Relative Trajectory Research Articles

Late-life depression and multimorbidity trajectories: the role of symptom complexity and severity.

as late-life depression is associated with poor somatic health, we aimed to investigate the role of depression severity and symptom phenotypes in the progression of somatic multimorbidity. we analysed data from 3,042 dementia-free individuals (60+) participating in the population-based Swedish National Study on Aging and Care in Kungsholmen. Using the baseline clinical assessment of 21 depressive symptoms from the Comprehensive Psychopathological Rating Scale, we: (i) diagnosed major, minor (in accordance with DSM-IV-TR) and subsyndromal depression; (ii) extracted symptom phenotypes by applying exploratory network graph analysis. Somatic multimorbidity was measured as the number of co-occurring chronic diseases over a 15-year follow-up. Linear mixed models were used to explore somatic multimorbidity trajectories in relation to baseline depression diagnoses and symptom phenotypes, while accounting for sociodemographic and behavioural factors. in multi-adjusted models, relative to individuals without depression, those with major (β per year: 0.33, 95% confidence interval [CI]: 0.06-0.61) and subsyndromal depression (β per year: 0.21, 95%CI: 0.12-0.30) experienced an accelerated rate of somatic multimorbidity accumulation, whereas those with minor depression did not. We identified affective, anxiety, cognitive, and psychomotor symptom phenotypes from the network analysis. When modelled separately, an increase in symptom score for each phenotype was associated with faster multimorbidity accumulation, although only the cognitive phenotype retained its association in a mutually adjusted model (β per year: 0.07, 95%CI: 0.03-0.10). late-life major and subsyndromal depression are associated with accelerated somatic multimorbidity. Depressive symptoms characterised by a cognitive phenotype are linked to somatic health change in old age.

Hydrodynamical Simulations of Black Hole Binary Formation in AGN Disks

We study close encounters between two single black holes (BHs) embedded in an AGN disk using a series of global 2D hydrodynamics simulations. We find that when the disk density is sufficiently high, bound BH binaries can be formed by the collision of their circum-single disks. Our analysis demonstrates that, after a BH pair passes the pericenter of their relative trajectory, post-collision gas drag may slow down the BHs, possibly forcing the two BHs to stay tightly bound. A binary formed by a close encounter can have a compact semimajor axis, large eccentricity, and retrograde orbital angular momentum. We provide a fitting formula that can accurately predict whether a close encounter can form a binary based on the gas mass and the incoming energy of the encounter. This fitting formula can be easily implemented in other long-term simulations that study the dynamical evolution of BHs in active galactic nucleus disks.

Strange Fruit: Racism and Community Life in the Chesapeake—1850 to the Present by John R. Wennersten

Reviewed by: Strange Fruit: Racism and Community Life in the Chesapeake—1850 to the Present by John R. Wennersten John G. Deal Strange Fruit: Racism and Community Life in the Chesapeake—1850 to the Present. By John R. Wennersten. (Washington, D.C.: New Academia Publishing, 2020. Pp. xiv, 225. Paper, $24.00, ISBN 978-1-7359378-4-7.) In Strange Fruit: Racism and Community Life in the Chesapeake—1850 to the Present, John R. Wennersten examines race relations on Maryland’s Eastern Shore to challenge assumptions about race on the national level. Organized chronologically, Strange Fruit will appeal to a general audience, [End Page 145] thanks to its lively prose, vivid descriptions, dramatic photos, and historical overviews that serve as guideposts for each chapter. It is a relatively short book of just over two hundred narrative pages. Wennersten begins with a brief history of Somerset County, noting its geographic isolation, which caused residents to identify themselves regionally, rather than as Marylanders. Wennersten moves quickly through the trajectory of race relations beginning in 1850, when Somerset County had a proportionately large number of free Black and enslaved persons (4,571 and 5,089, respectively), while the white population stood at 15,332. Owing to its isolation, the county had about the same population in 2020 as it did in 1850. Wennersten describes the abuses and indignities heaped on enslaved persons, the domestic slave trade, and (thanks to Somerset County’s border state location) escapes to freedom. Despite efforts by the county’s slaveholding elite, Maryland’s new state constitution outlawed slavery in September 1864. In post–Civil War Somerset County, freedmen faced white intransigence as they entered a world of new political opportunities, demanded civil rights, and participated in a free labor economy. Many formerly enslaved people became watermen and contributed to the Eastern Shore’s expanding seafood industry. As the nineteenth century drew to a close, race relations deteriorated further with the advent of Jim Crow segregation and efforts to restrict Black voting rights in Maryland. Making effective use of local and state records, contemporary newspapers, and his own interviews, Wennersten hits his stride as the narrative enters the twentieth century. To show how violence against Black people in Somerset County intensified, he vividly describes the murder of George Armwood in 1933. Armwood was falsely accused of raping an elderly white woman. A white mob hauled him out of his jail cell, stabbed him to death, and dragged him through the streets, at which point he was hanged and burned. In response, a New York City teacher named Abel Meeropol wrote a poem that began with the verse, “Southern trees bearing strange fruit. Blood on the leaves and blood at the roots” (p. 137). The state of race relations on the Eastern Shore during the twentieth century mirrored conditions in other regions. The local canning industry exploited Black labor, and many young African Americans migrated elsewhere in search of work. While exploring these larger themes, Wennersten also reveals interesting details, such as the use of German prisoners of war as agricultural workers during World War II, a move that undercut Black wages. Like other communities around the country, African Americans on the Eastern Shore demanded an end to segregation in schools, restaurants, and hotels during the 1960s. Blacks had few white allies in their efforts, and protesters were met with violence that sometimes escalated into riots. Aligning with the present-day African American experience nationwide, Black people on the Eastern Shore continue to confront limited access to medical care, higher mortality rates, underrepresentation in public offices, and violence perpetrated against them. Reflecting on the persistence of racism in the Chesapeake, Wennersten titles his last chapter “Semper Eadem,” which translates to “always the same” (p. 205). [End Page 146] John G. Deal Library of Virginia Copyright © 2023 The Southern Historical Association

THE BATTLE OF CHALDIRAN: CAUSES AND CONSEQUENCES

The general trajectory of Ottoman-Safavid relations during the 235 years period between 1501 and 1736 outstandingly marked by persisting hostility and military conflict with brief and rare intervals of tranquility. The Battle of Chaldiran that took place in 1514 was the first major Ottoman-Safavid military clash and it was an important event in the history of Islam. The battle tested the military strength of two Muslim powers of the time and ended in favour of the Ottomans. The battle occurred for a good number of reasons and finally it left a long lasting legacy for both the Ottoman empire and for the Safavid state. This article makes a humble attempt to critically present the battle of Chaldiran from a historical point of view. To that purpose, the article first addresses the points of contention that ultimately resulted in the armed clash between the Safavids and the Ottomans at Chaldiran. The article next looks into the devastating consequences of the battle.

An Adaptive ORB-SLAM3 System for Outdoor Dynamic Environments.

Recent developments in robotics have heightened the need for visual SLAM. Dynamic objects are a major problem in visual SLAM which reduces the accuracy of localization due to the wrong epipolar geometry. This study set out to find a new method to address the low accuracy of visual SLAM in outdoor dynamic environments. We propose an adaptive feature point selection system for outdoor dynamic environments. Initially, we utilize YOLOv5s with the attention mechanism to obtain a priori dynamic objects in the scene. Then, feature points are selected using an adaptive feature point selector based on the number of a priori dynamic objects and the percentage of a priori dynamic objects occupied in the frame. Finally, dynamic regions are determined using a geometric method based on Lucas-Kanade optical flow and the RANSAC algorithm. We evaluate the accuracy of our system using the KITTI dataset, comparing it to various dynamic feature point selection strategies and DynaSLAM. Experiments show that our proposed system demonstrates a reduction in both absolute trajectory error and relative trajectory error, with a maximum reduction of 39% and 30%, respectively, compared to other systems.

Critique and change: The “what”, “why”, “how”, and “so what”

Critique and change: The “what”, “why”, “how”, and “so what”

Rendezvous and proximity operations design of an active debris removal service to a large constellation fleet

This work presents the design of rendezvous and close proximity operations for an active debris removal service for maintenance and disposal of a large constellation fleet. The design drivers of the service are safety and robustness of the operations, capability to remove a satellite under every condition, and high level of autonomy to reduce the service-related operations’ cost. Accordingly, the most challenging case of a rendezvous with a uncooperative non-collaborative target satellite is considered and a strategy to reduce its rotational motion is also presented. As for the rendezvous, the focus is on the relative trajectory design. First a guidance solution capable to maximise the observability property of the angles-only relative navigation problem is developed. Second, a set of convenient relative trajectories to enable target inspection for various illumination conditions is selected and an approach to ensure safe transitions among them is settled. Both these designed strategies can be readily implemented on autonomous spaceborne systems. Simulations are run for two constellation fleets, differing in mass of the single s/c and orbit’s altitude and inclination.

Spherically Constrained Relative Motion Trajectories in Low Earth Orbit

This paper considers a satellite inspection mission where the deputy satellite is required to remain a fixed distance away from the chief satellite. This constraint on the deputy’s state is modeled as the surface of a sphere. Finding minimum energy solutions to travel from one point to another point on the sphere requires solving a nonconvex optimal control problem. Various novel suboptimal algorithms are proposed that can guarantee a feasible solution. These algorithms are benchmarked by optimal values obtained via a global continuation method, and their computational performance is analyzed in a statistical setting.

Social Health and Cognitive Change in Old Age: Role of Brain Reserve.

Individual aspects of social health (SH; eg, network, engagement, support) have been linked to cognitive health. However, their combined effect and the role of the structural properties of the brain (brain reserve [BR]) remain unclear. We investigated the interplay of SH and BR on cognitive change in older adults. Within the Swedish National Study on Aging and Care-Kungsholmen, 368 dementia-free adults aged ≥60 years with baseline brain magnetic resonance imaging were followed over 12 years to assess cognitive change. A measure of global cognition was computed at each of the 5 waves of assessment by averaging domain-specific Z scores for episodic memory, perceptual speed, semantic memory, and letter and category fluency. An SH composite score was computed at baseline by combining leisure activities and social network. BR was proxied by total brain tissue volume (TBTV). Linear mixed models (adjusted for sociodemographic, vascular, and genetic factors) were used to estimate cognitive trajectories in relation to SH and TBTV. Interaction analysis and stratification were used to examine the interplay between SH and TBTV. Moderate-good SH (n=245; vs poor, β-slope=0.01, 95% confidence interval [CI] = 0.002-0.02, p= 0.018) and moderate-to-large TBTV (n=245; vs small, β-slope=0.03, 95% CI=0.02-0.04, p< 0.001) were separately associated with slower cognitive decline. In stratified analysis, moderate-good SH was associated with higher cognitive levels (but not change) only in participants with moderate-to-large TBTV (β-intercept=0.21, 95% CI=0.06-0.37, p< 0.01; interaction SH * TBTV, p< 0.05). Our findings highlight the interplay between SH and BR that likely unfolds throughout the entire life course to shape old-age cognitive outcomes. ANN NEUROL 2023;93:844-855.

Model predictive control for formation reconfiguration exploiting quasi-periodic tori in the cislunar environment

Given the numerous possibilities that formation flying space missions can enable, being able to design and govern relative trajectories in this scenario is fundamental. Particularly interesting, due to the installation and operation of the Lunar Gateway, which will represent the next human outpost in the cislunar environment, will be the exploitation of formation flying missions in the vicinity of this lunar station. The nonlinear dynamics by which the Earth-Moon system is characterised offers the possibility to find bounded relative trajectories which can be used to design the formation. In order to best exploit the formation potential, some reconfiguration manoeuvres can be used, which by changing the relative geometry can increase the versatility and adaptation of the mission. In this paper, a Model Predictive Guidance and Control strategy is proposed and applied to perform rephasing manoeuvres in the harsh environment of the Near Rectilinear Halo Orbits. By including first a limited thrust constraint and then a collision avoidance, a more mission-oriented approach is provided to the system. To further increase the robustness of the on-board algorithms, an adaptive logic is provided to the different tuning weights involved in the Model Predictive Control scheme. In this way, a more flexible system is obtained, which is capable of optimally working also in the presence of a high-fidelity simulation scenario, including discrepancies with the simplified on-board dynamical model.

Three-Dimensional Space-and-Time-Synchronized Target-Tracking Control Under Input Saturation

In this article, we present a space-and-time synchronized control method for target-tracking problems under input saturation in the three-dimensional (3-D) framework of polar coordinates. We first utilize the prescribed-distance controller to design a reference relative trajectory, aiming to formulate a synchronization of space and time. By doing this, the specified position can be approached at its predetermined instant and the relative trajectory in space is independent of time. Next, through correlating and decoupling the reference/actual kinematics between the self vehicle and the target, time and space are separated, controlled independently. To further address the existing closed-loop system errors, we propose a dynamic velocity assignment of the relative reference trajectory, which is an independent extra degree of freedom, to alleviate the negative effects caused by input saturation. Finally, numerical simulations are provided to demonstrate the effectiveness and superiority of the proposed scheme.

Личностные регуляторы построения образа будущего на разных этапах профессионализации

Background. In today's rapidly changing world, it is extremely important to maintain one's own trajectory in relation to life goals, the image of the future at different stages of professionalization. In this regard, it is relevant to determine personal regulators that allow for conscious and purposeful influencing the achievement of the expected future and their change in the process of professionalization. Objective. The study had its purpose to investigate the image of the future, its characteristics (completeness, clarity, time perspective), functions and personal regulators (self-regulation, coping behavior and life orientations) at different stages of professionalization. Methods. The study implemented quantitative methods: a basic questionnaire by V.I. Morosanova "Style of self-regulation of behavior - SSPM", 2015; “Time Perspective Questionnaire” (F. Zimbardo, 1997) adapted by A. Syrtsova, 2007; "Test of Life-Meaning Orientations" (Crumbaugh, Maholick, 1964) adapted by D.A. Leontiev, 2000; methodology "WCQ – Ways of Coping Questionnaire" (R. Lazarus and S. Folkman, 1985) adapted by T.L. Kryukova, E.V. Kuftyak, M.S. Zamyshlyaeva, 2004. And qualitative methods: the method “Unfinished Sentences” (Sachs, Levy, 1950) modified by the authors and metaphorical associative maps “Roads” (G. Salpeter, 2014) for which the author’s semi-standardized interview was developed (S.I. Konzhin, M.V. Saporovskaya, 2021). Sample. The study involved 184 people - men and women from 16 to 40 years old (M = 23.2; SD = 7.43) who gave informed consent to participate in it. The respondents were divided into three empirical groups: respondents at the stage of professional self-determination (aged 16-17); respondents at the stage of obtaining professional education (aged 18-25); respondents engaged in professional activities (aged 26-40). Results. The study revealed significant differences in the influence of self-regulation, coping behavior and life-meaning orientations on the time perspective of the future at different stages of professionalization. Content-analysis allowed to establish the structure, clarity, and completeness of the image of the future. Regression analysis indicated that “Locus of control-Self”, the coping strategy “Planning to solve a problem” and the regulatory-cognitive competence “Planning” make the greatest contribution to the regulation of the Future image of the respondents. Focus on the Future, the relevance of planning the Future image have certain differences and specifics at the different stages of professionalization. Conclusions. Locus of control, strategies of coping behavior and regulatory competencies can be considered as personal regulators of creating an image of the future at different stages of professionalization.

Formation Flying Lyapunov-Based Control Using Lorentz Forces

A formation flying control algorithm using the Lorentz force for Low Earth Orbits to achieve a trajectory with required shape and size is proposed in the paper. The Lorentz force is produced as a result of interaction between the Earth’s magnetic field and an electrically charged spacecraft. Achievement of the required trajectories represents a challenge since the control in three-dimensional space is a scalar value of the satellite’s charge. A Lyapunov-based control algorithm is developed for elimination of the initial relative drift after the launch. It also aims at reaching a required amplitudes for close relative trajectories for in-plane and out-of-plane motion. Due to the absence of full controllability, the algorithm is incapable of correcting all the parameters of the relative trajectory such as in-plane and out-of-plane phase angles. The proposed control allows to converge to the trajectory with required shape and size, though with some oscillating errors in the vicinity of the required trajectory parameters. Numerical simulation of the relative motion is used to study performance of the control algorithm for one case of one controlled satellite and two cases of five controlled satellites forming a nested ellipses and train formations. The convergence time and final trajectory accuracy are evaluated for different control parameters and orbits using Monte Carlo approach.

German-Norwegian Relations in the Second Half of 2010s: Political and Military Aspects

The article characterizes the relations between the NATO member states which are also Arctic states in military-political sphere. In this situation Norway is a valuable partner not only for the USA but also for European NATO member states and especially Germany considering its ambitions as full-fare global power. The goal of article is to explore trajectory and dynamics of German-Norwegian relations in political-military sphere in the second half of 2010s. The paper issues the functioning of negotiation link A. Merkel — E. Solberg and also German steps which led to its launch. The author shows the importance of Norway for Germany as an Arctic and in this regard explores Germany’s Arctic strategy. Germany tried to neutralize the negative effect of Norway’s lack of EU membership and also the unwillingness of Norway to join PESCO platform. There was the spill-over effect when the experience of full-fare cooperation in political sphere was also moved to the military sphere at the end of 2010s. The paper explores the features of the competition between the USA and Germany for influence over Norway in the context of the US and German Arctic ambitions. The author concludes about the possibilities and difficulties of the further rise of German-Norwegian relations for the perspective by the early 2020s.

Trajectory Tracking Control of Intelligent Driving Vehicles Based on MPC and Fuzzy PID

To improve the stability and accuracy of quintic polynomial trajectory tracking, an MPC (model predictive control) and fuzzy PID (proportional‐integral‐difference)‐ based control method are proposed. A lateral tracking controller is designed by using MPC with rule‐based horizon parameters. The lateral tracking controller controls the steering angle to reduce the lateral tracking errors. A longitudinal tracking controller is designed by using a fuzzy PID. The longitudinal controller controls the motor torque and brake pressure referring to a throttle/brake calibration table to reduce the longitudinal tracking errors. By combining the two controllers, we achieve satisfactory trajectory tracking control. Relative vehicle trajectory tracking simulation is carried out under common scenarios of quintic polynomial trajectory in the Simulink/Carsim platform. The result shows that the strategy can avoid excessive trajectory tracking errors which ensures a better performance for trajectory tracking with high safety, stability, and adaptability.

Aerodynamic Analysis of an Entry Capsule at Titan in Transition Regime

The interest of the scientific community in Titan, Saturn’s largest moon, is still strong. In fact, after the successful Cassini–Huygens mission, which landed the Huygens capsule on Titan, other missions are planned in the coming years. The aims of this work are to provide the extent of global aerodynamic force, to provide thermal and aerodynamic loads on a capsule entering Titan atmosphere, and to evaluate the effects of chemistry on 1) flowfield parameters, 2) surface catalyticity, 3) temperature and pressure distributions on a heat shield, and 4) global aerodynamic force. To develop this study, the authors used the Huygens capsule and related entry trajectory. The study was carried out in the altitude interval of 295–470 km by means of the direct simulation Monte Carlo codes: DS2V for the solution of two-dimensional/axisymmetric flowfields, and DS3V for the solution of three-dimensional flowfields. The Titan atmosphere is a mixture of nitrogen, methane, and argon. The chemical model is made of 221 reactions, making gas around the capsule a mixture of 18 species. Chemistry strongly influences local aerodynamic quantities, both in the flowfield and on the capsule surface; whereas the chemical effects on the global aerodynamic force are negligible. Our computations also verified the lack of ionization.

10-Year trajectories of depressive symptoms and subsequent brain health in middle-aged adults

Depressive symptoms differ in severity and stability over time. Trajectories depicting these changes, particularly those with high late-life depressive symptoms, have been associated with poor brain health at old age. To better understand these associations across the lifespan, we examined depressive symptoms trajectories in relation to brain health in middle age. We included 1676 participants from the ORACLE Study, all were expecting a child at baseline (mean age 32.8, 66.6% women). Depressive symptoms were assessed at baseline, 3 years and 10 years after baseline. Brain health (global brain volume, subcortical structures volume, white matter lesions, cerebral microbleeds, cortical thickness, cortical surface area) was assessed 15 years after baseline. Using k-means clustering, four depressive symptoms trajectories were identified: low, low increasing, decreasing, and high increasing symptoms. The high increasing trajectory was associated with smaller brain volume compared to low symptoms, not surviving multiple testing correction. The low increasing trajectory was associated with more cortical thickness in a small region encompassing the right lateral occipital cortex compared to low symptoms. These findings show that longitudinal depressive symptoms trajectories are only minimally associated with brain health in middle age, suggesting that associations may only emerge later in life.

Assembly Strategy for Modular Components Using a Dual-Arm Space Robot with Flexible Appendages

Space robotic systems tend to be more flexible and equipped with some appendages, such as solar panels and communication antennas. The inevitable vibration in the flexible appendage will occur during space missions, and it in turn affects the attitude of the rigid base due to coupling dynamics. This study develops an assembly scheme for a dual-arm space robot with flexible appendages to assemble two modular components and to minimize the disturbance force caused by the manipulators to the base and flexible appendages. The assembly strategy consists of two stages, a preassembly stage which transports the two components to desired relative states, and a trajectory tracking stage to achieve the final assembly. In the first stage, based on a relative Jacobian matrix in the base frame, an optimal objective function is formulated in terms of the relative position and attitude errors between the two components. Thereby, more freedom of manipulators is released for minimizing disturbance forces. Notably, two virtual points are created to describe the relative position between the two components. In the second stage, two components are driven to follow a relative trajectory for the final assembly with an unchanged relative attitude. Finally, numerical simulations are conducted to demonstrate the efficiency of the proposed assembly strategy.

A Semi-analytical Method of Calculating Nuclear Collision Trajectory in the QCD Phase Diagram

The finite nuclear thickness affects the energy density (t) and conserved-charge densities such as the net-baryon density nB(t) produced in heavy ion collisions. While the effect is small at high collision energies where the Bjorken energy density formula for the initial state is valid, the effect is large at low collision energies, where the nuclear crossing time is not small compared to the parton formation time. The temperature T(t) and chemical potentials µ(t) of the dense matter can be extracted from the densities for a given equation of state (EOS). Therefore, including the nuclear thickness is essential for the determination of the T-µB trajectory in the QCD phase diagram for relativistic nuclear collisions at low to moderate energies such as the RHIC-BES energies. In this proceeding, we will first discuss our semi-analytical method that includes the nuclear thickness effect and its results on the densities є(t), nB(t), nQ(t), and nS(t). Then, we will show the extracted T(t), µB(t), µQ(t), and µS(t) for a quark-gluon plasma using the ideal gas EOS with quantum or Boltzmann statistics. Finally, we will show the results on the T-µB trajectories in relation to the possible location of the QCD critical end point. This semi-analytical model provides a convenient tool for exploring the trajectories of nuclear collisions in the QCD phase diagram.

Waist Circumference Trajectories in Relation to Blood Pressure and the Risk of Hypertension in Chinese Adults.

Central obesity is associated with a higher risk of hypertension. This study aimed to analyze waist circumference (WC) trajectories and discover their association with blood pressure and the risk of hypertension. The data were obtained from the China Health and Nutrition Survey (CHNS), with a sample of 11,885 adults aged 18 or older. Trajectory groups of WC were identified by group-based trajectory modeling. Three trajectory groups were identified in males: "normal-stable group" (group 1), "normal-increase to central obesity group" (group 2), and "central obesity-slight decrease group" (group 3). There were also three identified in females: "normal-increase to central obesity group" (group 1), "normal-stable group" (group 2), and "central obesity-increase group" (group 3). For males, compared with group 1, systolic blood pressure (SBP) and diastolic blood pressure (DBP) increased by 2.47 mmHg and 2.13 mmHg, respectively, in group 2, and by 3.07 mmHg and 2.54 mmHg, respectively, in group 3. The adjusted hazard ratios (HR) and 95% confidence interval (95% CI) of hypertension in groups 2 and 3 were 1.16 (1.06-1.28) and 1.29 (1.10-1.50), respectively. For females, compared with group 2, SBP and DBP increased by 1.69 mmHg and 1.68 mmHg, respectively, in group 1, and by 4.96 mmHg and 2.77 mmHg, respectively, in group 3. The HR and 95% CI of hypertension in groups 2 and 3 were 1.21 (1.07-1.36) and 1.52(1.17-1.99), respectively. We found that the WC trajectory was a risk factor for hypertension and elevated blood pressure independent of basal WC. Increased risk of hypertension was nonlinearly associated with annual WC increase.