Angular Elements Research Articles

Determining of correlation relationship between angular elements of external orientation

The current state of development of science and technology definitely influenced the introduction of UAVs in various areas of economic development and military affairs. And this trend, since it brought positive results, will continue to grow. Therefore, the study of UAV capabilities, both design and operational, is a necessary component. The authors proposed a new algorithm for processing the results of digital shooting and determining the dependencies of the influence of the angular elements of the external orientation (EEO) of the images, which will make it possible to significantly improve the accuracy of the searched terrain coordinates. One of the main requirements for aircraft-type UAVs used in aerial surveying is absolutely horizontal flight. That is, maintaining the minimum angles of inclination of the external orientation of the images. And so, the idea arose to find the correlation coefficients between them when modeling the angles of inclination α and ω relative to the fixed angle ϰ (since this angle is actually compensated with the help of an aero device). So, if there is such a dependence, then based on the values of these values, it is possible to introduce a correction in the design of a micro-UAV and thereby increase stability during horizontal flight. Everything will depend on the value of the correlation coefficient: the larger it is, the more significant the possibility of improvement in the design of the UAV. Such modifications can be the displacement of the center of gravity of the structure, the profile and quantitative parameters of the plane, the shape of the fuselage, etc. The application of this direction will lead to the determination of the exact parameters of the EEO, since the installation of an accurate stabilization system and the determination of the angular EEO images (INS) on these devices is not possible, since there are often restrictions on the loading of UAVs. Regarding the determination of linear EEO, the issue can be solved by installing a dual-frequency GPS receiver on the UAV, which will allow obtaining the coordinates of the projection centers with an accuracy of 1–2 cm. The refinement of the EEO of digital images leads to an increase in the accuracy of the spatial coordinates of object points.

Face recognition based on general structure and angular face elements

Face recognition based on general structure and angular face elements

Polarization factors and their effects on the rotational gyromagnetic ratio

The effect of the polarizations on the collective gyromagnetic ratio (g R ) has been investigated in detail using the Rotational Invariant Quasiparticle Phonon Nuclear Model (RI-QPNM). The model includes an axially symmetric mean-field potential, monopole pairing, spin-dependent residual interactions, and the restoration forces determined according to Pyatov’s prescription for rotational invariance. The restoration of the rotational symmetry gives a solution at the zero energy associated with the rotational branch of nucleonic motion, allowing us to obtain the g R -factors of the core. The remaining solutions lead to the appearance of configuration mixing in the excitation spectrum of the odd-mass deformed nucleus. The configuration mixing quenches both spin and angular momentum matrix elements and affects the contribution of the odd particle to the g R . It has been demonstrated that the polarization factors associated with the ΔK = 1 matrix elements are essential to achieve quantitative agreement with the experimental data. It has also been shown that the general assumption for core polarization, i.e., is insufficient to explain the experimental data.

Natural selection rules: new positivity bounds for massive spinning particles

We derive new effective field theory (EFT) positivity bounds on the elastic 2 → 2 scattering amplitudes of massive spinning particles from the standard UV properties of unitarity, causality, locality and Lorentz invariance. By bounding the t derivatives of the amplitude (which can be represented as angular momentum matrix elements) in terms of the total ingoing helicity, we derive stronger unitarity bounds on the s- and u-channel branch cuts which determine the dispersion relation. In contrast to previous positivity bounds, which relate the t-derivative to the forward-limit EFT amplitude with no t derivatives, our bounds establish that the t-derivative alone must be strictly positive for sufficiently large helicities. Consequently, they can provide stronger constraints beyond the forward limit which can be used to constrain dimension-6 interactions with a milder assumption about the high-energy growth of the UV amplitude.

Nonlinear method for determining external orientation elements of digital images obtained from drone

We have suggested the method of application of a direct solving of the systems of nonlinear equations for finding the elements of external orientation (EEO) to perform aerial photography by unmanned aerial vehicles (UAVs). The elements of external orientation functions search for the minimum of the function F , which is the sum of squares of coordinate differences on the image and is calculated by the measured coordinates on the ground, or the minimum of the function G, which is constructed using co-linearity and is the sum of squares of differences of the given coordinates Xi, Yi, Zi (i=1,2,…,n) on the ground and those which were calculated by the values xi, yi (i=1,2,…,n) measured on the image. In contrast to the classical approach, the choice of such a type of function is due to the possibility of implementing the algorithm using mathematical packages. Since some of the unknown coordinates Xi, Yi, Zi (the origin of the coordinate system is the center of projection) are included in the function G as arguments linearly, fulfillment of the conditions of the minimum of this function (equality of partial zero derivatives) in this case is simpler. This allows us to determine them through the angular elements of the EEO, which reduces the system of six equations to the system of three equations, being dependent on the angular elements. The function G is differentiated with respect to the variables dependent on the angular elements to obtain the three other equations. The obtained in this way system of equations is solved by the parameter variation method and gives us the solution of the required EEOs with a given accuracy. The proposed algorithm gives us a real opportunity to clarify the values of EEO, moreover, the linear EEOs are determined with maximum accuracy, that makes it possible to increase the accuracy of the spatial coordinates of the points of the terrain. The application of digital image processing from UAVs will significantly extend the range of implementation of aerial photography from UAVs to solve a variety of topographic, cadastral and engineering problems. The proposed technique was tested on the relevant materials of aerial photography from UAVs at control points, which made it possible to confirm the optimality of the technique.

Исследование точности формирования снимка камерами со шторно-щелевым затвором при съемке с беспилотных воздушных судов

Quite often aerial survey made by unmanned aerial vehicle (UAV) is carried out using digital non-metric cameras that have rolling shutters. Variations in speed of a UAV and its angular elements of exterior orientation during aerial survey cause distortions in the images generated by the camera, which affects the accuracy of the processing results. The article shows the variations in the elements of exterior orientation during the operation of a rolling shutter and describes the way of its detection by flight recorder. The values of image distortion, caused by the variations in the angular elements of the exterior orientation of a snapshot, are calculated for the Sony Alpha A6000 digital non-metric camera.

A comprehensive nonlinear dynamic model for ball screw feed system with rolling joint characteristics

Modern tendency of machine tools design requires more accurate model to predict the system dynamics, in order to anticipate its interaction with machining process. In this paper, a comprehensive dynamic model of ball screw feed system (BSFS) considering nonlinear kinematic joints is introduced to investigate the varying dynamic characteristics when worktable is subjected to combined load from six directions. The load–deformation relationship of each kinematic joint is dealt with a set of translational and angular spring elements. The nonlinear restoring force function of each joint involving coupling displacement is calculated. Based on the lumped mass method, the analytical 18-DOF dynamic equation is formulated by the analysis of the interaction force between joints. Model verification tests are conducted. The worktable response exhibits the abundant and fascinating nonlinear phenomena arising in nonlinear joint and coupling effect. The nonlinear behavior behaves significant difference owing to the variations of excitation, platform position, screw length, preload and damping of joints. Thus, the model is promising for comprehension of machine dynamic behavior and for development of sophisticated control strategy.

THE STUDY OF THE “CETUS” UNMANNED AERIAL VEHICLE FOR TOPOGRAPHIC AERIAL SURVEYING

The work aims to analyze and study the possibilities of using “Cetus” unmanned aerial vehicle (UAV) for performing topographic aerial surveys. The authors developed and tested aircraft-type UAV for topographic aerial photography. The studies were conducted on a specialized landfill, at which there is an appropriate number of situational points whose coordinates are determined with high accuracy. These points were used as both reference and control points. The obtained UAV aerial survey materials were subjected to a phototriangulation process to determine the orientation elements and to analyze, first and foremost, the angular orientation elements. The surveying was carried out on a mountainous territory, where the spatial coordinates of 37 situational points were determined by the method of ground-based GPS survey with an average accuracy of up to 0.05 m. These points were used as reference and control points. Aerial photography was performed in such a way that the scale of the images was as uniform as possible. The design solutions implemented in the Cetus UAV provide all the possibilities to perform aerial surveys of territories in strict compliance with the projected flight parameters. UAV equipment provides the necessary real-time correction of the position of the aerial camera. At the same time the optimum straightness of routes, stability of scales and mutual overlapping of pictures is reached. Regarding the accuracy of obtaining the spatial coordinates of the points of terrain objects, using “Cetus” UAV surveys, plans can even be made on a scale of even 1: 1000. As a result of the creation of the UAV “Cetus”, it became possible to perform the topographic aerial survey of the territories and to create large-scale orthophotos that fully meet the instructions. As a result of testing the “Cetus” UAV, it can be used in production processes when drawing up topographic plans for a large-scale series: 1: 1000 – 1: 5000, which will significantly save the cost of performing topographic work.

The Fourier approximation for orbital elements for the members of very young asteroid families

We applied the Fourier approximation in studying the dynamics of very young asteroid families (younger than 1.6 Myr). As the output, we obtained a new system of approximated orbital elements, which is comparable to classical elements. We have found only one significant discrepancy in the perihelion longitude rate of the Rampo family's main member. Moreover, we extended our system of approximated elements by including amplitudes and frequencies of the periodic variations of angular elements.

Photonic quantum Hall effect and multiplexed light sources of large orbital angular momenta

The quantum Hall effect involves electrons confined to a two-dimensional plane subject to a perpendicular magnetic field, but it also has a photonic analogue1–6. Using heterostructures based on structured semiconductors on a magnetic substrate, we introduce compact and integrated coherent light sources of large orbital angular momenta7 based on the photonic quantum Hall effect1–6. The photonic quantum Hall effect enables the direct and integrated generation of coherent orbital angular momenta beams of large quantum numbers from light travelling in leaky circular orbits at the interface between two topologically dissimilar photonic structures. Our work gives direct access to the infinite number of orbital angular momenta basis elements and will thus enable multiplexed quantum light sources for communication and imaging applications. A topological photonic crystal design directly generates light that carries orbital angular momentum with high quantum numbers. The beam contains several different states at the same time, promising integrated and multiplexed light sources.

Исследование точности определения пространственных координат из обработки изображений с беспилотного воздушного судна

The authors present the results of numerical experiments aimed to determine the mean square error, which can be used to obtain the spatial coordinates of the object’s under study points through processing images obtained from UAVs using only on-Board global satellite and inertial navigation equipment on drones. At those experiments, aerial photography from the UAVs was modeled for mapping and solving the engineering task of creating a three-dimensional building (structure) model. A pair of images was simulated for the research. The results using the characteristics of the GNSS inertial solutions Trimble АРХ-15 UAV and Trimble АРХ-20 UAV are presented. The experiments show that at solving engineering tasks under conditions corresponding to an arbitrary case of aerial photography, in order to determinie the spatial coordinates with the mean square error not more than 15 mm, the same error of determining the linear elements of external orientation should be 2–5 mm, and the angular elements 10–20ʺ. This significantly exceeds the characteristics corresponding to the post-processing mode for the specified GNSS-inertial solutions. The authors show the effect of angular elements’ external orientation errors to resulting the mean square error of each coordinate and a possible approach to reducing it.

Investigation responses of the diagrid structural system of high-rise buildings equipped with Tuned mass damper using new dynamic method

Due to the shortage of land in cities and population growth, the significance of high rise buildings has risen. Controlling lateral displacement of structures under different loading such as an earthquake is an important issue for designers. One of the best systems is the diagrid method which is built with diagonal elements with no columns for manufacturing tall buildings. In this study, the effect of the distribution of the tuned mass damper (TMD) on the structural responses of diagrid tall buildings was investigated using a new dynamic method. So, a diagrid structural systems with variable height with TMDs was solved as an example of structure. The reason for the selection of the diagrid system was the formation of a stiffness matrix for the diagonal and angular elements. Therefore, the effect of TMDs distribution on the story drift, base shear and structural behaviour were studied. The obtained outcomes showed that the TMDs distribution does not significantly affect on improving the behaviour of the diagrid structural system during an earthquake. Furthermore, the new dynamic scheme represented in this study has good performance for analyzing different systems.

The features of application of different systems of orientation angles at the processing of aerospace images

The angular elements of external orientation characterize the position of a shooting camera relative to the coordinate system in which the spatial coordinates of the points of the object under study are determined from the processing of its images. In many cases of aerial photography, e.g. shooting from an unmanned aerial vehicle, as well as in the case of space survey, the values of the orientation angles could be very significant. This paper presents the results of numerical experiments for five different systems of external orientation angles (Euler angles). The studies were performed using the condition of complanarity, which is the basis of space forward intersection. For a space forward intersection, a model of errors in determining spatial coordinates for five systems of shooting camera orientation angles has been developed. In the numerical experiments, the general case of aerial photography from an unmanned aerial vehicle and of space survey of the Earth were simulated. By comparing the root-mean-square errors (RMSE) in determining the spatial coordinates obtained using the studied systems of external orientation angles, the features of the use of these systems of orientation angles were revealed. The results of the research will allow to determine the spatial coordinates of the points of the studied objects with a greater degree of reliability by photogrammetry methods.

θ-deformed multi-dimensional fermion algebras

The conventional d-dimensional fermion algebra does not have a Hopf algebra structure. It is shown that this algebra can be deformed by introducing angular elements and by combining the commutative sine-cosine algebra with the Clifford algebra so that the resulting d-dimensional fermion algebra is a Hopf algebra.

Aesthetic Perception of Line Patterns: Effect of Edge-Orientation Entropy and Curvilinear Shape.

Curvilinearity is a perceptual feature that robustly predicts preference ratings for a variety of visual stimuli. The predictive effect of curved/angular shape overlaps, to a large degree, with regularities in second-order edge-orientation entropy, which captures how independent edge orientations are distributed across an image. For some complex line patterns, edge-orientation entropy is actually a better predictor for what human observers like than curved/angular shape. The present work was designed to disentangle the role of the two features in artificial patterns that consisted of either curved or angular line elements. We systematically varied these patterns across two more dimensions, edge-orientation entropy and the number of lines. Eighty-three participants rated the stimuli along three aesthetic dimensions (pleasing, harmonious, and complex). Results showed that curved/angular shape was a stronger predictor for ratings of pleasing and harmonious if the stimuli consisted of a few lines that were clearly discernible. By contrast, edge-orientation entropy was a stronger predictor for the ratings if the stimuli showed many lines, which merged into a texture. No such differences were obtained for complexity ratings. Our findings are in line with results from neurophysiological studies that the processing of shape and texture, respectively, is mediated by different cortical mechanisms.

Production of wooden I-beams from angular elements for low-rise housing

Due to the deterioration of the environmental situation, an increasing number of coniferous trees are affected by butt heart rot. For a more sustainable use of resources, one needs to use round assortments with the presence of sound rot for the manufacture of sawn products. I-beams are widely used in low-rise wooden housing construction. High installation speed without the use of heavy equipment and ease of assembly increase the speed and adaptability of building construction. A method for manufacturing I-beams from corner elements obtained as a result of cutting round timber with heart rot is proposed. The elements of the angular cross section are glued together to obtain an I-beam. The strength characteristics of an I-beam glued from angular cross-sectional elements are determined. It was established that the design characteristics of I-beams obtained by the proposed technology withstand operational loads. Values of normative and shear stresses arising upon application of loads do not exceed 50% of the permissible values. The beam deflection does not exceed 80% of the permissible deflection value. The use of round timber with core rot increases wood resources for low-rise housing.

Application of unmanned aerial vehicles for solving engineering tasks

The article discusses the use of unmanned aerial vehicles in solving engineering tasks. Information about the current state of the market of unmanned aerial vehicles and services with their use is provided. The most frequently used unmanned aerial vehicles and their characteristics are considered. Modern methods of obtaining and principles of processing images obtained from unmanned aerial vehicles and trends towards further development of the aerial photography process are described. The results are presented: modeling the influence of angular elements of external orientation on the accuracy of the obtained spatial coordinates of terrain points; studies of determining the volume of soil and creating a three-dimensional model of an engineering object (building) based on aerial photography obtained from an unmanned aerial vehicle multicopter. The accuracy of determining the volume of soil was controlled using a digital terrain model obtained using a total station. Control of the accuracy of building a three-dimensional model of an engineering object was performed by comparing the distances between the points of the object obtained from the three-dimensional model and the total station measurements. As follows from the results of the article, an unmanned aerial vehicle can be an effective tool for solving some engineering problems. The results obtained are comparable to the accuracy of classical methods, provided that the correct choice of the type of unmanned aerial vehicle and the correct approach to processing obtained images.

K* production in the KN → Kπp reaction * * Supports from the National Natural Science Foundation of China (U1832160, 11375137), the Natural Science Foundation of Shaanxi Province (2019JM-025) and the Fundamental Research Funds for the Central Universities

We investigate the production in the reaction using the effective Lagrangian approach and the isobar model. To describe this reaction, we first take into account the contributions from the , and exchanges, as in previous studies. We find that although the experimental data can be generally described, there are some obvious discrepancies between the model and the experiments. To improve the model, we consider the contributions of the axial-vector meson and hyperon exchange. It is shown that a large contribution of the axial-vector meson exchange can significantly improve the results. This may indicate that the coupling of the axial-vector meson, e.g. , is large in the channel. To verify our model, measurements of the angular distributions and spin density matrix elements of in the reaction would be helpful, and we make predictions for this reaction for a future comparison.

Moving daily average of the hourly magnetic field values - the example of usage at Novosibirsk Observatory during 2011 (results and prospects)

The parameters of the equivalent central dipole calculated using hourly values of the magnetic field elements during 2011: the angular elements transformed to the hourly values of the geographic coordinates of the North magnetic pole and the intensity values transformed to local magnetic constant. Next step is the calculation of the daily mean values at every hour. This method applied to both current digital data and historical data presented as monthly tables of hourly values. The advantage of method is its ability to show the changes of the magnetic field independently from daily variation. Using of the “integrate” parameters (the magnetic pole coordinates and local magneto constant) allows detect the regional features of its variations. The features in the daily values compared with anomalous geological and geophysical events observed in the past and predicted in the near future.

Chaotic Rotation and Evolution of Asteroids and Small Planets in High-eccentricity Orbits around White Dwarfs

Abstract Observed planetary debris in white dwarf atmospheres predominately originate from the destruction of small bodies on highly eccentric (>0.99) orbits. Despite their importance, these minor planets have coupled physical and orbital evolution, which has remained largely unexplored. Here, we present a novel approach for estimating the influence of fast chaotic rotation on the orbital evolution of high-eccentricity triaxial asteroids, and formally characterize the propagation of their angular rotation velocities and orbital elements as random time processes. By employing the impulse approximation, we demonstrate that the violent gravitational interactions during periastron passages transfer energy between the orbit and asteroid’s rotation. If the distribution of spin impulses were symmetric around zero, then the net result would be a secular decrease of the semimajor axis and a further increase of the eccentricity. We find evidence, however, that the chaotic rotation may be self regulated in such a manner that these effects are reduced or nullified. We discover that asteroids on highly eccentric orbits can break themselves apart—in a type of YORP-less (Yarkovsky–O’Keefe–Radzievskii–Paddack) rotational fission—without actually entering the Roche radius, with potentially significant consequences for the distribution of debris and energy requirements for gravitational scattering in metal-polluted white dwarf planetary systems. This mechanism provides a steady stream of material impacting a white dwarf without rapidly depleting the number of small bodies in the stellar system.