cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spin-wave theory in a randomly disordered lattice: A Heisenberg ferromagnet
Creators: name: Weiss, Z. J.
name: Massih, A. R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Starting from the hamiltonian for the Heisenberg ferromagnet which comprise randomly distributed nonmagnetic ions as impurities in a Bravais lattice, we express the spin operators by means of the Dyson-Maleev transformation in terms of the Bose operators of the second quantization. Then by using methods of quantum statistical field theory, we derive the partition function and the free energy for the system. We adopt the Matsubara thermal perturbation method to a portion of the hamiltonian which describes the interaction between magnons and the stationary field of nonmagnetic ions. Upon averaging over all possible distributions of impurities, we express the free energy of the system as a function of the mean impurity concentration. Subsequently, we set up the double-time single particle Green function at temperature T in the momentum space in terms of magnon operators and derive the equation of motion for the Green function through the Heisenberg equation of motion and then solve the resulting equation. From this, we calculate the self-energy and then the spectral density for the system. We apply the formalism to the case of the simple cubic lattice and compute the density of states, the spectral density function and the lifetime of the magnons as a function of energy for several values of the mean concentration of nonmagnetic ions in the lattice. We calculate magnon energy spectrum as a function of average impurity concentration fraction c, which shows that for low lying states, the excitation energy increases continuously with c in the studied range 0.1 < c < 0.7. We use the spectral density function to compute some thermal quantities. We have obtained closed form expressions for the configurationally averaged physical quantities of interest in a unified fashion as functions of c to any order of c applicable below a critical percolation concentration.
description: 61 pages, 10 figures (main text)
A model for periodic blazars
Creators: name: Sobacchi, Emanuele
name: Sormani, Mattia C.
name: Stamerra, Antonio
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We describe a scenario to explain blazar periodicities with timescales of $\sim$ few years. The scenario is based on a binary super-massive black hole (SMBH) system in which one of the two SMBH carries a jet. We discuss the various mechanisms that can cause the jet to precess and produce corkscrew patterns through space with a scale of $\sim$ few pc. It turns out that the dominant mechanism responsible for the precession is simply the imprint of the jet-carrying SMBH orbital speed on the jet. Gravitational deflection and Lense-Thirring precession (due to the gravitational field of the other SMBH) are second order effects. We complement the scenario with a kinematical jet model which is inspired to the spine-sheath structure observed in M87. One of the main advantages of such a structure is that it allows the peak of the synchrotron emission to scale with frequency according to $νF\propto ν^ξ$ as the viewing angle is changed, where $ξ$ is not necessarily 3 or 4 as in the case of jets with uniform velocity, but can be $ξ\sim 1$. Finally, we apply the model to the source PG1553+113, which has been recently claimed to show a $T_{\rm obs}=(2.18\pm 0.08)\text{ yr}$ periodicity. We are able to reproduce the optical and gamma-ray light curves and multiple synchrotron spectra simultaneously. We also give estimates of the source mass and size.
description: Accepted for publication in MNRAS
ERICC Working Paper _ Education Data Systems in Northwest Syria
Creators: name: ERICC Consortium
name: Nasser, Rabie
name: Meskhi, Michael
name: Carter, Ann
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 390201
subject: Education policy

description: Syria has been engulfed in a violent conflict since 2011 which has severely damaged the country’s foundations of peace, justice and development. The Northwest of Syria (henceforth NW Syria) has witnessed brutal military operations that have led to a huge toll of people killed and injured, missing, tortured and forcibly displaced. In addition to a destruction of infrastructure, there has been degradation of social relations and environment, and distortion of public institutions.The education sector and learning process have suffered from severe damages to the drivers of learning, namely, accessibility, quality, continuity and coherence. This data systems report aims to provide in-depth insights on the current landscape of education in North West Syria, focusing on existing data systems, including information on access, quality, continuity, and identifying notable data gaps.The study is based on key informant interviews (KIIs) with key stakeholders who have knowledge of the education data systems in NW Syria. This paper presents findings on the current education data systems and explores what types and quality of data they collect. It identifies challenges affecting the data systems from three angles, namely, context, outputs and processes, in addition to suggesting policy options.Context: The conflict significantly disrupted Syria's education data systems, causing fragmentation, and capacity and infrastructure damage. Pre-conflict educational institutions in NW Syria became nonfunctional, and data collection ceased in many areas. In the absence of a coherent national system, multiple non-state actors (Syrian Interim Government (SiG) and Syria Salvation Government (SSG)), external actors (Turkish government), humanitarian organisations (UN agencies, international non-governmental organisations - INGOs), and local civil society organisations and initiatives (Assistance Coordination Unit – ACU, and non-governmental organisations - NGOs), have attempted to fill the gap.The current education data systems operate in an environment where there is lack of security and conflicting priorities among the key actors. There is a lack of coordination and integration among the data systems, and further challenges linked to the dominance of short-term humanitarian approaches, and the dependency on funding from external donors.
Finite-dimensional collisionless kinetic theory
Creators: name: Burby, J. W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A collisionless kinetic plasma model may often be cast as an infinite-dimensional noncanonical Hamiltonian system. I show that, when this is the case, the model can be discretized in space and particles while preserving its Hamiltonian structure, thereby producing a finite-dimensional Hamiltonian system that approximates the original kinetic model. I apply the general theory to two example systems: the relativistic Vlasov-Maxwell system with spin, and a gyrokinetic Vlasov-Maxwell system.
description: 12 pages, 2 columns. V2 includes funding acknowledgments
Algorithmen und Doomscrolling: Welche neuen Risiken für Jugendliche im Umgang mit sozialen Medien entstehen und wie die Soziale Arbeit sie im Umgang damit unterstützen kann
Creators: name: Cucchi, Benjamin
name: Petrecca, Luca
Publisher: name: Zenodo
Year: 2023

description: Der Umgang mit dem digitalen Wandel ist von grosser Bedeutung für die Soziale Arbeit. Die zunehmende Verschiebung der Lebenswelt Jugendliche in die digitale Welt und sozialen Medien fordert neue Massnahmen und bringt neue Gefahren mit sich und verändern Erfahrungen, Sozialisation und Kompetenzerarbeitung der Jugendlichen. Ziel dieser Arbeit ist es, die neusten Dynamiken von sozialen Medien zu erfassen, Risiken zu benennen und dadurch einen neuen Fokus der Präventionsarbeit der Sozialen Arbeit festzulegen. Dies geschieht durch eine Analyse der Risikofaktoren, gefolgt vom Kompetenzverständnis nach Habermass und der Ausarbeitung von Schutzfaktoren durch Hypothesen in Bezug auf die potenziellen Gefährdungen, wobei die Allgemeine Normative Handlungstheorie zur Strukturierung des Vorgehens verwendet wird. Darauf folgt eine Analyse der bestehenden Angebote, auf welchen die Jugendliche zugreifen können oder die Schutzfaktoren in ihrem direkten Umfeld fördern und aufrechterhalten. Die Angebote werden untersucht, ob sie zu einem passenden Zeitpunkt erfolgen, ob sie die verschiedenen Schutzfaktoren genügend abdecken und ob es Überschneidung der Sozialen Arbeit und dem Lehrplan 21 gibt. Aus diesen Erkenntnissen erfolgt eine Evaluation und Empfehlung der von der Sozialen Arbeit zu priorisierenden Massnahmen und zu erarbeitenden Kompetenzen aufgrund der in Fachliteratur ausgearbeiteten Definitionen von Medienkompetenz und Schutzfaktoren. Die Schlussfolgerung der Bachelorarbeit ist, dass die Medienprävention nicht neu erfunden, sondern laufend an neu Entwicklung angepasst werden muss, was insbesondere die Weiterbildung der Medienkompetenzen der Fachkräfte beinhaltet.
description: + Code Diss LU: hslusa basp be + Code Diss LU: hslusa basa be + Fussnote: Bachelor-Arbeit, Hochschule Luzern – Soziale Arbeit, Studienrichtung Sozialpädagogik & Sozialarbeit, 2023 + NL-Code: NLLUHSA202309
Quantum dynamics of trapped ions in a dynamic field gradient using dressed states
Creators: name: Wölk, Sabine
name: Wunderlich, Christof
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Novel ion traps that provide either a static or a dynamic magnetic gradient field allow for the use of radio frequency (rf) radiation for coupling internal and motional states of ions, which is essential for conditional quantum logic. We show that the coupling mechanism in the presence of a dynamic gradient is the same, in a dressed state basis, as in the case of a static gradient. Then, it is shown how demanding experimental requirements arising when using a dynamic gradient could be overcome. Thus, using dressed states in a dynamic gradient field could decisively reduce experimental complexity on the route towards a scalable device for quantum information science based on rf-driven trapped ions.
description: 5 pages
Narrativa e empatia. Lições do cérebro e da literatura
Creators: name: Abrantes, Ana Margarida
Publisher: name: Povos e Culturas
Year: 2014

description: A investigação recente revela uma correlação positiva entre o hábito de ler narrativas literárias e o desenvolvimento da teoria da mente, cognitiva e afetiva, esta última relacionada com a empatia (Kidd & Castano, 2013; Mar, Oatley, Hirsh, dela Paz, & Peterson, 2006). Para explicar esta correlação, é necessário considerar o conceito de empatia na relação entre mente, corpo e cérebro. Na perspetiva neurobiológica das teorias da simulação, as mesmas estruturas são ativadas na experiência direta de emoções e ainda quando as emoções são detetadas no Outro (Gallese, 2001; Damásio 1999). Do ponto de vista cultural, a empatia é entendida numa constelação triádica de dois agentes em interação e de um observador que toma o partido de um desses agentes (Breithaupt, 2009). A dimensão narrativa da empatia é um elemento estruturante da representação dessa interação e da tomada de partido espontânea do observador. Na narrativa literária, a empatia é direcionada a instâncias subjetivas particulares da história. A voz que conta a história pode influenciar a tomada de partido por uma ou outra personagem. Quando a atenção do leitor se dirige para esta voz, revela-se uma outra forma de empatia: a perceção de uma instância subjetiva conceptual, que convida o leitor a partilhar um ponto de vista sobre uma realidade. Esta é uma forma de intersubjetividade possibilitada pelos sistemas simbólicos da cultura. A consciência desta experiência de atenção partilhada, que na literatura é constitutiva e esteticamente intensa, é porventura uma explicação para a correlação positiva entre a teoria da mente e a literatura.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Excitation of surface plasmon polariton modes with multiple nitrogen vacancy centers in single nanodiamonds
Creators: name: Kumar, Shailesh
name: Lausen, Jens L.
name: Garcia-Ortiz, Cesar E.
name: Andersen, Sebastian K. H.
name: Roberts, Alexander S.
name: Radko, Ilya P.
name: Smith, Cameron L. C.
name: Kristensen, Anders
name: Bozhevolnyi, Sergey I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Nitrogen-vacancy (NV) centers in diamonds are interesting due to their remarkable characteristics that are well suited to applications in quantum-information processing and magnetic field sensing, as well as representing stable fluorescent sources. Multiple NV centers in nanodiamonds (NDs) are especially useful as biological fluorophores due to their chemical neutrality, brightness and room-temperature photostability. Furthermore, NDs containing multiple NV centers also have potential in high-precision magnetic field and temperature sensing. Coupling NV centers to propagating surface plasmon polariton (SPP) modes gives a base for lab-on-a-chip sensing devices, allows enhanced fluorescence emission and collection which can further enhance the precision of NV-based sensors. Here, we investigate coupling of multiple NV centers in individual NDs to the SPP modes supported by silver surfaces protected by thin dielectric layers and by gold V-grooves (VGs) produced via the self-terminated silicon etching. In the first case, we concentrate on monitoring differences in fluorescence spectra obtained from a source ND, which is illuminated by a pump laser, and from a scattering ND illuminated only by the fluorescence-excited SPP radiation. In the second case, we observe changes in the average NV lifetime when the same ND is characterized outside and inside a VG. Fluorescence emission from the VG terminations is also observed, which confirms the NV coupling to the VG-supported SPP modes.
description: 22 pages, 13 figures
The destabilizing effect of external damping: Singular flutter boundary for the Pfluger column with vanishing external dissipation
Creators: name: Tommasini, Mirko
name: Kirillov, Oleg N.
name: Misseroni, Diego
name: Bigoni, Davide
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Physics (physics.class-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Elastic structures loaded by nonconservative positional forces are prone to instabilities induced by dissipation: it is well-known in fact that internal viscous damping destabilizes the marginally stable Ziegler's pendulum and Pfluger column (of which the Beck's column is a special case), two structures loaded by a tangential follower force. The result is the so-called 'destabilization paradox', where the critical force for flutter instability decreases by an order of magnitude when the coefficient of internal damping becomes infinitesimally small. Until now external damping, such as that related to air drag, is believed to provide only a stabilizing effect, as one would intuitively expect. Contrary to this belief, it will be shown that the effect of external damping is qualitatively the same as the effect of internal damping, yielding a pronounced destabilization paradox. Previous results relative to destabilization by external damping of the Ziegler's and Pfluger's elastic structures are corrected in a definitive way leading to a new understanding of the destabilizating role played by viscous terms.
description: 19 pages, 6 figures
TripJudge: A Relevance Judgement Test Collection for TripClick Health Retrieval
Creators: name: Althammer, Sophia
name: Hofstätter, Sebastian
name: Verberne, Suzan
name: Hanbury, Allan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Robust test collections are crucial for Information Retrieval research. Recently there is a growing interest in evaluating retrieval systems for domain-specific retrieval tasks, however these tasks often lack a reliable test collection with human-annotated relevance assessments following the Cranfield paradigm. In the medical domain, the TripClick collection was recently proposed, which contains click log data from the Trip search engine and includes two click-based test sets. However the clicks are biased to the retrieval model used, which remains unknown, and a previous study shows that the test sets have a low judgement coverage for the Top-10 results of lexical and neural retrieval models. In this paper we present the novel, relevance judgement test collection TripJudge for TripClick health retrieval. We collect relevance judgements in an annotation campaign and ensure the quality and reusability of TripJudge by a variety of ranking methods for pool creation, by multiple judgements per query-document pair and by an at least moderate inter-annotator agreement. We compare system evaluation with TripJudge and TripClick and find that that click and judgement-based evaluation can lead to substantially different system rankings.
description: To be published at CIKM 2022 as resource paper
Sentimentos como marcadores e operadores em uma ética do reconhecimento
Creators: name: Henriques, Mendo Castro
Publisher: name: Povos e Culturas
Year: 2014

description: O artigo introduz a importância dos juízos de valor nas vivências quotidianas, enquadrando-a na distinção entre conhecer e reconhecer no âmbito de uma filosofia da consciência. Apropriada essa matriz explicativa, retoma a distinção lonerganiana entre emoções intencionais e não-intencionais, resposta intencional ao prazer e à dor; caraterísticas básicas da resposta intencional de valor e acrescenta a dimensão de relacionamento, de origem buberiana. Depois, examina como sentimentos e argumentos interagem nas avaliações presentes numa sequência de atitudes fundamentais, que recupera e ultrapassa a orientação lonerganiana e buberiana. Esta dupla dinâmica ajuda a situar de que modo os sentimentos podem ser, simultaneamente, integradores e operadores de atos de conhecimento e de reconhecimento.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Spin excitations in an all-organic double quantum dot molecule
Creators: name: Koole, Max
name: Hummelen, Jan C.
name: van der Zant, Herre S. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We realize a strongly coupled double quantum dot in a single all-organic molecule by introducing a non-conjugated bridge in between two identical conjugated moieties. Spin-1/2 Kondo and Kondo enhanced low-energy excitations for respectively the odd and even electron occupation are observed in off-resonant transport. The ground state in the even occupation can be the singlet or the triplet state varying between samples. This observation suggests that both anti-ferromagnetic and ferromagnetic interactions between spins are of the same order of magnitude.
Neurobiologia e psicologia da empatia pontos de partida para a investigação e intervenção da promoção da empatia
Creators: name: Gaspar, Augusta
Publisher: name: Povos e Culturas
Year: 2014

description: A empatia é um constructo importante, objeto crescente de investigação na atualidade e recentemente reconhecida como um mecanismo biológico que muito contribui para a homeostasia social e sucesso das sociedades humanas. Neste capítulo centro-me em três aspetos da empatia: esclarecer no que consiste empatia, pois é possível encontrarmos estudos com resultados muito divergentes entre si, e isso deve-se sobretudo ao facto de fazerem recurso de medidas distintas de empatia, algumas das quais, não traduzem realmente empatia; dado que a empatia está ligada à cooperação, à ajuda interpessoal, ao altruísmo, ela é um aspeto do comportamento humano que envolve custos e por vezes sacrifícios muito elevados; neste âmbito, o senso comum leva-nos com frequência para a ideia de que ela é uma segunda natureza, algo que temos de construir sobre a natureza humana, mais egoísta, menos empática. Neste ponto, farei a revisão de estudos que permitem refutar esta ideia e que, pelo contrário, apontam para a empatia como um aspeto essencial da natureza humana, uma chave para a sobrevivência das comunidades da nossa espécie. Finalmente, e atendendo a que a empatia é um traço desejável, e mesmo após o argumento de que faz parte da natureza humana é reconhecido que nem todos os humanos a apresentam por igual, discutem-se estratégias que poderão conduzir a uma estimulação da empatia enquanto traço num indivíduo, mas também enquanto resposta imediata a uma situação.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Guided Waves Damage Detection in Beams utilising Bayesian Artificial Neural Network Model Class selection
Creators: name: Ng, C.T.
name: Liew, Chin Kian
name: Veidt, Martin
Publisher: name: Singapore Institute of Technology
Year: 2023
Subjects: Mechanical engineering not elsewhere classified
Neural networks

description: This paper presents a damage detection methodology utilising an Artificial Neural Network (ANN) pattern recognition approach to identify the location and severity of damages in beams. The Bayesian model class selection method is employed to determine an optimum ANN model, hence avoiding subjective judgement during the ANN design process. Simulated first order longitudinal guided waves signals for beams with different damage locations and severities are pre-processed using discrete wavelet transformation to reduce ANN processing time and are then used as input patterns to train the ANN. The trained network is employed to identify unknown damages in beams with simulated damage cases.
Density functional theory study of substitutional oxygen in diamond
Creators: name: Etmimi, K. M.
name: Briddon, P. R.
name: Abutruma, A. M.
name: Sghayer, A.
name: Farhat, S. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A few studies have been recently presented for the existence of oxygen in diamond, for example, the N3 EPR centres have been theoretically and experimentally assigned the model made up from complex of substitutional nitrogen and substitutional oxygen as nearest neighbours. We present ab initio calculations of substitutional oxygen in diamond in terms of stability, electronic structures, geometry and hyperfine interaction and show that substitutional oxygen with C$_{2v}\,$, $S=1$ is the ground state configuration. We find that oxygen produces either a donor or acceptor level depending on the position of the Fermi level.
description: 7 pages, 3 figures
title: Registered Nurses' Ability to Discriminate Similar Human Need Fulfillment Alterations Specific to Chronic Obstructive Pulmonary Disease and to Diabetes Mellitus
Creators: name: Waite, Kathleen Bowen
Publisher: name: Old Dominion University Libraries
Year: 1983

description: The problem for this research study was to ascertain if registered nurses of varying educational backgrounds and experience discriminated similar human needs as being altered by specific pathologic states. The two pathologic states studied were chronic obstructive pulmonary disease and diabetes mellitus, chosen for their high prevalence in the population. A population sample of 55 registered nurses practicing on medical units in five hospital settings were surveyed. Data for this study were collected using the Human Needs Assessment Scales developed for this study. It was determined that registered nurses in this study did discriminate similar human need fulfillment alterations specific to the two pathologic states with some differences found in priority placement and mean values when the responses of baccalaureate degree, associate degree, and diploma graduates were compared. The number of working years experienced by the participants had little influence in this study.
Comunicação e cognição na era digital
Creators: name: Dias, Patrícia
Publisher: name: Povos e Culturas
Year: 2014

description: Este artigo explora a relação entre comunicação e cognição no ambiente digital contemporâneo, entendendo as estruturas cognitivas como elemento integrante do processo comunicacional e partindo do argumento de que estas são moldadas pela imersão digital. Tendo como enquadramento os conceitos de ‘infoxicação’ e de ‘bolha-filtro’, este artigo explora as noções de ‘infosaturação’ e de ‘tecno-agendamento’ como formas de entender o impacto das tecnologias digitais atuais nas estruturas cognitivas e na comunicação. As tecnologias digitais estão em mudança, passando de um paradigma centrado no utilizador para um maior enfoque na própria tecnologia, e portanto os seus efeitos refletem essas mudanças. Face ao excesso de informação e ao empoderamento possibilitados pelas tecnologias digitais, os utilizadores tendem a selecionar informação que reforça as suas crenças e opiniões prévias, bem como a aderir a sugestões de aplicações que se baseiam no registo do comportamento anterior e no cruzamento de perfis de utilizadores. Este artigo explora os efeitos destas práticas em termos do grau de atividade dos utilizadores, cada vez mais delegada na web inteligente, e também na informação com que contatam, cada vez mais redundante.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
GNPassGAN: Improved Generative Adversarial Networks For Trawling Offline Password Guessing
Creators: name: Yu, Fangyi
name: Martin, Miguel Vargas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.2

description: The security of passwords depends on a thorough understanding of the strategies used by attackers. Unfortunately, real-world adversaries use pragmatic guessing tactics like dictionary attacks, which are difficult to simulate in password security research. Dictionary attacks must be carefully configured and modified to represent an actual threat. This approach, however, needs domain-specific knowledge and expertise that are difficult to duplicate. This paper reviews various deep learning-based password guessing approaches that do not require domain knowledge or assumptions about users' password structures and combinations. It also introduces GNPassGAN, a password guessing tool built on generative adversarial networks for trawling offline attacks. In comparison to the state-of-the-art PassGAN model, GNPassGAN is capable of guessing 88.03\% more passwords and generating 31.69\% fewer duplicates.
description: 9 pages, 8 tables, 3 figures
Concurrent growth and formation of electrically contacted monolayer transition metal dichalcogenides on bulk metallic patterns
Creators: name: Khadka, Sudiksha
name: Lindquist, Miles
name: Aleithan, Shrouq
name: Blumer, Ari
name: Wickramasinghe, Thushan
name: Kordesch, Martin
name: Stinaff, Eric
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: While new species and properties of two-dimensional (2D) materials are being reported with extraordinary regularity, a significant bottleneck in the field is the ability to controllably process material into working devices. We report a chemical vapor deposition process to selectively grow 2D material in a deterministic manner around lithographically defined bulk metallic patterns which concurrently provide as-grown contacts to the material. Monolayer films, with lateral extent of up to hundreds of microns are controllably grown on and around patterned regions of transition metals. By using different combinations of metallic pattern and oxide based precursor, heterostructured MoS2/WS2 growth has been observed as well. The materials display strong luminescence, monolayer Raman signatures, and relatively large crystal domains. In addition to producing high optical quality monolayer material deterministically and selectively over large regions, the metallic patterns remain conductive and therefore have the advantage of providing as-grown metallic contacts to the material, offering a path for simple device fabrication and large scale production
Design and implementation of image processing system for Lumen social robot-humanoid as an exhibition guide for Electrical Engineering Days 2015
Creators: name: Sya, Setyaki Sholata
name: Prihatmanto, Ary Setijadi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Human-Computer Interaction (cs.HC)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences
subject: I.2.10; H.5.2

description: Lumen Social Robot is a humanoid robot development with the purpose that it could be a good friend to all people. In this year, the Lumen Social Robot is being developed into a guide in the exhibition and in the seminar of the Final Exam of undergraduate and graduate students in Electrical Engineering ITB, named Electrical Engineering Days 2015. In order to be the guide in that occasion, Lumen is supported by several things. They are Nao robot components, servers, and multiple processor systems. The image processing system is a processing application system that allows Lumen to recognize and determine an object from the image taken from the camera eye. The image processing system is provided with four modules. They are face detection module to detect a person's face, face recognition module to recognize a person's face, face tracking module to follow a person's face, and human detection module to detect humans based on the upper parts of person's body. Face detection module and human detection module are implemented by using the library harcascade.xml on EMGU CV. Face recognition module is implemented by adding the database for the face that has been detected and store it in that database. Face tracking module is implemented by using the Smooth Gaussian filter to the image. ----- Lumen Sosial Robot merupakan sebuah pengembangan robot humanoid agar dapat menjadi teman bagi banyak orang. Sistem pengolahan citra merupakan sistem aplikasi pengolah yang bertujuan Lumen dapat mengenali dan mengetahui suatu objek pada citra yang diambil dari camera mata Lumen. System pengolahan citra dilengkapi dengan empat buah modul, yaitu modul face detection untuk mendeteksi wajah seseorang, modul face recognition untuk mengenali wajah orang tersebut, modul face tracking untuk mengikuti wajah seseorang, dan modul human detection untuk mendeteksi manusia berdasarkan bagian tubuh atas orang
description: Lumen, image processing system, face detection, face recognition, face tracking, human detection
Acoustically tuneable optical transmission through a subwavelength hole with a bubble
Creators: name: Maksymov, Ivan S.
name: Greentree, Andrew D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Other Condensed Matter (cond-mat.other)
subject: Biological Physics (physics.bio-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Efficient manipulation of light with sound in subwavelength-sized volumes is important for applications in photonics, phononics and biophysics, but remains elusive. We theoretically demonstrate the control of light with MHz-range ultrasound in a subwavelength, 300 nm wide water-filled hole with a 100 nm radius air bubble. Ultrasound-driven pulsations of the bubble modulate the effective refractive index of the hole aperture, which gives rise to spectral tuning of light transmission through the hole. This control mechanism opens up novel opportunities for tuneable acousto-optic and optomechanical metamaterials, and all-optical ultrasound transduction.
description: 4 pages, 6 figures
Envelhecimento cognitivo: do normal ao patológico
Creators: name: Ribeiro, Filipa Delgado Neiva Correia
Publisher: name: Povos e Culturas
Year: 2014

description: Com o aumento da esperança média de vida, há cada vez mais pessoas que vivem até mais tarde e estas, inevitavelmente, envelhecem. As queixas de memória são as mais frequentes queixas cognitivas do envelhecimento normal. Mas são também um dos mais frequentes sinais de alterações patológicas no cérebro, durante o envelhecimento. A constatação de que as perdas na memória e/ou noutras funções cognitivas, são superiores às esperadas para o grupo etário e para o nível de escolaridade do sujeito, é uma peça chave na caracterização do quadro. Em muitos destes casos de queixas cognitivas, os resultados da avaliação clínica e neuropsicológica revelam alterações cognitivas, de causa desconhecida, mas sem gravidade suficiente para se justificar um diagnóstico de demência. O conceito de “Defeito Cognitivo Ligeiro” (DCL), foi proposto para caracterizar este estádio. Os estudos longitudinais mostram que os sujeitos classificados com DCL, têm um risco maior de progredir para demência, principalmente, doença de Alzheimer (DA), mas nem todos progridem. Tem sido feito um grande investimento na descoberta de marcadores de doença de Alzheimer que permitam um diagnóstico precoce e nos ajudem a compreender as causas da DA. Paralelamente, muitas equipas de investigação tentam conhecer os factores que influenciam o desenvolvimento da DA. Um dos factores protectores de demência mais referidos é a escolaridade e associados à escolaridade, o nível ocupacional e as actividades de lazer. Não conhecemos ainda a causa da DA mas mantermo-nos activos, física e cognitivamente o maior número de anos possível, parece ser determinante para lidar com as suas consequências.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Análise fenomenológica de um caso de «cegueira psíquica»
Creators: name: Morujão, Carlos
Publisher: name: Povos e Culturas
Year: 2014

description: Fará sentido falar ainda de consciência? Não poderá a linguagem com que descrevemos os nossos atos ser substituída, com vantagem, pela linguagem que é própria das neurociências? Não deveremos hoje falar apenas de cérebro e de mecanismos neurais? Contra as teses eliminacionistas, mas também contra as que definem os estados conscientes como um conjunto de qualidades subjetivas e quase inapreensíveis, o presente ensaio defende a validade das três hipóteses seguintes: 1) a necessidade de falar de consciência para dar conta das experiências vividas de nós mesmos, dos outros e do mundo; 2) a intencionalidade como característica irredutível da consciência, impossível de explicar numa linguagem fisicalista ou na base de modelos computacionais; 3) a relação indissolúvel da consciência com o corpo e com os esquemas corporais de orientação no mundo. Acima de tudo (apoiado nas análises de Merleau-Ponty e, em parte, de Edmund Husserl), o presente ensaio pretende demonstrar que as tentativas de reduzir os fenómenos mentais a estados cerebrais enfermam de um vício inultrapassável: elas recorrem, para explicar tais fenómenos, a uma linguagem fisicalista inapropriada para compreender a sua especificidade, cavando um fosso entre elas próprias, por um lado, e, por outro, a experiência vivida desses fenómenos e a linguagem em que ela se exprime.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Milky Way Kinematics. II. A uniform inner Galaxy HI terminal velocity curve
Creators: name: McClure-Griffiths, N. M.
name: Dickey, J. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using atomic hydrogen (HI) data from the VLA Galactic Plane Survey we measure the HI terminal velocity as a function of longitude for the first quadrant of the Milky Way. We use these data, together with our previous work on the fourth Galactic quadrant, to produce a densely sampled, uniformly measured, rotation curve of the Northern and Southern Milky Way between $3~{\rm kpc} < R < 8~{\rm kpc}$. We determine a new joint rotation curve fit for the first and fourth quadrants, which is consistent with the fit we published in McClure-Griffiths \& Dickey (2007) and can be used for estimating kinematic distances interior to the solar circle. Structure in the rotation curves is now exquisitely well defined, showing significant velocity structure on lengths of $\sim 200$ pc, which is much greater than the spatial resolution of the rotation curve. Furthermore, the shape of the rotation curves for the first and fourth quadrants, even after subtraction of a circular rotation fit shows a surprising degree of correlation with a roughly sinusoidal pattern between $4.2 < R < 7$ kpc.
description: 24 pages, 8 figures. Accepted for publication in the Astrophysical Journal
Global transport in a nonautonomous standard map
Creators: name: Calleja, Renato
name: del-Castillo-Negrete, Diego
name: Martinez-del-Rio, David
name: Olvera, Arturo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: A non-autonomous version of the standard map with a periodic variation of the parameter is introduced and studied. Symmetry properties in the variables and parameters of the map are found and used to find relations between rotation numbers of invariant sets of the autonomous realization of the period-two case of the map. The role of the nonautonomous dynamics on period-one orbits, stability and bifurcation is studied. The critical boundaries for the global transport and the destruction of invariant circles with fixed rotation number are studied in detail using direct computation and a continuation method. In the case of global transport, the critical boundary has a particular symmetrical horn shape. The results are contrasted with similar calculations found in the literature.
description: 11 figures
O processamento da dor física e da dor social
Creators: name: Canaipa, Rita
Publisher: name: Povos e Culturas
Year: 2014

description: A experiência da dor encontra-se entre as mais intensas e marcantes experiências humanas. É parte integrante da dialéctica com o mundo exterior, estruturando os nossos limites fisiológicos e psicológicos permanentemente. Tem um valor fundamental na sobrevivência, garantindo o afastamento de estímulos e situações que poderiam ameaçar a vida. Conhecida por todos os ser humanos e, infelizmente, presente cronicamente em muitos deles, representa um desafio à compreensão científica. Nos últimos anos as Neurociências têm conseguido caracterizar os processos biológicos envolvidos na dor, bem como o papel que o contexto emocional, social e cultural pode ter nesta experiência. De entre as várias emoções que podem modular o processamento da dor física, a dor social, isto é, a dor que ocorre em situações de perda de relações sociais significativas, partilha processos comportamentais, neurocognitivos e moleculares com a dor física (Eisenberger, 2012). Nesta perspectiva, um indivíduo que seja capaz de antecipar adequadamente os riscos para a sua integridade física, evitando situações em que possa sentir dor, mas não seja capaz de antecipar os perigos sociais, afastando-se ou sendo rejeitado pelo grupo, pode ficar igualmente em situação de risco do ponto de vista do seu bem estar. Diversos estudos têm procurado compreender de que forma estes dois fenómenos se poderão relacionar. São estes estudos que procuramos aqui rever, na expectativa de clarificar a pertinência desta área de investigação e o potencial clínico que o conhecimento das interligações entre estes tipos de dor poderá ter na prática clínica, sobretudo na dor crónica.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Design and implementation of computational platform for social-humanoid robot Lumen as an exhibition guide in Electrical Engineering Days 2015
Creators: name: Syarif, Ahmad
name: Prihatmanto, Ary Setijadi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Robotics (cs.RO)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences
subject: I.2.9; C.2.4

description: Social Robot Lumen is an Artificial Intelligence development project that aims to create an Artificial Intelligence (AI) which allows a humanoid robot to communicate with human being naturally. In this study, Lumen will be developed to be a tour guide in Electrical Engineering Days 2015 exhibition. In developing an AI, there are a lot of modules that need to be developed separately. To make the development easier, we need a computational platform which becomes basis for all developers to give easiness in developing the modules in parallel way. That computational platform that developed by the writer is called Lumen Server. Lumen Server has two main function, which are to be a bridge between all Lumen intelligence modules with NAO robot, and to be the communication bridge between those Lumen intelligence modules. For the second function, Lumen Server implements the AMQP protocol using RabbitMQ. Besides that, writer also developed a control system for robot movement called Lumen Motion. Lumen motion is implemented by modelling the movement of NAO robot and also by creating a control system using fuzzy logic controller. Writer also developed a program that connects all Lumen intelligence modules so that Lumen can act like a tour guide. The implementation of this program uses FSM and event-driven program. From implementation result, all the features which were designed are successfully implemented. By the developing of this computational platform, it can ease the development of Lumen in the future. For next development, it must be focused on creating integration system so that Lumen can be more responsive to the environment. ----- Sosial Robot Lumen adalah proyek pengembangan kecerdasan buatan yang bertujuan untuk menciptakan kecerdasan buatan atau artificial intelligence (AI) yang memungkinkan robot untuk dapat berkomunikasi dengan manusia secara alami.
description: Keywords: robot, humanoid, server, RabbitMQ, Fuzzy Logic Controller, AI
Multi-wavelength properties of IGR J05007-7047 (LXP 38.55) and identification as a Be X-ray binary pulsar in the LMC
Creators: name: Vasilopoulos, G.
name: Haberl, F.
name: Delvaux, C.
name: Sturm, R.
name: Udalski, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report on the results of a $\sim$40 d multi-wavelength monitoring of the Be X-ray binary system IGR J05007-7047 (LXP 38.55). During that period the system was monitored in the X-rays using the Swift telescope and in the optical with multiple instruments. When the X-ray luminosity exceeded $10^{36}$ erg/s we triggered an XMM-Newton ToO observation. Timing analysis of the photon events collected during the XMM-Newton observation reveals coherent X-ray pulsations with a period of 38.551(3) s (1 σ), making it the 17$^{th}$ known high-mass X-ray binary pulsar in the LMC. During the outburst, the X-ray spectrum is fitted best with a model composed of an absorbed power law ($Γ=0.63$) plus a high-temperature black-body (kT $\sim$ 2 keV) component. By analysing $\sim$12 yr of available OGLE optical data we derived a 30.776(5) d optical period, confirming the previously reported X-ray period of the system as its orbital period. During our X-ray monitoring the system showed limited optical variability while its IR flux varied in phase with the X-ray luminosity, which implies the presence of a disk-like component adding cooler light to the spectral energy distribution of the system.
description: 11 pages, 11 figures, Accepted for publication in MNRAS
Estimulação magnética transcraniana para a reabilitação das doenças do cérebro
Creators: name: Rodrigues, Inês Tello R. M.
Publisher: name: Povos e Culturas
Year: 2014

description: Com o aumento da esperança média de vida, aumenta também a comorbilidade de patologias associadas ao envelhecimento e a consequente busca por novas terapias e abordagens de tratamento das doenças do cérebro. Neste contexto específico, as técnicas de neuromodulação, onde se enquadra a Estimulação Magnética Transcraniana (TMS), têm tido avanços promissores e suscitado grande interesse por parte da comunidade científica pelo seu potencial terapêutico. A TMS resulta da produção de campos magnéticos variáveis no tempo, induzindo a produção de correntes eléctricas no córtex cerebral, modificando a excitabilidade intra-cortical e activando estruturas corticais e subcorticais distantes ao longo de conecções específicas. Pretende-se, com este artigo, apresentar uma breve revisão da literatura sobre este tema de forma a evidenciar as diferentes aplicações clínicas desta técnica na reabilitação de pessoas com doenças neurológicas.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Envelhecimento cerebral, na perspetiva das neurociências cognitivas do envelhecimento
Creators: name: Nunes, Maria Vânia Silva
Publisher: name: Povos e Culturas
Year: 2014

description: Começaremos este artigo por enquadrar sinteticamente a necessidade de estudar o envelhecimento cerebral, revendo de seguida as principais alterações associadas ao envelhecimento cerebral com expressão ao nível cognitivo. Discutiremos depois fatores que podem mediar a manifestação cognitiva das alterações ao nível cerebral, bem como intervenções que podem promover um melhor envelhecimento.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!
Tunable Strong Magnetic Anisotropy in Two-Dimensional van der Waals Antiferromagnets
Creators: name: Xiao, Feiping
name: Tong, Qingjun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that anisotropic energy of a 2D antiferromagnet is greatly enhanced via stacking on a magnetic substrate layer, arising from the sublattice-dependent interlayer magnetic interaction that defines an effective anisotropic energy. Interestingly, this effective energy couples strongly with the interlayer stacking order and the magnetic order of the substrate layer, providing unique mechanical and magnetic means to control the antiferromagnetic order. These two types of control methods affect distinctly the sublattice magnetization dynamics, with a change of the ratio of sublattice precession amplitudes in the former and its chirality in the later. In moiré superlattices formed by a relative twist or strain between the layers, the coupling with stacking order introduces a landscape of effective anisotropic energy across the moiré, which can be utilized to create nonuniform antiferromagnetic textures featuring periodically localized low-energy magnons.
description: 8 pages, 4 figures
O cérebro e a actividade física
Creators: name: Pereira, Tiago
Publisher: name: Povos e Culturas
Year: 2014

description: Os benefícios da actividade física na função cerebral, saúde mental e na performance cognitiva têm sido bem documentados por vários autores ao longo dos últimos anos. No entanto, os efeitos da actividade física na actividade cerebral levantam algumas dúvidas relacionadas com o facto de que, se estas alterações serão locais ou um resultado a nível global no cérebro. Desde as diferenças entre actividades físicas de maior intensidade e outras em que o controlo motor é um ponto chave para o sucesso, sabe-se hoje que não podemos dissociar os efeitos do exercício e da actividade física da função cerebral. Este facto tem influência não apenas na estruturação de planos de treino em atletas, mas também nos benefícios dependentes do exercício físico ao nível do processamento cognitivo e nas doenças neurodegenerativas.
description: Povos e Culturas, No 18 (2014): O cérebro: o que a ciência nos diz!