Fine structures of solar radio type III bursts and their possible relationship with coronal density turbulence

Solar radio type III bursts are believed to be the most sensitive signatures of near-relativistic electron beam propagation in the corona. A solar radio type IIIb-III pair burst with fine frequency structures, observed by the Low Frequency Array (LOFAR) with high temporal (~10 ms) and spectral (12.5 kHz) resolutions at 30–80 MHz, is presented. The observations show that the type III burst consists of many striae, which have a frequency scale of about 0.1 MHz in both the fundamental (plasma) and the harmonic (double plasma) emission. We investigate the effects of background density fluctuations based on the observation of striae structure to estimate the density perturbation in the solar corona. It is found that the spectral index of the density fluctuation spectrum is about −1.7, and the characteristic spatial scale of the density perturbation is around 700 km. This spectral index is very close to a Kolmogorov turbulence spectral index of −5/3, consistent with a turbulent cascade. This fact indicates that the coronal turbulence may play the important role of modulating the time structures of solar radio type III bursts, and the fine structure of radio type III bursts could provide a useful and unique tool to diagnose the turbulence in the solar corona

Geometry of the set of quantum correlations

It is well known that correlations predicted by quantum mechanics cannot be explained by any classical (local-realistic) theory. The relative strength of quantum and classical correlations is usually studied in the context of Bell inequalities, but this tells us little about the geometry of the quantum set of correlations. In other words, we do not have good intuition about what the quantum set actually looks like. In this paper we study the geometry of the quantum set using standard tools from convex geometry. We find explicit examples of rather counter-intuitive features in the simplest non-trivial Bell scenario (two parties, two inputs and two outputs) and illustrate them using 2-dimensional slice plots. We also show that even more complex features appear in Bell scenarios with more inputs or more parties. Finally, we discuss the limitations that the geometry of the quantum set imposes on the task of self-testing.Comment: 11 + 8 pages, 6 figures, v2: added an argument relating self-testing and extremality, v3: typos corrected, results unchanged, published versio

Toward Agile Situated Visualization: An Exploratory User Study

We introduce AVAR, a prototypical implementation of an agile situated visualization (SV) toolkit targeting liveness, integration, and expressiveness. We report on results of an exploratory study with AVAR and seven expert users. In it, participants wore a Microsoft HoloLens device and used a Bluetooth keyboard to program a visualization script for a given dataset. To support our analysis, we (i) video recorded sessions, (ii) tracked users' interactions, and (iii) collected data of participants' impressions. Our prototype confirms that agile SV is feasible. That is, liveness boosted participants' engagement when programming an SV, and so, the sessions were highly interactive and participants were willing to spend much time using our toolkit (i.e., median >= 1.5 hours). Participants used our integrated toolkit to deal with data transformations, visual mappings, and view transformations without leaving the immersive environment. Finally, participants benefited from our expressive toolkit and employed multiple of the available features when programming an SV.Comment: CHI '20 Extended Abstract

Defining a New NLP Playground

The recent explosion of performance of large language models (LLMs) has changed the field of Natural Language Processing (NLP) more abruptly and seismically than any other shift in the field's 80-year history. This has resulted in concerns that the field will become homogenized and resource-intensive. The new status quo has put many academic researchers, especially PhD students, at a disadvantage. This paper aims to define a new NLP playground by proposing 20+ PhD-dissertation-worthy research directions, covering theoretical analysis, new and challenging problems, learning paradigms, and interdisciplinary applications.Comment: EMNLP Findings 2023 "Theme Track: Large Language Models and the Future of NLP

The Value of MSCT Signs in Differential Diagnosis of Pathological Types of Acute Appendicitis

Objective: To investigate the value of multi-slice spiral CT (MSCT) signs in differential diagnosis of pathological types of acute appendicitis. Methods: 78 patients with acute appendicitis confirmed through surgery and pathology in our hospital from October 2018 to September 2019 were retropectively analyzed. All patients underwent multi-slice spiral CT examination before operation while some patients with unclear appendicitis were performed curved surface reconstruction (CPR), then we analyzed the differences of MSCT signs in different types of appendicitis. Results: Among the 78 patients, 28 were simple appendicitis, 33 were suppurative appendicitis and 17 were gangrenous appendicitis. In the variance analysis, the difference between the appendiceal lumen diameter and the peripheral fat density in the three pathological types of appendicitis was statistically significant. In Spearman's rank correlation analysis, the P values of periappendiceal exudation, appendiceal bezoar, extraluminal effusion, mesangial thickening and intraluminal effusion were all less than 0.05, but their Rs values were different. Among them, periappendiceal exudation and mesangial thickening showed strong correlation with appendiceal typing. Conclusion: MSCT showed that signs including appendiceal lumen diameter, peripheral fat density, mesangial thickening and periappendiceal exudation held quite strong clinical guiding significance in the differential diagnosis of pathological types of acute appendicitis