Straight-line Trajectory Research Articles

Geometry-Induced Acceleration in Case of a Straight-Line Target Trajectory in Bistatic Radar

Bistatic radar signal processing often assumes a constant velocity for target detection. The bistatic geometry alters, however, the effectively measurable velocity in relation to the target position and motion even if the target has a constant ground speed. Hence, the bistatic geometry induces instantaneous bistatic target acceleration. This is especially the case if a straight-line target trajectory cuts across several closely spaced velocity isolines. The letter tries to quantify this geometry-induced instantaneous bistatic acceleration, in general, for straight-line target trajectories. Thereby, position-dependent acceleration values are derived for a practical use case.

An ISAR-SAR Based Method for Indoor Localization Using Passive UHF RFID System With Mobile Robotic Platform

A novel RFID inverse synthetic aperture radar (ISAR)-synthetic aperture radar (SAR) localization method is proposed and demonstrated which exploits reference tags with known locations to estimate the trajectory of a mobile platform and locate target tags with unknown locations. A system that integrates a mobile robot with an integrated RFID reader and antenna is used to obtain phase measurements of both reference and target tags when the robot is moving along its trajectory. The ISAR algorithm estimates the antenna trajectory and a novel ISAR-SAR loop then adjusts the estimated trajectory. The estimated trajectory is combined with phase measurements of the target tags to determine their location. The performance is compared to SAR using a LiDAR measured antenna trajectory. Similar localization accuracy (15 cm MAE) is achieved using LiDAR-SAR or ISAR-SAR method with a straight-line trajectory and higher accuracy (6 cm) is achieved using ISAR-SAR method than LiDAR-SAR method (8 cm) with an L-shape trajectory.

UAV-Assisted Time-Efficient Data Collection via Uplink NOMA

Due to the mobility and line-of-sight conditions, unmanned aerial vehicle (UAV) is deemed as a promising solution to sensor data collection. On the other hand, it is vital to guarantee the timeliness of information for UAV-assisted data collection. In this paper, we propose a time-efficient data collection scheme, in which multiple ground devices upload their data to the UAV via uplink non-orthogonal multiple access (NOMA). The total flight time of the UAV is equally divided into <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> time slots. The duration of each time slot is minimized by jointly optimizing the straight-line trajectory, device scheduling, and transmit power. To solve this mixed integer non-convex optimization problem, we decompose it into two steps. In the first step, we study the device scheduling strategy based on the UAV trajectory and the channel gains between the UAV and ground devices, through which the original problem can be greatly simplified. In the second step, the duration of each time slot is minimized by optimizing the transmit power and the UAV trajectory. An iterative algorithm based on alternating optimization is proposed, where each subproblem can be alternatively solved by applying successive convex approximation with the device scheduling updated at the end of each iteration. Numerical results are presented to evaluate the effectiveness of the proposed scheme.

532 - “Mapping the Lived Experiences: The Dyad Journey of People with Agitation in Alzheimer’s and Their Care Partners”

AbstractA substantial amount of analysis has been dedicated to understanding the individual journeys of the “patient” and the “caregiver” in Alzheimer’s disease. This work has provided valuable insights, but a few priorities remain:how is the lived experience journey in Alzheimer’s shaped by the complexities of agitation and other behavioral aspects of the disease;how can insights from “social listening” analysis structure our understanding of these journeys;how can we understand the dyad journey of the person with Alzheimer’s and the care partner as well as the interactions therein, particularly through the lens of agitation.This project, “Mapping the Lived Experiences” recasts the Alzheimer’s journey to better reflect these priorities. We offer a visual interpretation of the journey with the rationale and proof points that underpin it.“Mapping the Lived Experiences” prioritizes agitation and other behavioral aspects of Alzheimer’s as pivotal, enduring challenges on the disease journey. We frame the journey into two overarching phases: “the first loss,” which accounts for the more widely recognized symptoms of the disease, such as memory loss and declining cognitive function; and “the second loss,” which is characterized by agitation and behavioral aspects of the disease. We structure the journey around “milestone moments” – moments when both the person with Alzheimer’s and the care partner recognize that the disease has taken a major progression.The “milestones” moment framework reflects an interpretive framework developed through an ongoing “social listening” research project. This social listening research allows analysis of the online conversation as it is happening in social channels and discussion boards, and it provides a poignant counterpoint to quantitative market research insofar as it illuminates the unfiltered, unmitigated experiences as articulated by the people who are learning in real-time to manage and live with Alzheimer’s. From social listening insights and analysis, our research posits that journeys – for both the person with Alzheimer’s and the care partner – are not linear, straight-line trajectories, but jagged, fragmented paths marked by “milestone moments” that shape thinking, understanding, and behavior.“Mapping the Lived Experiences” offers a dyad visualization and articulations, as it fuses the journeys of the person with lived experience and the care partner together in the same visual space. This approach reveals how, over time, these journey relate, inform, and ultimately depart from one another. This dyad offers new insights into both the lived experience and care partner journeys.

Calculation of energy loss in antiproton collisions with many-electron systems using Ehrenfest's theorem

Energy loss in collisions of charged projectiles with many-electron systems can be dealt with in time-dependent density functional theory by invoking Ehrenfest's theorem for the time evolution of expectation values of observables. We derive an exact expression for the evaluation of energy loss for systems described in a target reference frame, which is a functional of the electron density. Using an approximation scheme, we then apply the expression to antiproton-atom collisions at intermediate and high energies within the framework of the basis generator method. The calculations are performed within the semiclassical approximation for the nuclear motion, and a straight-line trajectory is employed. The energy loss is evaluated from an expectation value of the time derivative of the time-dependent projectile potential, and it avoids the problem of identifying the excited and ionized many-electron contributions in the many-electron wave function. There is also no need to invoke the independent-event model, since the calculations are performed within the framework of the independent-electron mean-field model. Detailed comparisons are provided for net ionization and total energy loss of antiprotons colliding with hydrogen, helium, neon, carbon, nitrogen, and oxygen. Reasonable agreement is found with the results from one-electron and two-electron calculations for atomic hydrogen and helium, and with experiment in the latter case. For the $\overline{p}\text{\ensuremath{-}}\mathrm{Ne}$ system at intermediate collision energies, we find discrepancies with previous work that included only single-electron transitions. The sequence of results for C, N, O, and Ne allows one to paint a consistent picture that awaits experimental verification.

Анализ траектории трещины гидроразрыва около пластовой выработки и условия ее прямолинейного роста

Model of the geomechanical state of a disc hydraulic fracture propagating in the solid rocks near the seam working is based on the methods of solid mechanics and fracture mechanics. Stress field in the coal-rock mass containing in-seam working and growing hydraulic fracture was constructed as a result of solving an elastoplastic problem, in which the area of plasticity is the extremely stressed zones of the edge parts of the seam. The stress field in the edge parts was determined in the course of the numerical solution of three boundary value problems of the seam limiting state. The criteria for the onset of the limiting state are the general criterion of the Coulomb — Mohr limiting state for the formation and a special criterion for the limiting state for its contact with the rock mass. By replacing the extremely stressed zones with the stresses acting on their contact with the rock mass, the elastoplastic problem is reduced to the second external boundary value problem of the theory of elasticity, which is solved by the method of boundary integral equations. At the relatively low fluid pressures in the pumping unit, the trajectory of the hydraulic fracture is a smooth curved line of the small length with a significant deviation of its ends from the direction of the seed crack. With increasing fluid pressure, the crack length increases, and the deviation from the direction of the seed crack decreases. There are fluid pressures at which the crack propagates in a straight line and practically does not change its original direction. The straight-line trajectory of the crack in the vicinity of the working located at different depths corresponds to a point on the graph of the dependence of the relative length of the crack on the fluid relative pressure. This graph is a straight line.

Surgical approach to the facial recess influences the acceptable trajectory of cochlear implantation electrodes.

To provide practical guidance to the operative surgeon by mapping the location, where acceptable straight-line virtual cochlear implant electrode trajectories intersect the facial recess. In addition, to investigate the influence of facial recess preparation, virtual electrode width and surgical approach to the cochlea on these available trajectories. The study was performed on imaging data from eight cadaveric temporal bones within the University of Melbourne Virtual Reality (VR) Temporal Bone Surgery Simulator. The facial recess was opened to varying degrees, and acceptable trajectory vectors with varying diameters were calculated for electrode insertions via cochleostomy or round window membrane (RWM). The percentage of acceptable insertion vectors through each location of the facial recess was visually represented using heatmaps. Seven of the eight bones allowed for acceptable vector trajectories via both cochleostomy and RWM approaches. These acceptable trajectories were more likely to lie superiorly within the facial recess for insertion via the round window, and inferiorly for insertion via cochleostomy. Cochleostomy insertions required a greater degree of preparation and skeletonisation of the junction of the facial nerve and chorda tympani within the facial recess. The width of the virtual electrode had only marginal impact on the availability of acceptable trajectories. Heatmaps emphasised the intimate relationship the acceptable trajectories have with the facial nerve and chorda tympani. These findings highlight the differences in the acceptable straight-line trajectories for electrodes when implanted via the round window or cochleostomy. There were notable exceptions to both surgical approaches, likely explained by the variation of hook region anatomy. The methodology used in this study holds promise for translation to patient specific surgical planning.

Computer Assisted Planning for Curved Laser Interstitial Thermal Therapy.

The clinical feasibility and potential of curved LiTT trajectories through steerable needles has yet to be investigated. This is the focus of our work. We propose a GPU-accelerated computer-assisted planning (CAP) algorithm for steerable needle insertions that generates optimized curved 3D trajectories with maximal ablation of the amygdalohippocampal complex and minimal collateral damage to nearby structures, while accounting for a variable ablation diameter ( 5-15 mm). Simulated trajectories and ablations were performed on 5 patients with mesial temporal sclerosis (MTS), which were identified from a prospectively managed database. The algorithm generated obstacle-free paths with significantly greater target area ablation coverage and lower PHG ablation variance compared to straight line trajectories. The presented CAP algorithm returns increased ablation of the amygdalohippocampal complex, with lower patient risk scores compared to straight-line trajectories. This is the first clinical application of preoperative planning for steerable needle based LiTT. This study suggests that steerableneedles have the potential to improve LiTT procedure efficacy whilst improving the safety and should thus be investigated further.

Mathematical model of passive withdrawal of a tractor unit

The article reveals the construction of a mathematical model for pulling a tractor unit under the influence of external off-centre forces. The model describes the movement of the tractor and takes into account the force interaction of the tractor propulsion with the soil, as well as the properties of the soil. The construction of a mathematical model of passive removal is based on a combination of two types of movement: controlled and uncontrolled. External forces distort the straight-line trajectory of the tractor. The machine operator is forced to make changes to the control constantly. This entails increased operator fatigue. A mathematical model can be used to design an automated control system. Such a system will automatically correct the rectilinear movement of the tractor. Correcting rectilinear movement is to automatically return the machine to a straight path. The mathematical model allows the analysis of passive withdrawal factors. Such factors include: the modulus of the external resistance force, its direction, and the point of application. Thus, the aim of the study is to build a mathematical model for the removal of the tractor unit under the influence of external off-centre forces. Note that the mathematical model can be applied to the following cases: ploughing operation, dozer blade angle, lying of roadsides with a grader. Improvement of this mathematical model may open up possibilities for studying other issues of passive removal.

WITHDRAWN: Design & development of a mathematical model for constructing a straight-line motion / trajectory for any mechanical robotic manipulator using bounded deviation concept along with its simulation by knot points

In this paper is provided, along with its simulation with knot points, a design and development of a mathematical model to create a straight-line motion and trajectory for any mechanical robotic handler using the boundary deviation principle. Here in the 3-dimensional Euclidean space, an algorithm for direct line motion is designed. An algorithm called the Constricted Non-conformity Algorithm (CNA) is introduced that to achieve a straight line, it can be used (the shortest path between the source & the target) through any type of robot (whether stationary robots or mobile robots). When the computer has been processed, this algorithm supplies the software interface for the mechanical robot. To get the robot to drive within the shortest distance situation, the mathematical model is used for straight line motion. C++ also executes a simulation to demonstrate the workings of the algorithm. A computational validation is often done by doing a case study to find a midpoint. The outcome of the simulation demonstrates how effective the technique is.

Walking Step Length Estimation Using Waist-Mounted Inertial Sensors With Known Total Walking Distance

This paper presents a new constrained optimization-based smoothing algorithm for walking step length estimation using waist-mounted inertial sensors, where the total walking distance is known. The walking trajectory is estimated by double integrating acceleration. Due to sensor noises, the walking step length estimation accuracy degrades as the walking distance becomes longer. To tackle this problem, we introduce a known distance straight-line walking trajectory constraint and a constant speed constraint to the smoothing algorithm. These constraints reduce the walking step estimation accuracy degradation even for long walking distance. Two experiments are conducted to evaluate the pedestrian trajectory and walking step length estimation accuracy. The accuracy of a 20 m walking trajectory estimation has been investigated in the first experiment. This experiment compares the estimated position and velocity with Lidar-based references. The second experiment is to demonstrate the usefulness of the proposed walking step length estimation method. The result shows that the average of mean relative errors is 0.6801% for three different walking speed levels. The proposed method can be applied to generate training data for walking step length estimation without requiring spatial infrastructure.

Effect of vibrating feeder pan geometry on radiometric separator performance

The article offers justifies the optimized shape for the vibrating feeder pan of a radiometric separator, which ensures the maximum travelling speed and uniform flow of ore material in the zone of radiation and recording. Three shapes of pans are discussed: rectangular, parabolic and triangular. It is found that motion of ore material along an inclined rectangular-shape pan is straight-linear. Distribution of ore particles along the width of the channel, which governs the scatter of the motion trajectories relative to the central axis of the channel, depends on the runoff point of particles from the outlet feeder. Proposed for the description of the motion trajectory of ore particles along an inclined channel of parabolic shape, the mathematical model demonstrates the curved and pendulum-wise motion of an ore particle with the attenuating amplitude. The motion of an ore particle in an inclined pan with the triangular-shape channel features the minimized scatter of motion trajectories relative to the central axis of the channel. The analysis of ore motion along vibrating feeder pans with different shape channels is carried out in Rocky DEM environment with regard to interaction of ore particles with the pan surface and with each other. The simulation modeling has proved the conclusions on the efficiency of the triangularshape profile of the vibrating feeder pan as it ensures uniform single-row flow of ore particles along the straight-line trajectory. The triangular shape of the pan contributes to the increased travelling speed of ore particles and, accordingly, to the enhanced capacity of the separator. The radiometric separator efficiency can be increased 1.5 times by changing from the parabolicshape channels to the triangular-shape profiles of vibrating feeder pans at the other operating conditions of radiometric separators being equal.

Dimensionality Reduction and Motion Clustering During Activities of Daily Living: Decoupling Hand Location and Orientation.

This article is the second in a two-part series analyzing human arm and hand motion during a wide range of unstructured tasks. In this work, we track the hand of healthy individuals as they perform a variety of activities of daily living (ADLs) in three ways decoupled from hand orientation: end-point locations of the hand trajectory, whole path trajectories of the hand, and straight-line paths generated using start and end points of the hand. These data are examined by a clustering procedure to reduce the wide range of hand use to a smaller representative set. Hand orientations are subsequently analyzed for the end-point location clustering results and subsets of orientations are identified in three reference frames: global, torso, and forearm. Data driven methods that are used include dynamic time warping (DTW), DTW barycenter averaging (DBA), and agglomerative hierarchical clustering with Ward's linkage. Analysis of the end-point locations, path trajectory, and straight-line path trajectory identified 5, 5, and 7 ADL task categories, respectively, while hand orientation analysis identified up to 4 subsets of orientations for each task location, discretized and classified to the facets of a rhombicuboctahedron. Together these provide insight into our hand usage in daily life and inform an implementation in prosthetic or robotic devices using sequential control.

Optical wave-packet with nearly-programmable group velocities

During the process of Bessel beam generation in free space, spatiotemporal optical wave-packets with tunable group velocities and accelerations can be created by deforming pulse-fronts of injected pulsed beams. So far, only one determined motion form (superluminal or luminal or subluminal for the case of group velocity; and accelerating or uniform-motion or decelerating for the case of acceleration) could be achieved in a single propagation path. Here we show that deformed pulse-fronts with well-designed axisymmetric distributions (unlike conical and spherical pulse-fronts used in previous studies) allow us to obtain nearly-programmable group velocities with several different motion forms in a single propagation path. Our simulation shows that this unusual optical wave-packet can propagate at alternating superluminal and subluminal group velocities along a straight-line trajectory with corresponding instantaneous accelerations that vary periodically between positive (acceleration) and negative (deceleration) values, almost encompassing all motion forms of the group velocity in a single propagation path. Such unusual optical wave-packets with nearly-programmable group velocities may offer new opportunities for optical and physical applications.

A Multiple Baseline Approach to Face Multipath

The positioning of tagged objects by means of the phase of the backscattered RFID signal is a challenging problem. Several approaches have been conceived in the years to face the problem of the narrow bandwidth of the RFID signal, which produces a periodic, and hence ambiguous, measurement of the tag-reader distance. One possible strategy is to exploit the movement of either the tag or the reader to collect a set of phase measurements which allow to solve the aforementioned ambiguity: this is, e.g., the approach pursued by SAR (Synthetic Aperture Radar) methods. In this article we propose an alternative approach which elaborates the sequence of phase samples in order to discover additional indicators that allow to improve the effectiveness of synthetic aperture methods. In particular we develop a strategy that permits to identify, among a set of measurements, the ones more strongly affected by the multipath. If a pattern emerges among the measurements without significant multipath (and this occurs if a low to moderate level of multipath characterizes the environment), by exploiting the good subset of measurements, it is possible to achieve an improvement in the positioning estimation. The method has been developed for a straight line trajectory: numerical results are reported in this article to illustrate the approach, while experimental results confirm its effectiveness.

CALCULATION OF SOILS CUTTING FORCE BY KNIFE TYPE CUTTING ELEMENTS OF THE EARTHMOVING MACHINE

The application of bucketless bottom unloading rotor with oblique cutting knife type cutting elements on the earthmoving machine allows enhancing significantly its excavation quantities in the road construction compared with widely used machinery as bulldozers, auto-graders. A loading diagram of the forces acting on an oblique cutter installed on a bucketless bottom unloading rotor is given. The action of forces is considered with account for the complex movement made by the cutting element in space as a result of the rotational movement and the end feed on the rotor along straight-line trajectory during layer by layer excavation of the soil by rotor cutter. The dependences were obtained for determining the components of the digging force by a single oblique cutting element of a bucketless bottom unloading rotor under straight-line end feed. The bucketless bottom unloading rotor with diagonal cutting knife type cutting elements, installed on the earthmoving machine’s frame, moving straightforwardly, allows not only to increase its output via rotation velocity of the bucketless bottom unloading rotor but also to excavate highly stiff soils, inaccessible for existing earthmoving machines.

Motion modeling of a non-holonomic wheeled mobile robot based on trajectory tracking control

Trajectory tracking is a problem of emphasis for the mobile robot. In this study, a coordinate transformation method was used to build a kinematic model of the wheeled mobile robot. A traditional proportional-integral-derivative control method was researched and improved by combining it with a neural network. A neural network proportional-integral-derivative trajectory tracking control method was thus designed, and a simulation experiment was performed using Simulink. The results show that in circular trajectory tracking control, the maximum errors of the X axis, Y axis, and θ were approximately 2.1 m, 2.3 m, and 0.4 rad, respectively, and that the system remained stable after running for 10 s. In straight-line trajectory tracking control, the maximum errors of the X axis, Y axis, and θ were approximately −0.8 m, 1.3 m, and 0.3 rad, respectively, and the system remained stable after running for 8 s. The error was relatively small, and the effect of trajectory tracking control was good. The studied method had good performance in terms of wheeled mobile robot trajectory tracking control and is worthy of further promotion and application.

Cognitive dynamics of intertemporal choice in gambling disorder

Gambling Disorder (GD) is a behavioral addiction characterized by the persistence of recurrent gambling behaviors despite serious adverse consequences. One of the key features of GD is a marked inability to delay gratification and an overall impairment of decision-making mechanisms. Indeed, in intertemporal choice (ITC) tasks, GD patients usually display a marked tendency to prefer smaller-sooner over larger-later rewards (temporal discounting, TD). However, ITC represents a highly verbal/explicit measure, and as such it might not be sensitive to implicit decision biases. Here we sought to uncover the implicit mechanisms underlying the ITC impairment in GD by employing the process-tracing method of mouse kinematics. To this aim, we collected and analyzed ITCs and kinematics measures from 24 GD patients and 23 matched healthy control participants (HC). In line with the relevant literature, the results showed that GD patients discounted future rewards more steeply compared to HCs. Additionally, the results of kinematics analyses showed that patients were characterized by a strong bias toward the immediate option, which was associated with straight-line trajectories. Conversely, the delayed option was selected with edge-curved trajectories, indicating a bias toward the immediate option which was revised in later stages of processing. Interestingly, kinematics indices were also found to be predictive of individual discounting preferences (i.e., discount rates) across the two groups. Taken together, these results suggest that kinematics indices, by revealing hidden and implicit patterns of attraction toward the unselected choice option, may represent reliable behavioral markers of TD in gambling disorder.

Stationary computed tomography with source and detector in linear symmetric geometry: Direct filtered backprojection reconstruction.

Inverse-geometry computed tomography (IGCT) could have great potential in medical applications and security inspections, and has been actively investigated in recent years. In this work, we explore a special architecture of IGCT in a stationary configuration: symmetric-geometry computed tomography (SGCT), where the x-ray source and detector are linearly distributed in a symmetric design. A direct filtered backprojection (FBP)-type algorithm is developed to analytically reconstruct images from the SGCT projections. In our proposed SGCT system, a big number of x-ray source points equally distributed along a straight-line trajectory will sequentially fire in an ultra-fast manner in one side, and an equispaced detector whose total length is comparable to that of the source will continuously collect data in the opposite side, as the object to be scanned moves into the imaging plane. We firstly present the overall design of SGCT. An FBP-type reconstruction algorithm is then derived for this unique imaging configuration. With finite length of x-ray source and detector arrays, projection data from one segment of SGCT scan are insufficient for an exact reconstruction. As a result, in practical applications, dual-SGCT scan whose detector segments are placed perpendicular to each other, is of particular interest and is proposed. Two segments of SGCT together can make sure that the passing rays cover at least 180 degrees for each and every point if carefully designed. In general, however, there exists a data redundancy problem for a dual-SGCT. So a weighting strategy is developed to maximize the use of projection data collected while avoid image artifacts. In addition, we further extend the fan-beam SGCT to cone beam and obtain a Feldkamp-Davis-Kress (FDK)-type reconstruction algorithm. Finally, we conduct a set of experimental studies both in simulation and on a prototype SGCT system and validate our proposed methods. A simulation study using the Shepp-Logan head phantom confirms that CT images can be exactly reconstructed from dual-SGCT scan and that our proposed weighting strategy is able to handle the data redundancy properly. Compared with the rebinning-to-parallel-beam method using the forward projection of an abdominal CT dataset, our proposed method is seen to be less sensitive to data truncation. Our algorithm can achieve 10.64lp/cm of spatial resolution at 50% modulation transfer functions point, higher than that of the rebinning method which can only reach at 9.42lp/cm even with extremely fine interpolation. Real experiments of a cylindrical object on a prototype SGCT further prove the effectiveness and practicability of the direct FBP method proposed, with similar level of noise performance to rebinning algorithm. A new concept of SGCT with linearly distributed source and detector is investigated in this work, in which spinning of sources and detectors is no longer needed during data acquisition, simplifying its system design, development, and manufacturing. A direct FBP-type algorithm is developed for analytical reconstruction from SGCT projection data. Numerical and real experiments validate our method and show that exact CT image can be reconstructed from dual-SGCT scan, where data redundancy problem can be solved by our proposed weighting function.

Variation of major elements and heavy metals occurrence in hybrid aspen (Populus tremuloides Michx. × P. tremula L.) tree rings in marginal land

Fast growing tree species such as Populus spp. in short rotation woody crop (SRWC) systems could be an environmentally friendly and cost-effective approach to ensure sustainable biomass production and mitigate the negative impacts on the environment caused by more intensive management aimed to promote additional biomass increment. Knowledge on variation of major biologically important elements’ and toxic heavy metals’ occurrence in fertilised hybrid aspen tree rings in marginal land may have important and relevant implications for the management practice and evaluation of element fluxes in SRWC ecosystems. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to determine the relative amount of major elements (K, Ca, Mg, P) and heavy metals (Cd, Hg, Pb) in stem wood plane on straight line trajectory starting from pith to bark with measurement step 0.1 mm. While inductively coupled plasma mass spectrometry (ICP-MS) was used to determine average content of the mentioned elements in mechanically separated tree rings to quantify data obtained using LA-ICP-MS method and expressed in relative units. Stem disc samples were collected from six year old hybrid aspen trees growing in marginal agricultural land in the central part of Latvia (hemi-boreal climate conditions) that were initially fertilised with biogas production residues, sewage sludge, and wood ash. We concluded that the content of analysed major elements and heavy metals in the hybrid aspen tree rings varied considerably not only within the analysed stem plane (across tree rings) of one sample tree, but also within one annual ring with significant differences between the content of major elements in earlywood and latewood. Nevertheless, the results of the content of major elements and heavy metals in hybrid aspen tree rings highlighted the significant impact of the initially used fertiliser (especially wood ash) on the average content of elements. Hybrid aspens can be considered bioindicators of both the management activities and general growing conditions even if soil pH is close to neutrality, suggesting a limited mobility of the heavy metals.