cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
High Temperature Quantum Kinetic Effect in Silicon Nanosandwiches
Creators: name: Bagraev, N. T.
name: Grigoryev, V. Yu.
name: Klyachkin, L. E.
name: Malyarenko, A. M.
name: Mashkov, V. A.
name: Romanov, V. V.
name: Rul, N. I.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The negative-U impurity stripes confining the edge channels of semiconductor quantum wells are shown to allow the effective cooling inside in the process of the spin-dependent transport, with the reduction of the electron-electron interaction. The aforesaid promotes also the creation of composite bosons and fermions by the capture of single magnetic flux quanta on the edge channels under the conditions of low sheet density of carriers, thus opening new opportunities for the registration of the quantum kinetic phenomena in weak magnetic fields at high temperatures up to the room temperature. As a certain version noted above we present the first findings of the high temperature de Haas-van Alphen, 300K, quantum Hall, 77K, effects as well as quantum conductance staircase in the silicon sandwich structure that represents the ultra-narrow, 2 nm, p-type quantum well (Si-QW) confined by the delta barriers heavily doped with boron on the n-type Si (100) surface.
description: 11 pages, 9 figures. arXiv admin note: substantial text overlap with arXiv:1601.05975, arXiv:1207.4928
Convolutional and tail-biting quantum error-correcting codes
Creators: name: Forney,, G. David
name: Grassl, Markus
name: Guha, Saikat
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Rate-(n-2)/n unrestricted and CSS-type quantum convolutional codes with up to 4096 states and minimum distances up to 10 are constructed as stabilizer codes from classical self-orthogonal rate-1/n F_4-linear and binary linear convolutional codes, respectively. These codes generally have higher rate and less decoding complexity than comparable quantum block codes or previous quantum convolutional codes. Rate-(n-2)/n block stabilizer codes with the same rate and error-correction capability and essentially the same decoding algorithms are derived from these convolutional codes via tail-biting.
description: 30 pages. Submitted to IEEE Transactions on Information Theory. Minor revisions after first round of reviews
Improved transfer of quantum information using a local memory
Creators: name: Giovannetti, Vittorio
name: Burgarth, Daniel
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate that the quantum communication between two parties can be significantly improved if the receiver is allowed to store the received signals in a quantum memory before decoding them. In the limit of an infinite memory, the transfer is perfect. We prove that this scheme allows the transfer of arbitrary multipartite states along Heisenberg chains of spin-1/2 particles with random coupling strengths.
description: 4 pages, 1 figure; added references to homogenization and asymptotic completeness
title: A state-of-the-science review of alcoholic beverages and polycyclic aromatic hydrocarbons
Creators: name: King, Liam
name: Aplin, Rebekah
name: Gill, Chris G.
name: Naimi, Timothy
Publisher: name: EHP Publishing
Year: 2024
Subjects: subject: Alcoholic beverages
subject: Polycyclic aromatic hydrocarbons

description: This article was originally published as: King, L., Aplin, R., Gill, C., & Naimi, T. (2024). A state-of-the-science review of alcoholic beverages and polycyclic aromatic hydrocarbons. Environmental Health Perspectives, 132(1), 016001-1-016001-6, https://doi.org/10.1289/EHP13506
description: Background: The association between alcohol and certain cancers is well established, yet beyond ethanol and its metabolite acetaldehyde, little is known about the presence of other carcinogenic compounds in alcoholic beverages, including polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (a Group I carcinogen). Objectives: We summarized the published literature on PAH levels in alcoholic beverages to identify potential gaps in knowledge to inform future research. Methods: Medline and Scopus were searched for primary research published from January 1966 to November 2023 that quantified PAH levels among various types of alcoholic beverages, including whisky, rum, brandy, gin, vodka, wine, and beer. Studies that were not primary literature were excluded; only studies that quantified PAH content in the specified alcoholic beverages were included. Results: Ten studies published from 1966 to 2019 met the criteria for review. Other than beverage type, no publication reported selection criteria for their samples of tested alcohol products. Studies used a variety of analytical methods to detect PAHs. Of the 10 studies, 7 were published after 2000, and 6 assessed products. Of the studies, 7 examined spirits; 3, beer; and 4, wines. Benzo[a]pyrene was most prevalent among spirit products, particularly whisky, with values generally exceeding acceptable levels for drinking water. Some beer and wine products also contained PAHs, albeit at lower levels and less frequently than spirit products. Discussion: PAHs are found in some alcohol products and appear to vary by beverage type. However, there is an incomplete understanding of their presence and levels among large, representative samples from the range of currently available alcohol products. Addressing this gap could improve understanding of alcohol–cancer relationships and may have important implications for public health and the regulation of alcohol products. In addition, novel methods, such as direct mass spectroscopy, may facilitate more thorough testing of samples to further investigate this relationship.
One-Loop Gluon Scattering Amplitudes in Theories with $N < 4$ Supersymmetries
Creators: name: Bidder, Steven J.
name: Bjerrum-Bohr, N. E. J.
name: Dunbar, David C.
name: Perkins, Warren B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Generalised unitarity techniques are used to calculate the coefficients of box and triangle integral functions of one-loop gluon scattering amplitudes in gauge theories with $N < 4$ supersymmetries. We show that the box coefficients in N=1 and N=0 theories inherit the same coplanar and collinear constraints as the corresponding N=4 coefficients. We use triple cuts to determine the coefficients of the triangle integral functions and present, as an example, the full expression for the one-loop amplitude $A^{N=1}(1^-,2^-,3^-,4^+,..,n^+)$.
description: 15 pages, minor typos corrected
Positive solutions of BVPs on the half-line involving functional BCs
Creators: name: Infante, Gennaro
name: Matucci, Serena
Publisher: name: arXiv
Year: 2020
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: Primary 34B40, secondary 34B10, 34B18

description: We study the existence of positive solutions on the half-line of a second order ordinary differential equation subject to functional boundary conditions. Our approach relies on a combination between the fixed point index for operators on compact intervals, a fixed point result for operators on noncompact sets, and some comparison results for principal and nonprincipal solutions of suitable auxiliary linear equations.
description: 13 pages
Depth as Attention for Face Representation Learning
Creators: name: Uppal, Hardik
name: Sepas-Moghaddam, Alireza
name: Greenspan, Michael
name: Etemad, Ali
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Face representation learning solutions have recently achieved great success for various applications such as verification and identification. However, face recognition approaches that are based purely on RGB images rely solely on intensity information, and therefore are more sensitive to facial variations, notably pose, occlusions, and environmental changes such as illumination and background. A novel depth-guided attention mechanism is proposed for deep multi-modal face recognition using low-cost RGB-D sensors. Our novel attention mechanism directs the deep network "where to look" for visual features in the RGB image by focusing the attention of the network using depth features extracted by a Convolution Neural Network (CNN). The depth features help the network focus on regions of the face in the RGB image that contains more prominent person-specific information. Our attention mechanism then uses this correlation to generate an attention map for RGB images from the depth features extracted by CNN. We test our network on four public datasets, showing that the features obtained by our proposed solution yield better results on the Lock3DFace, CurtinFaces, IIIT-D RGB-D, and KaspAROV datasets which include challenging variations in pose, occlusion, illumination, expression, and time-lapse. Our solution achieves average (increased) accuracies of 87.3\% (+5.0\%), 99.1\% (+0.9\%), 99.7\% (+0.6\%) and 95.3\%(+0.5\%) for the four datasets respectively, thereby improving the state-of-the-art. We also perform additional experiments with thermal images, instead of depth images, showing the high generalization ability of our solution when adopting other modalities for guiding the attention mechanism instead of depth information
description: 16 pages, 11 figures, Accepted to IEEE Transactions on Information Forensics and Security 2021
Scheduling and Power Control for Wireless Multicast Systems via Deep Reinforcement Learning
Creators: name: Raghu, Ramkumar
name: Panju, Mahadesh
name: Aggarwal, Vaneet
name: Sharma, Vinod
Publisher: name: arXiv
Year: 2020
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Multicasting in wireless systems is a natural way to exploit the redundancy in user requests in a Content Centric Network. Power control and optimal scheduling can significantly improve the wireless multicast network's performance under fading. However, the model based approaches for power control and scheduling studied earlier are not scalable to large state space or changing system dynamics. In this paper, we use deep reinforcement learning where we use function approximation of the Q-function via a deep neural network to obtain a power control policy that matches the optimal policy for a small network. We show that power control policy can be learnt for reasonably large systems via this approach. Further we use multi-timescale stochastic optimization to maintain the average power constraint. We demonstrate that a slight modification of the learning algorithm allows tracking of time varying system statistics. Finally, we extend the multi-timescale approach to simultaneously learn the optimal queueing strategy along with power control. We demonstrate scalability, tracking and cross layer optimization capabilities of our algorithms via simulations. The proposed multi-timescale approach can be used in general large state space dynamical systems with multiple objectives and constraints, and may be of independent interest.
description: arXiv admin note: substantial text overlap with arXiv:1910.05308
Matrix factorizations and link homology II
Creators: name: Khovanov, Mikhail
name: Rozansky, Lev
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Algebra (math.QA)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57M25

description: To a presentation of an oriented link as the closure of a braid we assign a complex of bigraded vector spaces. The Euler characteristic of this complex (and of its triply-graded cohomology groups) is the HOMFLYPT polynomial of the link. We show that the dimension of each cohomology group is a link invariant.
description: 37 pages, 20 figures; version 2 corrects an inaccuracy in the proof of Proposition 3
Percepção de conhecimento e satisfação dos Agentes Comunitários de Saúde com seu trabalho, em um município do Rio Grande do Sul, RS - Formulários Google.pdf
Creators: name: LAIS CAROLINI PAULESKI
Publisher: name: figshare
Year: 2021
Subjects: subject: 111717 Primary Health Care
subject: FOS: Health sciences

description: Percepções sobre o trabalho dos agentes comunitários de saúde de Santa Cruz do Sul
Metal Halide Perovskite Nanocrystals: Synthesis, Post-Synthesis Modifications and Their Optical Properties
Creators: name: Shamsi, Javad
name: Urban, Alexander S.
name: Imran, Muhammad
name: De Trizio, Luca
name: Manna, Liberato
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Metal halide perovskites represent a flourishing area of research, driven by both their potential application in photo-voltaics and optoelectronics, and for the fundamental science underpinning their unique optoelectronic properties. The advent of colloidal methods for the synthesis of halide perovskite nanocrystals has brought to the attention inter-esting aspects of this new type of materials, above all their defect-tolerance. This review aims to provide an updated survey of this fast-moving field, with a main focus on their colloidal synthesis. We examine the chemistry and the ca-pability of different colloidal synthetic routes to control the shape, size and optical properties of the resulting nano-crystals. We also provide an up to date overview of their post-synthesis transformations, and summarize the various so-lution processes aimed at fabricating halide perovskite-based nanocomposites. We then review the fundamental optical properties of halide perovskite nanocrystals, by focusing on their linear optical properties, on the effects of quantum confinement and, then, on the current knowledge of their exciton binding energies. We also discuss the emergence of non-linear phenomena such as multiphoton absorption, biexcitons and carrier multiplication. At last, we provide an outlook in the field, with the most cogent open questions and possible future directions.
Percepções sobre o trabalho dos agentes comunitários de saúde de Santa Cruz do Sul - parecer do CEP
Creators: name: LAIS CAROLINI PAULESKI
Publisher: name: figshare
Year: 2021
Subjects: subject: 111717 Primary Health Care
subject: FOS: Health sciences

description: Acceptance of the research ethics committee entitled: Perceptions about the work of community health agents in Santa Cruz do Sul
Comment on `Heating of Enceladus due to the dissipation of ocean tides' by R. Tyler
Creators: name: Beuthe, Mikael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Dissipation of ocean potential energy is proposed by Tyler (2020) as a new mechanism leading to possible high-power states for Enceladus. I show here that this process actually results from viscoelastic dissipation within the crust. For plausible values of Enceladus's ocean thickness, crustal dissipation can be computed with the standard approach of static deformations of solid layers by equilibrium tides.
description: 12 pages, 2 figures
Decodificador de binario de 2 bits a display de 7 segmentos - Bloques combinacionales
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2021
Subjects: Electrónica Digital
Funciones lógicas
Puertas lógicas
Circuitos combinacionales
Mapas de Karnaugh
Simulación

description: Presentación de clase que explica cómo funcionan los displays de siete segmentos y cómo hacer el circuito lógico que convierte un número binario de 2 bits para mostrarlo en un display de siete segmentos. Se introduce también el procedimiento para implementar el circuito si el número de la entrada fuese de 4 bits, ya sea BCD (de 0 a 9) o hexadecimal (de 0 a 15). Video de la presentación disponible: https://youtu.be/m7oDCPnt9Bo Video del tutorial del simulador de circuito del ejemplo: https://youtu.be/dt5Y_P4Xqd0 Video con tutorial del simulador con circuitos integrados de la serie 74: https://youtu.be/A5sYTEI7anY
Measuring Law Over Time: A Network Analytical Framework with an Application to Statutes and Regulations in the United States and Germany
Creators: name: Coupette, Corinna
name: Beckedorf, Janis
name: Hartung, Dirk
name: Bommarito, Michael
name: Katz, Daniel Martin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computers and Society (cs.CY)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: How do complex social systems evolve in the modern world? This question lies at the heart of social physics, and network analysis has proven critical in providing answers to it. In recent years, network analysis has also been used to gain a quantitative understanding of law as a complex adaptive system, but most research has focused on legal documents of a single type, and there exists no unified framework for quantitative legal document analysis using network analytical tools. Against this background, we present a comprehensive framework for analyzing legal documents as multi-dimensional, dynamic document networks. We demonstrate the utility of this framework by applying it to an original dataset of statutes and regulations from two different countries, the United States and Germany, spanning more than twenty years (1998-2019). Our framework provides tools for assessing the size and connectivity of the legal system as viewed through the lens of specific document collections as well as for tracking the evolution of individual legal documents over time. Implementing the framework for our dataset, we find that at the federal level, the United States legal system is increasingly dominated by regulations, whereas the German legal system remains governed by statutes. This holds regardless of whether we measure the systems at the macro, the meso, or the micro level.
description: 32 pages, 13 figures (main paper); 32 pages, 14 figures (supplementary information)
Electrónica digital con circuitos integrados básicos (1) - Encender un led con el 74HC04
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2021
Subjects: Electrónica digital
Circuitos integrados
Puertas lógicas
Serie 7400
HCMOS

description: Prácticas con circuitos integrados de la serie 7400, utilizando la familia 74HC. Primera práctica que explica un diseño muy elemental para aprender a realizar las conexiones en la placa de inserción, calcular los valores de las resistencia, leer las hojas de características y finalmente encender un led utilizando un inversor. Video disponible https://youtu.be/NsBdEsCLees
Incommensurate magnetic ground state revealed by RXS in the frustrated spin system Ca3Co2O6
Creators: name: Agrestini, S.
name: Mazzoli, C.
name: Bombardi, A.
name: Lees, M. R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have performed a resonant x-ray scattering study at the Co pre-K edge on a single crystal of Ca3Co2O6. The measurements reveal an abrupt transition to a magnetically ordered state immediately below T_N = 25 K, with a magnetic correlation length in excess of 5500 Å along the c-axis chains. There is no evidence for modifications to the Co$^{3+}$ spin state. A temperature dependent modulation in the magnetic order along the c-axis and an unusual decrease in the magnetic correlation lengths on cooling are observed. The results are compatible with the onset of a partially disordered antiferromagnetic structure in Ca3Co2O6.
description: RevTex 4, 5 pages + 3 figures
Dilated Convolutional Attention Network for Medical Code Assignment from Clinical Text
Creators: name: Ji, Shaoxiong
name: Cambria, Erik
name: Marttinen, Pekka
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Medical code assignment, which predicts medical codes from clinical texts, is a fundamental task of intelligent medical information systems. The emergence of deep models in natural language processing has boosted the development of automatic assignment methods. However, recent advanced neural architectures with flat convolutions or multi-channel feature concatenation ignore the sequential causal constraint within a text sequence and may not learn meaningful clinical text representations, especially for lengthy clinical notes with long-term sequential dependency. This paper proposes a Dilated Convolutional Attention Network (DCAN), integrating dilated convolutions, residual connections, and label attention, for medical code assignment. It adopts dilated convolutions to capture complex medical patterns with a receptive field which increases exponentially with dilation size. Experiments on a real-world clinical dataset empirically show that our model improves the state of the art.
description: The 3rd Clinical Natural Language Processing Workshop at EMNLP 2020
Recursive renormalization of the singlet one-pion-exchange plus point-like interactions
Creators: name: Timoteo, V. S.
name: Frederico, T.
name: Delfino, A.
name: Tomio, Lauro
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The subtracted kernel approach is shown to be a powerful method to be implemented recursively in scattering equations with regular plus point-like interactions. The advantages of the method allows one to recursively renormalize the potentials, with higher derivatives of the Dirac-delta, improving previous results. The applicability of the method is verified in the calculation of the $^1S_0$ nucleon-nucleon phase-shifts, when considering a potential with one-pion-exchange plus a contact interaction and its derivatives. The $^1S_0$ renormalization parameters are fitted to the data. The method can in principle be extended to any derivative order of the contact interaction, to higher partial waves and to coupled channels.
description: 12 pages, 3 figures
Theory of dark-state polariton collapses and revivals
Creators: name: Jenkins, S. D.
name: Matsukevich, D. N.
name: Chaneliere, T.
name: Kuzmich, A.
name: Kennedy, T. A. B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the dynamics of dark-state polaritons in an atomic ensemble with ground-state degeneracy. A signal light pulse may be stored and retrieved from the atomic sample by adiabatic variation of the amplitude of a control field. During the storage process, a magnetic field causes rotation of the atomic hyperfine coherences, leading to collapses and revivals of the dark-state polariton number. These collapses and revivals should be observable in measurements of the retrieved signal field, as a function of storage time and magnetic field orientation.
description: 5 pages, 3 figures
Dispersion Managed Generation of Peregrine Solitons and Kuznetsov-Ma Breather in an Optical Fiber
Creators: name: Mahato, Dipti Kanika
name: Govindarajan, A.
name: Lakshmanan, M.
name: Sarma, Amarendra K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Optical rogue waves and its variants have been studied quite extensively in the context of optical fiber in recent years. It has been realized that dispersion management in optical fiber is experimentally much more feasible compared to its nonlinear counterpart. In this work, we report Kuznetsov-Ma (KM)-like breathers from the first three orders of rational solutions of the nonlinear Schrödinger equation with periodic modulation of the dispersion coefficient along the fiber axis. The breather dynamics are then controlled by proper choice of modulating parameters. Additionally, the evolution of new one-peak and two-peak breather-like solutions has been displayed corresponding to the second-order rational solution. Direct numerical simulations based on modulational instability has also been executed which agree well with the analytical results, thereby making the proposed system more feasible for experimental realization.
Recent progress in antiferromagnetic dynamics
Creators: name: Yuan, H. Y.
name: Yuan, Zhe
name: Duine, Rembert A.
name: Wang, X. R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Spintronics, since its inception, has mainly focused on ferromagnetic materials for manipulating the spin degree of freedom in addition to the charge degree of freedom, whereas much less attention has been paid to antiferromagnetic materials. Thanks to the advances of micro-nano-fabrication techniques and the electrical control of the Néel order parameter, antiferromagnetic spintronics is booming as a result of abundant room temperature materials, robustness against external fields and dipolar coupling, and rapid dynamics in the terahertz regime. For the purpose of applications of antiferromagnets, it is essential to have a comprehensive understanding of the antiferromagnetic dynamics at the microscopic level. Here, we first review the general form of equations that govern both antiferromagnetic and ferrimagnetic dynamics. This general form unifies the previous theories in the literature. We also provide a survey for the recent progress related to antiferromagnetic dynamics, including the motion of antiferromagnetic domain walls and skyrmions, the spin pumping and quantum antiferromagnetic spintronics. In particular, open problems in several topics are outlined. Furthermore, we discuss the development of antiferromagnetic quantum magnonics and its potential integration with modern information science and technology.
description: 7 pages, 2 figures
Conan S.
Creators: name: Young, Conan S.
Publisher: name: University of British Columbia
Year: 2009

description: ORF1696 is included as part of the bchFNBHLMORFl 696puhA superoperon found within the photosynthesis gene cluster on the chromosome of Rhodobacter capsulatus and mutation of ORF1696 results in reduced levels of the light-harvesting I (LHI) complex in cells grown photosynthetically. ORF1696 mutant strains were created by insertion of antibiotic resistance cartridges at different sites within the ORF1696 gene in a strain that lacks the lightharvesting II (LHII) complex. All of the mutant strains were deficient in the LHI complex, including one (ΔNae) with a disruption located 13 codons before the 3' end of the gene. A 5'-proximal disruption after the 31st codon of ORF1696 resulted in a mutant strain (ΔMun) with a novel absorption spectrum. The two more 3' mutant strains (ΔStu and ΔNae) were restored to levels close to the parental strain phenotype when frans-complemented with a plasmid expressing the ORF1696 gene, but ΔMun was not. The absorption spectrum of ΔMun resembled that of a strain which had a polar mutation in ORF1696. A comparison of LHI complex assembly kinetics showed that assembly occurred 2.8-fold faster in the parental strain compared to strain ΔStu. In contrast, LHI complex decay occurred 1.7-fold faster in the ORF1696 parental strain than in ΔStu. These results indicate that the major activity of the ORF1696 protein is in LHI complex assembly. A membrane topology model of the ORF1696 protein is proposed consisting of twelve membrane-spanning domains with both the N - and C-termini localized to the cytoplasmic side of the membrane similar to that predicted for the PucC protein of R. capsulatus which is required to maintain levels of the LHII complex. Suggestions for the function of the ORF1696 protein in LHI complex assembly are also proposed.
Combined and Comparative Analysis of Power Spectra
Creators: name: Sturrock, P. A.
name: Scargle, J. D.
name: Walther, G.
name: Wheatland, M. S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In solar physics, especially in exploratory stages of research, it is often necessary to compare the power spectra of two or more time series. One may, for instance, wish to estimate what the power spectrum of the combined data sets might have been, or one may wish to estimate the significance of a particular peak that shows up in two or more power spectra. One may also on occasion need to search for a complex of peaks in a single power spectrum, such as a fundamental and one or more harmonics, or a fundamental plus sidebands, etc. Visual inspection can be revealing, but it can also be misleading. This leads one to look for one or more ways of forming statistics, which readily lend themselves to significance estimation, from two or more power spectra. We derive formulas for statistics formed from the sum, the minimum, and the product of two or more power spectra. A distinguishing feature of our formulae is that, if each power spectrum has an exponential distribution, each statistic also has an exponential distribution.
description: 26 pages, 4 figures
Memorias e imágenes por pantalla VGA (7). Imágenes en color con una única memoria
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2021
Subjects: diseño digital
Memorias
VGA
Imágenes
Circuitos digitales

description: Transparencias de clase que explican cómo mostrar imágenes con profunidad de color de varios bits utilizando una memoria. Video disponible: https://youtu.be/Oyckgeg_nnE
description: {"references": ["Machado, F. et al, (2011). Dise\u00f1o de sistemas digitales con VHDL. http://hdl.handle.net/10115/5700", "Machado, F., Borromeo, S. (2010). Dise\u00f1o de circuitos digitales con VHDL. http://hdl.handle.net/10115/4045", "Machado, F., (2011). Problemas resueltos de Electr\u00f3nica Digital. http://hdl.handle.net/10115/5727"]}
A resolution of the Trans-Planckian problem in the R_h=ct universe
Creators: name: Melia, Fulvio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The recent measurement of a cutoff k_min in the fluctuation power spectrum P(k) of the cosmic microwave background may vitiate the possibility that slow-roll inflation can simultaneously solve the horizon problem and account for the formation of structure via the growth of quantum fluctuations in the inflaton field. Instead, we show that k_min may be interpreted more successfully in the R_h=ct cosmology, as the first mode exiting from the Planck scale into the semi-classical Universe shortly after the Big Bang. In so doing, we demonstrate that such a scenario completely avoids the well-known trans-Planckian problem plaguing standard inflationary cosmology.
description: 7 pages. Accepted for publication in Astronomische Nachrichten
Mean-field expansion in Bose-Einstein condensates with finite-range interactions
Creators: name: Schützhold, Ralf
name: Uhlmann, Michael
name: Xu, Yan
name: Fischer, Uwe R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present a formal derivation of the mean-field expansion for dilute Bose-Einstein condensates with two-particle interaction potentials which are weak and finite-range, but otherwise arbitrary. The expansion allows for a controlled investigation of the impact of microscopic interaction details (e.g., the scaling behavior) on the mean-field approach and the induced higher-order corrections beyond the s-wave scattering approximation.
description: 6 pages of RevTex4; extended discussion, added references
Freeform imaging system design with multiple reflection surfaces
Creators: name: Nie, Yunfeng
name: Shafer, David R.
name: Ottevaere, Heidi
name: Thienpont, Hugo
name: Duerr, Fabian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Reflective imaging systems form an important part of photonic devices such as spectrometers, telescopes, augmented and virtual reality headsets or lithography platforms. Reflective optics provide unparalleled spectral performance and can be used to reduce overall volume and weight. So far, most reflective designs have focused on two or three reflections, while four-reflection freeform designs can deliver a higher light throughput (faster F-number) as well as a larger field-of-view (FOV). However, advanced optical design strategies for four-reflection freeform systems have been rarely reported in literature. This is due to the increased complexity in solution space but also the fact that additional mirrors hinder a cost-effective realization (manufacture, alignment, etc.). Recently, we have proposed a novel design method to directly calculate the freeform surface coefficients while merely knowing the mirror positions and tilts. Consequently, this method allows laymen with basic optical design knowledge to calculate 'first time right' freeform imaging systems in a matter of minutes. This contrasts with most common freeform design processes, which requires considerable experience, intuition or guesswork. Firstly, we demonstrate the effectiveness of the proposed method for a four-mirror high-throughput telescope with 250mm-focal-length, F/2.5 and a wide rectangular FOV of 8.5° x 25.5°. In a subsequent step, we propose an effective three-mirror but four-reflection imaging system, which consists of two freeform mirrors and one double-reflection spherical mirror. Compared with common three-mirror and three-reflection imagers, our novel multi-reflection system shows unprecedented possibilities for an economic implementation while drastically reducing the overall volume.
description: 18 pages, 8 figures, submitted to journal
Instrucciones de control (branches) - Diseño básico de un procesador RISC-V
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2021
Subjects: arquitectura de computadores
RISC-V
Microarquitectura
ISA

description: Presentación de clase del diseño de un procesador básico RISC-V monociclo. En esta presentación se describe cómo implementar instrucciones de control condicionales (branches). Video disponible: https://youtu.be/UzCLsPhydBY Enlace para convertir programa en ensamblador a memoria ROM VHDL: https://github.com/felipe-m/img_rom
description: {"references": ["Patterson, David; Waterman, Andrew (2018). Gu\u00eda Pr\u00e1ctica de RISC-V: El Atlas de una Arquitectura Abierta (Al\u00ed Lemus, Eduardo Corpe\u00f1o, trads.). p. 215. ISBN 978-0-9992491-2-3", "Andrew Waterman, Krste Asanovic, The RISC-V Instruction Set Manual. Vol I: User-Level ISA. v2.2 https://riscv.org/specifications/", "Andrew Waterman, Design of the RISC-V Instruction Set Architecture. http://www2.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-1.html", "David Money Harris, Sarah L. Harris, Digital Design and Computer Architecture", "David Patterson, John Hennessy. Computer Organization and Design. RISC-V Edition"]}
Effective field theory for closed strings near the Hagedorn temperature
Creators: name: Brustein, Ram
name: Zigdon, Yoav
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discuss interacting, closed, bosonic and superstrings in thermal equilibrium at temperatures close to the Hagedorn temperature in flat space. We calculate S-matrix elements of the strings at the Hagedorn temperature and use them to construct a low-energy effective action for interacting strings near the Hagedorn temperature. We show, in particular, that the four-point amplitude of massless winding modes leads to a positive quartic interaction. Furthermore, the effective field theory has a generalized conformal structure, namely, it is conformally invariant when the temperature is assigned an appropriate scaling dimension. Then, we show that the equations of motion resulting from the effective action possess a winding-mode-condensate background solution above the Hagedorn temperature and present a worldsheet conformal field theory, similar to a Sine-Gordon theory, that corresponds to this solution. We find that the Hagedorn phase transition in our setup is second order, in contrast to a first-order transition that was found previously in different setups.
description: Typos corrected
Multiplexor de 2 entradas - Circuitos combinacionales
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2020
Subjects: Electrónica Digital
Bloques combinacionales
Puertas lógicas

description: Presentación de clase del multiplexor de dos entradas. Video de la presentación disponible: https://youtu.be/LElFYHnz1Ls v1.1: Corregido error en las tablas de verdad de las páginas 19 a la 22
Phase control of the fractional conductance of silicon nanosandwich-structures
Creators: name: Rul, N. I.
name: Bagraev, N. T.
name: Klyachkin, L. E.
name: Malyarenko, A. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present the experimental data of the electric features of the silicon nanosandwichstructures obtained by silicon planar technology in the frameworks of the Hall geometry that represent the ultra-shallow silicon quantum well of 2 nm wide that are confined by delta-barrier heavily doped with boron, which create the edge channels used as the phase controllers of electric signals. The formation of the negative-U dipole boron centers, which appear to confine the edge channels, results in the effective mass dropping and corresponding reduction of the electron-electron interaction thereby giving rise to the macroscopic quantum phenomena at high temperatures up to room temperature. The phase control of the longitudinal conductance is observed by changing either the magnitude of the source-drain current or the voltage applied to the external gate of the silicon nanosandwiches within the quantum Faraday effect.
description: 5 pages, 4 figures
Magneto-optical imaging of magnetic flux patterns in superconducting films with antidots
Creators: name: Yurchenko, V. V.
name: Woerdenweber, R.
name: Galperin, Yu. M.
name: Shantsev, D. V.
name: Vestgaarden, J. I.
name: Johansen, T. H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Superconducting YBaCuO thin films were equipped with a special arrangement of antidots (holes) of 1 micron radius in order to guide the stream of magnetic flux moving in (or out of) the sample. The flux distribution and its dynamics were visualized using real-time magneto-optical imaging. It is clearly demonstrated that one-dimensional antidot arrays strongly facilitate propagation of magnetic flux. We also demonstrate a possibility to alter the direction of flux motion in a controlled way by special arrangement of intercepting antidot arrays. Our resolution was sufficient for observation of flux in particular antidots, which allows a more detailed dynamic analysis of such systems.
description: 4 pages, 5 figures, submitted to Physica C, Proc. of VORTEX-IV Workshop on Crete-2005
Choptuik Scaling and The Merger Transition
Creators: name: Kol, Barak
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The critical solution in Choptuik scaling is shown to be closely related to the critical solution in the black-string black-hole transition (the merger), through double analytic continuation, and a change of a boundary condition. The interest in studying various space-time dimensions D for both systems is stressed. Gundlach-Hod-Piran off-critical oscillations, familiar in the Choptuik set-up, are predicted for the merger system and are predicted to disappear above a critical dimension D*=10. The scaling constants, Delta(D), gamma(D), are shown to combine naturally to a single complex number.
description: 19 pages, 4 figures, 2 tables. v2: added details on reference, typographical changes. v3: see `Note Added' at end of Introduction
Negative entropy production rates in Drude-Sommerfeld metals
Creators: name: Bonança, Marcus V. S.
name: Nazé, Pierre
name: Deffner, Sebastian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: It is a commonly accepted creed that in typical situations the rate of entropy production is non-negative. We show that this assertion is not entirely correct if a time-dependent, external perturbation is not compensated by a rapid enough decay of the response function. This is demonstrated for three variants of the Drude model to describe electrical conduction in noble metals, namely the classical free electron gas, the Drude-Sommerfeld model, and the Extended Drude-Sommerfeld model. The analysis is concluded with a discussion of potential experimental verifications and ramifications of negative entropy production rates.
description: 6+4 pages, 10 figures
Multiplexor de 4 entradas - Circuitos combinacionales
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2020
Subjects: Electrónica Digital
Bloques combinacionales
Puertas lógicas

description: Presentación de clase del multiplexor de cuatro entradas. Se explica cómo hacerlo con puertas lógicas, con un decodificador y con multiplexores de dos entradas con y sin habilitación. La presentación de los multiplexores de 2 entradas está disponible: https://doi.org/10.5281/zenodo.3723216 Video de la presentación disponible: https://youtu.be/oLKFXejJ4PI
Kelu-1 is a Binary L Dwarf: First Brown Dwarf Science from Laser Guide Star Adaptive Optics
Creators: name: Liu, Michael C.
name: Leggett, Sandy K.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (Abridged) We present near-IR imaging of the nearby L dwarf Kelu-1 obtained with the Keck sodium laser guide star adaptive optics (LGS AO) system as part of a high angular resolution survey for substellar binaries. Kelu-1 was one of the first free-floating L dwarfs identified, and the origin of its overluminosity compared to other similar objects has been a long-standing question. Our images clearly resolve Kelu-1 into a 0.29'' (5.4 AU) binary, and a previous non-detection by HST demonstrates that the system is a true physical pair. Binarity explains the properties of Kelu-1 that were previously noted to be anomalous compared to other early-L dwarfs. We estimate spectral types of L1.5-L3 and L3-L4.5 for the two components, giving model-derived masses of 0.05-0.07 Msun and 0.045-0.065 Msun for an estimated age of 0.3-0.8 Gyr. More distant companions are not detected to a limit of 5-9 Mjup. The presence of lithium absorption indicates that both components are substellar, but the weakness of this feature relative to other L dwarfs can be explained if only Kelu-1B is Li-bearing. Determining whether both or only one of the components possesses lithium could constrain the age of Kelu-1 (and other Li-bearing L binaries) with higher precision than is possible for most ultracool field objects. These results are the first LGS AO observations of brown dwarfs and demonstrate the potential of this new instrumental capability for substellar astronomy.
description: 24 pages, Astrophysical Journal, in press (Nov 20, 2005 issue). Note that Figure 1 of the PDF version is degraded by arxiv.org, but the Postscript version is fine. Version 2 includes very minor changes to match the published version
Decodificador de 3 a 8 - Circuitos combinacionales
Creators: name: Machado, Felipe
Publisher: name: Zenodo
Year: 2020
Subjects: Electrónica Digital
Bloques combinacionales
Puertas lógicas

description: Presentación de clase sobre el decodificador de 3 a 8 con habilitación. Fundamentos de electrónica digital Se explica primero cómo implementarlo utilizando puertas lógicas y luego cómo se implementa utilizando decodificadores de 2 a 4. La presentación de los decodificadores de 2 a 4 está disponible: https://doi.org/10.5281/zenodo.3706609 Video de la presentación disponible: https://youtu.be/IyYyuDfyXWs
description: {"references": ["Machado, F. and Borromeo, S., 2010. Dise\u00f1o de circuitos digitales con VHDL. http://hdl.handle.net/10115/4045"]}
Optical-Cavity-Induced Current
Creators: name: Moddel, Garret
name: Weerakkody, Ayendra
name: Doroski, David
name: Bartusiak, Dylan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The formation of a submicron optical cavity on one side of a metal-insulator-metal (MIM) tunneling device induces a measurable electrical current between the two metal layers with no applied voltage. Reducing the cavity thickness increases the measured current. Eight types of tests were carried out to determine whether the output could be due to experimental artifacts. All gave negative results, supporting the conclusion that the observed electrical output is genuinely produced by the device. We interpret the results as being due to the suppression of vacuum optical modes by the optical cavity on one side of the MIM device, which upsets a balance in the injection of electrons excited by zero-point fluctuations. This interpretation is in accord with observed changes in electrical output as other device parameters are varied. A feature of the MIM devices is their femtosecond-fast transport and scattering times for hot charge carriers. The fast capture in these devices is consistent with a model in which an energy ΔE may be accessed from zero-point fluctuations for a time Δt, following a ΔEΔt uncertainty-principle-like relation governing the process.
description: 18 pages, minor wording changes, references added
title: Topological error correcting processes from fixed-point path integrals
Creators: name: Bauer, Andreas
Publisher: name: Freie Universität Berlin
Year: 2024
Subjects: subject: Quantum error correction
subject: Topological quantum error correcting codes
subject: Fixed-point path integral
subject: Stabilizer toric code
subject: Subsystem toric code
subject: CSS Floquet code
subject: Quantum information theory
classificationCode: 539
subject: Moderne Physik

description: We propose a unifying paradigm for analyzing and constructing topological quantum error correcting codes as dynamical circuits of geometrically local channels and measurements. To this end, we relate such circuits to discrete fixed-point path integrals in Euclidean spacetime, which describe the underlying topological order: If we fix a history of measurement outcomes, we obtain a fixed-point path integral carrying a pattern of topological defects. As an example, we show that the stabilizer toric code, subsystem toric code, and CSS Floquet code can be viewed as one and the same code on different spacetime lattices, and the honeycomb Floquet code is equivalent to the CSS Floquet code under a change of basis. We also use our formalism to derive two new error-correcting codes, namely a Floquet version of the 3+1-dimensional toric code using only 2-body measurements, as well as a dynamic code based on the double-semion string-net path integral.