Description Of Space Research Articles

Robust interpolation for dispersed gas‐droplet flows using statistical learning with the fully Lagrangian approach

SummaryA novel methodology is presented for reconstructing the Eulerian number density field of dispersed gas‐droplet flows modelled using the fully Lagrangian approach (FLA). In this work, the nonparametric framework of kernel regression is used to accumulate the FLA number density contributions of individual droplets in accordance with the spatial structure of the dispersed phase. The high variation which is observed in the droplet number density field for unsteady flows is accounted for by using the Eulerian‐Lagrangian transformation tensor, which is central to the FLA, to specify the size and shape of the kernel associated with each droplet. This procedure enables a high level of structural detail to be retained, and it is demonstrated that far fewer droplets have to be tracked in order to reconstruct a faithful Eulerian representation of the dispersed phase. Furthermore, the kernel regression procedure is easily extended to higher dimensions, and inclusion of the droplet radius within the phase space description using the generalised fully Lagrangian approach (gFLA) additionally enables statistics of the droplet size distribution to be determined for polydisperse flows. The developed methodology is applied to a range of one‐dimensional and two‐dimensional steady‐state and transient flows, for both monodisperse and polydisperse droplets, and it is shown that kernel regression performs well across this variety of cases. A comparison is made against conventional direct trajectory methods to determine the saving in computational expense which can be gained, and it is found that times fewer droplet realisations are needed to reconstruct a qualitatively similar representation of the number density field.

Розроблення програмного забезпечення для сегментації даних по фото та відео інформації

The object of this research is the process of perception of individual objects in photos and videos for further analysis of the situation in the city. The subject of the research is image processing for selection, classification, and further use of the obtained information about the objects in the photo. The goal is to create information technology for the segmentation of individual segments in photos and videos obtained with the help of unmanned aerial vehicles (in particular, drones) in urban scenes. Main tasks: analysis of existing methods of data segmentation; implementation of an algorithm that would perform segmentation of data by various terrain objects; software testing; and formation of research results. The following results were obtained: existing models of image segmentation were examined for limitations and shortcomings. On the basis of identified shortcomings, the requirements for the developed system were formed. During the analysis of the subject area, the main problems were identified and described and the task to be automated was determined. During the design of algorithms for solving problems, the sequence of the execution of each process was determined. The design of the software included a description of the information space of the system and the user interface. The user interface was chosen after analyzing the main types of user interfaces. To assess the quality of the data processing, existing metrics were used – IoU, pixel accuracy, and the discrepancy matrix. During testing, errors that occur during data segmentation and their causes were determined, after their elimination, the correct result of image segmentation was shown. Conclusions. The scientific novelty of the obtained results is that although there is still no segmentation method that fully satisfies all needs for the analysis of the category of images obtained by drones, the developed software allows uploading images and templates to them as benchmarks for artificial intelligence. perform segmentation and verify the correctness of this segmentation visually and using the IoU metric, the mismatch matrix. The software can be improved by automating the process of creating a reference pattern, training the model on more data, and integrating the created software into a larger system that would work directly with the drone.

ГИДРОНИМЫ АДЫГЕИ КАК ИСТОЧНИК ЭТНОКУЛЬТУРНОЙ ИНФОРМАЦИИ

The article is devoted to the study of a group of regional hydronyms that have lost their connection with the appellative. It is established that the study of the etymology, semantics of a hydronym, the definition of its original appearance is impossible without the involvement of ethnocultural material, which confirms the need to use an integrated approach to the study of toponyms, since such an approach makes it possible to correctly describe units and allows for the «reconstruction» of the regional toponymic space, toponymic field. Purpose: The description of the toponymic space of the region (the Republic of Adygea) and hydronyms in particular involves a detailed analysis of all units, allowing to reflect the entire toponymic picture. In the toponymy of the region, there are names that have lost their connection with appellatives. The establishment of etymology, semantics and the initial appearance of such units is impossible without the involvement of ethno-cultural material. Such an approach provides an opportunity that makes it possible to carry out a correct description of units and allows for the «reconstruction» of the regional toponymic space. Methods: The basis for the correct description of the etymology and semantics of names of specific geographical objects is the conservatism of toponymic models characteristic of the language. The research was conducted using phonetic, word-formation, etymological, semantic analysis. The basis for solving ethnolinguistic problems was the combination of onomasiological and semasiological aspects of research. Results: To establish the etymology of a toponym, it is necessary to take into account the principles of nomination characteristic of the self-consciousness and worldview of the people inhabiting a certain territory, reflected in culture and language, as well as the place of a specific name in the systemic organization of the regional toponymic field. Ethnocultural information captured in toponymy is what helps a linguist researcher to determine the principles of nomination characteristic of a particular language reflecting the worldview of the people. Discussion: The description of the toponymic space of the region (not only the Republic of Adygea), taking into account the system relations and the field approach, the identification of the main nomination techniques, clarification of the etymology, semantics of individual geographical objects traditionally associated with the regional landscape and being components of the regional onomastic field, seems very relevant and promising. The detailed analysis of hydronyms allows reconstructing the entire toponymic space of the region, makes it possible to consider the entire system as a whole.

On the convex hull of convex quadratic optimization problems with indicators

We consider the convex quadratic optimization problem in Rn\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb {R}^{n}$$\\end{document} with indicator variables and arbitrary constraints on the indicators. We show that a convex hull description of the associated mixed-integer set in an extended space with a quadratic number of additional variables consists of an (n+1)×(n+1)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(n+1) \ imes (n+1)$$\\end{document} positive semidefinite constraint (explicitly stated) and linear constraints. In particular, convexification of this class of problems reduces to describing a polyhedral set in an extended formulation. While the vertex representation of this polyhedral set is exponential and an explicit linear inequality description may not be readily available in general, we derive a compact mixed-integer linear formulation whose solutions coincide with the vertices of the polyhedral set. We also give descriptions in the original space of variables: we provide a description based on an infinite number of conic-quadratic inequalities, which are “finitely generated.” In particular, it is possible to characterize whether a given inequality is necessary to describe the convex hull. The new theory presented here unifies several previously established results, and paves the way toward utilizing polyhedral methods to analyze the convex hull of mixed-integer nonlinear sets.

The reservoir rock volumetric concentration and tortuosity description of pore space of Xa field, Niger Delta Basin

The assessment of rock reservoir volume concentration is necessary as it accounts for the appreciable pore spaces available for hydrocarbon and other targets. Raw well d-ata from oil wells A, B and C in some parts of the Niger Delta Basin (XA Field) were used for porosity estimates in sandstone and shale formations. Using the Microsoft Excel for analysis, gamma ray log, density log with respect to depth were generated. The results of these curves were used to estimate porosity and create models for porosity-formation factor with respect to density effect. The major findings revealed the average porosity values as about 20% for well A, 17% for well B and 19% for well C. The results show that increase in density gives rise to a decrease in porosity in both lithologies. In order to establish a relationship between porosity of this Field rock reservoir, a plot of porosity with formation factor due to density influence was necessary. These curves lead to several equations with the average for linear curves as FD= —400øXA+98.8 and FD = (–2øXA+4.9) .×10–3for fractional and percentage porosities respectively. These models show that both parameters are strongly related with coefficients of 0.9723 (for both plots from well A), 0.8274 (for both plots from well B) and 0.9689 (for both plots from well C) for XA Field. These results correspond to the non-linear relation, øXA = 0.8006 FD–0.465 0.9689as the original values of the cementation exponent and the tortuosity factor are obtained, if the formation factor is considered as the subject.

Symplectic Density Matrix

The quasi amplitude of probability, a concept associated with the Wigner function, is used to introduce the notion of symplectic density matrix, $$\rho$$ . The Liouville-Von Neumann equation is derived in phase space by using symmetry. The physical content of $$\rho$$ is analyzed in detail, in particular with the study of the classical limit. The first application addresses the problem of quark-antiquark interaction, described by the so-called Cornell potential. The matrix $$\rho$$ is calculated, providing a phase space description of the quark-antiquark state. For the model considered here, the quark confinement is derived, such that the distance of confinement is about 4 GeV $$^{-1}$$ . This result improves theoretical calculations in the literature, approaching to the order of experimental results. Another application is the calculation of $$\rho$$ considering mixed state systems. Since $$\rho$$ is a density of probability, the entropy is defined without ambiguity, and as such the Gibbs ensemble is introduced for a quantum system in the phase space representation. Then a harmonic oscillator system at finite temperature is studied. The second mixed state system is a maximally entangled bipartite state. In these applications, when it is possible, the nature of $$\rho$$ is compared with the Wigner function.

A comprehensive assessment of image processing variability in pore structural investigations: Conventional thresholding vs. machine learning approaches

Broad ion beam - scanning electron microscopy (BIB-SEM) is an important technology for quantitative description of pore space and detailed investigation of pore structure in mudstones and shales. To obtain quantitative data from BIB-SEM images, image processing is required. However, the effect of different image processing approaches on the segmentation results has not been well documented yet. Particularly the interpretation of pore boundaries approaching the maximum image resolution can represent a major challenge. This study addresses the variability in image processing by comparing conventional thresholding with advanced machine learning methods and analysing the sensitivity of results to different segmentation. The test dataset consists of large area BIB-SEM maps of 12 Middle Miocene mudstone samples from the Vienna Basin, Austria. Segmentation of pore space and organic matter was performed using the thresholding method in ImageJ and the machine learning-based pixel classification in ilastik. The results show that the selected greyscale thresholding algorithm in ImageJ significantly affected the resolved porosity (1.7% to 2.8% variation) relative to the average total porosity of 4.5%. Compared to ImageJ, ilastik provides comparable results with better efficiency in separating pores from organic matter. However, the obtained pore information is inevitably influenced by variations in boundary delineation and feature identification due to inherent differences in the image processing methods and varying representativeness of image maps themselves. Overall, the study findings highlight the importance of carefully selecting image processing methods and considering their potential impact on the accuracy and reliability of pore characterization in mudstones and shales.

Bundle theoretic descriptions of massless single-particle state spaces; how do we perceive a moving quantum particle

Recently, a bundle theoretic description of massive single-particle state spaces, which is better suited for Relativistic Quantum Information Theory than the ordinary Hilbert space description, has been suggested. However, the mathematical framework presented in that work does not apply to massless particles. It is because, unlike massive particles, massless particles cannot assume the zero momentum state and hence the mass shell associated with massless particles has non-trivial cohomology. To overcome this difficulty, this paper suggests a new framework that can be applied to massless particles. Applications to the cases of massless particles with spin-1 and 2, namely photon and graviton, will reveal that the field equations, the gauge conditions, and the gauge freedoms of Electromagnetism and General Relativity naturally arise as manifestations of an inertial observer’s perception of the internal quantum states of a photon and a graviton, respectively. Finally, we show that gauge freedom is exhibited by all massless particles, except those with spin-0 and 1/2.

Experimental Study on EOR in Shale Oil Cores during Associated Gasflooding: A Case Study from Yanchang Formation, Ordos Basin

Summary A significant amount of associated gas has been produced from shale oil reservoirs in the Ordos Basin, northern China, in recent years, which has provided an opportunity for using low-cost, associated gas in enhanced oil recovery (EOR) projects. However, there are few other reports of EOR projects in shale oil reservoirs using associated gas, and a quantitative evaluation of the technique is needed. Therefore, we conducted associated gas and waterflooding experiments in shale oil samples at constant and gradually increasing injection pressure while monitoring the spatial distribution of movable and residual oil by means of nuclear magnetic resonance (NMR) technology. Before the injection experiments, we performed mercury intrusion tests and measured the NMR transverse relaxation time, T2, of fully saturated samples to characterize the pore-throat size distribution of rock samples. Furthermore, we established a novel and robust mathematical model based on a fractal description of the pore space and a capillary tube model to determine the lower limit of the pore radius of movable oil, rc, during gas- and waterflooding. We observed that the oil recovery factor at a low injection pressure (i.e., 0.6 MPa) during the associated gasflooding was lower than that during waterflooding under both constant pressure injection mode and gradually increasing pressure injection mode. However, the performance of associated gasflooding was greatly improved by increasing the injection pressure. High injection pressure indeed produced a higher oil recovery factor, thinner residual oil film thickness, and smaller rc during associated gasflooding than during waterflooding under both injection modes. These differences in behavior appear to be linked to dissimilarities in flooding mechanisms at high and low injection pressures. Our main conclusion is that associated gasflooding at high injection pressure (i.e., 6 MPa) has a better potential for enhancing the oil recovery factor than waterflooding in shale oil reservoirs.

Hamiltonian facets of classical gauge theories on E-manifolds

Manifolds with boundary, with corners, b-manifolds and foliations model configuration spaces for particles moving under constraints and can be described as E-manifolds. E-manifolds were introduced in Nest and Tsygan (2001 Asian J. Math. 5 599–635) and investigated in depth in Miranda and Scott (2021 Rev. Mat. Iberoam. 37 1207–24). In this article we explore their physical facets by extending gauge theories to the E-category. Singularities in the configuration space of a classical particle can be described in several new scenarios unveiling their Hamiltonian aspects on an E-symplectic manifold. Following the scheme inaugurated in Weinstein (1978 Lett. Math. Phys. 2 417–20), we show the existence of a universal model for a particle interacting with an E-gauge field. In addition, we generalise the description of phase spaces in Yang–Mills theory as Poisson manifolds and their minimal coupling procedure, as shown in Montgomery (1986 PhD Thesis University of California, Berkeley), for base manifolds endowed with an E-structure. In particular, the reduction at coadjoint orbits and the shifting trick are extended to this framework. We show that Wong’s equations, which describe the interaction of a particle with a Yang–Mills field, become Hamiltonian in the E-setting. We formulate the electromagnetic gauge in a Minkowski space relating it to the proper time foliation and we see that our main theorem describes the minimal coupling in physical models such as the compactified black hole.

Symmetric configuration spaces of linkages

A configuration of a linkage $$\Gamma $$ is a possible positioning of $$\Gamma $$ in $${{\mathbb {R}}}^{d}$$ , and the collection of all such forms the configuration space $${\mathcal {C}}(\Gamma )$$ of $$\Gamma $$ . We here introduce the notion of the symmetric configuration space of a linkage, in which we identify configurations which are geometrically indistinguishable. We show that the symmetric configuration space of a planar polygon has a regular cell structure, provide some principles for calculating this structure, and give a complete description of the symmetric configuration space of all quadrilaterals and of the equilateral pentagon.

Clifford odd and even objects offer description of internal space of fermions and bosons, respectively, opening new insight into the second quantization of fields

In a long series of works the author has demonstrated that the model named the spin-charge-family theory offers the explanation for all in the standard model assumed properties of the fermion and boson fields, as well as for many of their so far observed properties if the space-time is ≥ (13 + 1) while fermions interact with gravity only. In this talk, I briefly report on the so far achievements of the theory. The main contribution demonstrates the offer of the Clifford odd and even objects for the description of the internal spaces of fermion (Clifford odd) and boson (Clifford even) fields, which is opening up a new understanding of the second quantization postulates for the fermion and boson fields: The “basis vectors” determined by the Clifford odd objects demonstrate all the properties of the internal space of fermions and transfer their anti-commutativity to their creation and annihilation operators, while the “basis vectors” determined by the Clifford even objects demonstrate all the properties of the internal space of boson fields and transfer their commutativity to their creation and annihilation operators. The toy model with d = (5 + 1) illustrates the statements.

Phase-Space Geometry and Optimal State Preparation in Quantum Metrology with Collective Spins

We revisit well-known protocols in quantum metrology using collective spins and propose a unifying picture for optimal state preparation based on a semiclassical description in phase space. We show how this framework allows for quantitative predictions of the timescales required to prepare various metrologically useful states, and that these predictions remain accurate even for moderate system sizes, surprisingly far from the classical limit. Furthermore, this framework allows us to build a geometric picture that relates optimal (exponentially fast) entangled probe preparation to the existence of separatrices connecting saddle points in phase space. We illustrate our results with the paradigmatic examples of the two-axis countertwisting and twisting-and-turning Hamiltonians, where we provide analytical expressions for all the relevant optimal timescales. Finally, we propose a generalization of these models to include p-body collective interaction (or p-order twisting), beyond the usual case of p=2. Using our geometric framework, we prove a no-go theorem for the local optimality of these models for p>2.Received 8 November 2022Revised 1 February 2023Accepted 28 March 2023DOI:https://doi.org/10.1103/PRXQuantum.4.020314Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum metrologyQuantum sensingTechniquesPhase space dynamicsQuantum InformationNonlinear DynamicsAtomic, Molecular & Optical

On the origin of force sensitivity in tests of quantum gravity with delocalised mechanical systems

The detection of the quantum nature of gravity in the low-energy limit hinges on achieving an unprecedented degree of force sensitivity with mechanical systems. Against this background we explore the relationship between the sensitivity of mechanical systems to external forces and properties of the quantum states they are prepared in. We establish that the main determinant of the force sensitivity in pure quantum states is their spatial delocalisation and we link the force sensitivity to the rate at which two mechanical systems become entangled under a quantum force. We exemplify this at the hand of two commonly considered configurations. One that involves gravitationally interacting objects prepared in non-Gaussian states such as Schrödinger-cat states, where the generation of entanglement is typically ascribed to the accumulation of a dynamical phase between components in superposition experiencing varying gravitational potentials. The other prepares particles in Gaussian states that are strongly squeezed in momentum and delocalised in position where entanglement generation is attributed to accelerations. We offer a unified description of these two arrangements using the phase-space representation of the interacting particles, and link their entangling rate to their force sensitivity, showing that both configurations get entangled at the same rate provided that they are equally delocalised in space. Our description in phase space and the established relation between force sensitivity and entanglement sheds light on the intricacies of why the equivalence between these two configurations holds, something that is not always evident in the literature, due to the distinct physical and analytical methods employed to study each of them. Notably, our findings demonstrate that while the conventional computation of entanglement via the dynamical phase remains accurate for systems in Schrödinger-cat states, it may yield erroneous estimations for systems prepared in squeezed cat states.

Groups of type E6 and E7 over rings via Brown algebras and related torsors

We study structurable algebras and their associated Freudenthal triple systems over commutative rings. The automorphism groups of these triple systems are exceptional groups of type E7, and we realize groups of type E6 as centralizers. When 6 is invertible, we further give a geometric description of homogeneous spaces of type E7/E6, and show that they parametrize principal isotopes of Brown algebras. As opposed to the situation over fields, we show that such isotopes may be non-isomorphic.

Clifford Odd and Even Objects in Even and Odd Dimensional Spaces Describing Internal Spaces of Fermion and Boson Fields

In a long series of works, it has been demonstrated that the spin-charge-family theory, assuming a simple starting action in even dimensional spaces with d≥(13+1), with massless fermions interacting with gravity only, offers the explanation for all assumed properties of the second quantized fermion and boson fields in the standard model, as well as offering predictions and explanations for several of the observed phenomena. The description of the internal spaces of the fermion and boson fields by the Clifford odd and even objects, respectively, justifies the choice of the simple starting action of the spin-charge-family theory. The main topic of the present article is the analysis of the properties of the internal spaces of the fermion and boson fields in odd dimensional spaces, d=(2n+1), which can again be described by the Clifford odd and even objects, respectively. It turns out that the properties of fermion and boson fields differ essentially from their properties in even dimensional spaces, resembling the ghosts needed when looking for final solutions with Feynman diagrams.

Горожанин в поисках сообщества: особенности организации дальневосточного городского пространства (на примере города Хабаровска)

As a rule, the tradition of analysis and description of the Russian city space marginalizes significant parts of this space. Thus, industrial zones, low-rise residential areas, etc. fall outside the concept of ‘city’. The Soviet ‘private sector’ often remains outside the scope of analysis, covering more than half of the city’s territory and a significant part of its population in individual settlements. This discussion in scientific papers has appeared recently, and we want to proceed with it in the space of Far Eastern cities. In this paper, we propose to look at these ‘marginal’ territories and the groups inhabiting them from a fundamentally different perspective, to consider them not as ‘territories of prospective development’, but as already established social space, with its inherent social significances and practices. From the framework of the Khabarovsk city we determine the ratio of ‘normal urban’ (regular urban development) and ‘marginal’ spaces on the basis of two years of observation, three series of in-depth interviews and analysis of statistics, demographic and spatial data, and then combine these two separated parts into a single object - the city, which, as we show in our work, is eminently characterized by both these types of spaces. As the study showed, it is in the ‘invisible’ part of the city that the most stable communities are formed, actively participating in the ‘struggle for the city’, organizing routine resistance to the aspirations of powerful agents to change their space. In areas of regular urban development, on the contrary, communities are increasingly replaced by ‘combinations’, associations regarding the use of common elements of urban infrastructure. At the same time, ‘meeting points’ appear between these parts, uniting the city, giving it a chance to form integrity, or at least coherence. The authors present an analysis of the urban space and urban communities of Khabarovsk in this article.

Moduli spaces of flat Riemannian metrics on 3- and 4-dimensional closed manifolds

We describe the topology of the moduli spaces of flat metrics for all the 3-dimensional closed manifolds. We give an algebraic description of the moduli spaces for the 4-dimensional closed flat manifolds with a single generator in their holonomy and, in some cases, also study their topology.

Linear Orthosets and Orthogeometries

Anisotropic Hermitian spaces can be characterised as anisotropic orthogeometries, that is, as projective spaces that are additionally endowed with a suitable orthogonality relation. But linear dependence is uniquely determined by the orthogonality relation and hence it makes sense to investigate solely the latter. It turns out that by means of orthosets, which are structures based on a symmetric, irreflexive binary relation, we can achieve a quite compact description of the inner-product spaces under consideration. In particular, Pasch’s axiom, or any of its variants, is no longer needed. Having established the correspondence between anisotropic Hermitian spaces on the one hand and so-called linear orthosets on the other hand, we moreover consider the respective symmetries. We present a version of Wigner’s Theorem adapted to the present context.

Low-dimensional life of critical Anderson electron

We show that critical Anderson electron in 3 dimensions is present in its spatial effective support, which was recently determined to be a region of fractal dimension ≈8/3, with probability 1 in infinite volume. Hence, its physics is fully confined to space of this lower dimension. Stated differently, effective description of space occupied by critical Anderson electron becomes a full description in infinite volume. We then show that it is a general feature of the effective counting dimension underlying these concepts, that its subnominal value implies an exact description by effective support.