cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Infinitesimal Rigidity for Cubulated Manifolds
Creators: name: Battista, Ludovico
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We prove the infinitesimal rigidity of some geometrically infinite hyperbolic 4- and 5-manifolds. These examples arise as infinite cyclic coverings of finite-volume hyperbolic manifolds obtained by colouring right-angled polytopes, already described in the papers arXiv:2009.04997 [math.GT] and arXiv:2105.14795 [math.GT]. The 5-dimensional example is diffeomorphic to $N \times \mathbb{R}$ for some aspherical 4-manifold $N$ which does not admit any hyperbolic structure. To this purpose we develop a general strategy to study the infinitesimal rigidity of cyclic coverings of manifolds obtained by colouring right-angled polytopes.
description: 33 pages, 23 figures. arXiv admin note: text overlap with arXiv:2009.04997
Accessing Possibility: Disability, Parent-Activists and Citizenship in Contemporary Russia
Creators: name: Hartblay, Cassandra
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2012

description: This paper highlights ethnographic case studies of two mothers caring for special needs children in Petrozavodsk, Russia (a city of 300,000 near the Finnish border). The still-prevalent institutionalization of children with disabilities in Russia means that there are few options for parents who choose to keep special needs children at home. Parent-activists in Petrozavodsk have staged two civil legal suits to enforce the right to public education guaranteed in the Constitution of the Russian Federation, resulting in a new inclusive education program in local schools. Examining these two case studies, I find that binary axes of autonomy/dependency and public/private that dominate teleologies of the postsoviet transition are upset by the hybrid strategies that the case studies illuminate. I propose that these refractions echo calls from anthropologists to find space for alterity within neoliberalism, and may offer new openings for a politics of disability justice and ethnography of the postsoviet both.
Quantum cosmology of the flat universe via closed real-time path integral
Creators: name: Wang, Hong
name: Wang, Jin
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Quantum cosmology is crucial to understand the evolution of the early universe. Despite significant progress, challenges still remain. For example, the role of time in quantum cosmology is unclear. Furthermore, the influence of the environment on the evolution of the quantum universe is challenging. In this work, we studied the evolution of the quantum universe non-perturbatively using the closed real-time path integral. The environments coupled to the quantum universe being considered are the radiation, the non-relativistic matter, or the dark matter. We evaluated the influence functional of the massless scalar field coupled with the flat FRW universe. We studied the evolution of the quantum universe by setting the initial state of spacetime as a Gaussian wave packet. In different scenarios, we show that the classical trajectory of the universe is consistent with the quantum evolution of the wave packet. The coherence, the absolute quantum fluctuation and the Gibbs entropy all monotonically increase with time, yet the relative quantum fluctuation decreases with time. We show that for a given size of the radiation dominated universe, the lower temperature corresponds to a more quantum universe. We find that the minimal coupling of the free massless scalar field with the flat FRW spacetime generally gives rise to the memory characterized via non-Markovian correlations. Finally, we show that under higher radiation temperatures, a small universe has a higher chance of a transition to a bigger universe.
Enhancing Few-shot Image Classification with Cosine Transformer
Creators: name: Nguyen, Quang-Huy
name: Nguyen, Cuong Q.
name: Le, Dung D.
name: Pham, Hieu H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper addresses the few-shot image classification problem, where the classification task is performed on unlabeled query samples given a small amount of labeled support samples only. One major challenge of the few-shot learning problem is the large variety of object visual appearances that prevents the support samples to represent that object comprehensively. This might result in a significant difference between support and query samples, therefore undermining the performance of few-shot algorithms. In this paper, we tackle the problem by proposing Few-shot Cosine Transformer (FS-CT), where the relational map between supports and queries is effectively obtained for the few-shot tasks. The FS-CT consists of two parts, a learnable prototypical embedding network to obtain categorical representations from support samples with hard cases, and a transformer encoder to effectively achieve the relational map from two different support and query samples. We introduce Cosine Attention, a more robust and stable attention module that enhances the transformer module significantly and therefore improves FS-CT performance from 5% to over 20% in accuracy compared to the default scaled dot-product mechanism. Our method performs competitive results in mini-ImageNet, CUB-200, and CIFAR-FS on 1-shot learning and 5-shot learning tasks across backbones and few-shot configurations. We also developed a custom few-shot dataset for Yoga pose recognition to demonstrate the potential of our algorithm for practical application. Our FS-CT with cosine attention is a lightweight, simple few-shot algorithm that can be applied for a wide range of applications, such as healthcare, medical, and security surveillance. The official implementation code of our Few-shot Cosine Transformer is available at https://github.com/vinuni-vishc/Few-Shot-Cosine-Transformer
.014 versus .016 in Alignment and Leveling: Does it Make a Difference?
Creators: name: Whitecotton, Bryan
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Objective: From an intuitive clinical standpoint, a more rigid archwire such as .016 should demonstrate greater efficacy for stage one tooth movement than a more flexible archwire such as .014. However, there is little to no clinical data to support this theory. This study hypothesizes that archwire dimension affects efficacy of tooth movement in Stage I orthodontic treatment due to variation in force magnitude, and this effect is independent of time due to constant force of superelastic wires. Materials and Methods: A prospective, randomized clinical trial was performed featuring 9 patients (18 dental arches) using .014 and .016 archwires. Double-blinded distribution of archwires was performed with intraoral scans obtained at 3 times points (baseline, 6 weeks, and 12 weeks). Digital measurements were performed based on Little’s Irregularity Index by a single examiner using Ortho Insight 3D. Geomagic was also used to assess Euclidean rigid motion with 6 degrees of freedom for all canines. 2-way repeated ANOVA was utilized, with the main effects being archwire dimension and time. Results: The first time interval showed greater reduction in incisor irregularity. Difference in mean translation was statistically significant between .014 and .016 in all 3 planes, as well as between the first and second time intervals for the z axis only. Finally, interaction between archwire dimension and time interval for translation was significant in the y and z planes. Conclusions: Archwire dimension does have an impact on efficacy of alignment, and alignment is, in fact, not independent of time.
Theoretical realization of hybrid Weyl state and associated high catalytic performance for hydrogen evolution in NiSi
Creators: name: Liu, Wei
name: Zhang, Xiaoming
name: Meng, Weizhen
name: Liu, Ying
name: Dai, Xuefang
name: Liu, Guodong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: For electrochemical hydrogen evolution reaction (HER), developing high-performance catalysts without containing precious metals has been a major research focus in the current. Herein, we show the feasibility of HER catalytic enhancement in Ni-based materials based on topological engineering from hybrid Weyl states. Via a high-throughput computational screening from 140 000 materials, we identify a chiral compound NiSi is a hybrid Weyl semimetal (WSM) with showing bulk type-I and type-II Weyl nodes and long surface Fermi arcs near the Fermi level. Sufficient evidences verify that topological charge carriers participate in the HER process, and make the certain surface of NiSi highly active with the Gibbs free energy nearly zero (0.07 eV), which is even lower than Pt and locates on the top of the volcano plots. This work opens up a new routine to develop no-precious-metal-containing HER catalysts via topological engineering, rather than traditional defect engineering, doping engineering, or strain engineering.
Privacy in Practice: Private COVID-19 Detection in X-Ray Images (Extended Version)
Creators: name: Lange, Lucas
name: Schneider, Maja
name: Christen, Peter
name: Rahm, Erhard
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Cryptography and Security (cs.CR)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Machine learning (ML) can help fight pandemics like COVID-19 by enabling rapid screening of large volumes of images. To perform data analysis while maintaining patient privacy, we create ML models that satisfy Differential Privacy (DP). Previous works exploring private COVID-19 models are in part based on small datasets, provide weaker or unclear privacy guarantees, and do not investigate practical privacy. We suggest improvements to address these open gaps. We account for inherent class imbalances and evaluate the utility-privacy trade-off more extensively and over stricter privacy budgets. Our evaluation is supported by empirically estimating practical privacy through black-box Membership Inference Attacks (MIAs). The introduced DP should help limit leakage threats posed by MIAs, and our practical analysis is the first to test this hypothesis on the COVID-19 classification task. Our results indicate that needed privacy levels might differ based on the task-dependent practical threat from MIAs. The results further suggest that with increasing DP guarantees, empirical privacy leakage only improves marginally, and DP therefore appears to have a limited impact on practical MIA defense. Our findings identify possibilities for better utility-privacy trade-offs, and we believe that empirical attack-specific privacy estimation can play a vital role in tuning for practical privacy.
description: Extended version of the paper accepted at the 20th International Conference on Security and Cryptography SECRYPT 2023. This version is more detailed and includes additional content: a longer results chapter and an appendix containing a proof
Windows Upon Planning History - Canberra
Creators: name: Fischer, Karl Friedhelm
Publisher: name: International Planning History Society Proceedings
Year: 2018

description: The conference theme ‘Looking at the world history of planning’ is echoed in a statement by U.S. urban designer Edmund Bacon on the 1911 Plan for Canberra, which he eulogized as ‘a Statement of World Culture’.1 Bacon was referring to the way in which the Griffins’ plan incorporated elements of space design derived from cultural realms as wide-ranging as those of Europe, the Americas, and Asia. However, the plan and its transformation in modern and post-modern times have also been objects of fundamental cultural controversies.2 Enthusiasts and opponents have dug in their heels and fought battles of uncertain outcomes. The core research question here is how to deal with the complex and controversial nature of these perspectives. In this situation, the paper applies the famous ‘Windows’ metaphor from the preface of Henry James’ novel ‘Portrait of a Lady’ as a narrative device to the context of planning history.3 It concludes that the windows opened upon ideas and realities, myths and models surrounding the Canberra Plan and its transformations may help negotiate between opposing views, different paradigms and conflicting cultural positions as potentially complementary and at least enlightening.
description: International Planning History Society Proceedings, Vol. 18 No. 1 (2018): Looking at the World History of Planning
Stacking up electron-rich and electron-deficient monolayers to achieve extraordinary mid- to far-infrared excitonic absorption: Interlayer excitons in the C3B/C3N bilayer
Creators: name: Tang, Zhao
name: Cruz, Greis J.
name: Jia, Fanhao
name: Wu, Yabei
name: Xia, Weiyi
name: Zhang, Peihong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Our ability to efficiently detect and generate far-infrared (i.e., terahertz) radiation is vital in areas spanning from biomedical imaging to interstellar spectroscopy. Despite decades of intense research, bridging the terahertz gap between electronics and optics remains a major challenge due to the lack of robust materials that can efficiently operate in this frequency range, and two-dimensional (2D) type-II heterostructures may be ideal candidates to fill this gap. Herein, using highly accurate many-body perturbation theory within the GW plus Bethe-Salpeter equation approach, we predict that a type-II heterostructure consisting of an electron rich C3N and an electron deficient C3B monolayers can give rise to extraordinary optical activities in the mid- to far-infrared range. C3N and C3B are two graphene-derived 2D materials that have attracted increasing research attention. Although both C3N and C3B monolayers are moderate gap 2D materials, and they only couple through the rather weak van der Waals interactions, the bilayer heterostructure surprisingly supports extremely bright, low-energy interlayer excitons with large binding energies of 0.2 ~ 0.4 eV, offering an ideal material with interlayer excitonic states for mid-to far-infrared applications at room temperature. We also investigate in detail the properties and formation mechanism of the inter- and intra-layer excitons.
description: 15 pages, 6 figures
Defining urban design in the Chilean context
Creators: name: De Souza, Gisela Barcellos
name: Tine Gimenez, Andre
Publisher: name: International Planning History Society Proceedings
Year: 2018

description: We intend to contribute to the understanding of the initial paths and penetration routes Urban Design and Urbanistic Project notions in the urban and architectural culture in Latin America. To this end, it focuses on the trajectory and intellectual work of a Chilean architect, Gustavo Munizaga, who was responsible for writing one of the first didactic texts on urban design in Latin America and did so contemporaneously with the first manifestations of the Modern Movement’s critical revision and the typomorphological approach in Chile.
description: International Planning History Society Proceedings, Vol. 18 No. 1 (2018): Looking at the World History of Planning
Realistic Spin Model for Multiferroic NiI$_2$
Creators: name: Li, Xuanyi
name: Xu, Changsong
name: Liu, Boyu
name: Li, Xueyang
name: Bellaiche, L.
name: Xiang, Hongjun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A realistic first-principle-based spin Hamiltonian is constructed for the type-II multiferroic NiI$_2$, using a symmetry-adapted cluster expansion method. Besides single ion anisotropy and isotropic Heisenberg terms, this model further includes the Kitaev interaction and a biquadratic term, and can well reproduce striking features of the experimental helical ground state, that are, {\it e.g.}, a proper screw state, canting of rotation plane, propagation direction and period. Using this model to build a phase diagram, it is demonstrated that, (i) the in-plane propagation direction of $\langle1\bar10\rangle$ is determined by the Kitaev interaction, instead of the long-believed exchange frustrations; and (ii) the canting of rotation plane is also dominantly determined by Kitaev interaction, rather than interlayer couplings. Furthermore, additional Monte Carlo simulations reveal three equivalent domains and different topological defects. Since the ferroelectricity is induced by spins in type-II multiferroics, our work also implies that Kitaev interaction is closely related to the multiferroicity of NiI$_2$.
A Large-Scale Characterization of How Readers Browse Wikipedia
Creators: name: Piccardi, Tiziano
name: Gerlach, Martin
name: Arora, Akhil
name: West, Robert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Despite the importance and pervasiveness of Wikipedia as one of the largest platforms for open knowledge, surprisingly little is known about how people navigate its content when seeking information. To bridge this gap, we present the first systematic large-scale analysis of how readers browse Wikipedia. Using billions of page requests from Wikipedia's server logs, we measure how readers reach articles, how they transition between articles, and how these patterns combine into more complex navigation paths. We find that navigation behavior is characterized by highly diverse structures. Although most navigation paths are shallow, comprising a single pageload, there is much variety, and the depth and shape of paths vary systematically with topic, device type, and time of day. We show that Wikipedia navigation paths commonly mesh with external pages as part of a larger online ecosystem, and we describe how naturally occurring navigation paths are distinct from targeted navigation in lab-based settings. Our results further suggest that navigation is abandoned when readers reach low-quality pages. Taken together, these insights contribute to a more systematic understanding of readers' information needs and allow for improving their experience on Wikipedia and the Web in general.
description: ACM Trans. Web, Vol. 1, No. 1, Article 1. Publication date: January 2023
A New Class of Problems in the Calculus of Variations
Creators: name: Ekeland, Ivar
name: Long, Yiming
name: Zhou, Qinglong
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Economics (econ.GN)
subject: Optimization and Control (math.OC)
subject: FOS: Economics and business
subject: FOS: Mathematics
subject: 49J40, 91B02, 49L99

description: This paper investigates an infinite-horizon problems in the one-dimensional calculus of variations, arising from the Ramsey model of endogeneous economic growth. Following Chichilnisky, we introduce an additional term, which models concern for the well-being of future generations. We show that there are no optimal solutions, but that there are equilibrium strateges, i.e. Nash equilibria of the leader-follower game between successive generations. To solve the problem, we approximate the Chichilnisky criterion by a biexponential criterion, we characterize its equilibria by a pair of coupled differential equations of HJB type, and we go to the limit. We find all the equilibrium strategies for the Chichilnisky criterion. The mathematical analysis is difficult because one has to solve an implicit differential equation in the sense of Thom. Our analysis extends earlier work by Ekeland and Lazrak. It is shown that optimal solutions a class of problems raising from time inconsistency problems in the framework of the neoclassical one-sector model of economic growth, and contains new results in environment economics. Without exogenous commitment mechanism, a notion of the equilibrium strategies instead of the optimal strategies is introduced. We characterized the equilibrium strategies by an integro-differential equation system. For two special criteria, the bi-exponential criteria and the Chichilnisky criteria, we established the existence of the equilibrium strategies.
Impact of nanoscale features on implant adherent cell osteoinduction and osteoconduction
Creators: name: Alves Daporta, Astrid P.
Publisher: name: University of North Carolina at Chapel Hill
Year: 2011

description: Objective; To investigate osteogenic and osteoinductive gene expression in cells interacting with modified titanium surfaces in-vitro and an in-vivo. Materials and Methods; Nano-topography was assessed by SEM. hMSC were plated onto cpTi disks (Nano: T1: Acid edged, oxidized; OS: TiO2 fluoride-modified. Micro: T2: Acid etched). RT-PCR was used to assess a wide array of osteoblast specific gene expression (Day 3, 7, 14, 28). Implants were placed in rat tibias (T1, T2, OS and TiOBlast - TiO2 blasted, micro), following harvesting 1, 3 and 7 days after placement. mRNA levels of RUNX-2, ALP and OSX were measured with RT-PCR. Results; In both cell culture and in-vivo experiments, osteoblastic differentiation occurred on all surfaces but to a greater extent on T1 and OS. Conclusions; Presence of nano-features on moderately rough cpTi is associated with marked osteoinduction of adherent hMSC and suggested positive modulation of bone response into the osteogenic pathway in-vivo.
Topological quantum catalyst: the case of two-dimensional traversing nodal line states associated with high catalytic performance for hydrogen evolution reaction
Creators: name: Wang, Lirong
name: Zhang, Xiaoming
name: Meng, Weizhen
name: Liu, Ying
name: Dai, Xuefang
name: Liu, Guodong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Topological quantum catalysts (TQCs), where metallic surface states from nontrivial band topology serve as the mechanism to favor heterogeneous catalysis processes, have been well demonstrated in three dimensional (3D) examples but have been rarely discussed in 2D scale. Here, we develop a design scheme to realize 2D TQCs with showing traversing nodal line at the Brillouin zone boundary, large Fermi arc on the edge, and nearly zero Gibbs free energy (ΔGH*) for hydrogen evolution reaction (HER). We demonstrate the 2D Cu2C2N4 sheet is a such example. The material manifests an open nodal line traversing the whole k-path S-Y. It shows a long Fermi arc that spans the entire edge boundary, which is robust against spin-orbit coupling and the H adsorption. As the result, the edge of Cu2C2N4 sheet is relatively active for HER catalysis with possessing a ΔGH* as low as 0.10 eV, which is comparable with that of Pt and superior to other traditional catalysts and 3D TQCs as well. Our work offers an effective route to develop high performance HER catalysis without containing noble metals by utilizing 2D TQCs with traversing nodal line.
On Word Error Rate Definitions and their Efficient Computation for Multi-Speaker Speech Recognition Systems
Creators: name: von Neumann, Thilo
name: Boeddeker, Christoph
name: Kinoshita, Keisuke
name: Delcroix, Marc
name: Haeb-Umbach, Reinhold
Publisher: name: arXiv
Year: 2022
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: We propose a general framework to compute the word error rate (WER) of ASR systems that process recordings containing multiple speakers at their input and that produce multiple output word sequences (MIMO). Such ASR systems are typically required, e.g., for meeting transcription. We provide an efficient implementation based on a dynamic programming search in a multi-dimensional Levenshtein distance tensor under the constraint that a reference utterance must be matched consistently with one hypothesis output. This also results in an efficient implementation of the ORC WER which previously suffered from exponential complexity. We give an overview of commonly used WER definitions for multi-speaker scenarios and show that they are specializations of the above MIMO WER tuned to particular application scenarios. We conclude with a discussion of the pros and cons of the various WER definitions and a recommendation when to use which.
description: Presented at ICASSP 2023
Close-Form Expression of One-Tap Normalized LMS Carrier Phase Recovery in Optical Communication Systems
Creators: name: Xu, Tianhua
name: Jacobsen, Gunnar
name: Popov, Sergei
name: Li, Jie
name: Liu, Tiegen
name: Zhang, Yimo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: C.2.5
subject: 78A55

description: The performance of long-haul high speed coherent optical fiber communication systems is significantly degraded by the laser phase noise and the equalization enhanced phase noise (EEPN). In this paper, the analysis of the one-tap normalized least-mean-square (LMS) carrier phase recovery (CPR) is carried out and the close-form expression is investigated for quadrature phase shift keying (QPSK) coherent optical fiber communication systems, in compensating both laser phase noise and equalization enhanced phase noise. Numerical simulations have also been implemented to verify the theoretical analysis. It is found that the one-tap normalized least-mean-square algorithm gives the same analytical expression for predicting CPR bit-error-rate (BER) floors as the traditional differential carrier phase recovery, when both the laser phase noise and the equalization enhanced phase noise are taken into account.
description: [SPIE] International Conference on Wireless and Optical Communications (ICWOC) 2016, W22
Singular limit of an Allen-Cahn equation with nonlinear diffusion
Creators: name: Kettani, Perla El
name: Funaki, Tadahisa
name: Hilhorst, Danielle
name: Park, Hyunjoon
name: Sethuraman, Sunder
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35K57, 35B40

description: We consider an Allen-Cahn equation with nonlinear diffusion, motivated by the study of the scaling limit of certain interacting particle systems. We investigate its singular limit and show the generation and propagation of an interface in the limit. The evolution of this limit interface is governed by mean curvature flow with a novel, homogenized speed in terms of a surface tension-mobility parameter emerging from the nonlinearity in our equation.
description: 30 pgs, 2 figures
Emergence, evolution and mutation
Creators: name: Zhang, Haoyan
Publisher: name: International Planning History Society Proceedings
Year: 2018

description: The Great Wall zone represents the largest area of land-use and land-cover change in China in the past 300 years, when the borders of agricultural production and settlement continued to move northward, forming the pattern of settlements we see today, realizing its transition from wartime to peacetime. Instead of focusing on the development of individual urban, how can we understand the evolution essence of settlement system, located in the transition zone between agriculture and animal husbandry, from the perspective of complex system? In this article, the distribution pattern can be considered as a spatial projection of region social order. Then, the fractal dimension of settlement distribution is calculated by GIS, so as to demonstrate the complexity of pattern. And then, characteristics and mechanisms of the settlement system in the Great Wall area during Ming and Qing Dynasties is further analyzed from 7 basic points of Complex Adaptive System. Finally, the idea of attracting basin can be used to make a further description about the process of evolution, namely structural break and non-structural evolution.
description: International Planning History Society Proceedings, Vol. 18 No. 1 (2018): Looking at the World History of Planning
Electron elastic scattering off $A$@C$_{60}$: The role of atomic polarization under confinement
Creators: name: Dolmatov, V. K.
name: Amusia, M. Ya.
name: Chernysheva, L. V.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: The present paper explores possible features of electron elastic scattering off endohedral fullerenes $A$@C$_{60}$. It focuses on how dynamical polarization of the encapsulated atom $A$ by an incident electron might alter scattering off $A$@C$_{60}$ compared to the static-atom-$A$ case, as well as how the C$_{60}$ confinement modifies the impact of atomic polarization on electron scattering compared to the free-atom case. The aim is to provide researchers with a "relative frame of reference" for understanding which part of the scattering processes could be due to electron scattering off the encapsulated atom and which due to scattering off the C$_{60}$ cage. To meet the goal, the C$_{60}$ cage is modeled by an attractive spherical potential of a certain inner radius, thickness, and depth which is a model used frequently in a great variety of fullerene studies to date. Then, the Dyson equation for the self-energy part of the Green's function of an incident electron moving in the combined field of an encapsulated atom $A$ and C$_{60}$ is solved in order to account for the impact of dynamical polarization of the encaged atom upon $e + A@{\rm C_{60}}$ scattering. The Ba@C$_{60}$ endohedral is chosen as the case study. The impact is found to be significant, and its utterly different role compared to that in $e + Ba$ scattering is unraveled.
description: 7 pages, 5 figures, published in Phys. Rev. A, the attached file is the original authors' file, i.e., not a PRA copyedited file
Linearized Boltzmann Collision Operator: I. Polyatomic Molecules Modeled by a Discrete Internal Energy Variable and Multicomponent Mixtures
Creators: name: Bernhoff, Niclas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 82C40 (Primary), 35Q20, 35Q70, 76P05 (Secondary)

description: The linearized collision operator of the Boltzmann equation can in a natural way be written as a sum of a positive multiplication operator, the collision frequency, and an integral operator. Compactness of the integral operator for monatomic single species is a classical result, while corresponding result for mixtures is more recently obtained. In this work the compactness of the operator for polyatomic single species, where the polyatomicity is modeled by a discrete internal energy variable, is studied. With a probabilistic formulation of the collision operator as a starting point, compactness is obtained by proving that the integral operator is a sum of Hilbert-Schmidt integral operators and approximately Hilbert-Schmidt integral operators, under some assumptions on the collision kernel. Self-adjointness of the linearized collision operator follows. Moreover, bounds on - including coercivity of - the collision frequency are obtained for a hard sphere model. Then it follows that the linearized collision operator is a Fredholm operator. The results can be extended to mixtures. For brevity, only the case of mixtures for monatomic species is accounted for.
description: 45 pages, 5 figures
On an explicit lower bound for the star discrepancy in three dimensions
Creators: name: Puchhammer, Florian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11K38, 11K06

description: Following a result of D.~Bylik and M.T.~Lacey from 2008 it is known that there exists an absolute constant $η>0$ such that the (unnormalized) $L^{\infty}$-norm of the three-dimensional discrepancy function, i.e, the (unnormalized) star discrepancy $D^{\ast}_N$, is bounded from below by $D_{N}^{\ast}\geq c (\log N)^{1+η}$, for all $N\in\mathbb{N}$ sufficiently large, where $c>0$ is some constant independent of $N$. This paper builds upon their methods to verify that the above result holds with $η<1/(32+4\sqrt{41})\approx 0.017357\ldots$
description: 15 pages, 1 figure; includes minor corrections as well as an additional brief section on the littlewood-paley inequalities
Sparsity-based Algorithm for Detecting Faults in Rotating Machines
Creators: name: He, Wangpeng
name: Ding, Yin
name: Zi, Yanyang
name: Selesnick, Ivan W.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Sound (cs.SD)
subject: FOS: Computer and information sciences

description: This paper addresses the detection of periodic transients in vibration signals for detecting faults in rotating machines. For this purpose, we present a method to estimate periodic-group-sparse signals in noise. The method is based on the formulation of a convex optimization problem. A fast iterative algorithm is given for its solution. A simulated signal is formulated to verify the performance of the proposed approach for periodic feature extraction. The detection performance of comparative methods is compared with that of the proposed approach via RMSE values and receiver operating characteristic (ROC) curves. Finally, the proposed approach is applied to compound faults diagnosis of motor bearings. The non-stationary vibration data were acquired from a SpectraQuest's machinery fault simulator. The processed results show the proposed approach can effectively detect and extract the useful features of bearing outer race and inner race defect.
Transport signatures of fragile-glass dynamics in the melting of the two-dimensional vortex lattice
Creators: name: Maccari, Ilaria
name: Pokharel, Bal K.
name: Terzic, Jasminka
name: Dutta, Surajit
name: Jesudasan, John
name: Raychaudhuri, Pratap
name: Lorenzana, José
name: De Michele, Cristiano
name: Castellani, Claudio
name: Benfatto, Lara
name: Popović, Dragana
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In two-dimensional (2D) systems, the melting from a solid to an isotropic liquid can occur via an intermediate phase that retains orientational order. However, in 2D superconducting vortex lattices, the effect of orientational correlations on transport, and their interplay with disorder remain open questions. Here we study a 2D weakly pinned vortex system in amorphous MoGe films over an extensive range of temperatures ($\bm{T}$) and perpendicular magnetic fields ($\bm{H}$) using linear and nonlinear transport measurements. We find that, at low fields, the resistivity obeys the Vogel-Fulcher-Tamman (VFT) form, $\bm{ρ(T)\propto\exp[-{W}(H)/(T-T_0(H))]}$, characteristic of fragile glasses. As $\bm{H}$ increases, $\bm{T_0(H)}$ is suppressed to zero, and a standard vortex liquid behavior consistent with a $\bm{T=0}$ superconducting transition is observed. Our findings, supported also by simulations, suggest that the presence of orientational correlations gives rise to a heterogeneous dynamics responsible for the VFT behavior. The effects of quenched disorder become dominant at high $\bm{H}$, where a crossover to a strong-glass behavior is observed. This is a new insight into the dynamics of melting in 2D systems with competing orders.
description: 16 pages, 12 figures
Spin and charge modulations in a single hole doped Hubbard ladder -- verification with optical lattice experiments
Creators: name: Zhu, Zheng
name: Weng, Zheng-Yu
name: Ho, Tin-Lun
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that pronounced modulations in spin and charge densities can be induced by the insertion of a single hole in an otherwise half-filled 2-leg Hubbard ladder. Accompanied with these modulations is a loosely bound structure of the doped charge with a spin-1/2, in contrast to the tightly bound case where such modulations are absent. These behaviors are caused by the interference of the Berry phases associated a string of flipped spins (or "phase strings") left behind as a hole travels through a spin bath with a short-range anti-ferromagnetic order. The key role of the phase strings is also reflected in how the system respond to increasing spin polarization, increasing the on-site repulsion, addition of a second hole, and increasing asymmetry between intra- and inter-chain hopping. Remarkably, all these properties persist down to ladders as short as $\sim 10$ sites. They can therefore be studied in cold atom experiments using the recently developed fermion microscope.
description: 5 pages, 4 figures
The newspaper internship game: how to be a winner
Creators: name: Hauser, Caroline K.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2006

description: Students, educators and journalism professionals agree that internships are the surest route to post-graduation employment in the newspaper industry. The three groups dedicate significant amounts of time and money to ensuring appropriate internship placements, but frustration persists on all sides. Using the newsgathering method outlined by Yopp and McAdams in 2003, this nontraditional thesis examines several structural factors of newspaper internships. Specifically, this includes the industry's trend toward offering fewer internships, racial and socioeconomic diversity issues, students' frustrations with the internship application process, and the difference in newspapers' philosophies for internships.
Tunnelling theory of Weyl semimetals in proximity to a metallic band
Creators: name: Goutte, L.
name: Pereg-Barnea, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the effects of tunnelling on the band structure and Fermi arc of a time-reversal broken Weyl semimetal (WSM). When coupled to a non-magnetic parabolic band, the WSM's chiral arc state lowers in energy and forms, together with a previously extended state, a noticeable spin-dependent asymmetry in the interface spectrum in the vicinity of the Weyl nodes. We study these effects with a lattice model which we solve numerically on a finite sample and analytically through using an ansatz on an infinite sample. Our ansatz agrees very well with the numerical simulation as it accurately describes the behaviour of the chiral state, from its energy asymmetry to the spin canting at the interface. We find that the tunnelling effectively increases the Fermi arc length, allowing for the presence of interface states beyond the bare Weyl nodes. These additional states may carry current along the interface and their contribution can be detected in the conductance. Across the interface, the spin-independent conductance reproduces the results of an electron tunnelling experiment to reveal the WSM's density of states. Besides conductivity, the effect of tunnelling between the WSM and the metallic band can be seen in quantum oscillations experiments which we briefly comment about.
description: 15 pages, 8 figures; typos corrected, reference added
Fundamental trade-off between the speed of light and the Fano factor of photon current in three-level lambda systems
Creators: name: Singh, Davinder
name: Jang, Seogjoo J.
name: Hyeon, Changbong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Electromagnetically induced slow-light medium is a promising system for quantum memory devices, but controlling its noise level remains a major challenge to overcome. This work considers the simplest model for such medium, comprised of three-level $Λ$-systems interacting with bosonic bath, and provides a new fundamental trade-off relation in light-matter interaction between the group velocity of light and the Fano factor of photon current due to radiative transitions. Considering the steady state limits of a newly derived Lindblad-type equation, we find that the Fano factor of the photon current maximizes to 3 at the minimal group velocity of light, which holds true universally regardless of detailed values of parameters characterizing the medium.
description: 14 pages, 5 figures
The chiral Lagrangian with three flavors and large-Nc sum rules
Creators: name: Heo, Yonggoo
name: Kobdaj, C.
name: Lutz, Matthias F. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We reconsider the chiral Lagrangian with three-flavor baryon fields. A systematic analysis of all LEC that contribute to the axial-vector and pseudoscalar currents in the baryon octet and decuplet fields at next-to-leading order is performed. While there are 4 LEC relevant at leading order, the number of relevant LEC at subleading chiral order is 23. For those a leading order large-$N_c$ analysis predicts 3 and 18 sum rules respectively. At the next accuracy level the number of sum rules is reduced to 2 and 8. Our results are illustrated by a tree-level analysis of available axial-vector coupling constants and strong decay widths of the baryon decuplet states.
description: 22 pages
Post-war transnational planning practices
Creators: name: Jafari, Ellmira
Publisher: name: International Planning History Society Proceedings
Year: 2018

description: While the communication of architectural/planning knowledge between core and periphery countries was intensified during the Cold War, it brought about new challenges regarding the relationship between imported ideas and the architectural culture of the host countries. The first master plan of Tehran, prepared by Victor Gruen and Abdolaziz Farmanfarmaian in the late-1960s, is an example of such cross-cultural dialogue, in particular with reference to the design of housing. This paper aims to examine how the first master plan introduced new low-cost housing strategy for the city of Tehran and how it affected the rapid marginalisation of the urban poor in the capital. Through a short review of the emergence of low-cost housing in Tehran since the 1940s and the examination of the two phases of the master plan, this paper seeks to unravel the complexity in the exchange of planning ideas from Western countries to Iran. In turn, the translation of Western ideas into domestic architectural vocabularies is examined through the changing local situation and the role of local mediators. The paper concludes that the privatisation of housing shifted the spotlight from state-led low-cost housing into the luxuries high-rise residential complexes which changed socio-spatial structure of the city.
description: International Planning History Society Proceedings, Vol. 18 No. 1 (2018): Looking at the World History of Planning
Exact solution of the planar motion of three arbitrary point vortices
Creators: name: Conte, Robert
name: de Seze, Laurent
Publisher: name: arXiv
Year: 2015
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 37E99, 70F07, 76B47

description: We give an exact quantitative solution for the motion of three vortices of any strength, which Poincaré showed to be integrable. The absolute motion of one vortex is generally biperiodic: in uniformly rotating axes, the motion is periodic. There are two kinds of relative equilibrium configuration: two equilateral triangles and one or three colinear configurations, their stability conditions split the strengths space into three domains in which the sets of trajectories are topologically distinct. According to the values of the strengths and the initial positions, all possible %RC motions are classified. Two sets of strengths lead to generic motions other than biperiodic. First, when the angular momentum vanishes, besides the biperiodic regime there exists an expansion spiral motion and even a triple collision in a finite time, but the latter motion is nongeneric. Second, when two strengths are opposite, the system also exhibits the elastic diffusion of a vortex doublet by the third vortex. For given values of the invariants, the volume of the phase space of this Hamiltonian system is proportional to the period of the reduced motion, a well known result of the theory of adiabatic invariants. We then formally examine the behaviour of the quantities that Onsager defined only for a large number of interacting vortices.
description: 40 pages, 11 figures. Book to appear, 80 years birthday of Prof Hao Bailin
Producing procrastination: negotiating affect and temporality in contemporary capitalism
Creators: name: Shaffer, Allyson Kaye
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: This thesis explores power, subjectivity, affect and temporality in contemporary capitalism in three parts. First, it uses a Foucauldian understanding of power to examine the subjectifying effects of the therapeutic discourse around procrastination as found in online-self-help articles. The second section reports on a focus group study in which clerical and administrative employees discussed procrastination, emotions and the use of alternate time management techniques in negotiating power relations in the immaterial workplace. The third section interprets the emotional politics engaged in each site: the emotions deployed by the disciplining therapeutic discourse, and the emotions negotiated and experienced by the focus group participants. Analyzing the ‘problem’ of procrastination can help provide a platform for better understanding affective, temporal subjectivity and the ways in which power is deployed, negotiated with and struggled over in the contemporary immaterial workplace.
Massless graviton in a model of quantum gravity with emergent spacetime
Creators: name: Lee, Sung-Sik
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In the model of quantum gravity proposed in JHEP 2020, 70 (2020), dynamical spacetime arises as a collective phenomenon of underlying quantum matter. Without a preferred decomposition of the Hilbert space, the signature, topology and geometry of an emergent spacetime depend upon how the total Hilbert space is partitioned into local Hilbert spaces. In this paper, it is shown that the massless graviton emerges in the spacetime realized from a Hilbert space decomposition that supports a collection of largely unentangled local clocks.
Spin Asymmetries in Electron-jet Production at the EIC
Creators: name: Kang, Zhong-Bo
name: Lee, Kyle
name: Shao, Ding Yu
name: Zhao, Fanyi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate all the possible spin asymmetries that can occur in back-to-back electron-jet production with hadron observed inside a jet in electron-proton collisions. We derive the factorization formalism for all spin asymmetries and perform phenomenological studies for the future electron ion collider kinematics. We illustrate that the back-to-back electron-jet production opens up new opportunities to study transverse momentum dependent fragmentation functions and distribution functions.
description: 5 pages, 4 figures. Contribution to the 24th International Spin Symposium (SPIN2021). JPS Conference Proceedings