cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Vibration-based Damage Detection of Structures
Creators: name: Emory, Benjamin Haynes
Publisher: name: Maryland Shared Open Access Repository
Year: 2010
Subjects: Damage Detection
Elevator Testing
Engineering Education
Inverse Problems
Modal Impact Device
Vibration

description: Vibration-based damage detection methods are of great interest because of their global nature as compared to standard localized non-destructive methods which are time consuming for large structures. In this work, vibration-based damage detection procedures are developed around a robust iterative algorithm that has been expanded to include two new optimization procedures, an improved computer program, and procedures for feature selection on structures with or without tension. The previous implementation of the iterative algorithm was successfully applied to beams and lightning masts using a few lower natural frequencies. The new implementation was successful at detecting stiffness changes in rectangular beams with and without tension, circular beams, and wire ropes modeled with beam elements. Detection of mass increase in a pipeline system using solid and shell elements is also shown. The new computer implementation allows for easy use of external models by computing the sensitivity matrices using the finite difference method. Including mass modification, new methods to overcome symmetry using length modification and targeted investigation are presented. The importance of step length is shown when the method fails because full step length is used. The importance of choosing a detection parameter is demonstrated when some the natural frequencies of a circular bar and a tensioned beam system increase and some decrease. Currently, there are two main methods used to perform modal testing: impact testing or shaker testing. The random impact method was successfully used on lightning masts to overcome external noise due to wind and on heavily damped elevator ropes. The main drawback is that for large structures, a heavy hammer has to be swung for 2-6 minutes for each test which is tiring. To overcome problems associated with the random impact method, a mechanical system was designed, built, and tested to implement the method. In the current research funding process educational outreach for the benefit of society is often required. Demonstrations of how this research and that of the Dynamic Systems and Vibrations Laboratory benefits society the development, delivery, and evaluation of an educational summer camp for high school students over six summers is presented.
Statistical behaviour of self-similar structures in canonical wall turbulence
Creators: name: Hwang, Jinyul
name: Lee, Jae Hwa
name: Sung, Hyung Jin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Townsend's attached-eddy hypothesis (AEH) provides a theoretical description of turbulence statistics in the logarithmic region in terms of coherent motions that are self-similar with the wall-normal distance (y). Here, we show the self-similar behaviour of turbulence motions contained within wall-attached structures of streamwise velocity fluctuations using the direct numerical simulation dataset of turbulent boundary layer, channel, and pipe flows ($Re_τ\approx 1000$) The physical sizes of the identified structures are geometrically self-similar in terms of height, and the associated turbulence intensity follows the logarithmic variation in all three flows. Moreover, the corresponding two-dimensional energy spectra are aligned along a linear relationship between the streamwise and spanwise wavelengths ($λ_x$ and $λ_z$, respectively) in the large-scale range ($12y < λ_x
description: 24 pages, Journal of Fluid Mechanics (in press)
Extent of pollution in planet-bearing stars
Creators: name: Li, S. -L.
name: Lin, D. N. C.
name: Liu, X. -W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (abridged) Search for planets around main-sequence (MS) stars more massive than the Sun is hindered by their hot and rapidly spinning atmospheres. This obstacle has been sidestepped by radial-velocity surveys of those stars on their post-MS evolutionary track (G sub-giant and giant stars). Preliminary observational findings suggest a deficiency of short-period hot Jupiters around the observed post MS stars, although the total fraction of them with known planets appears to increase with their mass. Here we consider the possibility that some very close- in gas giants or a population of rocky planets may have either undergone orbital decay or been engulfed by the expanding envelope of their intermediate-mass host stars. If such events occur during or shortly after those stars' main sequence evolution when their convection zone remains relatively shallow, their surface metallicity can be significantly enhanced by the consumption of one or more gas giants. We show that stars with enriched veneer and lower-metallicity interior follow slightly modified evolution tracks as those with the same high surface and interior metallicity. As an example, we consider HD149026, a marginal post MS 1.3 Msun star. We suggest that its observed high (nearly twice solar) metallicity may be confined to the surface layer as a consequence of pollution by the accretion of either a planet similar to its known 2.7-day-period Saturn-mass planet, which has a 70 Mearth compact core, or a population of smaller mass planets with a comparable total amount of heavy elements. It is shown that an enhancement in surface metallicity leads to a reduction in effective temperature, in increase in radius and a net decrease in luminosity. The effects of such an enhancement are not negligible in the determinations of the planet's radius based on the transit light curves.
description: 25 pages, 8 figures, submitted to ApJ
LRG at SemEval-2021 Task 4: Improving Reading Comprehension with Abstract Words using Augmentation, Linguistic Features and Voting
Creators: name: Sharma, Abheesht
name: Pandey, Harshit
name: Chhablani, Gunjan
name: Bhartia, Yash
name: Dash, Tirtharaj
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In this article, we present our methodologies for SemEval-2021 Task-4: Reading Comprehension of Abstract Meaning. Given a fill-in-the-blank-type question and a corresponding context, the task is to predict the most suitable word from a list of 5 options. There are three sub-tasks within this task: Imperceptibility (subtask-I), Non-Specificity (subtask-II), and Intersection (subtask-III). We use encoders of transformers-based models pre-trained on the masked language modelling (MLM) task to build our Fill-in-the-blank (FitB) models. Moreover, to model imperceptibility, we define certain linguistic features, and to model non-specificity, we leverage information from hypernyms and hyponyms provided by a lexical database. Specifically, for non-specificity, we try out augmentation techniques, and other statistical techniques. We also propose variants, namely Chunk Voting and Max Context, to take care of input length restrictions for BERT, etc. Additionally, we perform a thorough ablation study, and use Integrated Gradients to explain our predictions on a few samples. Our best submissions achieve accuracies of 75.31% and 77.84%, on the test sets for subtask-I and subtask-II, respectively. For subtask-III, we achieve accuracies of 65.64% and 62.27%.
description: 10 pages, 4 figures, SemEval-2021 Workshop, ACL-IJCNLP 2021
Cosmological Evolution of the Duty Cycle of Quasars
Creators: name: Wang, Jian-Min
name: Chen, Yan-Mei
name: Zhang, Fan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Quasars are powered by accretion onto supermassive black holes, but the problem of the duty cycle related to the episodic activity of the black holes remains open as one of the major questions of cosmological evolution of quasars. In this Letter, we obtain quasar duty cycles based on analyses of a large sample composed of 10,979 quasars with redshifts $z\le2.1$ from the Sloan Digital Sky Survey (SDSS) Data Release Three. We estimate masses of quasar black holes and obtain their mass function (MF) of the present sample. We then get the duty cycle $\barδ(z)=10^{-3}\sim 1$ based on the Sołtan's argument, implying that black holes are undergoing multiple episodic activity. We find that the duty cycle has a strong evolution. By comparison, we show that evolution of the duty cycle follows the history of cosmic star formation rate (SFR) density in the Universe, providing intriguing evidence for a natural connection between star formation and triggering of black hole activity. Feedback on star formation from black hole activity is briefly discussed.
description: Accepted by ApJL, 4 pages and 2 Figures
Localizing gravity on thick branes: a solution for massive KK modes of the Schroedinger equation
Creators: name: Barbosa-Cendejas, Nandinii
name: Herrera-Aguilar, Alfredo
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We generate scalar thick brane configurations in a 5D Riemannian space time which describes gravity coupled to a self-interacting scalar field. We also show that 4D gravity can be localized on a thick brane which does not necessarily respect Z_2-symmetry, generalizing several previous models based on the Randall-Sundrum system and avoiding the restriction to orbifold geometries as well as the introduction of the branes in the action by hand. We begin by obtaining a smooth brane configuration that preserves 4D Poincar'e invariance and violates reflection symmetry along the fifth dimension. The extra dimension can have either compact or extended topology, depending on the values of the parameters of the solution. In the non-compact case, our field configuration represents a thick brane with positive energy density centered at y=c_2, whereas in the compact case we get pairs of thick branes. We recast as well the wave equations of the transverse traceless modes of the linear fluctuations of the classical solution into a Schroedinger's equation form with a volcano potential of finite bottom. We solve Schroedinger equation for the massless zero mode m^2=0 and obtain a single bound wave function which represents a stable 4D graviton and is free of tachyonic modes with m^2<0. We also get a continuum spectrum of Kaluza-Klein (KK) states with m^2>0 that are suppressed at y=c_2 and turn asymptotically into plane waves. We found a particular case in which the Schroedinger equation can be solved for all m^2>0, giving us the opportunity of studying analytically the massive modes of the spectrum of KK excitations, a rare fact when considering thick brane configurations.
description: 8 pages in latex. We corrected signs in the field equations, the expressions for the scalar field and the self-interacting potential. Due to the fact that no changes are introduced in the warp factor, the physics of the system remains the same
Robust Face Alignment by Multi-order High-precision Hourglass Network
Creators: name: Wan, Jun
name: Lai, Zhihui
name: Liu, Jun
name: Zhou, Jie
name: Gao, Can
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Heatmap regression (HR) has become one of the mainstream approaches for face alignment and has obtained promising results under constrained environments. However, when a face image suffers from large pose variations, heavy occlusions and complicated illuminations, the performances of HR methods degrade greatly due to the low resolutions of the generated landmark heatmaps and the exclusion of important high-order information that can be used to learn more discriminative features. To address the alignment problem for faces with extremely large poses and heavy occlusions, this paper proposes a heatmap subpixel regression (HSR) method and a multi-order cross geometry-aware (MCG) model, which are seamlessly integrated into a novel multi-order high-precision hourglass network (MHHN). The HSR method is proposed to achieve high-precision landmark detection by a well-designed subpixel detection loss (SDL) and subpixel detection technology (SDT). At the same time, the MCG model is able to use the proposed multi-order cross information to learn more discriminative representations for enhancing facial geometric constraints and context information. To the best of our knowledge, this is the first study to explore heatmap subpixel regression for robust and high-precision face alignment. The experimental results from challenging benchmark datasets demonstrate that our approach outperforms state-of-the-art methods in the literature.
description: Accep by IEEE Transactions on Image Processing 2020.10.14
Grußwort des Ökumenischen Patriarchen Bartholomaios auf dem Symposium in Thessaloniki zu 500 Jahren Reformation
Creators: name: Bartholomaios I., Konstantinopel
name: Müller, Andreas
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 66 Nr. 3 (2017): Ökumenische Rundschau, Band 66, Heft 3
Electric dipole polarizability in neutron-rich Sn isotopes as a probe of nuclear isovector properties
Creators: name: Li, Zhengzheng
name: Niu, Yifei
name: Long, Wenhui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The determination of nuclear symmetry energy, and in particular, its density dependence, is a long-standing problem for nuclear physics community. Previous studies have found that the product of electric dipole polarizability $α_D$ and symmetry energy at saturation density $J$ has a strong linear correlation with $L$, the slope parameter of symmetry energy. However, current uncertainty of $J$ hinders the precise constraint on $L$. We investigate the correlations between electric dipole polarizability $α_D$ (or times symmetry energy at saturation density $J$) in Sn isotopes and the slope parameter of symmetry energy $L$ using the quasiparticle random-phase approximation based on Skyrme Hartree-Fock-Bogoliubov. A strong and model-independent linear correlation between $α_D$ and $L$ is found in neutron-rich Sn isotopes where pygmy dipole resonance (PDR) gives a considerable contribution to $α_D$, attributed to the pairing correlations playing important roles through PDR. This newly discovered linear correlation would help one to constrain $L$ and neutron-skin thickness $ΔR_\textnormal{np}$ stiffly if $α_D$ is measured with high resolution in neutron-rich nuclei. Besides, a linear correlation between $α_D J$ in a nucleus around $β$-stability line and $α_D$ in a neutron-rich nucleus can be used to assess $α_D$ in neutron-rich nuclei.
Fresh, Fair and Energy-Efficient Content Provision in a Private and Cache-Enabled UAV Network
Creators: name: Yang, Peng
name: Guo, Kun
name: Xi, Xing
name: Quek, Tony Q. S.
name: Cao, Xianbin
name: Liu, Chenxi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this paper, we investigate a private and cache-enabled unmanned aerial vehicle (UAV) network for content provision. Aiming at delivering fresh, fair, and energy-efficient content files to terrestrial users, we formulate a joint UAV caching, UAV trajectory, and UAV transmit power optimization problem. This problem is confirmed to be a sequential decision problem with mixed-integer non-convex constraints, which is intractable directly. To this end, we propose a novel algorithm based on the techniques of subproblem decomposition and convex approximation. Particularly, we first propose to decompose the sequential decision problem into multiple repeated optimization subproblems via a Lyapunov technique. Next, an iterative optimization scheme incorporating a successive convex approximation (SCA) technique is explored to tackle the challenging mixed-integer non-convex subproblems. Besides, we analyze the convergence and computational complexity of the proposed algorithm and derive the theoretical value of the expected peak age of information (PAoI) to estimate the content freshness. Simulation results demonstrate that the proposed algorithm can achieve the expected PAoI close to the theoretical value and is more 22.11% and 70.51% energy-efficient and fairer than benchmark algorithms.
Exceeding 400% tunnel magnetoresistance at room temperature in epitaxial Fe/MgO/Fe(001) spin-valve-type magnetic tunnel junctions
Creators: name: Scheike, Thomas
name: Xiang, Qingyi
name: Wen, Zhenchao
name: Sukegawa, Hiroaki
name: Ohkubo, Tadakatsu
name: Hono, Kazuhiro
name: Mitani, Seiji
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Giant tunnel magnetoresistance (TMR) ratios of 417% at room temperature (RT) and 914% at 3 K were demonstrated in epitaxial Fe/MgO/Fe(001) exchanged-biased spin-valve magnetic tunnel junctions (MTJs) by tuning growth conditions for each layer, combining sputter deposition for the Fe layers, electron-beam evaporation of the MgO barrier, and barrier interface tuning. Clear TMR oscillation as a function of the MgO thickness with a large peak-to-valley difference of ~80% was observed when the layers were grown on a highly (001)-oriented Cr buffer layer. Specific features of the observed MTJs are symmetric differential conductance (dI/dV) spectra for the bias polarity and plateau-like deep local minima in dI/dV (parallel configuration) at |V| = 0.2~0.5 V. At 3K, fine structures with two dips emerge in the plateau-like dI/dV, reflecting highly coherent tunneling through the Fe/MgO/Fe. We also observed a 496% TMR ratio at RT by a 2.24-nm-thick-CoFe insertion at the bottom-Fe/MgO interface.
description: 21 pages, 7 figures
On Maximizing Coverage in Gaussian Relay Networks
Creators: name: Aggarwal, Vaneet
name: Bennatan, Amir
name: Calderbank, A. Robert
Publisher: name: arXiv
Year: 2008
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Results for Gaussian relay channels typically focus on maximizing transmission rates for given locations of the source, relay and destination. We introduce an alternative perspective, where the objective is maximizing coverage for a given rate. The new objective captures the problem of how to deploy relays to provide a given level of service to a particular geographic area, where the relay locations become a design parameter that can be optimized. We evaluate the decode and forward (DF) and compress and forward (CF) strategies for the relay channel with respect to the new objective of maximizing coverage. When the objective is maximizing rate, different locations of the destination favor different strategies. When the objective is coverage for a given rate, and the relay is able to decode, DF is uniformly superior in that it provides coverage at any point served by CF. When the channel model is modified to include random fading, we show that the monotone ordering of coverage regions is not always maintained. While the coverage provided by DF is sensitive to changes in the location of the relay and the path loss exponent, CF exhibits a more graceful degradation with respect to such changes. The techniques used to approximate coverage regions are new and may be of independent interest.
description: 17 pages,8 figures, Submitted to IEEE Trans. Inf. Th, Oct. 2007
Testing the Stationarity Assumption in Software Effort Estimation Datasets
Creators: name: Bosu, Michael Franklin
name: MacDonell, Stephen G.
name: Whigham, Peter
Publisher: name: arXiv
Year: 2020
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Software effort estimation (SEE) models are typically developed based on an underlying assumption that all data points are equally relevant to the prediction of effort for future projects. The dynamic nature of several aspects of the software engineering process could mean that this assumption does not hold in at least some cases. This study employs three kernel estimator functions to test the stationarity assumption in three software engineering datasets that have been used in the construction of software effort estimation models. The kernel estimators are used in the generation of non-uniform weights which are subsequently employed in weighted linear regression modeling. Prediction errors are compared to those obtained from uniform models. Our results indicate that, for datasets that exhibit underlying non-stationary processes, uniform models are more accurate than non-uniform models. In contrast, the accuracy of uniform and non-uniform models for datasets that exhibited stationary processes was essentially equivalent. The results of our study also confirm prior findings that the accuracy of effort estimation models is independent of the type of kernel estimator function used in model development.
description: 7 pages, conference, 1 table, 2 figures
FUSE observations of HD 5980: The wind structure of the eruptor
Creators: name: Koenigsberger, Gloria
name: Fullerton, Alexander W.
name: Massa, Derck
name: Auer, Lawrence H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: HD 5980 is a unique system containing one massive star (star A) that is apparently entering the luminous blue variable phase, and an eclipsing companion (star B) that may have already evolved beyond this phase to become a Wolf-Rayet star. In this paper we present the results from FUSE observations obtained in 1999, 2000, and 2002 and one far-UV observation obtained by ORFEUS/BEFS in 1993 shortly before the first eruption of HD 5980. The eight phase-resolved spectra obtained by FUSE in 2002 are analyzed in the context of a wind-eclipse model. This analysis shows that the wind of the eruptor obeyed a very fast velocity law in 2002, which is consistent with the line-driving mechanism. Large amplitude line-profile variations on the orbital period are shown to be due to the eclipse of star B by the wind of star A, although the eclipse due to gas flowing in the direction of star B is absent. This can only be explained if the wind of star A is not spherically symmetric, or if the eclipsed line radiation is "filled-in" by emission originating from somewhere else in the system, e.g., in the wind-wind collision region. Except for a slightly lower wind speed, the ORFEUS/BEFS spectrum is very similar to the spectrum obtained by FUSE at the same orbital phase: there is no indication of the impending eruption. However, the trend for decreasing wind velocity suggests the occurrence of the "bi-stability" mechanism, which in turn implies that the restructuring of the circumbinary environment caused by the transition from "fast, rarefied wind" to "slow, dense wind" was observed as the eruptive event. The underlying mechanism responsible for the long-term decrease in wind velocity that precipitated this change remains an open issue.
description: 19 pages, 13 figures
A constant comparative analysis of opposition campaign leaders’ experiences during a controversial referendum about alcohol sale initiated by a commercial interest
Creators: name: Shoveller, Jean Anne
Publisher: name: University of British Columbia
Year: 2009

description: The Ottawa Charter For Health Promotion defines health promotion as "the process of enabling people to increase control over, and improve, their health" (World Health Organization, 1986, p. 1). Subsequently, health promotion policy-making, practice, and research promised a broader view of the concept of health and strategies to promote health, including an increased emphasis on decentralized participatory approaches and efforts to affect policies influencing health. The literature emphasizes the cooperative rather than the confrontational aspects of participation, offering limited knowledge about how participation relates to what citizens experience when they take on leadership roles during referendums. This study examines the history of opposition at the neighbourhood level during a controversial, health-related referendum. This study seeks to generate hypotheses about the experience of campaign leaders during such a process of participation and confrontation. Semi-structured interviews were conducted with three opposition campaign leaders and two key informants. Data were coded and organized into a theoretical framework, guided by the principles of the constant comparative method. Participating in a referendum is the core category around which all other concepts clustered and has three major stages. The first stage, becoming involved, has three phases: activating, anticipating, and structuring. The second stage, being involved, has five phases: bargaining, relinquishing, overcoming, concretizing, and elevating. Remaining involved, the final stage, has two phases: reconstituting and recovering. Implications for the literature regarding citizen participation, the incorporation of citizen participation in decision making in health promotion, and changes in the process of creating healthful public policy are discussed. The referendum under study polarized citizens according to their emotional responses to complex issues, rather than facilitating broad-based citizen participation in cooperative decision making. Three alternatives to conducting referendums are suggested: deliberative opinion polling, development of a sense of proactive agency within communities, and promotion of equitable power distribution among citizens.
On the Assumption of Initial Factorization in the Master Equation for Weakly Coupled Systems I: General Framework
Creators: name: Tasaki, S.
name: Yuasa, K.
name: Facchi, P.
name: Kimura, G.
name: Nakazato, H.
name: Ohba, I.
name: Pascazio, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We analyze the dynamics of a quantum mechanical system in interaction with a reservoir when the initial state is not factorized. In the weak-coupling (van Hove) limit, the dynamics can be properly described in terms of a master equation, but a consistent application of Nakajima-Zwanzig's projection method requires that the reference (not necessarily equilibrium) state of the reservoir be endowed with the mixing property.
description: 33 pages
Deterministic Fast Scrambling with Neutral Atom Arrays
Creators: name: Hashizume, Tomohiro
name: Bentsen, Gregory
name: Weber, Sebastian
name: Daley, Andrew J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Fast scramblers are dynamical quantum systems that produce many-body entanglement on a timescale that grows logarithmically with the system size $N$. We propose and investigate a family of deterministic, fast scrambling quantum circuits realizable in near-term experiments with arrays of neutral atoms. We show that three experimental tools -- nearest-neighbour Rydberg interactions, global single-qubit rotations, and shuffling operations facilitated by an auxiliary tweezer array -- are sufficient to generate nonlocal interaction graphs capable of scrambling quantum information using only $O(\log N)$ parallel applications of nearest-neighbor gates. These tools enable direct experimental access to fast scrambling dynamics in a highly controlled and programmable way, and can be harnessed to produce highly entangled states with varied applications.
description: 7 pages with 4 figures (plus 7-page supplement with 4 figures); updated to match published version
String tensions of SU(N) gauge theories in 2+1 dimensions
Creators: name: Bringoltz, Barak
name: Teper, Michael
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We calculate the energy spectrum of closed strings in SU(N) gauge theories with N=2,3,4,6,8 in 2+1 dimensions to a high accuracy. We attempt to control all systematic errors, and this allows us to perform a precise comparison with different theoretical predictions. When we study the dependence of the string mass on its length L we find that the Nambu-Goto prediction is a very good approximation down to relatively short lengths, where the Luscher term alone is insufficient. We then isolate the corrections to the Luscher term, and compare them to recent theoretical predictions, which indeed seem to be mildly preferred by the data. When we take these corrections into account and extract string tensions from the string masses, we find that their continuum limit is lower by 2%-1% from the predictions of Karabli, Kim, and Nair. The discrepancy decreases with N, but when we extrapolate our results to N=oo we still find a discrepancy of 0.88% which is a 4.5 sigma effect.
description: Lattice 2006, PoS format, 7 pages
Neuronal Oscillations on Evolving Networks: Dynamics, Damage, Degradation, Decline, Dementia, and Death
Creators: name: Goriely, Alain
name: Kuhl, Ellen
name: Bick, Christian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Dynamical Systems (math.DS)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Neurodegenerative diseases, such as Alzheimer's or Parkinson's disease, show characteristic degradation of structural brain networks. This degradation eventually leads to changes in the network dynamics and degradation of cognitive functions. Here, we model the progression in terms of coupled physical processes: The accumulation of toxic proteins, given by a nonlinear reaction-diffusion transport process, yields an evolving brain connectome characterized by weighted edges on which a neuronal-mass model evolves. The progression of the brain functions can be tested by simulating the resting-state activity on the evolving brain network. We show that while the evolution of edge weights plays a minor role in the overall progression of the disease, dynamic biomarkers predict a transition over a period of 10 years associated with strong cognitive decline.
Informe OTEA 2020
Creators: name: Alonso-Epelde, Eva
name: Rodríguez-Zúñiga, Alejandro
name: González-Eguino, Mikel
Publisher: name: Observatorio de la Transición Energética y la Acción Climática (OTEA)
Year: 2021

description: Informe anual 2020 del Observatorio de la Transición Energética y la Acción Climática (OTEA)
Soliton resolution for critical co-rotational wave maps and radial cubic wave equation
Creators: name: Duyckaerts, Thomas
name: Kenig, Carlos
name: Martel, Yvan
name: Merle, Frank
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper we prove the soliton resolution conjecture for all times, for all solutions in the energy space, of the co-rotational wave map equation. To our knowledge this is the first such result for all initial data in the energy space for a wave-type equation. We also prove the corresponding results for radial solutions, which remain bounded in the energy norm, of the cubic (energy-critical) nonlinear wave equation in space dimension 4.
Global Road Damage Detection: State-of-the-art Solutions
Creators: name: Arya, Deeksha
name: Maeda, Hiroya
name: Ghosh, Sanjay Kumar
name: Toshniwal, Durga
name: Omata, Hiroshi
name: Kashiyama, Takehiro
name: Sekimoto, Yoshihide
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: This paper summarizes the Global Road Damage Detection Challenge (GRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data'2020. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that maintains a leaderboard for the participants. In the presented case, the data constitute 26336 road images collected from India, Japan, and the Czech Republic to propose methods for automatically detecting road damages in these countries. In total, 121 teams from several countries registered for this competition. The submitted solutions were evaluated using two datasets test1 and test2, comprising 2,631 and 2,664 images. This paper encapsulates the top 12 solutions proposed by these teams. The best performing model utilizes YOLO-based ensemble learning to yield an F1 score of 0.67 on test1 and 0.66 on test2. The paper concludes with a review of the facets that worked well for the presented challenge and those that could be improved in future challenges.
description: 11 Pages, 2 Figures, 3 Tables
Clash of the Titans
Creators: name: Faura, Joseph Jeremy
Publisher: name: Maryland Shared Open Access Repository
Year: 2011
Subjects: Art
Celebrity
Collage
Culture
Mythology
Ritual

description: The aim of this thesis is to explore myth and ritual as they relate to contemporary culture. To place this topic within a larger context, I focus on the work of Joseph Campbell, Mary Douglas, and George Bataille, among others. Campbell argues that a meaningful transformation can occur through an individual's exploration of his or her personal symbols, myths and rituals. The ritual-like aspects that I perform, individually, as part of my artistic process, result in work that is perverse and subversive, powerful and transformative. This production is not unlike that of the Dadaists and Surrealists, artists who created work that subverted and reinterpreted contemporary visual language. I describe my work, Clash of the Titans, in light of my research on myth, ritual, and the individual, and also in the context of contemporary artists Nancy Spero, Wangechi Mutu, and Jess (Burgess Collins).
BubbleTongueRemix
Creators: name: Fannon, Jill Kathleen
Publisher: name: Maryland Shared Open Access Repository
Year: 2011
Subjects: performance
photography

description: This item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu.
The Topological Origin of the Peierls-Nabarro Barrier
Creators: name: Hocking, Brook J.
name: Ansell, Helen S.
name: Kamien, Randall D.
name: Machon, Thomas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Crystals and other condensed matter systems described by density waves often exhibit dislocations. Here we show, by considering the topology of the ground state manifolds (GSMs) of such systems, that dislocations in the density phase field always split into disclinations, and that the disclinations themselves are constrained to sit at particular points in the GSM. Consequently, the topology of the GSM forbids zero-energy dislocation glide, giving rise to a Peirels-Nabarro barrier.
description: 5 pages, 4 figures
Influence of shear stress on the adhesion of S. aureus to immobilized platelets
Creators: name: George, Niraj P.E.
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Staphylococcus aureus
Clumping factor A (ClfA)
Endocarditis
Fibronectin Binding Proteins (Fnbps)
Biofilms
Engineering, Chemical (0542)
Engineering, Biomedical (0541)

description: The surge of Staphylococcus aureus as a pandemic public health threat has created a critical need to understand the pathogenesis of infection at a molecular level. Staphylococcus; aureus can cause serious and potentially fatal illnesses such as acute infectious endocarditis; osteomyelitis, septic arthritis, pneumonia and septicemia. The molecular pathogenesis of these infections involves bacterial adherence via surface structures called adhesins that bind to ligands in the host. Often, the bacterial adhesion takes place in the blood stream where fluid shear stress may influence binding events. The first part of our research characterizes the adhesive interactions between shake flask grown cells and immobilized platelets, at two; distinct time points of growth (early and late growth) under physiologically relevant shear rates using a parallel plate flow chamber. Our results demonstrate a markedly elevated binding efficiency for late growth phase staphylococci to immobilized platelets, compared with that of the early growth phase cells in the high shear regime. During the late growth phase, fibrinogen in concert with von Willebrand factor (vWf) potentiates S. aureus-platelet; binding via shear-dependent mechanisms. Furthermore, a shear dependant binding role is observed for S. aureus adhesins ClfA, SdrCDE and Spa. By contrast, fibrinogen, but not vWf, supports the adhesion of early growth phase S. aureus at the high wall shear rates. During the early growth phase, ClfA is identified as the dominant staphylococcal adhesion receptor, with Fnbps playing a supporting role. Nearly 65% of infective diseases are associated with the presence of bacterial biofilms. The formation of secondary sites of infection likely results from metastatic seeding of biofilm-shed bacteria through the bloodstream, where shed bacteria may adhere at sites of vascular damage. The second part of this research characterizes the binding of biofilm-shed planktonic cells versus those grown as shake flask cultures to platelets under conditions mimicking vascular wall shear rates. Planktonic cells demonstrate significantly lower levels of adhesion to platelets versus their shake flask grown counterparts. Furthermore, these binding levels directly correlate with the surface expression level of adhesion molecules. Taken together, our results suggest that the mode of growth, the temporal receptor expression pattern and the level of hydrodynamic shear govern S. aureus adhesion to a thrombotic surface.
Bounds on the shear load of cohesionless granular matter
Creators: name: Ellenbroek, Wouter G.
name: Snoeijer, Jacco H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We characterize the force state of shear-loaded granular matter by relating the macroscopic stress to statistical properties of the force network. The purely repulsive nature of the interaction between grains naturally provides an upper bound for the sustainable shear stress, which we analyze using an optimization procedure inspired by the so-called force network ensemble. We establish a relation between the maximum possible shear resistance and the friction coefficient between individual grains, and find that anisotropies of the contact network (or the fabric tensor) only have a subdominant effect. These results can be considered the hyperstatic limit of the force network ensemble and we discuss possible implications for real systems. Finally, we argue how force anisotropies can be related quantitatively to experimental measurements of the effective elastic constants.
description: 17 pages, 6 figures. v2: slightly rearranged, introduction and discussion rewritten
Emergent superconductivity by Re doping in type -II Weyl semimetal NiTe2
Creators: name: Mandal, M.
name: Singh, R. P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Recently topological superconductors emerge as a platform to realise Majorana Fermions which has potential application in topological quantum computation. Superconductivity in these materials can be realised by chemical doping, high pressure or proximity effect. Herein we report the emergent superconductivity in single-crystals of Re doped type-II Weyl semimetal NiTe2. The magnetic and transport measurements highlight that Re substitution in Ni-site induces superconductivity at a maximum temperature of 2.36 K. Hall effect and specific heat measurements indicate that Re substitution is doping hole and facilitates the emergence of superconductivity by phonon softening and enhancing the electron-phonon coupling.
description: 5 pages, 7 figures
Virtual Reality Environment for the Conceptual Design of Mechanisms
Creators: name: Alvarez, Juan Camilo
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: Conceptual Design
Mechanical Design
Mechanism Design
Multibody Dynamics
Virtual Reality

description: The goal of this thesis is to provide a mechanism design tool to address some of the issues encountered in early design stages by current available technologies in industry and academia. As a solution, we present Virtual Reality Mechanism Design Studio (VRMDS). VRMDS is an intuitive virtual environment (VE) for supporting the interactive design and simulation of mechanisms. The studio allows users to build spatial or planar mechanisms through intuitive operations and subsequently simulate their dynamic motion. Written in Python script language, VRMDS provides 3D stereoscopic immersive visualization, haptic enabled interaction, head and hand tracking and a user-friendly graphical user interface (GUI). A data model for organizing the data structure of links and commonly used mechanical joints is designed and implemented upon the basis of the Vizard Virtual Reality (VR) library. Within the virtual environment, the user can create links and assemble them into mechanisms by defining joints between links. Simultaneously a corresponding MATLAB's SimMechanics model is automatically created at run time. The dynamics simulation of mechanisms is enabled by interfacing with the dynamics solver built-in SimMechanics. The user may choose to run the system in an immersive VR environment or a desktop environment. The result is a versatile mechanism design tool that is beneficial to the early stages of the design process.
On the Assumption of Initial Factorization in the Master Equation for Weakly Coupled Systems II: Solvable Models
Creators: name: Yuasa, K.
name: Tasaki, S.
name: Facchi, P.
name: Kimura, G.
name: Nakazato, H.
name: Ohba, I.
name: Pascazio, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We analyze some solvable models of a quantum mechanical system in interaction with a reservoir when the initial state is not factorized. We apply Nakajima-Zwanzig's projection method by choosing a reference state of the reservoir endowed with the mixing property. In van Hove's limit, the dynamics is described in terms of a master equation. We observe that Markovianity becomes a valid approximation for timescales that depend both on the form factors of the interaction and on the observables of the reservoir that can be measured.
description: 25 pages
Letter from John McRae to James Goldie, August 4, 1910
Creators: name: MacRae, John
Publisher: name: The University of British Columbia
Year: 2017

description: Letter to James Goldie from John McRae (Manager of the Royal Bank of Canada in Vernon, B.C.), dated August 4, 1910, regarding payments due under escrow, with reference to Frank Hewer and J.E. McAllister.
Vibration-Based Structural Damage Detection with Applications to Structures with Bolted Joints
Creators: name: He, Kun
Publisher: name: Maryland Shared Open Access Repository
Year: 2011
Subjects: forward problem
inverse problem
Levenberg-Marquardt method
logistic function transformation
loosening of bolted joints
vibration-based damage detection

description: A structural damage detection method that uses changes in natural frequencies to detect damage has advantages over conventional nondestructive tests in detecting various types of damage using minimum measurement data. Two major challenges associated with the applications of the vibration-based damage detection method to practical engineering structures are addressed: accurate modeling of test structures and the development of a robust inverse algorithm to identify damage, which are defined as the forward and inverse problems associated with the damage detection method, respectively. To resolve the forward problem, new physics-based finite element (FE) modeling techniques for fillets in thin-walled beams and bolted joints are developed, so that complex structures with thin-walled beams and/or bolted joints can be accurately modeled with a reasonable model size. To resolve the inverse problem, a robust iterative algorithm using a trust-region method, called the Levenberg-Marquardt (LM) method is developed to accurately detect the locations and extent of damage using a minimum number of measured natural frequencies. The LM method can ensure global convergence of the iterations in solving severely underdetermined systems and deal with damage detection problems with relatively large modeling error and measurement noise. The vibration-based damage detection method developed is applied to various structures including lightning masts, a space frame structure and one of its components, and a pipeline. The locations and extent of damage can be successfully detected in experimental damage detection. In the numerical simulation where there is no modeling error and measurement noise, the exact locations and extent of damage can be detected.
Radius and Structure models for the First Super-Earth Planet
Creators: name: Valencia, Diana
name: Sasselov, Dimitar D.
name: O'Connell, Rirchard J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: With improving methods and surveys, the young field of extrasolar planets has recently expanded into a qualitatively new domain - terrestrial (mostly rocky) planets. The first such planets were discovered during the past year, judging by their measured masses of less than 10 Earth-masses ($M_{\oplus}$) or Super-Earths. They are introducing a novel physical regime that has not been explored before as such planets do not exist in our Solar System. Their composition can be either completely terrestrial or harbour an extensive ocean (water and ices) above a rocky core. We model the structure and properties of the first Super-Earth (mass $\sim$ 7.5 $M_{\oplus}$) discovered in 2005, illustrating the possibilities in composition and providing radius evaluations in view of future detection of similar planets by transits. We find that a threshold in radius exists for which larger values indicate that a Super-Earth most certainly has an extensive water content. In the case of GJ876d this threshold is at about 12000 km. Our results show that unique characterization of the bulk composition of Super-Earths will be possible in future transit studies.
description: 22 pages, 3 tables, 5 figures; Article will appear in ApJ Jan 2007 issue