Miracle-dz/UniFAR-FTUs huggingface dataset:
Explorations of Infinitesimal Inverse Spectral Geometry

Spectral geometry is a mathematical discipline that studies the relationship between the geometry of Riemannian manifolds and the spectra of natural differential operators defined on them. The spectra of Laplacians are the ones most studied in this context. A sub-field of this discipline, called inverse spectral geometry, studies how much geometric information one can recover from such spectra. The motivation behind our study of inverse spectral geometry is a physical one. It has recently been proposed that inverse spectral geometry could be the missing mathematical link between quantum field theory and general relativity needed to unify those theories into a single theory of quantum gravity [47]. Unfortunately, this proposed link is not well understood. Most of the efforts in inverse spectral geometry were historically concentrated on the generation of counterexamples to the most general formulation of inverse spectral geometry and the few positive results that exist are quite limited. In order to remedy to that, it has been proposed to linearize the problem, and study an infinitesimal version of inverse spectral geometry [47]. In this thesis, I begin by reviewing the theory of pseudodifferential operators and using it to prove the spectral theorem for elliptic operators. I then define the commonly used Laplacians and survey positive and negative results in inverse spectral geometry. Afterwards, I briefly discuss a coordinate free reformulation of Riemannian geometry via the notion of spectral triple. Finally, I introduce a formulation of inverse spectral geometry adapted for numerical implementations and apply it to the inverse spectral geometry of a particular class of star-shaped domains in R.
Markov Switching Models for Volatility: Filtering, Approximation and Duality

This paper is devoted to show duality in the estimation of Markov Switching (MS) processes for volatility. It is well-known that MS-GARCH models suffer of path dependence which makes the estimation step unfeasible with usual Maximum Likelihood procedure. However, by rewriting the MS-GARCH model in a suitable linear State Space representation, we are able to give a unique framework to reconcile the estimation obtained by the Kalman Filter and with some auxiliary models proposed in the literature. Reasoning in the same way, we present a linear Filter for MS-Stochastic Volatility (MS-SV) models on which different conditioning sets yield more flexibility in the estimation. Estimation on simulated data and on short-term interest rates shows the feasibility of the proposed approach.
Geopolitical risks and asset prices: Wealth effects of delisting regulation on Chinese companies listed on the U.S. exchanges

This study investigates the shareholder wealth effect of the passage of de-listing regulation on Chinese companies listed on the U.S. stock exchanges. Using a standard event study methodology similar to Dodd and Warner (1983) and Travlos (1987), we study three events leading up to the passage and the signing of the Holding Foreign Companies Accountable Act (HFCAA). The HFCAA mandates companies to provide assurance that they are not owned or controlled by a foreign government. In addition, the law requires that these companies provide access to the U.S. Public Company Accounting Oversight Board (PCAOB) to examine their financial audits. The results of our study show a significant negative wealth effect around three test events for a sample of Chinese companies listed on U.S. stock exchanges. These findings suggest that geopolitical tensions significantly affect firm value, thus affirming the notion that bilateral or multilateral tensions, once translated in to policy changes, do trickle down to the individual firm level, thereby providing direct evidence of the link between geopolitical uncertainty (risk) and asset prices. These results contribute to and extend the growing body of literature (Egger & Zhu, 2020) on geopolitical tensions and stock returns. Our findings have implications for those nations’ economies that are, directly or indirectly, a party to similar geopolitical alignments or rivalries.
Using a hybrid encoding method based on the hexagonal resonators to increase the coding capacity of chipless RFID tags

A chipless RFID tag was designed using two hexagonal resonators. By defining a relation for the phases of S‐parameters and rotating the resonators around their axes, a senary coding scheme was obtained at the resonant frequency. The designed resonator was able to generate six different codes using six different phase parameters at 3.03 GHz. While the conventional binary (“0” and “1”) coding of ordinary tags makes minimal use of bandwidth capacity, the senary coding in the proposed design allowed the use of a larger bandwidth capacity. Requiring much fewer resonators for generating more codes, the proposed technique leads to significantly smaller tags. Using the proposed tag with two resonators, 62 = 36 different codes can be generated; more generally, an n‐resonator tag of the proposed type can create 6n different codes.
Chronic Lateral Ankle Instability Treated With Tendon Allografting: A Preliminary Comparison of Arthroscopic and Open Anatomic Ligament Reconstruction

Background: Roughly 30% of patients with chronic lateral ankle instability (CLAI) have long-lasting painful instability requiring surgical intervention. Ligament reconstruction with the traditional open method and using tendon allografts can provide sufficient mechanical stability for severe CLAI. Arthroscopic ligament reconstruction with tendon allograft has recently been introduced to treat CLAI. Purpose: In this study, we describe an arthroscopic ligament reconstruction procedure involving the use of the tendon allograft for patients with CLAI, and we compare the efficacy of this procedure with open ligament reconstruction with tendon allograft. Study Design: Cohort study; Level of evidence, 3. Methods: We enrolled 10 patients (4 men and 6 women) with CLAI (mean age, 37.3 years; range, 16-57 years) who underwent arthroscopic ligament reconstruction with tendon allografting between November 2017 and June 2019. The control group consisted of 10 patients who received open tendon allograft reconstruction. Preoperative and 2-year postoperative functional outcomes were evaluated using the American Orthopaedic Foot & Ankle Society ankle-hindfoot scale (AOFAS), Karlsson Ankle Functional Score (KAFS), pain visual analog scale (VAS), 12-Item Short Form Health Survey (SF-12), and Tegner activity score (TAS). Results: The mean operative time was 118 and 110 minutes in the arthroscopic and open groups, respectively. At 2-year follow-up, scores on the AOFAS improved significantly compared with preoperatively, from 71.3 to 96.4 (P = .006) in the arthroscopic group, and from 68.6 to 96.7 (P = .005) in the open group. The postoperative AOFAS, VAS, KAFS, and SF-12 scores did not differ significantly between the 2 groups; however, the TAS score was significantly higher in the arthroscopic reconstruction group compared with in the open group (7 vs 6.1, respectively; P = .01). Conclusion: Arthroscopic ligament reconstruction with tendon allografting resulted in sufficient ankle stability and no donor-site morbidity. This procedure can yield similar functional outcomes to open reconstruction technique and may be an option for the management of CLAI.
Models of magnetic field evolution and effective viscosity in weakly collisional extragalactic plasmas

In weakly collisional plasmas such as the intracluster medium (ICM), the viscous stress and the rate of change of the magnetic energy are proportional to the local pressure anisotropy, so subject to constraints imposed by the pressure-anisotropydriven microinstabilities (mirror and firehose) and controlled by the local instantaneous plasma β. The dynamics of such plasmas can be dramatically different from a conventional MHD fluid. The plasma is expected to stay locally marginal with respect to the instabilities, but how it does this remains an open question. Two models of magnetic-field evolution are investigated. In the first, marginality is achieved via suppression of the rate of change of the field. In the second, the instabilities give rise to anomalous collisionality, reducing pressure anisotropy to marginal — at the same time decreasing viscosity and so increasing the turbulent rate of strain. Implications of these two models are studied in a simplified zero-dimensional setting. In the first model, the field grows explosively but on a time scale that scales with the initial β, while in the second, dynamical field strength can be reached in one large-scale turbulence turn-over time regardless of the initial seed. Both models produce very intermittent fields. Both also suffer from fairly strong constraints on their applicability: for typical cluster-core conditions, scale separation between the fluid motions (with account of suppressed viscous stress) and the miscoscale fluctuations breaks down at β � 10 4 10 5 . At larger β (weaker fields), a fully collisionless plasma dynamo theory is needed to justify field growth from a tiny primordial seed. However, the models discussed here are appropriate for studying the structure of the currently observed field as well as large-scale dynamics and thermodynamics of the magnetized ICM or similarly dilute astrophysical plasmas.
Free-Convective Heat Transfer: With Many Photographs of Flows and Heat Exchange

Basic Statements and Equations of Free Convection. - Free Convection on a Plane. - Free Convection on Curved Surfaces. - Natural Convection in Enclosures. - Free Convection in Tubes and Channels, on Ribbed Surfaces and in Tube Bundles. - Nonstationary Processes of Free Convection. - Heat Transfer by Mixed Convection. - Heat Transfer in Media with Special Properties.
Psychiatric Symptoms and Frequency of Eating out among Commuters in Beijing: A Bidirectional Association?

Background: Mental illness places as a distant first in global burdens, exceeding both cardiovascular and circulatory diseases, in terms of the years lived with the disability. The emergence of the new and burgeoning area of “Nutrition Psychiatry” offers promise in improving mental health with diet. Mental health and well-being are critical to commuters but rarely recieve the attention they need. This study aimed to examine the bidirectional relationship between the frequency of eating out and depression, anxiety, and stress symptoms in a sample of Beijing commuters. Methods: A total of 3337 commuters (mean (SD) age, 38.78 (10.41); 74.74% males) from the cohort study CHCN-BTH were included. The psychiatric symptoms were evaluated using a 21-item self-reported depression–anxiety–stress scale (DASS-21). A Cochran–Armitage trend chi-square test, restricted cubic spline, multiple logistic regression, multinomial logit models, and E-values were performed to estimate the associations between eating out and psychiatric symptoms in both directions. Results: A daily rate of eating out more than 50% had a higher risk for depression (OR, 95% CI: 1.68, 1.184–2.393), anxiety (1.73, 1.259–2.369), and stress (1.99, 1.191–3.329) than the individuals eating at home. A higher frequency of eating out for lunch was significantly associated with an increased risk of depression (1.78, 1.28–2.46), anxiety (1.67, 1.26–2.23), and stress (2.05, 1.31–3.22). Similar results were found when eating out for dinner with increased risks for depression 2.20 (1.59, 3.06), anxiety 1.91 (1.42, 2.59), and stress 2.61 (1.68, 4.05). There is limited evidence supporting the effects of psychiatric symptoms on the frequency of eating out in the reverse analyses. Conclusions: The frequency of eating out is positively associated with an increased risk of psychiatric symptoms, especially when eating out for lunch and dinner. People eating at home have the lowest risk of suffering psychiatric symptoms, followed by those eating in the workplace canteen. Eating at home should be considered for future recommendations for the prevention of psychiatric symptoms.
Effective medium theory : principles and applications

1. Essentials 1.1 Lorentz field 1.2 Clausius-Mossotti 1.3 Maxwell-Garnett 1.4 Bruggeman 1.5 Green's functions formulation 1.6 Summary and equivalence 2. Rigorous results 2.1 Introduction 2.2 Variational bounds 2.3 The concentric shell model 2.4 Spectral representation 2.5 Exactly soluble models 2.6 Reciprocity theorems 3. Dynamical theory 3.1 Introduction 3.2 Review 3.3 Macroscopic electrodynamics 3.4 Quasi-static regime 3.5 Displacement current and wave scattering 3.6 Mie scattering 3.7 Dynamical effective medium theory 3.8 Open problems 4. Limitations and beyond 4.1 Introductory remarks 4.2 Higher order terms 4.3 Percolation and criticality 4.4 Mie resonances 4.5 Multiple scattering 4.6 Competing interactions 4.7 Two body effective medium 4.8 Non-equilibrium 5. Related theories 5.1 Comments 5.2 Coherent potential approximation 5.3 Feynman diagrams 5.4 Localization of light 5.5 Classical theory of liquids 5.6 Density functional theories 5.7 Hubbard model, CPA and DFT 5.8 Summary 6. EMT applications 6.1 Introduction 6.2 Electric and magnetic properties 6.3 Optical properties 6.4 Granular high Tc superconductors 6.5 Hydrodynamics of suspensions 6.6 Mechanical properties 6.7 Nonlinear composites 6.8 Conclusions Appendices A.1 Stationery properties of UP and UR A.2 Evaluation of the last term in equation (2.18)
Soft vortex matter in a type-I/type-II superconducting bilayer

Magnetic flux patterns are known to strongly differ in the intermediate state of type-I and type-II superconductors. Using a type-I/type-II bilayer we demonstrate hybridization of these flux phases into a plethora of unique new ones. Owing to a complicated multi-body interaction between individual fluxoids, many different intriguing patterns are possible under applied magnetic field, such as few-vortex clusters, vortex chains, mazes or labyrinthal structures resembling the phenomena readily encountered in soft matter physics. However, in our system the patterns are tunable by sample parameters, magnetic field, current and temperature, which reveals transitions from short-range clustering to long-range ordered phases such as parallel chains, gels, glasses and crystalline vortex lattices, or phases where lamellar type-I flux domains in one layer serve as a bedding potential for type-II vortices in the other - configurations clearly beyond the soft-matter analogy.
Analysis of Arrhenius activation energy on magnetohydrodynamic gyrotactic microorganism flow through porous medium over an inclined stretching sheet with thermophoresis and Brownian motion

This paper aims to examine the combined effects of Arrhenius activation and microorganisms on unsteady flow through a porous medium with thermophoresis and Brownian motion over an inclined stretching sheet. The governing partial differential equations are transformed into a set of non-linear ordinary differential equations using similarity analysis. The resultant non-linear coupled ordinary differential equations are solved numerically using the boundary value problem solver in MATLAB. The effects of the physical parameter such as magnetic field parameter ( M ), thermal radiation parameter ( R ), permeability parameter ( K ), Eckert number ( E c ), thermophoresis parameter ( N t ) and Brownian motion parameter ( N b ) on the velocity, temperature, concentration profiles, skin friction coefficient, Nusselt number, and the local Sherwood number are presented and analysed graphically. The comparison has been made with previously published work, and there is a good agreement. These results may be helpful in geothermal engineering, energy conversation and disposal of nuclear waste material. Furthermore, scientists can employ this technique in medical fields such as gene therapy and the synthesis of drug delivery systems.
Indoor target tracking with deep learning-based YOLOv3 model

For the problem of real-time indoor localization of workers in factory workshops and corridors, the pre-trained YOLOv3 detection model based on deep learning network is used to realize the visual localization of unmarked dynamic targets by monocular cameras. This method only needs a fixed-position camera in the measured area to complete real-time detection and localization of moving targets in the measured area. The algorithm is verified by simulation and experiment, and the personnel localization error of 8.2cm on the X axis and 19.57cm on the Y axis is obtained. Compared with other localization methods, it has the advantages of relatively low hardware cost, simple system setup, high algorithm portability, good practicability and industrial promotion value.
LIGHT ECHOES FROM SUPERNOVA 2014J IN M82

Type Ia SN 2014J exploded in the nearby starburst galaxy M82 = NGC 3032 and was discovered at Earth about seven days later on 2014 January 21, reaching maximum light in V around 2014 February 5. SN 2014J is the closest SN Ia in at least four decades and probably many more. Recent Hubble Space Telescope/WFC3 imaging (2014 September 5 and 2015 February 2) of M82 in the vicinity of SN 2014J reveals a light echo at radii of about 0.6 arcsec from the supernova (SN; corresponding to about 12 pc at the distance of M82). Likely additional light echoes reside at a smaller radii of about 0.4 arcsec The major echo signal corresponds to echoing material about 330 pc in the foreground of SN 2014J and tends to be bright where pre-existing nebular structure in M82 is also bright. The second, likely echo corresponds to foreground distances of 80 pc in front of the SN. Even one year after maximum light, there are indications of further echo structures appearing at smaller radii, and future observations may show how extinction in these affect detected echo farther from the SN, which will affect interpretation of details of the three-dimensional structure of this gas and dust. Given enough data, we might even use these considerations to constrain the near-SN material’s shadowing on distant echoing clouds, even without directly observing the foreground structure. This is in addition to echoes in the near future that might also reveal circumstellar structure around SN 2014J’s progenitor star from direct imaging observations and other techniques.
Two-Stage Robust Distribution Network Reconfiguration Against Failures of Lines and Renewable Generations

Network reconfiguration is a significant strategy to enhance the resiliences of distribution systems against contingencies. This paper proposes a two-stage robust network reconfiguration model to maximize the power supply under the uncertain failures of both lines and renewable generators. In stage 1, before the contingencies are realized, the network topology is reconfigured into several subsystems supplied by conventional generators. Then the contingencies are launched to the reconfigured distribution system, inducing load curtailments. In stage 2, the flexible resources, e.g., conventional and renewable generators, and energy storages, are dispatched to guarantee the maximal power supply under the worst-case contingencies. To solve the two-stage robust model, we develop a column & constraint generation (C&CG) algorithm. The network reconfiguration decision is made in the master problem according to an increasing amount of worst-case scenarios generated by the subproblem. Simulation results demonstrate the performance of the network reconfiguration decision of the two-stage robust model and verify the effectiveness of the C&CG algorithm to deal with the proposed model.
Effect of Nursing Outcome-Oriented Intervention on Airway Management in Elderly Long-Term Bedridden Patients

Objective This study intended to explore the nursing outcome-oriented intervention's effect on airway management in elderly long-term bedridden patients. Methods A total of 120 cases of elderly long-term bedridden patients admitted to our hospital from May 2018 to June 2020 were enrolled and randomly divided into the observation group (n = 60) and control group (n = 60). The control group received the routine nursing intervention, while the observation group received the nursing outcome-oriented intervention. Forced expiratory volume (FEV1), forced vital capacity (FVC), and maximal voluntary ventilation (MVV) in the first second were compared between the two groups before and after the intervention. The pulmonary infection of the two groups was observed. Total protein, hemoglobin, albumin, and cholesterol levels were compared between the two groups. Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) were used to evaluate the two groups' psychological status before and after the intervention. The Generic Quality of Life Inventory-74 (GQOLI-74) assessed the two groups' quality of life. Results After the intervention, the levels of FEV1, FVC, and MVV; total protein, hemoglobin, albumin, and cholesterol; and scores of physical function, psychological function, social function, and material life function in the observation group were higher than those in the control group. Pulmonary infection, secondary infection, the infection rate is more than 3%, HAMA, and HAMD scores, and the incidence of pressure ulcers, aspiration, constipation, and the falling bed was lower than those in the control group, with statistical significance (all P < 0.05). Conclusion Nursing outcome-oriented intervention can effectively improve lung function, pulmonary infection, nutritional status, negative mood, and quality of life of long-term bedridden elderly patients.
PHOTOMETRIC DECOMPOSITION OF MERGERS IN DISK GALAXIES

Several observational studies and numerical simulations suggest that mergers must contribute to the evolution of galaxies; however, the role that they play is not yet fully understood. In this paper we study a sample of 52 double nucleus disk galaxies that are considered as candidates for a minor merger event. The luminosity of each of the nuclei and their relative separation are derived from a multi-component photometric fit of the galaxies in the Sloan Digital Sky Survey optical images. We find that the nuclei in most of the sources have projected separations ⩽4 kpc. The ratio of nuclear luminosities indicates that most of the systems are likely in the coalescence stage of a major merger. This is supported by the existence of a single galaxy disk in 65% of the systems studied and the finding of a correlation between nuclear luminosity and host luminosity for the single-disk systems: those sources fitted with as single disk are in a more evolved stage of the merger and present an enhancement of the nuclear luminosity compared to the double-disk systems, as expected from simulations of galaxy mergers. Finally, we identify a sample of 19 double nucleus disk galaxies in which the two nuclei are physically separated by ⩽1 kpc and constitute thus a sample of sub-kpc binary active galactic nucleus candidates.
TEM Investigation of Asymmetric Deposition-Driven Crystalline-to-Amorphous Transition in Silicon Nanowires

Controlling the shape and internal strain of nanowires (NWs) is critical for their safe and reliable use and for the exploration of novel functionalities of nanodevices. In this work, transmission electron microscopy was employed to examine bent Si NWs prepared by asymmetric electron-beam evaporation. The asymmetric deposition of Cr caused the formation of nanosized amorphous-Si domains; the non-crystallinity of the Si NWs was controlled by the bending radius. No other intermediate crystalline phase was present during the crystalline-to-amorphous transition, indicating a direct phase transition from the original crystalline phase to the amorphous phase. Moreover, amorphous microstructures caused by compressive stress, such as amorphous Cr domains and boxes, were also observed in the asymmetric Cr layer used to induce bending, and the local non-crystallinity of Cr was lower than that of Si under the same bending radius.