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Recognition of a user's influence level has attracted much attention as human interactions move online. Influential users have the ability to sway others' opinions to achieve some goals. As a result, predicting users' level of influence can help to understand social networks, forecast trends, prevent misinformation, etc. However, predicting user influence is a challenging problem because the concept of influence is specific to a situation or a domain, and user communications are limited to text. In this work, we define user influence level as a function of community endorsement and develop a model that significantly outperforms the baseline by leveraging demographic and personality data. This approach consistently improves RankDCG scores across eight different domains.

We propose a mechanism which can generate supercurrents in spin-orbit coupled superconductors with charged magnetic inclusions. The basic idea is that through spin-orbit interaction, the in-plane electric field near the edge of each inclusion appears to the electrons as an effective spin-dependent gauge field; if Cooper pairs can be partially spin polarized, then each pair experiences a nonzero \textit{net} transverse pseudo-gauge field. We explore the phenomenology of our mechanism within a Ginzburg-Landau theory, with parameters determined from a microscopic model. Depending on parameters, our mechanism can either enhance or reduce the total magnetization upon superconducting condensation. Given an appropriate distribution of inclusions, we show how our mechanism can generate superconducting vortices without any applied orbital magnetic field. Surprisingly, the vortices form \textit{nonlocally}; they are situated in between the inclusions. Our mechanism can produce similar qualitative behavior to the "magnetic memory effect" observed in 4Hb-TaS$_2$. However, the magnitude of the effect in that material seems larger than our model can naturally explain., Comment: 11 pages, 2 figures

Statewide annual assessments are designed to help guide educational decisions by evaluating student growth and learning so resources can be equitably distributed. They also provide valuable individual results that summarize how each student is progressing against grade-level academic standards, identify additional ways their school system can support their academic success, and allow families to demand appropriate actions from their education leaders. This report offers guidance on how schools can better communicate the results of students' federally required annual tests so parents can be better informed about how their students are doing in school and work with educators to get appropriate support. Specifically, this brief: (1) Calls for individual assessment reporting results to be integrated into existing communications with families; (2) Highlights the role that trusted voices play in communicating this information; (3) Identifies best practices for designing individual score reports for students and families; and (4) Offers promising strategies and policy recommendations that advocates can push for to improve assessment reporting at the state level.

Single-shot ptychography is a quantitative phase imaging method wherein overlapping beams of light arranged in a grid pattern simultaneously illuminate a sample, allowing a full ptychographic dataset to be collected in a single shot. It is primarily used at optical wavelengths, but there is interest in using it for X-ray imaging. However, the constraints imposed by X-ray optics have limited the resolution achievable to date. In this work, we reinterpret single-shot ptychography as a structured illumination method by viewing the grid of beams as a single, highly structured illumination function. Pre-calibrating this illumination and reconstructing single-shot data using the randomized probe imaging algorithm allows us to account for the overlap and coherent interference between the diffraction arising from each beam. We achieve a resolution 3.5 times finer than the numerical aperture-based limit imposed by traditional algorithms for single-shot ptychography. We argue that this reconstruction method will work better for most single-shot ptychography experiments and discuss the implications for the design of future single-shot X-ray microscopes., Comment: 4 pages, 3 figures

REBCO tape has successfully used in ultra-high field magnets. Mechanically, it is very strong in its length direction but is prone to delamination in the thickness direction. In an epoxy impregnated REBCO magnet, thermal strain alone could delaminate the conductor. Even for dry wound REBCO coil, a conductor with very low delamination strength is still a concern. Therefore, it is important to characterize the delamination strength of the conductor. In the past decade, significant progresses have been made in the characterization of REBCO delamination strength. Among several developed characterization methods, the 90 degree peel test is simple to setup and seems to offer reproducible results. Therefore, this test could be used as a reliable method to characterize the relative delamination strength of REBCO tapes for quality control purposes. This paper presents our development of 90 degree peel test method for quality assurance test of the 40 T all-superconducting magnet project at the National High Magnetic Field Laboratory. We investigated the factors that influence the test results, such as thickness and RRR of the copper layer. We found that peel strength increases with decreasing Cu thickness. We also found that peel strength is positively correlated with RRR of the copper. Despite these effects, 90 degree peel test is still a valuable quality assurance tool to evaluate delamination strength for large volume of tapes with the same copper thickness., Comment: ASC 2024 conference, Salt Lake City UT, Sept. 2-6, 2024

Residual resistance ratio (RRR) of Cu stabilizer in REBCO coated conductor is an important design parameter for REBCO magnets. In this work, we measured RRR of electroplated Cu stabilizer in commercial REBCO tapes. Over 130 samples were measured for the quality assurance programs of REBCO magnet projects at the National High Magnetic Field Laboratory, USA (NHMFL). The average RRR value was above 50. In order to investigate the factors that influence RRR, several samples were analyzed by using scanning electron microscopy, secondary ion mass spectroscopy, and inductively coupled plasma mass spectroscopy. We found that, in our samples, RRR was strongly correlated with the grain size. We demonstrated that RRR was primarily determined by grain boundary resistivity. Lower RRR was also strongly correlated with higher concentration of chlorine impurity. This is explained by that higher chlorine impurity hindered the grain growth in the room temperature self annealing process resulting smaller grain. Smaller grain resulted in lower RRR. In addition, thermal annealing significantly enhanced RRR. An activation energy of 0.4 eV was obtained from the annealing experiment which corresponds to the activation of Cu grain growth., Comment: 18 pages

In rare earth nickelates (RENiO$_3$), electron-lattice coupling drives a concurrent metal-to-insulator and bond disproportionation phase transition whose microscopic origin has long been the subject of active debate. Of several proposed mechanisms, here we test the hypothesis that pairs of self-doped ligand holes spatially condense to provide local spin moments that are antiferromagnetically coupled to Ni spins. These singlet-like states provide a basis for long-range bond and spiral spin order. Using magnetic resonant X-ray scattering on NdNiO$_3$ thin films, we observe the chiral nature of the spin-disproportionated state, with spin spirals propagating along the crystallographic (101)$_\mathrm{ortho}$ direction. These spin spirals are found to preferentially couple to X-ray helicity, establishing the presence of a hitherto-unobserved macroscopic chirality. The presence of this chiral magnetic configuration suggests a potential multiferroic coupling between the noncollinear magnetic arrangement and improper ferroelectric behavior as observed in prior studies on NdNiO$_3$ (101)$_\mathrm{ortho}$ films and RENiO$_3$ single crystals. Experimentally constrained theoretical double-cluster calculations confirm the presence of an energetically stable spin-disproportionated state with Zhang-Rice singlet-like combinations of Ni and ligand moments., Comment: 6 pages, 4 figures

The dynamics of domain walls in a square of permalloy (Ni$_{81}$Fe$_{19}$; Py) upon excitation with an oscillating magnetic field of 4 mT amplitude were recorded by pump-probe ptychography with X-ray magnetic circular dichroism (XMCD) at the Ni L$_3$-edge. The 2.5 $\mu$m Py square of 160 nm thickness forms a vortex flux-closure pattern with domain walls that fall into alternating out-of-plane magnetization states due to the interplay of in-plane shape and growth-induced perpendicular anisotropies. Dynamic modes of the domain wall structure were excitable along with the vortex core gyration with frequencies of 500 MHz and 1 GHz. Micromagnetic simulations served to corroborate the imaged domain wall motion.

We consider optical response in multi-band, multi-layer two-dimensional superconductors. Within a simple model, we show that linear response to AC gating can detect collective modes of the condensate, such as Leggett and clapping modes. We show how trigonal warping of the superconducting order parameter can help facilitate detection of clapping modes. Taking rhombohedral trilayer graphene as an example, we consider several possible pairing mechanisms and show that all-electronic mechanisms may produce in-gap clapping modes. These modes, if present, should be detectable in the absorption of microwaves applied via the gate electrodes, which are necessary to enable superconductivity in this and many other settings; their detection would constitute strong evidence for unconventional pairing. Last, we show that absorption at frequencies above the superconducting gap $2 |\Delta|$ also contains a wealth of information about the gap structure. Our results suggest that linear spectroscopy can be a powerful tool for the characterization of unconventional two-dimensional superconductors., Comment: Published version

Humans express ideas, beliefs, and statements through language. The manner of expression can carry information indicating the author's degree of confidence in their statement. Understanding the certainty level of a claim is crucial in areas such as medicine, finance, engineering, and many others where errors can lead to disastrous results. In this work, we apply a joint model that leverages words and part-of-speech tags to improve hedge detection in text and achieve a new top score on the CoNLL-2010 Wikipedia corpus.

In recent years, radicalization is being increasingly attempted on video-sharing platforms. Previous studies have been proposed to identify online radicalization using generic social context analysis, without taking into account comprehensive viewer traits and how those can affect viewers' perception of radicalizing content. To address the challenge, we examine QAnon, a conspiracy-based radicalizing group, and have designed a comprehensive questionnaire aiming to understand viewers' perceptions of QAnon videos. We outline the traits of viewers that QAnon videos are the most appealing to, and identify influential factors that impact viewers' perception of the videos.

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations., Comment: 34 pages, 2 figures, 4 tables, 49 pages of Supplemental material, 2 supplemental figures

When Congress reauthorized the Elementary and Secondary Schools Act in 2015, it intended to send a strong signal: any further encroachment of federal authority on the nation's K-12 schools needed to end. Compared to its more prescriptive predecessor in 2000, known as No Child Left Behind, the new law, dubbed "ESSA" for the Every Student Succeeds Act, established a set of goals states should strive to meet, only one of which is the subject of this analysis: Ensuring that all students have equal access to qualified and effective teachers. Before the law's signing in 2015, there was momentum around this issue with the federal government requiring states to submit "equity plans" and offering significant guidance to states on how to do so. This report examines the status of the ESSA provision six years after it was signed into law, analyzing how states responded to the law's requirement that they must collect and report the necessary data documenting the equitable distribution of their teacher talent among their schools.

Large high field superconducting magnets often requires high current superconducting cables. In order to develop these cables, a facility capable of providing high magnetic field with large sampling area as well as electrical current of tens of kA is essential. A superconducting transformer is an energy-efficient and low-cost way to provide large current to superconducting cables. Previously, we co-developed a superconducting transformer and successfully tested it to a maximum output current of 45 kA in zero magnetic field. In this work, this superconducting transformer is installed to the 12 T split solenoid magnet at the National High Magnetic Field Laboratory (NHMFL). We calibrated it by using this facility to measure critical current of a NbTi Rutherford cable as a function of magnetic field up to 10 T, and compare the results with those available in the literature. In addition, a strand extracted from the NbTi cable is tested for critical current. The critical current of the extracted strand is scaled and compared with critical current of the cable. The accuracy of the critical current measurement using this superconducting transformer is discussed in detail. This work concludes the commissioning of this superconducting transformer which combined with the 12 T split magnet will provide unique cable testing capability for future cable development for the NHMFL and its users., Comment: 11 pages, 9 figures

The High-Luminosity LHC Accelerator Upgrade Project (AUP) in the U.S. will construct quadrupole magnets to be delivered to CERN. An initial 3 tons, over 600 km total length of conductor was procured under the LHC Accelerator R&D Program (LARP) for this project. Programs for quality control(QC) at the supplier and quality verification (QV) at the laboratories were solidified into components of the overall quality plan for strand procurement under AUP. Measurements of the critical current (Ic) and residual resistance ratio (RRR), and related probes and techniques, are central to the quality plan. Described below is the verification testing that has taken place at the National High Magnetic Field Laboratory (NHMFL). Testing challenges are presented by the high sensitivity of these wires. In addition, new RRR test software was developed to accommodate challenges presented by meeting international standards with existing configurations of test strands., Comment: 4 pages, 7 figures

Advances on no-insulation REBCO coil technology has made understanding and controlling contact resistivity increasingly im-portant. Praffin (wax) impregnation is a process that has been used for improving mechanical stability of insulated and no-insulation REBCO coils. Wax impregnation is beneficial in both no-insulation coils and insulated coils with additional copper sta-bilizer or multiple conductors. In the latter scenario, contact re-sistance between conductor and additional stabilizer is also im-portant. It is crucial to understand the effects of wax impregna-tion on contact resistivity (Rct). We designed and built an appa-ratus to use short REBCO samples which simulates the behavior of Rct in a pancake coil during the wax impregnation process. Rct was measured at 77 K before and after the wax impregnation. In addition, a single pancake coil was wound to test the effect of wax impregnation. This coil simulates the NHMFL 32 T magnet Coil A in winding stresses. Rct was measured at 77 K and 4.2 K before and after wax impregnation. We found that wax impregnation does not significantly change contact resistivity. This means that wax impregnation can be used in coils without compromising the current sharing ability between turns. The experimental process and results are discussed., Comment: 4 pages, 4 figures

By the end of October 2022, the US HL-LHC Accelerator Upgrade Project (AUP) had completed fabrication of ten MQXFA magnets and tested eight of them. The MQXFA magnets are the low beta quadrupole magnets to be used in the Q1 and Q3 Inner Triplet elements of the High Luminosity LHC. This AUP effort is shared by BNL, Fermilab, and LBNL, with strand verification tests at NHMFL. An important step of the AUP QA plan is the testing of MQXFA magnets in a vertical cryostat at BNL. The acceptance criteria that could be tested at BNL were all met by the first four production magnets (MQXFA03-MQXFA06). Subsequently, two magnets (MQXFA07 and MQXFA08) did not meet some criteria and were disassembled. Lessons learned during the disassembly of MQXFA07 caused a revision to the assembly specifications that were used for MQXFA10 and subsequent magnets. In this paper, we present a summary of: 1) the fabrication and test data of all the MQXFA magnets; 2) the analysis of MQXFA07/A08 test results with characterization of the limiting mechanism; 3) the outcome of the investigation, including the lessons learned during MQXFA07 disassembly; and 4) the finite element analysis correlating observations with test performance.

Experiments have observed superconductivity in atomically-thin metallic layers deposited on semiconducting substrates. As in any superconductor, it is important to determine the structure of the superconducting pairing function in order to reveal the mechanism responsible for superconductivity. To that end, we study the possible superconducting states of two-dimensional triangular lattices. We calculate the quasiparticle interference (QPI) patterns which would result from various nearest-neighbor pairing order parameters, and show how the QPI can be used to distinguish between those order parameters. The QPI patterns are the momentum-space representations of real-space local density-of-states fluctuations: the QPI signal at momentum $q$ reveals the strength of scattering processes at that momentum transfer. We show how characteristic differences between scattering from charge disorder (i.e. impurities) and from order-parameter disorder (i.e. vortices) can be used to identify the angular momentum of the superconducting pairs., Comment: 12 pages, 8 figures

Privacy concerns have attracted increasing attention in data-driven products due to the tendency of machine learning models to memorize sensitive training data. Generating synthetic versions of such data with a formal privacy guarantee, such as differential privacy (DP), provides a promising path to mitigating these privacy concerns, but previous approaches in this direction have typically failed to produce synthetic data of high quality. In this work, we show that a simple and practical recipe in the text domain is effective: simply fine-tuning a pretrained generative language model with DP enables the model to generate useful synthetic text with strong privacy protection. Through extensive empirical analyses on both benchmark and private customer data, we demonstrate that our method produces synthetic text that is competitive in terms of utility with its non-private counterpart, meanwhile providing strong protection against potential privacy leakages., Comment: ACL 2023 Main Conference (Honorable Mention)

Lensless imaging methods that account for partial coherence have become very common in the past decade. However, there are no metrics in use for comparing partially coherent light fields, despite the widespread use of such metrics to compare fully coherent objects and wavefields. Here, we show how reformulating the mean squared error and Fourier ring correlation in terms of quantum state fidelity naturally generalizes them to partially coherent wavefields. These results fill an important gap in the lensless imaging literature and will enable quantitative assessments of the reliability and resolution of reconstructed partially coherent wavefields., Comment: 4 pages, 1 figure

Percolation refers to an interesting class of problems related to the properties of disordered systems, usually formulated in terms of objects randomly placed on an underlying lattice or continuum. Despite the simplicity of the setup, most percolative systems undergo a phase transition from a disconnected state with many disjoint clusters to a state where a finite fraction of the lattice sites are connected to a single cluster. As in the case of thermodynamic phase transitions, power law dependencies generically near the critical percolation threshold. The origin of these dependencies can be understood through the lens of scaling and renormalization, and indeed many quantitative results can be acquired using these tools. In this paper we study the percolation problem on a hierarchical lattice, where exact results for the critical exponents can be obtained from a decimation procedure. We calculate analytic results for the full set of geometric critical exponents and confirm their consistency with simulation. Finally, we set up an interesting renormalization group for the conductivity of the system and use it to computationally extract the conductivity exponent t., Comment: 5 pages, 4 figures. Originally prepared for 8.334, statistical physics 2 at MIT