Spatially-resolved Energetic Electron Properties for the 21 May 2004 Flare from Radio Observations and 3D Simulations

We investigate in detail the 21 May 2004 flare using simultaneous observations of the Nobeyama Radioheliograph, Nobeyama Radiopolarimeters, Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and Solar and Heliospheric Observatory (SOHO). The flare images in different spectral ranges reveal the presence of a well-defined single flaring loop in this event. We have simulated the gyrosynchrotron microwave emission using the recently developed interactive IDL tool GX Simulator. By comparing the simulation results with the observations, we have deduced the spatial and spectral properties of the non-thermal electron distribution. The microwave emission has been found to be produced by the high-energy electrons ($>100$ keV) with a relatively hard spectrum ($\delta\simeq 2$); the electrons were strongly concentrated near the loop top. At the same time, the number of high-energy electrons near the footpoints was too low to be detected in the RHESSI images and spatially unresolved data. The SOHO Extreme-ultraviolet Imaging Telescope images and the low-frequency microwave spectra suggest the presence of an extended "envelope" of the loop with lower magnetic field. Most likely, the energetic electron distribution in the considered flare reflects the localized (near the loop top) particle acceleration (injection) process accompanied by trapping and scattering.Comment: Accepted for publication in Solar Physic

3D Radio and X-Ray Modeling and Data Analysis Software: Revealing Flare Complexity

We have undertaken a major enhancement of our IDL-based simulation tools developed earlier for modeling microwave and X-ray emission. The object-based architecture provides an interactive graphical user interface that allows the user to import photospheric magnetic field maps and perform magnetic field extrapolations to almost instantly generate 3D magnetic field models, to investigate the magnetic topology of these models by interactively creating magnetic field lines and associated magnetic flux tubes, to populate the flux tubes with user-defined nonuniform thermal plasma and anisotropic, nonuniform, nonthermal electron distributions; to investigate the spatial and spectral properties of radio and X-ray emission calculated from the model, and to compare the model-derived images and spectra with observational data. The application integrates shared-object libraries containing fast gyrosynchrotron emission codes developed in FORTRAN and C++, soft and hard X-ray codes developed in IDL, a FORTRAN-based potential-field extrapolation routine and an IDL-based linear force free field extrapolation routine. The interactive interface allows users to add any user-defined radiation code that adheres to our interface standards, as well as user-defined magnetic field extrapolation routines. Here we use this tool to analyze a simple single-loop flare and use the model to constrain the 3D structure of the magnetic flaring loop and 3D spatial distribution of the fast electrons inside this loop. We iteratively compute multi-frequency microwave and multi-energy X-ray images from realistic magnetic fluxtubes obtained from an extrapolation of a magnetogram taken prior to the flare, and compare them with imaging data obtained by SDO, NoRH, and RHESSI instruments. We use this event to illustrate use of the tool for general interpretation of solar flares to address disparate problems in solar physics.Comment: 12 pages, 11 figures, ApJ accepte

Radio echo in the turbulent corona and simulations of solar drift-pair radio bursts

Drift-pair bursts are an unusual type of solar low-frequency radio emission, which appear in the dynamic spectra as two parallel drifting bright stripes separated in time. Recent imaging spectroscopy observations allowed for the quantitative characterization of the drifting pairs in terms of source size, position, and evolution. Here, the drift-pair parameters are qualitatively analyzed and compared with the newly developed Monte Carlo ray-tracing technique simulating radio-wave propagation in the inhomogeneous anisotropic turbulent solar corona. The results suggest that drift-pair bursts can be formed due to a combination of refraction and scattering processes, with the trailing component being the result of turbulent reflection (turbulent radio echo). The formation of drift-pair bursts requires an anisotropic scattering with the level of plasma density fluctuations comparable to that in type III bursts, but with a stronger anisotropy at the inner turbulence scale. The anisotropic radio-wave scattering model can quantitatively reproduce the key properties of drift-pair bursts: the apparent source size and its increase with time at a given frequency, the parallel motion of the source centroid positions, and the delay between the burst components. The trailing component is found to be virtually cospatial and following the main component. The simulations suggest that drift-pair bursts are likely to be observed closer to the disk center and below 100 MHz due to the effects of free–free absorption and scattering. The exciter of drift pairs is consistent with propagating packets of whistlers, allowing for a fascinating way to diagnose the plasma turbulence and the radio emission mechanism

WAYS OF DEVELOPMENT OF THE POTENTIAL OF STATE IN THE MARINE ECONOMIC COMPLEX: ECOLOGICAL AND ECONOMIC ASPECTS

At present, issues of assessing the impact of economic activity on the environment as an integral part of the country’s economic development are becoming more and more relevant. Environmental problems of the development of a marine economy complex may restrain the development of the economic potential of the state. Moreover, the dynamic development of the state’s economy is possible only when economic entities adhere to the norms of an ecological nature. In this regard, the problem of assessing the impact on the environment, in particular, in the maritime complex in the projection of the economic component of development, as well as in this sense and the rational use of natural resources, is of paramount importance. The environmental tension is most often due to the placement of powerful chemical and petrochemical industries in the area of the maritime complex. In some areas, the level of environmental pollution is quite high due to the location of large facilities in the electric power industry (thermal and nuclear power plants). The economic component of the environmental impact assessment of the maritime complex is that one and the same natural resource is most often used by the economic entities of several countries. Therefore, the assessment of the impact on the environment and the achievement of a balanced distribution of ecological and economic benefits for the rational use of natural resources, especially in the maritime complex, are today of great relevance. The purpose of the article is to analyse the problems of ecological and economic orientation in the maritime complex and, on the basis of generalization of such problems, to provide recommendations on systematization of measures for the comprehensive rational development of economic relations, taking into account the features of the coastal zone and the marine economic complex. Methodology. Analytical market reviews, materials of periodicals, resources of the Internet are the informational and methodological basis of the investigation. To achieve the goal set, the following general scientific and special methods were used: economic and mathematical methods, structural-logical analysis, analogy, synthesis, comparison and integration, factor analysis. Result. The system of measures of an economic and legal nature, which should be taken into account for successful and rational use of the marine economic complex in economic activity, is substantiated. Problematic aspects and directions of their elimination are determined. The proposed model of the ecological and economic system of the maritime complex acquires a special significance in the context of the supranational task of developing measures for optimizing and rational use of natural resources on a global scale. The directions of the reform of the legal framework are considered. Practical value. The system of measures of economic and legal character and their individual types can be applied for optimization and rational use of marine (water) resources, taking into account the peculiarities of economic development and the state of the marine-economic complex in Ukraine and in other states. Value/originality. Most scientific works are devoted to the consideration of theoretical aspects of ecologicaleconomic systems, namely, the refinement of the essence of this instrument as a form of modern financial and economic dynamics. A part of the work is devoted to the consideration of the common features and national peculiarities of ecological and economic systems in individual countries and regions. The authors consider the issues of elaboration of measures for the optimization of economic activity, which combines the abovementioned aspects with the peculiarities of the formation of ecological-economic systems in the marine faring complex. It is also important to take into account the impact of planned legislative reforms on the development of economic activity in the marine faring complex of Ukraine. The account of the peculiarities of the maritime complex in the framework of the national economy allowed developing directions for its further development

Dielectric barrier discharge KrCl - and XeCl-excilamps radiation power control by pressure jump method

The energy dissipation processes in dielectric barrier discharge KrCl- and XeCl-excilamps at various voltage, frequencies and pulse duration are revealed by a pressure jump method. It is offered and tested a way of radiation power calculation in conditions of non-uniform filling of device bulb by discharge plasma. The previous data (Pikulev A.A., Sosnin E.A., 2010-2013) are confirmed. The regularity was formulated: conditions of maximal ultraviolet radiation power corresponds to conditions of maximal heat release in plasma. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Corona with Streamers in Atmospheric Pressure Air in a Highly Inhomogeneous Electric Field

The paper presents research data on positive and negative coronas in atmospheric pressure air in a highly inhomogeneous electric field. The data show that irrespective of the polarity of pointed electrodes placed in a high electric field (200 kV/cm), this type of discharge develops via ball streamers even if the gap voltage rises slowly (0.2 kV/ms). The start voltage of first positive streamers, compared to negative ones, is higher and the amplitude and the frequency of their current pulses are much lower: about two times and more than two orders of magnitude, respectively. The higher frequency of current pulses from negative streamers provides higher average currents and larger luminous areas of negative coronas compared to positive ones. Positive and negative cylindrical streamers from a pointed to a plane electrode are detected and successive discharge transitions at both polarities are identified

Intrinsic Dimension Estimation for Robust Detection of AI-Generated Texts

Rapidly increasing quality of AI-generated content makes it difficult to distinguish between human and AI-generated texts, which may lead to undesirable consequences for society. Therefore, it becomes increasingly important to study the properties of human texts that are invariant over text domains and various proficiency of human writers, can be easily calculated for any language, and can robustly separate natural and AI-generated texts regardless of the generation model and sampling method. In this work, we propose such an invariant of human texts, namely the intrinsic dimensionality of the manifold underlying the set of embeddings of a given text sample. We show that the average intrinsic dimensionality of fluent texts in natural language is hovering around the value $9$ for several alphabet-based languages and around $7$ for Chinese, while the average intrinsic dimensionality of AI-generated texts for each language is $\approx 1.5$ lower, with a clear statistical separation between human-generated and AI-generated distributions. This property allows us to build a score-based artificial text detector. The proposed detector's accuracy is stable over text domains, generator models, and human writer proficiency levels, outperforming SOTA detectors in model-agnostic and cross-domain scenarios by a significant margin

Topological Data Analysis for Speech Processing

We apply topological data analysis (TDA) to speech classification problems and to the introspection of a pretrained speech model, HuBERT. To this end, we introduce a number of topological and algebraic features derived from Transformer attention maps and embeddings. We show that a simple linear classifier built on top of such features outperforms a fine-tuned classification head. In particular, we achieve an improvement of about $9\%$ accuracy and $5\%$ ERR on four common datasets; on CREMA-D, the proposed feature set reaches a new state of the art performance with accuracy $80.155$. We also show that topological features are able to reveal functional roles of speech Transformer heads; e.g., we find the heads capable to distinguish between pairs of sample sources (natural/synthetic) or voices without any downstream fine-tuning. Our results demonstrate that TDA is a promising new approach for speech analysis, especially for tasks that require structural prediction. Appendices, an introduction to TDA, and other additional materials are available here - https://topohubert.github.io/speech-topology-webpages/Comment: Accepted to INTERSPEECH 2023 conferenc

Estimação de número de pessoas em vídeos

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2017.Devido ao aumento populacional e à grande disponibilidade de câmeras, existe uma demanda para saber quantas pessoas transitam em certas áreas, seja por questões comerciais ou mesmo por questões de segurança, aumentando o interesse na área da Estimação do Número de Pessoas. A contagem de pessoas, vinda da análise de imagens de vídeo, têm várias aplicações, principalmente para sistemas de vigilância e segurança. Neste trabalho, um método de Estimação de Número de Pessoas é discutido e implementado, utilizando duas técnicas combinadas. A primeira é o Fluxo Óptico de Lukas-Kanade, que é utilizada para estimar o movimento entre os frames do vídeo. Após uma filtragem espacial (ou blocagem) e uma filtragem temporal, há uma inferência de onde os objetos estão localizados. Posteriormente, a técnica de Agrupamento Hierárquico é empregada para agrupar tais objetos em clusters. Por fim, o número de pessoas é mapeado pelo número de clusters distintos. Além disso, uma filtragem de vetores similares foi proposta antes do Agrupamento Hierárquico, gerando dois resultados para cada vídeo testado: um Resultado sem a filtragem e um Resultado com a Filtragem. Foram testados 5 vídeos, com número de pessoas variando de 0 a 5. A acurácia variou de 69,0% a 98,2%.Estimating the number of people based on video imagery has attracted attention due to population growth and high availability of cameras. People counting has several applications for commercial and security reasons. In this work, a method for estimating the number of people in a video sequence is discussed and implemented using two combined techniques. The first technique is the Lukas-Kanade Optical Flow method, which is used to estimate the motion between the frames of the video. After this, a spatial filtering (or blocking) and a temporal filtering are employed to infer where the objects are located. Subsequently, the Hierarchical Clustering technique is used to group such objects into clusters, and the number of people is mapped by the number of different clusters. In addition, a similar vector filtering is proposed before the Hierarchical Clustering, generating two results for each video: a Result without filtering and a Result with Filtering. Five videos were tested, with the number of people ranging from 0 to 5. Results show an accuracy ranging from 69,0% to 98,2%