cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Rhythmic Gesticulator: Rhythm-Aware Co-Speech Gesture Synthesis with Hierarchical Neural Embeddings
Creators: name: Ao, Tenglong
name: Gao, Qingzhe
name: Lou, Yuke
name: Chen, Baoquan
name: Liu, Libin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Sound (cs.SD)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Graphics (cs.GR)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Automatic synthesis of realistic co-speech gestures is an increasingly important yet challenging task in artificial embodied agent creation. Previous systems mainly focus on generating gestures in an end-to-end manner, which leads to difficulties in mining the clear rhythm and semantics due to the complex yet subtle harmony between speech and gestures. We present a novel co-speech gesture synthesis method that achieves convincing results both on the rhythm and semantics. For the rhythm, our system contains a robust rhythm-based segmentation pipeline to ensure the temporal coherence between the vocalization and gestures explicitly. For the gesture semantics, we devise a mechanism to effectively disentangle both low- and high-level neural embeddings of speech and motion based on linguistic theory. The high-level embedding corresponds to semantics, while the low-level embedding relates to subtle variations. Lastly, we build correspondence between the hierarchical embeddings of the speech and the motion, resulting in rhythm- and semantics-aware gesture synthesis. Evaluations with existing objective metrics, a newly proposed rhythmic metric, and human feedback show that our method outperforms state-of-the-art systems by a clear margin.
description: SIGGRAPH Asia 2022 (Journal Track); Project Page: https://pku-mocca.github.io/Rhythmic-Gesticulator-Page/
Keldysh Wormholes and Anomalous Relaxation in the Dissipative Sachdev-Ye-Kitaev Model
Creators: name: García-García, Antonio M.
name: Sá, Lucas
name: Verbaarschot, Jacobus J. M.
name: Zheng, Jie Ping
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the out-of-equilibrium dynamics of a Sachdev-Ye-Kitaev (SYK) model, $N$ fermions with a $q$-body interaction of infinite range, coupled to a Markovian environment. Close to the infinite-temperature steady state, the real-time Lindbladian dynamics of this system is identical to the near-zero-temperature dynamics in Euclidean time of a two-site non-Hermitian SYK with intersite coupling whose gravity dual has been recently related to wormhole configurations. We show that the saddle-point equations in the real-time formulation are identical to those in Euclidean time. Indeed, an explicit calculation of Green's functions at low temperature, numerical for $q = 4$ and analytical for $q = 2$ and large $q$, illustrates this equivalence. Only for very strong coupling does the decay rate approach the linear dependence on the coupling characteristic of a dissipation-driven approach to the steady state. For $q > 2$, we identify a potential gravity dual of the real-time dissipative SYK model: a double-trumpet configuration in a near-de Sitter space in two dimensions with matter. This configuration, which we term a Keldysh wormhole, is responsible for a finite decay rate even in the absence of coupling to the environment.
description: 52 pages, 9 figures. v2: added comments to explain a possible connection with dS$_2$ and improved the finite-$N$ calculations and their interpretation. v3: minor corrections, references added, version as published
DALL-E-Bot: Introducing Web-Scale Diffusion Models to Robotics
Creators: name: Kapelyukh, Ivan
name: Vosylius, Vitalis
name: Johns, Edward
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We introduce the first work to explore web-scale diffusion models for robotics. DALL-E-Bot enables a robot to rearrange objects in a scene, by first inferring a text description of those objects, then generating an image representing a natural, human-like arrangement of those objects, and finally physically arranging the objects according to that goal image. We show that this is possible zero-shot using DALL-E, without needing any further example arrangements, data collection, or training. DALL-E-Bot is fully autonomous and is not restricted to a pre-defined set of objects or scenes, thanks to DALL-E's web-scale pre-training. Encouraging real-world results, with both human studies and objective metrics, show that integrating web-scale diffusion models into robotics pipelines is a promising direction for scalable, unsupervised robot learning.
description: Webpage and videos: ( https://www.robot-learning.uk/dall-e-bot ) Published in IEEE Robotics and Automation Letters (RA-L)
Embedability between right-angled Artin groups
Creators: name: Kim, Sang-hyun
name: Koberda, Thomas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 20F36

description: In this article we study the right-angled Artin subgroups of a given right-angled Artin group. Starting with a graph $\gam$, we produce a new graph through a purely combinatorial procedure, and call it the extension graph $\gam^e$ of $\gam$. We produce a second graph $\gam^e_k$, the clique graph of $\gam^e$, by adding extra vertices for each complete subgraph of $\gam^e$. We prove that each finite induced subgraph $Λ$ of $\gam^e$ gives rise to an inclusion $A(Λ)\to A(\gam)$. Conversely, we show that if there is an inclusion $A(Λ)\to A(\gam)$ then $Λ$ is an induced subgraph of $\gam^e_k$. These results have a number of corollaries. Let $P_4$ denote the path on four vertices and let $C_n$ denote the cycle of length $n$. We prove that $A(P_4)$ embeds in $A(\gam)$ if and only if $P_4$ is an induced subgraph of $\gam$. We prove that if $F$ is any finite forest then $A(F)$ embeds in $A(P_4)$. We recover the first author's result on co--contraction of graphs and prove that if $\gam$ has no triangles and $A(\gam)$ contains a copy of $A(C_n)$ for some $n\geq 5$, then $\gam$ contains a copy of $C_m$ for some $5\le m\le n$. We also recover Kambites' Theorem, which asserts that if $A(C_4)$ embeds in $A(\gam)$ then $\gam$ contains an induced square. Finally, we determine precisely when there is an inclusion $A(C_m)\to A(C_n)$ and show that there is no "universal" two--dimensional right-angled Artin group.
description: 35 pages. Added an appendix and a proof that the extension graph is quasi-isometric to a tree
Excitonic Condensate in Flat Valence and Conduction Bands of Opposite Chirality
Creators: name: Sethi, Gurjyot
name: Cuma, Martin
name: Liu, Feng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Excitonic Bose-Einstein condensation (EBEC) has drawn increasing attention recently with the emergence of 2D materials. A general criterion for EBEC, as expected in an excitonic insulator (EI) state, is to have negative exciton formation energies in a semiconductor. Here, using exact diagonalization of multi-exciton Hamiltonian modelled in a diatomic Kagome lattice, we demonstrate that the negative exciton formation energies are only a prerequisite but insufficient condition for realizing an EI. By a comparative study between the cases of both a conduction and valence flat bands (FBs) versus that of a parabolic conduction band, we further show that the presence and increased FB contribution to exciton formation provide an attractive avenue to stabilize the EBEC, as confirmed by calculations and analyses of multi-exciton energies, wave functions and reduced density matrices. Our results warrant a similar many-exciton analysis for other known/new candidates of EIs, and demonstrate the FBs of opposite parity as a unique platform for studying exciton physics, paving the way to material realization of spinor BEC and spin-superfluidity.
title: Targeting the RON-MSP axis and harnessing antitumour γδ T cells to counteract breast cancer metastasis
Creators: name: Remak, Sarah-Jane
Publisher: name: University of Glasgow
Year: 2021

description: Breast cancer metastasis accounts for 90% of breast cancer-related deaths. Triplenegative breast cancer (TNBC) is the most aggressive breast cancer subtype and associated with the poorest prognosis, limited treatment options and high relapse rates. Therefore, exploiting new targets to abrogate metastasis are required. We show that mammary tumours from K14Cre;Brca1F/F;Trp53F/F (KB1P) mice, a mouse of model TBNC, have elevated expression of macrophage-stimulation protein (MSP), the ligand of the tyrosine kinase receptor Recepteur d’orginine nantais (RON). Using cell lines derived from KB1P mammary tumours, we observed that endogenous MSP promotes invasiveness in vitro, which can be pharmacologically abrogated by a RON inhibitor. The role of the cancer cell-initiated γδ T cell - IL-17 - neutrophil axis in breast cancer metastasis has been demonstrated in a mouse model of lobular breast cancer. We observed that this metastatic cascade is also relevant in KB1P mice. In contrast to their IL-17 producing counterparts, IFNγ γδ T cells are implied to have anti-tumourigenic potential, but their role in breast cancer metastasis remains elusive. We found that expression of the Vγ1 variant of the T-cell receptor (TCR) is specific to IFNγ γδ T cells. Successful depletion of these cells with an anti- Vγ1antibody was accompanied with a reduction of IFNγ expression on CD3+ T cells. Our long-term goal is to combine γδ T cell immunotherapy with other targeted anticancer therapies. Here, we describe the RON-MSP as viable target for breast cancer treatment and provide initial evidence for a protective anti-tumourigenic role of IFNγ γδ T cells in breast cancer metastasis by priming CD8+ T cells to exert their cytotoxic function.
Modeling high-energy cosmic ray induced terrestrial muon flux: A lookup table
Creators: name: Atri, Dimitra
name: Melott, Adrian L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: On geological timescales, the Earth is likely to be exposed to an increased flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. Typical cosmic ray energies may be much higher than the ~ 1 GeV flux which normally dominates. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the radiation dose. Muons contribute 85% to the radiation dose from cosmic rays. This enhanced dose could be potentially harmful to the biosphere. This mechanism has been discussed extensively in literature but has never been quantified. Here, we have developed a lookup table that can be used to quantify this effect by modeling terrestrial muon flux from any arbitrary cosmic ray spectra with 10 GeV - 1 PeV primaries. This will enable us to compute the radiation dose on terrestrial planetary surfaces from a number of astrophysical sources.
F-Theorem without Supersymmetry
Creators: name: Klebanov, Igor R.
name: Pufu, Silviu S.
name: Safdi, Benjamin R.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The conjectured F-theorem for three-dimensional field theories states that the finite part of the free energy on S^3 decreases along RG trajectories and is stationary at the fixed points. In previous work various successful tests of this proposal were carried out for theories with {\cal N}=2 supersymmetry. In this paper we perform more general tests that do not rely on supersymmetry. We study perturbatively the RG flows produced by weakly relevant operators and show that the free energy decreases monotonically. We also consider large N field theories perturbed by relevant double trace operators, free massive field theories, and some Chern-Simons gauge theories. In all cases the free energy in the IR is smaller than in the UV, consistent with the F-theorem. We discuss other odd-dimensional Euclidean theories on S^d and provide evidence that (-1)^{(d-1)/2} \log |Z| decreases along RG flow; in the particular case d=1 this is the well-known g-theorem.
description: 34 pages, 2 figures; v2 refs added, minor improvements; v3 refs added, improved section 4.3; v4 minor improvements
Attention-Based Generative Neural Image Compression on Solar Dynamics Observatory
Creators: name: Zafari, Ali
name: Khoshkhahtinat, Atefeh
name: Mehta, Piyush M.
name: Nasrabadi, Nasser M.
name: Thompson, Barbara J.
name: da Silva, Daniel
name: Kirk, Michael S. F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: NASA's Solar Dynamics Observatory (SDO) mission gathers 1.4 terabytes of data each day from its geosynchronous orbit in space. SDO data includes images of the Sun captured at different wavelengths, with the primary scientific goal of understanding the dynamic processes governing the Sun. Recently, end-to-end optimized artificial neural networks (ANN) have shown great potential in performing image compression. ANN-based compression schemes have outperformed conventional hand-engineered algorithms for lossy and lossless image compression. We have designed an ad-hoc ANN-based image compression scheme to reduce the amount of data needed to be stored and retrieved on space missions studying solar dynamics. In this work, we propose an attention module to make use of both local and non-local attention mechanisms in an adversarially trained neural image compression network. We have also demonstrated the superior perceptual quality of this neural image compressor. Our proposed algorithm for compressing images downloaded from the SDO spacecraft performs better in rate-distortion trade-off than the popular currently-in-use image compression codecs such as JPEG and JPEG2000. In addition we have shown that the proposed method outperforms state-of-the art lossy transform coding compression codec, i.e., BPG.
description: Accepted to IEEE 21$^{st}$ International Conference on Machine Learning and Applications 2022 (ICMLA) - Selected for Oral Presentation
Le interazioni tra organismi: un percorso didattico per la prima liceo
Creators: name: Mascitti, Anna Lisa
Publisher: name: Scuola Universitaria della Svizzera Italiana (SUPSI)
Year: 2019

description: Questo lavoro di diploma vuole essere una proposta di traduzione didattica sul tema delle interazioni tra organismi (competizione, predazione, simbiosi) per una prima liceo. Il progetto è stato applicato in due classi del Liceo Cantonale di Bellinzona, nell’anno scolastico 2018/2019. In questo percorso didattico ho proposto un abbinamento tra la lezione frontale-dialogata e lezione basata su lavori di gruppo. Il ciclo di lezioni si è concluso con delle presentazioni orali da parte degli allievi su diversi casi-studio. La combinazione di due modalità didattiche profondamente diverse tra loro ha permesso non solo di trasmettere una serie di conoscenze e competenze, ma anche di mantenere viva l’attenzione degli allievi (anche quelli meno interessati verso la materia). Il percorso è incentrato sullo studente, al fine di favorire la sua comprensione del tema dal punto di vista disciplinare e l’acquisizione di competenze trasversali quali: analisi di un testo scientifico, capacità di sintesi e affinamento della produzione orale. Durante l’arco del ciclo di lezioni previste in questo lavoro di diploma, la motivazione degli allievi è stata elevata: ciò ha permesso loro di raggiungere gli obiettivi disciplinari e transdisciplinari prefissi all’inizio di questo lavoro. In conclusione, il percorso didattico proposto è sicuramente valido, anche se necessita di alcune modifiche per essere riproposto in futuro. Relatore: Orlando Petrini. Materia: Biologia.
Divergence of the variance of the optical phase in gain-switched semiconductor lasers described by stochastic rate equations
Creators: name: Valle, Angel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we report a theoretical study of the phase diffusion in a gain-switched single-mode semiconductor laser. We use stochastic rate equations for the electrical field to analyze the phase statistics of the gain-switched laser. Their use avoid the instabilities obtained with rate equations for photon number and optical phase when the photon number is small. However we show that a new problem appears when integrating with the field equations: the variance of the optical phase becomes divergent. This divergence can not be observed with the numerical integration of the commonly used equations for photon number and optical phase because of the previous instabilities. The divergence of the phase variance means that this quantity does not reach a fixed value as the integration time step is decreased. We obtain that the phase variance increases as the integration time step decreases with no sign of saturation behaviour even for tiny steps. We explain the divergence by making the analogy of our problem with the 2-dimensional Brownian motion. The fact that the divergence appears is not surprising because already in 1940 Paul Lèvy demonstrated that the variance of the polar angle in a 2-dimensional Brownian motion is a divergent quantity. Our results show that stochastic rate equations for photon number and phase are not appropriated for describing the phase statistics when the photon number is small. Simulation of the stochastic rate equations for the electrical field are consistent with Lèvy's results but gives unphysical results since an infinite value is obtained for a quantity that can be measured.
Decoherence, Entanglement Negativity and Circuit Complexity for Open Quantum System
Creators: name: Bhattacharyya, Arpan
name: Hanif, Tanvir
name: Haque, S. Shajidul
name: Paul, Arpon
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we compare the saturation time scales for complexity, linear entropy and entanglement negativity for two open quantum systems. Our first model is a coupled harmonic oscillator, where we treat one of the oscillators as the bath. The second one is a type of Caldeira Leggett model, where we consider a one-dimensional free scalar field as the bath. Using these open quantum systems, we discovered that both the complexity of purification and the complexity from operator state mapping is always saturated for a completely mixed state. More explicitly, the saturation time scale for both types of complexity is smaller than the saturation time scale for linear entropy. On top of this, we found that the saturation time scale for linear entropy and entanglement negativity is of the same order for the Caldeira Leggett model.
description: 40 pages, 8 figures
Characterizing the beneficial ecological association of endophytic bacteria with lodgepole pine trees naturally-regenerating at unreclaimed gravel mining pits
Creators: name: Padda, Kiran Preet
Publisher: name: University of British Columbia
Year: 2020

description: Forest landscapes are commonly affected by human disturbances giving rise to degraded edaphic conditions such as poor soil structure, inadequate plant-nutrients, and in some cases like gravel mining, a complete loss of topsoil. Gravel mining has led to the prevalence of highly-disturbed sites in the central interior region of British Columbia, Canada that have very limited soil nitrogen-levels due to the presence of gravelly-substrates, lack of forest floor, and low atmospheric nitrogen-deposition. Despite such severe conditions, lodgepole pine trees are thriving at these unreclaimed gravel pits, with tissue nitrogen-contents and growth-rates seemingly unaffected by low soil nitrogen-levels, indicating that pine trees could be accessing an unknown nitrogen-source. One possibility could be biological nitrogen-fixation (BNF) by endophytic diazotrophs (nitrogen-fixing bacteria living asymptomatically within plants). Testing this possibility, 77 potential endophytic diazotrophs were isolated from internal tissues of pine trees growing at two gravel pits in this region. Of these, 32 strains showed positive nitrogenase activity in the acetylene reduction assay. Fourteen strains that consistently showed high nitrogenase activity were selected for a year-long greenhouse study to evaluate their ability to sustain pine growth under nitrogen-poor conditions. After one year, all strains colonized the internal tissues of pine and accumulated 23%-53% of the host’s foliar nitrogen via BNF as estimated through a 15N isotope-dilution assay. Furthermore, bacterial inoculation significantly enhanced pine seedling length (31%-64%) and biomass (100%-311%). The presence of the nifH gene was also confirmed in all 14 strains. In addition to BNF, most strains demonstrated considerable potential to promote plant growth via several other mechanisms including phosphate solubilization, siderophore production, ACC deaminase activity, IAA production and lytic enzyme activity. Notably, three Pseudomonas strains (AN1r, AR1r, SN1r) contributed >50% of the host’s foliar nitrogen, showed the highest activity in multiple growth-promoting assays and enhanced seedling biomass by 4-fold. These results suggest that lodgepole pine trees may be dependent on endophytic bacteria for their survival and growth, indicating a unique ecological association that may explain natural pine-regeneration on bare gravel. However, this beneficial association must be validated under field conditions to determine their future value in restoring ecosystem productivity at disturbed sites.
Magnet field sensing beyond the standard quantum limit under the effect of decoherence
Creators: name: Matsuzaki, Yuichiro
name: Benjamin, Simon C.
name: Fitzsimons, Joseph
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Entangled states can potentially be used to outperform the standard quantum limit which every classical sensor is bounded by. However, entangled states are very susceptible to decoherence, and so it is not clear whether one can really create a superior sensor to classical technology via a quantum strategy which is subject to the effect of realistic noise. This paper presents an investigation of how a quantum sensor composed of many spins is affected by independent dephasing. We adopt general noise models including non-Markovian effects, and in these noise models the performance of the sensor depends crucially on the exposure time of the sensor to the field. We have found that, by choosing an appropriate exposure time within non-Markovian time region, an entangled sensor does actually beat the standard quantum limit. Since independent dephasing is one of the most typical sources of noise in many systems, our results suggest a practical and scalable approach to beating the standard quantum limit.
Additional file 2 of FLA14 is required for pollen development and preventing premature pollen germination under high humidity in Arabidopsis
Creators: name: Miao, Yingjing
name: Cao, Jiashu
name: Huang, Li
name: Yu, Youjian
name: Lin, Sue
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 2:
Local fibered right adjoints are polynomial
Creators: name: Kock, Anders
name: Kock, Joachim
Publisher: name: arXiv
Year: 2010
Subjects: subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18D30, 18D15

description: For any locally cartesian closed category E, we prove that a local fibered right adjoint between slices of E is given by a polynomial. The slices in question are taken in a well known fibered sense.
description: 15 pages, LaTeX; final version (v2), to appear in Math. Struct. Comp. Sci
Counting Links and Knots in Complete Graphs
Creators: name: Abrams, Loren
name: Mellor, Blake
name: Trott, Lowell
Publisher: name: arXiv
Year: 2010
Subjects: subject: Geometric Topology (math.GT)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 57M15, 57M27, 05C10

description: We investigate the minimal number of links and knots in complete partite graphs. We provide exact values or bounds on the minimal number of links for all complete partite graphs with all but 4 vertices in one partition, or with 9 vertices in total. In particular, we find that the minimal number of links for $K_{4,4,1}$ is 74. We also provide exact values or bounds on the minimal number of knots for all complete partite graphs with 8 vertices.
description: 24 pages, 12 figures; v2 adds an appendix describing the program used to count the links and knots in examples
Weighted Centroid Algorithm for Estimating Primary User Location: Theoretical Analysis and Distributed Implementation
Creators: name: Wang, Jun
name: Urriza, Paulo
name: Han, Yuxing
name: Čabrić, Danijela
Publisher: name: arXiv
Year: 2010
Subjects: subject: Performance (cs.PF)
subject: Information Theory (cs.IT)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Information about primary transmitter location is crucial in enabling several key capabilities in cognitive radio networks, including improved spatio-temporal sensing, intelligent location-aware routing, as well as aiding spectrum policy enforcement. Compared to other proposed non-interactive localization algorithms, the weighted centroid localization (WCL) scheme uses only the received signal strength information, which makes it simple to implement and robust to variations in the propagation environment. In this paper we present the first theoretical framework for WCL performance analysis in terms of its localization error distribution parameterized by node density, node placement, shadowing variance, correlation distance and inaccuracy of sensor node positioning. Using this analysis, we quantify the robustness of WCL to various physical conditions and provide design guidelines, such as node placement and spacing, for the practical deployment of WCL. We also propose a power-efficient method for implementing WCL through a distributed cluster-based algorithm, that achieves comparable accuracy with its centralized counterpart.
description: 24 pages, 10 figures, resubmitted with major revisions to IEEE Transactions on Wireless Communications
Amorphous and polycrystalline routes towards a chiral spin liquid
Creators: name: Grushin, Adolfo G.
name: Repellin, Cécile
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that a chiral spin liquid spontaneously emerges in partially amorphous, polycrystalline, or ion-irradiated Kitaev materials. In these systems, time-reversal symmetry is broken spontaneously due to a non-zero density of plaquettes with an odd number of edges, $n_{odd}$. This mechanism opens a sizeable gap, at small $n_{odd}$ compatible with that of typical amorphous materials and polycrystals, and which can alternatively be induced by ion-irradiation. We find that the gap is proportional to $n_{odd}$, saturating at $n_{odd}\sim 40\%$. Using exact diagonalization, we find that the chiral spin liquid is approximately as stable to Heisenberg interactions as Kitaev's honeycomb spin liquid model. Our results open up a significant number of non-crystalline systems where chiral spin liquids can emerge without external magnetic fields.
description: 4+3 figures, closed to published version
Edificio abitativo, Gordola
Creators: name: Papis, Daniele
Publisher: name: Scuola Universitaria della Svizzera Italiana (SUPSI)
Year: 2016

description: L’oggetto del lavoro da me redatto è un edificio a destinazione residenziale di sette piani, cinque dei quali fuori terra, che ospitano 19 appartamenti totali, e due interrati, il primo dei quali adibito ad autorimessa ed il secondo a piano cantina. L’immobile risulta essere ubicato a Gordola, al mappale 1078, nelle adiacenze della strada denominata “Via San Gottardo”. L’elemento strutturale che garantisce il trasferimento dei carichi derivanti dai cinque piani fuori terra sugli appoggi del piano autorimessa è una soletta di ridistribuzione in calcestruzzo armato precompresso.
Average output entropy for quantum channels
Creators: name: King, Christopher
name: Moser, David K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the regularized average Renyi output entropy $\bar{S}_{r}^{\reg}$ of quantum channels. This quantity gives information about the average noisiness of the channel output arising from a typical, highly entangled input state in the limit of infinite dimensions. We find a closed expression for $β_{r}^{\reg}$, a quantity which we conjecture to be equal to $\Srreg$. We find an explicit form for $β_{r}^{\reg}$ for some entanglement-breaking channels, and also for the qubit depolarizing channel $Δ_λ$ as a function of the parameter $λ$. We prove equality of the two quantities in some cases, in particular we conclude that for $Δ_λ$ both are non-analytic functions of the variable $λ$.
description: 32 pages, several plots and figures; positivity condition added for Theorem on entanglement breaking channels; new result for entrywise positive channels
Resonating Valence Bond States in an Electron-Phonon System
Creators: name: Han, Zhaoyu
name: Kivelson, Steven A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study a simple electron-phonon model on square and triangular versions of the Lieb-lattice using an asymptotically exact strong coupling analysis. At zero temperature and electron density $n = 1$ (one electron per unit cell), for various ranges of parameters in the model, we exploit a mapping to the quantum dimer model to establish the existence of a spin-liquid phase with $\mathbb{Z}_2$ topological order (on the triangular lattice) and a multi-critical line corresponding to a quantum critical spin liquid (on the square lattice). In the remaining part of the phase diagram, we find a host of charge-density-wave phases (e.g. valence-bond crystals), a conventional s-wave superconducting phase, and with the addition of a small Hubbard $U$ to tip the balance, a phonon-induced d-wave superconducting phase. Under a special condition, we find a hidden pseudo-spin $SU(2)$ symmetry that implies an exact constraint on the superconducting order parameters.
description: The title is changed from "Resonating Valence Bond States and other surprises in an Electron-Phonon System"
Beyond Schwarzschild-de Sitter spacetimes: II. An exact non-Schwarzschild metric in pure $R^{2}$ gravity and new anomalous properties of $R^{2}$ spacetimes
Creators: name: Nguyen, Hoang Ky
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In our recent publication (Phys. Rev. D 106, 104004 (2022)), we advanced a program that Buchdahl originated but prematurely abandoned circa 1962 (Nuovo Cimento 23, 141 (1962)). Therein we obtained an exhaustive class of metrics that constitute the branch of non-trivial solutions to the pure $R^{2}$ field equation in vacuo. The Buchdahl-inspired metrics in general possess non-constant scalar curvature, thereby defeating the generalized Lichnerowicz theorem previously advocated for quadratic gravity. We found that the said theorem makes an overly strong assumption on the asymptotic falloff in the spatial derivatives of the Ricci scalar, rendering it violable against the Buchdahl-inspired metrics. In this paper, we shall further extend our work mentioned above by showing that, within the class of Buchdahl-inspired metrics, the asymptotically flat member takes on an exact closed analytical expression. The new metric is characterized by a horizon radius $r_{\text{s}}$ and the Buchdahl parameter $k$, the latter of which arises via the higher-derivative nature of $R^{2}$ gravity. For $k=0$, the new metric recovers the classic Schwarzschild metric. Equipped with the exact expression of the new metric, we shall analytically construct the Kruskal-Szekeres diagram for pure $R^{2}$ spacetime. We find that the Buchdahl parameter $k$ fundamentally modifies the properties of $R^{2}$ spacetime structures in a variety of ways.
description: 23 pages, 13 figures
Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays
Creators: name: Wang, Hao
name: Afanasev, Andrei
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We developed theoretical formalism for generation of optical vortices by phased arrays of atoms. Using Jacobi-Anger expansion, we demonstrate the resulting field topology and determine the least number of array elements necessary for generation of vortices with a given topological charge. Vector vortices were considered, taking into account both spin and orbital angular momenta of electromagnetic fields. It was found that for the vortex field near the phase singularity, the transverse-position dependence of 3D polarization parameters is independent of the distance to the radiation source.
description: 10 pages, 7 figures
Conductivity of 2D many-component electron gas, partially-quantized by magnetic field
Creators: name: Entin, M. V.
name: Magarill, L. I.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The 2D semimetal consisting of heavy holes and light electrons is studied. The consideration is based on assumption that electrons are quantized by magnetic field while holes remain classical. We assume also that the interaction between components is weak and the conversion between components is absent. The kinetic equation for holes colliding with quantized electrons is utilized. It has been stated that the inter-component friction and corresponding correction to the dissipative conductivity $σ_{xx}$ {\it do not vanish at zero temperature} due to degeneracy of the Landau levels. This correction arises when the Fermi level crosses the Landau level. The limits of kinetic equation applicability were found. We also study the situation of kinetic memory when particles repeatedly return to the points of their meeting.
description: 13 pages, 1 figure
FOOD AS MEDICINE: FOOD CONSUMPTION PATTERNS AND REPORTED ILLNESSES AMONG HOUSEHOLDS
Creators: name: OGUNMODEDE, Adewale Moses
name: OMONONA, Bolarin Titus
name: OGUNMODEDE, Adewale Moses
name: OMONONA, Bolarin Titus
Publisher: name: Unknown
Year: 2020
Subjects: subject: Agricultural and Food Policy
subject: Consumer/Household Economics
subject: Crop Production/Industries
subject: Food Consumption/Nutrition/Food Safety
subject: Food Security and Poverty
subject: Health Economics and Policy
subject: food consumption pattern
subject: diet diversity
subject: urbanisation
subject: whole food

description: Rapid changes in climate and urban growth, changing demographics and heterogeneity of urban lifestyles are resulting in a shift in food consumption patterns, with a preference for foods with minimal processing time, quality and taste in Nigeria; but does there exist any relationship between food consumption pattern and reported illnesses among households? For better understanding, this study uses cross-sectional primary data, to thus, examine the relationship between food consumption patterns and the reported illnesses among households in Nigeria. Using a multistage sampling procedure, 250 households in two different local government areas were randomly selected. The study revealed that male household head consumed more plant-based whole food (0.6064) and therefore reported a lower incidence of illnesses (2.18) as compared to the female head whose consumption is lower (0.5644) with higher reported illnesses (3.13). The study further revealed that household members (41-50 years) are most aware of a plant-based whole food (54.17%) with lower reported illness (2.18), whereas members (61-80 years) have the highest reported illness (2.62) because they are the least aware (0.6189). Results also showed that people in the urban areas are prone to more sickness (2.04) than rural areas (1.79) because they are exposed to more choices of processed foods as compared to fresh farm foods available in the rural areas. Households’ consumption patterns were influenced by household head sex, income, location, level of awareness of plant-based whole food, and total food expenditure. Therefore, while the existence of rural-urban food linkages will ensure wider households’ access to quality whole foods needed to reduce reported illnesses; increasing households’ income will enhance diet diversity and reduction in Nigeria’s food insecurity. Also, more attention should be given to educating the people especially through media channels on the benefits of consuming plant-based whole food.
description: doi: 10.15414/raae.2020.23.02.81-91; https://roaae.org/issue/review-of-agricultural-and-applied-economics-raae-vol-23-no-2-2020-2/?article=food-as-medicine-food-consumption-patterns-and-reported-illnesses-among-households
PGS, Comune di Montecenesi – Quartiere di Camignolo
Creators: name: Lancetti, Andrea
Publisher: name: Scuola Universitaria della Svizzera Italiana (SUPSI)
Year: 2018

description: Il tema della tesi è l’allestimento del Piano Generale di Smaltimento del Quartiere di Camignolo. Risulta di grande importanza la concezione di un PGS funzionale al fine di garantire un corretto smaltimento delle acque che tuteli le acque superficiali e sotterranee. Il documento tratta cinque corsi d’acqua, per ciascuno si analizza la situazione attuale, i punti critici e le varie immissioni.
Composite fermion pairing induced by Landau level mixing
Creators: name: Zhao, Tongzhou
name: Balram, Ajit C.
name: Jain, J. K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Pairing of composite fermions provides a possible mechanism for fractional quantum Hall effect at even denominator fractions and is believed to serve as a platform for realizing quasiparticles with non-Abelian braiding statistics. We present results from fixed-phase diffusion Monte Carlo calculations which predict that substantial Landau level mixing can induce a pairing of composite fermions at filling factors $ν=1/2$ and $ν=1/4$ in the $l=-3$ relative angular momentum channel, thereby destabilizing the composite-fermion Fermi seas to produce non-Abelian fractional quantum Hall states.
Da uno spazio stradale urbano a orientamento veicolare ad uno spazio polifunzionale a orientamento insediativo
Creators: name: Braga, Stefano
Publisher: name: Scuola Universitaria della Svizzera Italiana (SUPSI)
Year: 2023

description: L'obiettivo dello studio è quello di identificare le esigenze di mobilità interna e di attraversamento di un quartiere a forte vocazione residenziale che contiene elementi e infrastrutture sociali, e di tradurre tali esigenze in un linguaggio di progettazione dello spazio pubblico e della mobilità urbana contemporaneo ed equilibrato, combinando i compiti legati al luogo e al transito.
Density functional theory beyond the linear regime: Validating adiabatic LDA
Creators: name: Helbig, N.
name: Fuks, J. I.
name: Casula, M.
name: Verstraete, M. J.
name: Marques, M. A. L.
name: Tokatly, I. V.
name: Rubio, A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a local density approximation (LDA) for one-dimensional (1D) systems interacting via the soft-Coulomb interaction based on quantum Monte-Carlo calculations. Results for the ground-state energies and ionization potentials of finite 1D systems show excellent agreement with exact calculations, obtained by exploiting the mapping of an $N$-electron system in $d$ dimensions, onto a single electron in $N\times d$ dimensions properly symmetrized by the Young diagrams. We conclude that 1D LDA is of the same quality as its three-dimensional (3D) counterpart, and we infer conclusions about 3D LDA. The linear and non-linear time-dependent responses of 1D model systems using LDA, exact exchange, and the exact solution are investigated and show very good agreement in both cases, except for the well known problem of missing double excitations. Consequently, the 3D LDA is expected to be of good quality beyond linear response. In addition, the 1D LDA should prove useful in modeling the interaction of atoms with strong laser fields, where this specific 1D model is often used.
description: 5 pages, 3 figures
Beyond Schwarzschild-de Sitter spacetimes: III. A perturbative vacuum with non-constant scalar curvature in $R+R^2$ gravity
Creators: name: Nguyen, Hoang Ky
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In violation of the generalized Lichnerowicz theorem advocated by Nelson and others, quadratic gravity admits vacua with non-constant scalar curvature. In a recent publication [Phys. Rev. D 106, 104004 (2022)], we revitalized a program that Buchdahl originated but prematurely abandoned circa 1962 [Nuovo Cimento 23, 141 (1962)], and uncovered a novel exhaustive class of static spherically symmetric vacua for pure $R^2$ gravity. The Buchdahl-inspired metrics we obtained therein are exact solutions which exhibit non-constant scalar curvature. A product of fourth-order gravity, the metrics entail a new (Buchdahl) parameter $k$ which allows the Ricci scalar to vary on the manifold. The metrics are able to defeat the generalized Lichnerowicz theorem by evading an overly strong restriction on the asymptotic falloff in the Ricci scalar as assumed in the theorem. The Buchdahl parameter $k$ is a new characteristic of pure $R^2$ gravity, a higher-derivative theory. By venturing that the Buchdahl parameter should be a universal hallmark of higher-derivative gravity at large, in this paper we seek to extend the concept to the quadratic action $R^2+γ\,(R-2Λ)$. We are able to determine that the quadratic field equation admits a perturbative vacuo that is valid up to the order $O(k^2)$. Conforming with our guiding intuition, the Ricci scalar is non-constant, including the asymptotically flat case, as long as $k\neq0$ and $γ\neq0$. The existence of such an asymptotically flat vacuo with non-constant scalar curvature defeats the generalized Lichnerowicz theorem in its entirety. Our finding thus warrants restoring the $R^2$ term in the full quadratic action, $γ\,R+β\,R^2-α\,C^{μνρσ}C_{μνρσ}$, when applying the Lü-Perkins-Pope-Stelle ansatz. Implications to the Lü-Perkins-Pope-Stelle solution are discussed herein.
description: 9 pages, no figures
Is string theory a theory of quantum gravity?
Creators: name: Giddings, Steven B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Some problems in finding a complete quantum theory incorporating gravity are discussed. One is that of giving a consistent unitary description of high-energy scattering. Another is that of giving a consistent quantum description of cosmology, with appropriate observables. While string theory addresses some problems of quantum gravity, its ability to resolve these remains unclear. Answers may require new mechanisms and constructs, whether within string theory, or in another framework.
description: Invited contribution for "Forty Years of String Theory: Reflecting on the Foundations," a special issue of Found. Phys., ed. by G 't Hooft, E. Verlinde, D. Dieks, S. de Haro. 32 pages, 5 figs., harvmac. v2: final version to appear in journal (small revisions)
Spatial impact trends on debris flow fans in southwestern British Columbia
Creators: name: Zubrycky, Sophia
Publisher: name: University of British Columbia
Year: 2020

description: Forecasting the spatial impact of debris flows is challenging due to complex runout behaviour, such as variable mobility and channel avulsions. Practitioners often base the probability of runout exceedance on a fan, or define avulsion scenarios, on judgement. To support decision making, spatial impact trends were studied at thirty active debris flow fans in southwestern British Columbia (SWBC), Canada. 176 debris flow impact areas covering an average observation period of 74 years were mapped using orthorectified historical airphotos, satellite imagery, topographic basemaps, lidar, and field observations. A graphical plotting method was developed that converts geospatial mapping to spatial impact heatmaps normalized by the fan boundary, allowing for comparison of runout trends across fans in the dataset. Probability of spatial impact was analyzed in two components: runout down-fan (i.e., how far debris flows tend to travel past the apex toward the fan toe) and runout cross-fan (i.e., how far debris flows tend to deviate from the previous flow path). For fans in SWBC, there is a characteristic decay in spatial impact probability from the fan apex and the previous flow path, represented by a normal and log-normal distribution for normalized runout in the down-fan and cross-fan components, respectively. Differences in spatial impact trends can be explained, in part, by event volume, Melton ratio, fan truncation, and fan activity, however not by fan morphometrics, such as the slope or the point at which channelization is lost. A tool was created that transposes the empirical runout distributions onto a fan to assist in risk-based decision making. Future work may involve fitting functions to the spatial impact data for a more robust and adaptable forecasting tool.