qualitativa como abordagem metodológica para o estudo ocorreu a partir de um estágio de vivência. Foram utilizadas a observação participante, entrevistas semiestruturadas, análise de documentos e resgate histórico da vida dos assentados. Os resultados indicaram que as regras, normas, limites de crédito, taxas de juros, dentre outros, são parâmetros distantes da realidade de agricultores assentados que desconhecem algum mecanismo contábil para gerir sua produção. A lógica dos agentes financeiros tende a desconsiderá-los como parcela especial de clientes para admissão no PRONAF. Os assentados acreditam que o PRONAF traz poucos benefícios para o assentamento, avançando na compreensão de propor um tipo de crédito, que apresente resultados dentro da realidade que trabalham. A assistência técnica no PRONAF caracterizou-se pela grande divergência entre a figura idealizada pelos assentados e a situação histórica e real do quadro de assistência técnica oferecido pelo programa. Mesmo assim, observou-se que os assentados estão cientes da importância desta para o desenvolvimento dos trabalhos no assentamento.
Magnetic ordering of itinerant systems; the role of kinetic exchange interaction
Creators: name: Górski, G.
name: Mizia, J.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The possibility of ferromagnetic ordering is revisited in the band model. The coherent potential approximation decoupling has been used for the strong on-site Coulomb interaction. The driving forces towards the ferromagnetism are the on-site and inter-site molecular fields coming from different Coulomb interactions. Another driving force is the lowering of the kinetic energy with growing magnetic moment coming from the dependence of the hopping integrals on occupation of the neighboring sites involved in hopping. This effect is described by the hopping interaction, $Δt$, and by what we call the exchange-hopping interaction, $t_{ex}$. The exchange-hopping interaction, which is the difference in hopping integrals for different occupation of neighboring lattice sites, acts in analogous way to the Hund's magnetic exchange interaction. The results are calculated for semi-elliptic density of states (DOS) and for the distorted semi-elliptic DOS with the maximum around the Fermi energy. They show a natural tendency towards the magnetic ordering at the end of the 3d row for the DOS with maximum density around the Fermi energy, when the hopping integrals grow with the occupation of the neighboring lattice sites.
description: 12 pages, 13 figures
Long-term absolute frequency stabilization of a hybrid-integrated InP-Si3N4 diode laser
Creators: name: van Rees, Albert
name: Winkler, Lisa V.
name: Brochard, Pierre
name: Geskus, Dimitri
name: van der Slot, Peter J. M.
name: Nölleke, Christian
name: Boller, Klaus-J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Hybrid integrated diode lasers based on combining semiconductor optical amplifiers with low-loss Si3N4-based feedback circuits enable great laser performance for advanced photonic circuits. In particular, using high-Q Si3N4 ring resonators for frequency-selective feedback provides wide spectral coverage, mode-hop free tuning, and high frequency stability on short timescales, showing as ultra-narrow intrinsic linewidths. However, many applications also require long-term stability, which can be provided by locking the laser frequency to a suitable reference. We present the stabilization of a hybrid-integrated laser, which is widely tunable around the central wavelength of 1550 nm, to a fiber-based optical frequency discriminator (OFD) and to an acetylene absorption line. By locking the laser to the OFD, the laser's fractional frequency stability is improved down to 2.1$\cdot$10$^{-12}$ over an averaging time of 0.5 ms. For absolute stability over longer times of several days, we successfully lock the laser frequency to an acetylene absorption line. This limits the frequency deviations of the laser to a range of less than 12 MHz over 5 days.
description: 12 pages, 6 figures
Electronic properties of graphyne-$N$ monolayer and its multilayer: even-odd effect and topological nodal line semimetalic phases
Creators: name: Kawakami, Takuto
name: Nomura, Takafumi
name: Koshino, Mikito
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the electronic structure and topological properties of monolayer and ABC-stacked multilayer of graphyne-$N$, which are a family of planar carbon sheets consisting of $sp$ and $sp_2$-bonding. By using the density-functional theory and the effective continuum model, we find a striking even-odd effect in the dependence of the band structure on $N$ (the number of carbon-carbon triple bonds between neighboring benzene rings). Specifically, even-$N$ graphyne monolayer has doubly-degenerate conduction and valence bands near the Fermi energy, and in its ABC multilayer, the band inversion of the doubly-degenerate bands leads to a nodal-line semimetal phase with non-trivial $\mathbb{Z}_2$ monopole charge. In contrast, odd-$N$ monolayer has singly-degenerate bands in separate valleys, and its ABC multilayer can have only $\mathbb{Z}_2$-trivial nodal lines. ABC graphynes with larger $N$ tend to be trivial insulators because of smaller interlayer coupling, while the external pressure induces a topological phase transition from the trivial phase to the nodal line semimetal phase.
description: 16 pages, 13 figures, 4 tables
title: Gemeindefinanz-Statistik für das Jahr 1930
title: Statistische Mittheilungen betreffend den Kanton Zürich
titleType: AlternativeTitle
title: Statistische Mitteilungen betreffend den Kanton Zürich
titleType: AlternativeTitle
title: Nebst Anhang: Die Armenunterstützungsverhältnisse und die Staatsbeiträge an die Armenausgaben der Gemeinden vom Jahre 1930
titleType: Subtitle
Creators: name: (:Unkn) Unknown
Publisher: name: Geschwister Ziegler & Co.
Year: 1932
Subjects: subject: 314 Allgemeine Statistiken zu Europa
subject: 336 Öffentliche Finanzen
subject: Kanton Zürich
subject: Amtliche Statistik
subject: Gemeindefinanzwirtschaft
subject: Finanzstatistik
subject: Steuerstatistik
subject: Sozialstatistik

description: Inhalt: Textteil (Die Betriebsrechnung ; Die wirklichen Betriebseinnahmen und Ausgaben nach ihrer Art ; Die Aufwendungen des Staates und der Gemeinden für das Volksschul- und Armenwesen ; Das Gemeindevermögen ; Die Gemeindesteuern) ; Tabellarischer Teil (Gemeindeweise Darstellungen ; Bezirksweise Zusammenstellungen) ; Übersicht der Gesamt-Ergebnisse ; Die Gemeindesteuer-Verhältnisse ; Anhang (Die Armenunterstützungs-Verhältnisse und die Staatsbeiträge an die Armenausgaben der Gemeinden vom Jahre 1930).
Near Lightcone Thermal Conformal Correlators and Holography
Creators: name: Parnachev, Andrei
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Heavy-heavy-light-light (HHLL) correlators of pairwise identical scalars in CFTs with a large central charge in any number of dimensions admit a double scaling limit where the ratio of the heavy conformal dimension to the central charge becomes large as the separation between the light operators becomes null. In this limit the stress tensor sector of a generic HHLL correlator receives contributions from the multi stress tensor operators with any number of stress tensors, as long as their twist is not increased by index contractions. We show how one can compute this leading twist stress tensor sector when the conformal dimension of the light operators is large and the stress tensor sector approximates the thermal CFT correlator. In this regime the value of the correlator is related to the length of the spacelike geodesic which approaches the boundary of the dual asymptotically AdS spacetime at the points of light operator insertions. We provide a detailed description of the infinite volume limit. In two spacetime dimensions the HHLL Virasoro vacuum block is reproduced, while in four spacetime dimensions the result is written in terms of elliptic integrals.
description: 6 pages, 1 figure; v2: minor changes, references added
title: Integrating renewable energy sources in marinas and nautical ports in Croatia : an innovative smart grid concept and business plan
Creators: name: Preda, Mircea
Publisher: name: TU Wien
Year: 2017
Subjects: subject: Marina
subject: Sustainability
subject: Sustainable development
subject: Smart-grid
subject: IOT Platform
subject: Environmental management
subject: Solar-Wind

description: Main objectives of this master thesis are to identify and assess the introduction of renewable energy sources in marinas and nautical ports, jointly with existing environmental programs building on the quality and environmental management and monitoring differentiators and demand estimation tools to achieve competitive advantage. The document explores the current status and drivers of smart grid disruptive technologies, as well as latest technological concepts to propose an integrated solution driving sustainable development towards the achievement of a zero emission marina. With the purpose to address such need, a smart grid concept is proposed integrating a hybrid renewable energy sources distribution system, energy management software and an IOT platform as a turnkey solution. The current scarcity of RES integration in marina operation, as well as increasing favorable market pull and technology push policies, have created an environment fostering innovation with first-mover advantage opportunities. With the emergence of such turn-key solution integrators, the thesis also aims at establishing an efficient methodology for such vehicles to provide a viable venture with a strong emphasis on customer preferred product attributes. Towards the achievement of the proposed objectives the author has decided on international literature review, an electronic audit of official websites of the marina operator electronic survey and business plan for the proposed concept. The results confirm the initial hypotheses and establish in a convincing matter that RES can be integrated into marina operators in line with current environmental programs through a viable smart grid concept. The originality of this master thesis lies in research of recent, international literature on the subject and empirical research performed resulting in the start-up launch proposal of an innovative turn-key solution integrator for marinas and nautical ports in Croatia.
Stress and deformation build-up in bonded composite patch repair
Creators: name: Curiel, Tomer Maurice
Publisher: name: University of British Columbia
Year: 2010

description: Bonded composite patch repairs have many advantages over traditional riveted doubler repairs and have been used successfully in a number of repair programs. A mismatch in the coefficients of thermal expansions of the patch and substrate causes thermally induced residual stresses, which are detrimental to the long-term service life of the repair. A dynamic mechanical thermal analyzer bimaterial beam technique is developed that can be used in a variety of different configurations and loading conditions for innovative and versatile characterization of time, temperature, and cure dependant material properties. The technique is first used to determine the stress relaxation modulus of a viscoelastic material bonded to an elastic substrate. The relaxation modulus of Lexan specimens are characterized, first as monolithic beams and then bonded to an elastic substrate. Results show that the relaxation modulus of Lexan can be determined from bimaterial beam relaxation tests. The temperature and cure dependant modulus of FM300 adhesive is then characterized by subjecting a bimaterial beam to a dynamic displacement while curing isothermally at a variety of temperatures. The results are fit to a model that defines the instantaneous modulus as a function of two variables - the instantaneous temperature and the instantaneous glass transition temperature. The technique is then extended to quantify the development of process induced residual stresses in beam specimens designed to simulate a bonded composite patch repair. In these beam specimens, residual stresses correspond to an out of plane deflection that can be monitored in-situ throughout a complete cure cycle. Specimens, consisting of a steel shim, an FM300 adhesive layer, and an AS4/3501-6 [0°]₂ composite patch, are subjected to a variety of cure cycles to determine the effects of cure time and temperature on the out of plane deflection in single- and multi-hold cycles. The experimental results are then compared to those obtained from a cure hardening instantaneously linear elastic (CHILE) model modified to include thermal softening. Results show that a reduction in thermally induced residual stresses is possible by modifying the cure cycle. Model sensitivities, cycle times, real versus idealized cycles, and the effects of thermal softening are also investigated. The DMA beam technique is shown to be an effective means of material characterization, as well as monitoring the out of plane deflection of bonded composite patch repair specimens throughout a cure cycle. Insight gained from these measurements can be used to optimize cure cycles so as to reduce the thermally induced residual stresses in real applications of bonded composite patch repairs.
Stability of the mixed phase in hybrid stars
Creators: name: Benhar, Omar
name: Rubino, Roberto
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The transition from hadronic matter to quark matter in the core of neutron stars is likely to be associated with the appearance of a mixed phase, leading to a smooth variation of the star density profile. We discuss the results of a systematic study of the properties of the mixed pase upon Coulomb and surface effects. A state of the art nonrelativistic equation of state of nuclear matter has been used for the low density phase, while quark matter has been described within the MIT bag model, including the effect of perturbative one-gluon exchange interactions. The implications for neutron star structure are discussed.
description: Submitted to Astronomy & Astrophysics
PANORAMA COMPETITIVO DO AGRONEGÓCIO BRASILEIRO, LOGÍSTICA DE TRANSPORTE E ARMAZENAMENTO E A IMPLEMENTAÇÃO DO PROTOCOLO DE CARTAGENA
Creators: name: Vieira Filho, José Eustáquio Ribeiro
name: Borges, Izaias Carvalho
name: Silveira, José Maria Ferreira Jardim Da
name: Vieira Filho, José Eustáquio Ribeiro
name: Borges, Izaias Carvalho
name: Silveira, José Maria Ferreira Jardim Da
Publisher: name: Unknown
Year: 2006
Subjects: subject: Agribusiness
subject: Agricultural and Food Policy
subject: Protocolo de Cartagena
subject: Transgênicos
subject: Competitividade e Logística

description: O presente trabalho tem como objetivo analisar o panorama competitivo do agronegócio brasileiro (questões logísticas) diante da implementação do Protocolo de Cartagena sobre Biossegurança (PC). Em termos gerais, tal protocolo contribui para que o fluxo transfronteiriço de Organismos Vivos Modificados (OVMs) seja transparente, visando medidas de segurança de proteção ao meio ambiente e levando em conta os riscos à saúde humana. No presente estudo, tem-se a confirmação de que, para os países exportadores, a escolha da identificação da carga com OVM em “pode conter” ou “contém” é de fundamental importância, já que tal decisão poderá acarretar custos extras, além aumentar de forma imprevisível os custos de transação, principalmente na interface entre portos do país exportador e importador. Não há, em contrapartida, evidências claras de que a expressão “contém” garanta benefícios correspondentes, que possam ser captados pelas partes envolvidas (produtores, intermediários e consumidores), assim como o cumprimento dos objetivos do Protocolo.
GESTÃO INTEGRADA E MEIO AMBIENTE EM UM EMPREENDIMENTO DE FRUTICULTURA
Creators: name: Schenini, Pedro Carlos
name: Silva, Fernando Amorim Da
name: Guindani, Roberto Ari
name: Rensi, Francini
name: Schenini, Pedro Carlos
name: Silva, Fernando Amorim Da
name: Guindani, Roberto Ari
name: Rensi, Francini
Publisher: name: Unknown
Year: 2006
Subjects: subject: Crop Production/Industries
subject: Farm Management
subject: Meio Ambiente
subject: Desenvolvimento Sustentável
subject: Sistema de Gestão Ambiental (SGA)
subject: NBR ISO 14.000
subject: Gestão Integrada (GI).

description: A atividade humana nas últimas décadas resultou em níveis inimagináveis de destruição e degradação, produzindo impactos negativos no meio ambiente e na qualidade de vida das pessoas. Em contrapartida a isso, governos, empresas, organizações sociais e outros membros da comunidade em geral têm-se preocupado em minimizar ou eliminar essa problemática sócio-ambiental. Diante desse contexto, o presente artigo teve por objetivo identificar a sistemática que permite a implantação da Gestão Integrada em um empreendimento de fruticultura, visando a conformidade em matéria de meio ambiente. Assim, foi realizado um estudo de caso com abordagem qualitativa, no qual foram identificados e analisados processos, legislação, normas e documentação necessária para implantar o uso da gestão integrada, visando a obtenção da conformidade na gestão ambiental, através de ações éticas e tecnicamente responsáveis. Os resultados obtidos apresentaram recomendações de documentos com os procedimentos, instruções e formulários para registro e demonstração do cumprimento efetivo das leis e normas de qualidade ambiental.
SeMemNN: A Semantic Matrix-Based Memory Neural Network for Text Classification
Creators: name: Fu, Changzeng
name: Liu, Chaoran
name: Ishi, Carlos Toshinori
name: Yoshikawa, Yuichiro
name: Ishiguro, Hiroshi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Text categorization is the task of assigning labels to documents written in a natural language, and it has numerous real-world applications including sentiment analysis as well as traditional topic assignment tasks. In this paper, we propose 5 different configurations for the semantic matrix-based memory neural network with end-to-end learning manner and evaluate our proposed method on two corpora of news articles (AG news, Sogou news). The best performance of our proposed method outperforms the baseline VDCNN models on the text classification task and gives a faster speed for learning semantics. Moreover, we also evaluate our model on small scale datasets. The results show that our proposed method can still achieve better results in comparison to VDCNN on the small scale dataset. This paper is to appear in the Proceedings of the 2020 IEEE 14th International Conference on Semantic Computing (ICSC 2020), San Diego, California, 2020.
Definition and Classification of Fermi Surface Anomalies
Creators: name: Lu, Da-Chuan
name: Wang, Juven
name: You, Yi-Zhuang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Superconductivity (cond-mat.supr-con)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose that the Fermi surface anomaly of symmetry group $G$ in any dimension is universally classified by $G$-symmetric interacting fermionic symmetry-protected topological (SPT) phases in $(0+1)$-dimensional spacetime. The argument is based on the perspective that the gapless fermions on the Fermi surface can be viewed as the topological boundary modes of Chern insulators in the phase space (position-momentum space). Given the non-commutative nature of the phase space coordinates, we show that the momentum space dimensions should be counted as negative dimensions for SPT classification purposes. Therefore, the classification of phase-space Chern insulators (or, more generally fermionic SPT phases) always reduces to a $(0+1)$-dimensional problem, which can then be answered by the cobordism approach. In addition to the codimension-1 Fermi surface case, we also discuss the codimension-$p$ Fermi surface case briefly. We provide concrete examples to demonstrate the validity of our classification scheme, and make connections to the recent development of Fermi surface symmetric mass generation.
description: 13 pages + references, 2 figures, 2 tables. Update Tab. II, clarifications to codimension-p Fermi surface, and references added
title: An analysis on the effects of disruptive mega-trends on work : a study on Austria
Creators: name: Barban, Alexandre Franz
Publisher: name: TU Wien
Year: 2017
Subjects: subject: Mega-trends
subject: technological revolution
subject: digitalization
subject: Neo-Schumpeterian
subject: Schumpeter
subject: Kondratieff

description: The world is changing, and it is changing quicker and quicker. Today it is about digitalization, tomorrow it could be about self-driving cars. Those rapid changes might put some pressure on the relation some category of workers have with work. The aim of this paper is to understand where we are today when referring to innovations. For this reason, the academic question of this study is "What could be the effect of the current mega trends on work in Austria?" The research question is divided into three sub-questions. The first one is about the possibility of facing a potential Technological Revolution. A detailed study of the existing theories from Kondratieff, Schumpeter and the Neo-Schumpeterian school from the eighties, associated with a pool of coming technologies as forecasted by Gartner, is the method used to answer this question. The results are showing an increased probability to face a new Technological Revolution. The second sub-question is about the destructive potential on work those new technologies might have in Austria. A detailed overview of fundamental indicators for Austria, combined with studies about the effect of digitalization on work, and with a home-developed scenario about self driving cars will answer this question. Again, the results are pointing to a turbulent direction. The last sub question was about the resilience of Austria to sustain this potential transformation phase. A set of interviews with professionals from the Austrian scene showed that the resilience is moderately high, with one main topic that needs to be improve: continuous education. With this conclusion, it is recommend to focus on the following problem: How to bring the right training to the persons who need it. Further set of studies how to do this would be welcome.
Αξιολόγηση του Εκπαιδευτικού Έργου Ι. Αξιολόγηση από εκπαιδευμένους αξιολογητές ΙΙ. Εσωτερική αξιολόγηση από τη Διεύθυνση του Σχολείου
Creators: name: Avraam Sachpatzidis
Publisher: name: figshare
Year: 2020
Subjects: subject: 130303 Education Assessment and Evaluation
subject: FOS: Educational sciences

description: Η αξιολόγηση του εκπαιδευτικού έργου παρουσιάζει μεγάλο ενδιαφέρον τις τελευταίες δεκαετίες από τους ερευνητές της εκπαιδευτικής αξιολόγησης τόσο σε εθνικό όσο και σε διεθνές επίπεδο. Το ενδιαφέρον αυτό συνδέεται άμεσα με την αναγκαιότητα για συνεχή βελτίωση της ποιότητας της παρεχόμενης εκπαίδευσης. Οι σύγχρονες κοινωνικές, οικονομικές, πολιτισμικές και τεχνολογικές αλλαγές επηρεάζουν καίρια την εκπαίδευση και ως προς τους στόχους της και ως προς τις δραστηριότητες που υλοποιούνται στο πλαίσιό της και ως προς τα αποτελέσματά της. Η διαρκής αναμόρφωση στοιχείων της εκπαίδευσης κρίνεται απαραίτητη- μέσα ωστόσο από μια συστηματική διαδικασία παρακολούθησης της ποιότητας και της αποτελεσματικότητάς τους. Η διερεύνηση τρόπων βελτίωσης της εκπαίδευσης αποτελεί τα τελευταία χρόνια στόχο της αξιολόγησης και έργο διάφορων ερευνητικών σχολών και ποικίλων εκπαιδευτικών φορέων και κρατικών οργανισμών διεθνώς.
Efficient physics-informed neural networks using hash encoding
Creators: name: Huang, Xinquan
name: Alkhalifah, Tariq
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Physics-informed neural networks (PINNs) have attracted a lot of attention in scientific computing as their functional representation of partial differential equation (PDE) solutions offers flexibility and accuracy features. However, their training cost has limited their practical use as a real alternative to classic numerical methods. Thus, we propose to incorporate multi-resolution hash encoding into PINNs to improve the training efficiency, as such encoding offers a locally-aware (at multi resolution) coordinate inputs to the neural network. Borrowed from the neural representation field community (NeRF), we investigate the robustness of calculating the derivatives of such hash encoded neural networks with respect to the input coordinates, which is often needed by the PINN loss terms. We propose to replace the automatic differentiation with finite-difference calculations of the derivatives to address the discontinuous nature of such derivatives. We also share the appropriate ranges for the hash encoding hyperparameters to obtain robust derivatives. We test the proposed method on three problems, including Burgers equation, Helmholtz equation, and Navier-Stokes equation. The proposed method admits about a 10-fold improvement in efficiency over the vanilla PINN implementation.
Gap-type Particle Acceleration in the Magnetospheres of Rotating Supermassive Black Holes
Creators: name: Katsoulakos, Grigorios
name: Rieger, Frank M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The detection of rapidly variable gamma-ray emission in active galactic nuclei has generated renewed interest in magnetospheric particle acceleration and emission scenarios. In order to explore its potential, we study the possibility of steady gap acceleration around the null surface of a rotating black hole magnetosphere. We employ a simplified (1D) description along with the general relativistic expression of Gauss's law, and we assume that the gap is embedded in the radiation field of a radiatively inefficient accretion flow. The model is used to derive expressions for the radial distribution of the parallel electric field component, the electron and positron charge density, the particle Lorentz factor, and the number density of $γ$-ray photons. We integrate the set of equations numerically, imposing suitable boundary conditions. The results show that the existence of a steady gap solution for a relative high value of the global current is in principle possible if charge injection of both species is allowed at the boundaries. We present gap solutions for different choices of the global current and the accretion rate. When put in context, our results suggest that the variable very high energy $γ$-ray emission in M87 could be compatible with a magnetospheric origin.
description: 20 pages, 11 figures; ApJ accepted; minor typos fixed to match published version
Framework for Strategic Guidance towards a Systemic Holistic Model for Thrivability
Creators: name: Fedeli, Morris
Publisher: name: University of Southern Queensland
Year: 2024
Subjects: THRIVE Framework
Thrivability
Sustainability
Business
Models
Regenerative

description: A framework for strategic guidance towards a systemic holistic model for thrivability

The fate of society is at a critical juncture, and unless we take immediate action to transform our way of life, we are destined for extinction. In recent years, the study of designing regenerative ecosystems has gained momentum as a means to achieve sustainability. However, to create a thriving society, we must develop sustainable entity models based on proven empirical outcomes that are scalable across regions, sectors, and organisations. This study leverages machine learning (a branch of artificial intelligence) to link categorical business model patterns to empirical sustainability performance measures, informing management theory and determining which business models are more sustainable at each scale level. Employing a design science research approach, the study develops nascent theory, devising the basis for technological rules, and creating the THRIVE Framework and Platform artefact. The THRIVE Framework includes 12 Foundational Focus Factors, and the THRIVE Platform is a software tool for demonstrating the impact of sustainable business models. The study also showcases the impact of the top 30 keystone actors through the Seafood Stewardship Index case study. Built on the framework for strategic sustainable development, the THRIVE Framework and THRIVE Platform features scenario analysis, allowing for experimentation and guiding society towards thrivable transformations. This study represents a crucial step towards a thrivable future and highlights the urgent need for immediate action at speed, scale, and scope. Thrivability is within our reach!
Hydrodynamics of Internal Shocks in Relativistic Outflows
Creators: name: Kino, M.
name: Mizuta, A.
name: Celotti, A.
name: Yamada, S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the hydrodynamical effects of two colliding shells, adopted to model internal shocks in various relativistic outflows such as gamma-ray bursts and blazars. We find that the density profiles are significantly affected by the propagation of rarefaction waves. A split-feature appears at the contact discontinuity of the two shells. The shell spreading with a few ten percent of the speed of light is also shown to be a notable aspect. The conversion efficiency of the bulk kinetic energy to internal one shows deviations from the widely-used inelastic two-point-mass-collision model. Observational implications are also shortly discussed.
description: 6 pages, 4 figures, Proceeding of International Symposium on High Energy Gamma-ray Astronomy (July 26-30, 2004, Heidelberg, Germany)
A EVOLUÇÃO DAS ATIVIDADES E RENDAS NÃO-AGRÍCOLAS NA PARAÍBA NOS ANOS 90
Creators: name: Lima, Joao Ricardo Ferreira De
name: Lima, Joao Ricardo Ferreira De
Publisher: name: Unknown
Year: 2006
Subjects: subject: Community/Rural/Urban Development
subject: ORNA
subject: Pluriatividade
subject: Paraíba
subject: Não-agrícola.

description: O problema central deste trabalho é entender a evolução das ocupações e das rendas das famílias rurais paraibanas nos anos 90. O objetivo é identificar a importância das atividades e das rendas não-agrícolas, além das transferências públicas/privadas para a melhoria e/ou manutenção das famílias nas áreas rurais. Para isto, analisamos a evolução das famílias rurais agrícolas, das famílias rurais não-agrícolas e das famílias rurais pluriativas nos anos 90, divididas entre empregadores, conta-própria, assalariados e não-ocupados. Estudamos também o comportamento dos rendimentos obtidos (pós plano Real) e a proporção de cada um no total. Comparamos ainda os rendimentos das famílias rurais agrícolas, pluriativas e não-agrícolas, de acordo com o estrato de área dos estabelecimentos. A metodologia utilizada foi uma pesquisa bibliográfica baseada em trabalhos produzidos dentro do projeto RURBANO e a análise das informações dos microdados das PNAD (Pesquisa Nacional por Amostra de Domicílio) do IBGE, relativas ao rural paraibano nos anos 90. A exemplo do que ficou demonstrado na situação nacional e regional, na Paraíba também se constata um crescimento das chamadas ORNA (ocupações rurais não-agrícolas), do aumento no número das famílias pluriativas e não-agrícolas residentes em áreas rurais, além de uma grande disparidade entre as rendas obtidas pelas famílias exclusivamente agrícolas daquelas não-agrícolas e pluriativas, principalmente nos anos secos. As famílias pluriativas dependem menos das transferências públicas e privadas, comparando com as famílias agrícolas. Constatamos que no período pós plano Real, as rendas agrícolas apresentam um movimento de forte queda e as rendas não-agrícolas possuem um movimento inverso, sempre crescendo a cada ano.
Rooted Spiral Trees on Hyper-cubical lattices
Creators: name: Sumedha
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study rooted spiral trees in 2,3 and 4 dimensions on a hyper cubical lattice using exact enumeration and Monte-Carlo techniques. On the square lattice, we also obtain exact lower bound of 1.93565 on the growth constant $λ$. Series expansions give $θ=-1.3667\pm 0.001$ and $ν= 1.3148\pm0.001$ on a square lattice. With Monte-Carlo simulations we get the estimates as $θ=-1.364\pm0.01$, and $ν= 1.312\pm0.01$. These results are numerical evidence against earlier proposed dimensional reduction by four in this problem. In dimensions higher than two, the spiral constraint can be implemented in two ways. In either case, our series expansion results do not support the proposed dimensional reduction.
description: replaced with published version
The Impact of Cosmic Rays on Thermal Instability in the Circumgalactic Medium
Creators: name: Butsky, Iryna S.
name: Fielding, Drummond B.
name: Hayward, Christopher C.
name: Hummels, Cameron B.
name: Quinn, Thomas R.
name: Werk, Jessica K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Large reservoirs of cold (~ 10^4 K) gas exist out to and beyond the virial radius in the circumgalactic medium (CGM) of all types of galaxies. Photoionization modeling suggests that cold CGM gas has significantly lower densities than expected by theoretical predictions based on thermal pressure equilibrium with hot CGM gas. In this work, we investigate the impact of cosmic ray physics on the formation of cold gas via thermal instability. We use idealized three-dimensional magnetohydrodynamic simulations to follow the evolution of thermally unstable gas in a gravitationally stratified medium. We find that cosmic ray pressure lowers the density and increases the size of cold gas clouds formed through thermal instability. We develop a simple model for how the cold cloud sizes and the relative densities of cold and hot gas depend on cosmic ray pressure. Cosmic ray pressure can help counteract gravity to keep cold gas in the CGM for longer, thereby increasing the predicted cold mass fraction and decreasing the predicted cold gas inflow rates. Efficient cosmic ray transport, by streaming or diffusion, redistributes cosmic ray pressure from the cold gas to the background medium, resulting in cold gas properties that are in-between those predicted by simulations with inefficient transport and simulations without cosmic rays. We show that cosmic rays can significantly reduce galactic accretion rates and resolve the tension between theoretical models and observational constraints on the properties of cold CGM gas.
description: Accepted for publication in ApJ; 28 pages, 15 figures. Simulation movies can be found at https://www.irynabutsky.me/movies
Contribution of microlensing to X-ray variability of distant QSOs
Creators: name: Zakharov, Alexander F.
name: Popovic, Luka C.
name: Jovanovic, Predrag
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Cosmologically distributed gravitational microlenses could be localized in galaxies (or even in bulge or halo of gravitational macrolenses) or could be distributed in a uniform way. We have analyzed both cases of such distributions. We found that the optical depth for gravitational microlensing caused by cosmologically distributed deflectors could be significant and could reach $10^{-2} - 0.1$ at $z\sim 2$. This means that cosmologically distributed deflectors may contribute significantlly to the X-ray variability of high-redshifted QSOs ($z>2$). Considering that the upper limit of the optical depth ($τ\sim 0.1$) corresponds to the case where dark matter forms cosmologically distributed deflectors, observations of the X-ray variations of unlensed QSOs can be used for the estimation of the dark matter fraction of microlenses.
description: 6 pages, to appear in "Impact of Gravitational Lensing on Cosmology", IAU Symposium 225, eds. Y. Mellier & G. Meylan
Interaction driven polarization shift in the $t-V-V'$ lattice fermion model at half filling: emergent Haldane phase
Creators: name: Hetényi, Balázs
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the $t-V-V'$ model in one dimension at half-filling. It is known that for large enough $V$ fixed, as $V'$ is varied, the system goes from a charge-density wave into a Luttinger liquid, then a bond-order, and then a second charge density wave phase. We find that the Luttinger liquid state is further split into two, separating parts with distinct values of the many-body polarization Berry phase. Inside this phase, the variance of the polarization is infinite in the thermodynamic limit, meaning that even if the polarization differs, it would not be measurable. However, in the gapped phases on each side of the Luttinger liquid, the polarization takes a different measurable value, implying topologically distinction. The key difference is that the large-$V'$ phases are link-inversion symmetric, while the small-$V'$ one is site-inversion symmetric. We show that large-$V'$ phase can be related to an $S=1$ spin chain, and exhibits many features of the Haldane phase. The lowest lying states of the entanglement spectrum display different degeneracies in the two cases, and we also find string order in the large-$V'$ phase. We also study the system under open boundary conditions, and suggest that the number of defects is related to the topology.
The Static Penta-quark Potential in Lattice QCD
Creators: name: Okiharu, Fumiko
name: Suganuma, Hideo
name: Takahashi, Toru T.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We perform the first study for the static penta-quark (5Q) potential in lattice QCD with $β$=6.0 and $16^3 \times 32$ at the quenched level. Accurate results of the 5Q potential are extracted from the 5Q Wilson loop using the smearing method, which enhances the ground-state component. The tetra-quark potential for the $\rm QQ$-$\rm {\bar Q}{\bar Q}$ system is also studied in lattice QCD. The multi-quark potentials are found to be well described as a sum of the one-gluon-exchange Coulomb term and the multi-Y linear confinement term based on the flux-tube picture.
description: Talk given at the International Workshop on PENTAQUARK04, SPring-8, Japan, 20-23 July 2004
Applications of deep learning in stock market prediction: recent progress
Creators: name: Jiang, Weiwei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Finance (q-fin.ST)
subject: Machine Learning (cs.LG)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: Stock market prediction has been a classical yet challenging problem, with the attention from both economists and computer scientists. With the purpose of building an effective prediction model, both linear and machine learning tools have been explored for the past couple of decades. Lately, deep learning models have been introduced as new frontiers for this topic and the rapid development is too fast to catch up. Hence, our motivation for this survey is to give a latest review of recent works on deep learning models for stock market prediction. We not only category the different data sources, various neural network structures, and common used evaluation metrics, but also the implementation and reproducibility. Our goal is to help the interested researchers to synchronize with the latest progress and also help them to easily reproduce the previous studies as baselines. Base on the summary, we also highlight some future research directions in this topic.
description: 97 pages, 12 figures, 14 tables
Relativistic calculations of the energies of the low-lying $1sns$, $1snp$, $1snd$ states and the probabilities of the one-photon $1snl\to 1sn'l'$ transitions in heliumlike uranium
Creators: name: Dulaev, N. K.
name: Kaygorodov, M. Y.
name: Malyshev, A. V.
name: Tupitsyn, I. I.
name: Shabaev, V. M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: For heliumlike uranium, the energies of the singly-excited $1sns$, $1snp$, and $1snd$ states with $n\leq 4$ and the probabilities of the one-photon $1s3d\to 1s2p$, $1s3p\to 1s2s$, $1s3p\to 1s2p$ and $1s4d\to 1s2p$ transitions are evaluated. The calculations are performed within the Breit approximation using the configuration-interaction method in the basis of the Dirac-Fock-Sturm orbitals. The QED corrections to the energy levels are calculated employing the model-QED-operator approach. The nuclear recoil, frequency-dependent Breit-interaction, nuclear polarization, and nuclear deformation corrections are taken into account as well.
title: Identifying and tackling the main factors causing unsustainability in construction industry in Slovakia
Creators: name: Lukačovič, Róbert
Publisher: name: TU Wien
Year: 2017
Subjects: subject: sustainability
subject: construction industry
subject: innovation
subject: environment

description: Engineering and construction industry plays a significant role in growing Slovak economy. Investors have only limited support in vague and unclear urban- and zone-planning data and local community is often omitted from the area development planning activities. Construction plans are often subject to significant changes during the preparation and construction phase, and include imperfections between respective parts of the plans. Vast majority of the construction projects incur significant cost and time-schedule overruns, often caused by investor's unclear project definition, unbalanced contracts and adaptations of building plans during construction projects. The environment both locally and globally is heavily affected by construction activities and building operations. Overworks during building phase and suboptimal design solutions has significant negative impact on the environment during entire project lifecycle. Based on literature research, analysis of construction projects case studies, investigation of conference reports and reviews, in combination with interviews with leading specialist on Slovak market, three main factors of unsustainability in construction industry in Slovakia have been identified and both triggers and actors for positive change have been determined. The the respective problem is currently discussed on the Slovak market, however the individual topics are considered as isolated cases, without broader understanding of connections and relationships between them. The thesis offers new perspective on the topic with outlined actions to be taken.