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1
Bonfanti, P., F. Simien, R. Rampazzo, and Ph Prugniel. "Kinematics of early-type galaxies in compact groups: HCG 67, HCG 74 and HCG 79." International Astronomical Union Colloquium 174 (2000): 50–53. http://dx.doi.org/10.1017/s0252921100054749.
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AbstractWe present measurements of stellar kinematics for seven early-type galaxies in HCG 67, HCG 74 and HCG 79. These data are aimed at studying the relation between the environment and the dynamics, structure and stellar content of early-type galaxies. In the present three groups, the kinematic features we observed cannot be associated unambiguously to physical interactions. Visible morphological peculiarities do not appear correlated with kinematical perturbations.
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Tuleshov, K. Amandyk, A. Kassymbek Ozhikenov, and K. Assylbek Ozhiken. "Investigation of Dynamical Peculiarities of Manipulator on the Basis of close Circuit Mechanism." Advanced Materials Research 705 (June 2013): 386–89. http://dx.doi.org/10.4028/www.scientific.net/amr.705.386.
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Manipulator dynamics is investigated on the basis of closed kinematic chain, in comparison to manipulator on the base of non-closed kinematic chain. Thereby the dynamic peculiarities of their driving actuators are considered. The solution of the task of program motion development was received as a solution of inverse task of kinematics. The modeling issues of investigated manipulators dynamics are resolved and the results were attained. The attained results demonstrate that the application of flat closed mechanisms as the operating device of manipulation robots is promising from the perspective of enhancement of their dynamical peculiarities.
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Geonea, Ionut, Alexandru Margine, and Alin Ungureanu. "Study upon the Dynamic Answer of Plane Manipulators." Advanced Materials Research 463-464 (February 2012): 1304–8. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.1304.
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The paper illustrates the structure of plane mechanical systems used to manipulators. In the first part are presented some kinematics schemes used to plane manipulators. These mechanisms are used to manipulators, positioning and control systems. In generally these mechanisms have two or three degree of mobility. The purpose of the paper is to study the dynamics of a plane manipulator mechanical system used to manipulate garbage containers. It is presented the kinematics scheme of a plane manipulator, used to this purpose and is presented the mechanism functional description. In the second part is presented the kinematical and dynamical analysis for the plane manipulator mechanism. In the last part of the paper are presented graphical results for the dynamics parameters.
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Fattah, A., and G. Kasaei. "Kinematics and dynamics of a parallel manipulator with a new architecture." Robotica 18, no. 5 (September 2000): 535–43. http://dx.doi.org/10.1017/s026357470000271x.
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In this paper, the kinematics and dynamics of a parallel manipulator with a new architecture supposed to be used as a moving mechanism in a flight simulator project is studied. This manipulator with three independent degrees of freedom consists of a moving platform connected to a based platform by means of three legs. Kinematic solutions for this manipulator at position, velocity and acceleration levels are obtained. Moreover, the dynamical equations of motion of the manipulator are determined using Newton-Euler's equations and applying the natural orthogonal complement (NOC) method. Using kinematics and dynamics and also performing simulation for different manoeuvres of moving platform, the motion and the actuator forces of the legs are obtained.
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Tiongco, Maria A., Enrico Vesperini, and Anna Lisa Varri. "Kinematical evolution of multiple stellar populations in star clusters." Monthly Notices of the Royal Astronomical Society 487, no. 4 (June 25, 2019): 5535–48. http://dx.doi.org/10.1093/mnras/stz1595.
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ABSTRACT We present the results of a suite of N-body simulations aimed at understanding the fundamental aspects of the long-term evolution of the internal kinematics of multiple stellar populations in globular clusters. Our models enable us to study the cooperative effects of internal, relaxation-driven processes and external, tidally induced perturbations on the structural and kinematic properties of multiple-population globular clusters. To analyse the dynamical behaviour of the multiple stellar populations in a variety of spin-orbit coupling conditions, we have considered three reference cases in which the tidally perturbed star cluster rotates along an axis oriented in different directions with respect to the orbital angular momentum vector. We focus specifically on the characterization of the evolution of the degree of differential rotation and anisotropy in the velocity space, and we quantify the process of spatial and kinematic mixing of the two populations. In light of recent and forthcoming explorations of the internal kinematics of this class of stellar systems by means of line-of sight and astrometric measurements, we also investigate the implications of projection effects and spatial distribution of the stars adopted as tracers. The kinematic and structural richness emerging from our models further emphasizes the need and the importance of observational studies aimed at building a complete kinematical picture of the multiple population phenomenon.
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Samurovic, S., A. Vudragovic, M. Jovanovic, and M. M. Cirkovic. "Low dark matter content of the nearby early-type galaxy NGC 821." Serbian Astronomical Journal, no. 188 (2014): 29–36. http://dx.doi.org/10.2298/saj1488029s.
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In this paper we analyze the kinematics and dynamics of the nearby early-type galaxy NGC 821 based on its globular clusters (GCs) and planetary nebulae (PNe). We use PNe and GCs to extract the kinematics of NGC 821 which is then used for the dynamical modelling based on the Jeans equation. We apply the Jeans equation using the Newtonian mass-follows-light approach assuming constant mass-to-light ratio and find that using such an approach we can successfully fit the kinematic data. The inferred constant mass-to-light ratio, 4:2 < M=LB < 12:4 present throughout the whole galaxy, implies the lack of significant amount of dark matter. We also used three different MOND approaches and found that we can fit the kinematic data without the need for additional, dark, component.
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Luo, Xian Hai, and Liang Zhen Li. "Dynamics Automatic Design of Planar Linkage Mechanism Based on Genetic Program." Advanced Materials Research 396-398 (November 2011): 2447–51. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.2447.
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Regarded planar linkage mechanism kinematic target and execution of kinematic pair constraint reaction restrictions as the quantitative objectives, established the comprehensive dynamic design fitness function with the distance between a kinematics target and execution of a set of practical movement points, and the difference between actual constraint reaction of kinematic pair and its limit. According to multi-branch tree expression and random configuration method to create mechanical initial population, driven by the fitness function, made the mechanical population evolution towards the target requirements by the use of copy, crossover and mutation operators of genetic program. In the evolutionary process, inserted kinematics and dynamics automatic analysis technique, design examples indicated that using a genetic program can search parallel in different mechanical configuration space, dimension space and inertia space, automatically searched to such kinds of mechanisms approximate kinematics target and dynamics requirements, thus fulfilling the dynamics automatic design.
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Laschowski, Brock, Naser Mehrabi, and John McPhee. "Inverse Dynamics Modeling of Paralympic Wheelchair Curling." Journal of Applied Biomechanics 33, no. 4 (August 2017): 294–99. http://dx.doi.org/10.1123/jab.2016-0143.
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Paralympic wheelchair curling is an adapted version of Olympic curling played by individuals with spinal cord injuries, cerebral palsy, multiple sclerosis, and lower extremity amputations. To the best of the authors’ knowledge, there has been no experimental or computational research published regarding the biomechanics of wheelchair curling. Accordingly, the objective of the present research was to quantify the angular joint kinematics and dynamics of a Paralympic wheelchair curler throughout the delivery. The angular joint kinematics of the upper extremity were experimentally measured using an inertial measurement unit system; the translational kinematics of the curling stone were additionally evaluated with optical motion capture. The experimental kinematics were mathematically optimized to satisfy the kinematic constraints of a subject-specific multibody biomechanical model. The optimized kinematics were subsequently used to compute the resultant joint moments via inverse dynamics analysis. The main biomechanical demands throughout the delivery (ie, in terms of both kinematic and dynamic variables) were about the hip and shoulder joints, followed sequentially by the elbow and wrist. The implications of these findings are discussed in relation to wheelchair curling delivery technique, musculoskeletal modeling, and forward dynamic simulations.
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Jordan, Christopher E. "Scale effects in the kinematics and dynamics of swimming leeches." Canadian Journal of Zoology 76, no. 10 (October 1, 1998): 1869–77. http://dx.doi.org/10.1139/z98-131.
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Slender-bodied organisms swimming with whole-body undulations exhibit what appears to be a high degree of kinematic parameter conservation, which is independent of body size. However, organisms of very different sizes swim in fundamentally different physical realms, owing to the relative scaling of viscous and inertial fluid stresses as a function of size and speed. In light of the size-dependent fluid forces, the kinematic constancy suggests three hypotheses: (1) swimming organisms adopt a single "ideal" swimming mode requiring the modification of muscle forces or motor patterns through ontogeny, (2) swimming kinematics are determined predominantly by the passive mechanical interaction of the body and the fluid, resulting in a single swimming mode independent of absolute body size, or (3) while undulatory swimming kinematics may be similar between organisms, there are important size-dependent kinematic differences. In this study, I address this issue by examining the swimming kinematics and dynamics of the medicinal leech Hirudo medicinalis L. as a function of body size. Over a 5-fold increase in body length, the relative amplitude of body undulations during swimming did not change; however, swimming speed, propulsive wave speed, and propulsive wave frequency all decreased, while propulsive wave number increased slightly, strongly supporting hypothesis 2. To determine the source of the observed size-dependent swimming kinematics, I manipulated the dynamic viscosity of the organism's fluid environment to alter the constraints placed on swimming behavior by the physical surroundings. In the elevated-viscosity treatment, all kinematic parameters changed in the opposite direction to that predicted by hypothesis 2, rejecting both the idea that swimming kinematics are simply determined by passive mechanical interactions and that leeches have a target swimming mode under active control.
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Hadian, Hamoon, Yasser Amooshahi, and Abbas Fattah. "Kinematics and Dynamics Modeling of a New 4-DOF Cable-Driven Parallel Manipulator." International Journal of Intelligent Mechatronics and Robotics 1, no. 4 (October 2011): 44–60. http://dx.doi.org/10.4018/ijimr.2011100103.
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This paper addresses the kinematics and dynamics modeling of a 4-DOF cable-driven parallel manipulator with new architecture and a typical Computed Torque Method (CTM) controller is developed for dynamic model in SimMechanics. The novelty of kinematic architecture and the closed loop formulation is presented. The workspace model of mechanism’s dynamic is obtained in an efficient and compact form by means of natural orthogonal complement (NOC) method which leads to the elimination of the nonworking kinematic-constraint wrenches and also to the derivation of the minimum number of equations. To verify the dynamic model and analyze the dynamical properties of novel 4-DOF cable-driven parallel manipulator, a typical CTM control scheme in joint-space is designed for dynamic model in SimMechanics.
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van der Marel, Roeland P. "Recent Progress in the Search for Black Holes in Galactic Nuclei." Symposium - International Astronomical Union 171 (1996): 117–20. http://dx.doi.org/10.1017/s0074180900232233.
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Massive nuclear black holes (BHs) of 106–109M⊙ are believed to be responsible for the the energy production in quasars and active galaxies, and are thought to be present in many quiescent galaxies as well. Dynamical evidence for this can be sought by studying the dynamics of gas and stars in galactic nuclei at high spatial resolution. This paper reviews the current evidence, with emphasis on some recent developments and ongoing projects. The evidence from water masers and gas kinematics in the active galaxies NGC 4258 and M87 is compelling. In quiescent galaxies only stellar kinematics are generally available. One well-studied case is M32. Stellar dynamical f(E, Lz) models with a few million solar mass BH fit the ground-based kinematical data remarkably well. N-body simulations of an edge-on f(E, Lz) model for M32 show that this model is stable. HST spectra should soon provide new and improved constraints on the presence of BHs in quiescent galaxies.
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Li, Hong Jun, Wei Jiang, Yu Yan, An Zhang, and Gan Zuo. "Operation Motion Planning and Principle Prototype Design of Four-Wheel-Driven Mobile Robot for High-Voltage Double-Split Transmission Lines." Mathematical Problems in Engineering 2020 (March 19, 2020): 1–17. http://dx.doi.org/10.1155/2020/6195320.
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In response to the problems of high labor intensity, high risk, and poor reliability of artificial live working, a four-wheel-driven spacer bar replacement mobile operation robot has been designed and developed in this paper, and the corresponding kinematic and dynamics model have been established, based on the established double models, the kinematics and dynamics numerical analysis can be realized through INVENTOR and ADAMS, respectively, based on the established kinematics and dynamics models . The results show that the simulation value of the robot joint displacement, velocity, acceleration, and joint force can be able to meet the requirements of kinematic and dynamic constraints during the robot operation. The robot prototype can meet the requirement of dual-split robot working space and the operation joint force control, which not only extend the robot adaptability to the multisplit lines heterogeneous operation environment but also provide an important theoretical technical support for the exploit of the robot physical prototype. Through the robot kinematics and dynamics analysis, the robot mechanical structure parameters and electrical control parameters have been effectively optimized. The weight and cost of the robot have been reduced by 12% and 15% compared to the existed studies. Finally, the robot principle prototype mobile platform has been developed, and the correctness of robot kinematics and dynamics simulation analysis has been verified through the robot principle prototype mobile platform.
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Barylski, Adam, and Norbert Piotrowski. "New Kinematic Systems in Single-Sided Lapping and their Influence on Lap Wear." Applied Mechanics and Materials 831 (April 2016): 14–24. http://dx.doi.org/10.4028/www.scientific.net/amm.831.14.
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Previous studies on one-sided lapping allow to state that not only parameters of lapping elements (i.e. properties of workpiece, abrasive grains and lapping plate) impact on a lapping efficiency. Influential are also kinematics and dynamics of the process. It is crucial to control an average velocity of lapping (v), a distribution of tangential acceleration (at), a nominal pressure (p), a lapping time (t) and disposal of workpiece in separator.Based on kinematics equations and the tribological models, the dimensionless distribution of the material removal volume and the trajectories of abrasive grains cutting on the lap were numerically simulated. Obtained information about excessive wear on lapping plate was the starting point to work out non-standard, single-plate lapping systems.In this paper ideas of unconventional lapping systems were presented. After numerous simulations and careful analysis it was observed, that the most desirable system is radial lapping system. It was point out that other systems are not very different from the standard kinematic system. Generated trajectories of an abrasive grain were almost identical. What is more, effects of kinematical parameters on the trajectories, velocities and accelerations observed in radial lapping system are shown.
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Ruggiero, Alessandro, and Alessandro Sicilia. "A Novel Explicit Analytical Multibody Approach for the Analysis of Upper Limb Dynamics and Joint Reactions Calculation Considering Muscle Wrapping." Applied Sciences 10, no. 21 (November 2, 2020): 7760. http://dx.doi.org/10.3390/app10217760.
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The aim of this paper is to present an explicit analytical biomechanical multibody procedure able to be implemented in the solution of the musculoskeletal systems inverse dynamics problems. The model is proposed in formal multibody analysis and implemented in the Matlab numerical environment. It is based on the constraint kinematical behaviour analysis and considers both linear muscle actuators and curved ones, by calculating the geodesic muscle path over wrapping surfaces fixed to the bodies. The model includes the Hill muscle approach in order to evaluate both the contractile elements’ actions and the passive ones. With the aim to have a first validation, the model was applied to the dynamical analysis of the “arm26” OpenSim model, an upper limb subjected to external forces of gravity and to known kinematics. The comparison of results shows interesting matching in terms of kinematical analysis, driving forces, muscles’ activations and joint reactions, proving the reliability of the proposed approach in all cases in which it is necessary to achieve in-silico explicit determinations of the upper limb dynamics and joint reactions (i.e., in joint tribological optimization).
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Tang, Liang, Yi Zhang, and Hua Deng. "Dynamic Modeling and Analysis of Underactuated Prosthetic Hand." Advanced Materials Research 655-657 (January 2013): 400–407. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.400.
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Based on the kinematic equation of index finger, the trajectory space of fingertip is analyzed, and the structural parameters of underactuated prosthetic hand have been optimized by ADAMS, which compare the trajectory space with the index-finger. Using the modeling methods of Lagrange dynamics equation, the dynamic model is established for the three-joint underactuated prosthetic finger, whose kinematic and dynamic characteristics also are analyzed. Finally, by the construction of the virtual prototype and its introduction into ADAMS for the dynamics simulation, the correctness of kinematics and dynamics model is verified by the dynamics simulation of virtual prototype.
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Zhao, Si Jun, Jia Yua Shan, and Lu Yan Bi. "6-Axis Serial Robot Simulation Based on SimulationX." Applied Mechanics and Materials 152-154 (January 2012): 1010–17. http://dx.doi.org/10.4028/www.scientific.net/amm.152-154.1010.
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This paper presents research and simulation analysis on kinematics and dynamics problem based on the 6-axis serial robot. By means of Denavit-Hartenberg method, the robot kinematics model is established as well as and the derivation process of kinematic and inverse kinematic resolution is described in detail. Furthermore, in software simulationX, robot system model including mechanical sub-system and control sub-system are founded. Additionally, through simulation, different performances of robot are illustrated based on different trajectory planning and control. In this way a theoretical reference is provided for the further study on trajectory planning and controls of 6-axis serial robot.
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Hwang, Yunn Lin, Thi Na Ta, and Cao Sang Tran. "Dynamic Analysis and Control of Hydraulic Machine System and Industrial Robotic Manipulators." Applied Mechanics and Materials 883 (July 2018): 1–7. http://dx.doi.org/10.4028/www.scientific.net/amm.883.1.
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Dynamic control on hydraulic machine system and kinematic control on industrial robotic manipulators are two studied topics in this research. The main objective of this study is to analyze dynamic, forward kinematic and inverse kinematic on a couple of mechanical systems and hydraulic mechanical systems in order to control these machines. The characteristics of hydraulic and manipulator robot parameters are firstly calculated by using dynamic theories. In the former topic, we perform an example on CNC machine tools which is designing a hydraulic controller to move a cutting tool along a circular path. Dynamics analysis, forward kinematics and inverse kinematics of industrial robotic are archived in the latter topic. Two experiments were also performed on RRR and RRRRRR manipulators by analyzing the inverse kinematic equations to make these robots follow the desired trajectories. This study takes innovations and achieves control improvement in different systems with optimization controller or trajectory planning.
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Cantat-Gaudin, T., C. Jordi, N. J. Wright, J. J. Armstrong, A. Vallenari, L. Balaguer-Núñez, P. Ramos, et al. "Expanding associations in the Vela-Puppis region." Astronomy & Astrophysics 626 (June 2019): A17. http://dx.doi.org/10.1051/0004-6361/201834957.
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Context. The Vela-Puppis region is known to host the Vela OB2 association as well as several young clusters featuring OB and pre-main-sequence stars. Several spatial and kinematic subgroups have been identified in recent years. Aims. By grouping stars based on their positions and velocity, we can address the question of the dynamical history of the region and the mechanisms that drove stellar formation. The Gaia DR2 astrometry and photometry enables us to characterise the 3D spatial and 3D kinematic distribution of young stars and to estimate the ages of the identified components. Methods. We used an unsupervised classification method to group stars based on their proper motions and parallax. We studied the expansion rates of the different identified groups based on 3D velocities and on corrected tangential velocities. We used theoretical isochrones to estimate ages. Results. The young stars can be separated into seven main groups of different ages and kinematical distribution. All groups are found to be expanding, although the expansion is mostly not isotropic. Conclusions. The size of the region, the age substructure, and the anisotropic expansion rates are compatible with a prolonged period of star formation in a turbulent molecular cloud. The current kinematics of the stars cannot be explained by internal processes alone (such as gas expulsion).
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Xi, F., and R. G. Fenton. "On flexible link manipulators: modeling and analysis using the algebra of rotations." Robotica 12, no. 4 (July 1994): 371–82. http://dx.doi.org/10.1017/s0263574700017392.
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SUMMARYIn this paper, a complete model of the elasto-kinematics is formulated in terms of a new kinematic notation, called the algebra of rotations. Based on this formulation, the elegant and concise expressions are derived for the displacement equation and especially the Jacobians governing the motion mapping between the manipulator tip and joint variables as well as link deflections. Introduction of the elasto-kinematics into the elasto-dynamics can directly take into consideration the nonlinear coupling between joint variables and link deflections, and thus improve the result of the elasto-dynamics.
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Staicu, Stefan. "Recursive modelling in dynamics of Delta parallel robot." Robotica 27, no. 2 (March 2009): 199–207. http://dx.doi.org/10.1017/s0263574708004451.
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SUMMARYRecursive matrix relations in kinematics and dynamics of a Delta parallel robot having three revolute actuators are established in this paper. The prototype of the manipulator is a three degrees-of-freedom space mechanism, which consists of a system of parallel closed kinematical chains connecting to the moving platform. Knowing the translation motion of the platform, we develop first the inverse kinematics problem and determine the position, velocity and acceleration of each robot's element. Further, the inverse dynamic problem is solved using an approach based on the fundamental principle of virtual work. Finally, a comparative study on time-history evolution of the torques of the three actuators is analysed.
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Tiongco, Maria A., Enrico Vesperini, and Anna Lisa Varri. "Kinematical evolution of Globular Clusters." Proceedings of the International Astronomical Union 14, S351 (May 2019): 524–27. http://dx.doi.org/10.1017/s1743921319009207.
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AbstractWe present several results of the study of the evolution of globular clusters’ internal kinematics, as driven by two-body relaxation and the interplay between internal angular momentum and the external Galactic tidal field. Via a large suite of N-body simulations, we explored the three-dimensional velocity space of tidally perturbed clusters, by characterizing their degree of velocity dispersion anisotropy and their rotational properties. These studies have shown that a cluster’s kinematical properties contain distinct imprints of the cluster’s initial structural properties, dynamical history, and tidal environment. Building on this fundamental understanding, we then studied the dynamics of multiple stellar populations in globular clusters, with attention to the largely unexplored role of angular momentum.
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Xin, Hong Bing, Qiang Huang, and Yue Qing Yu. "Structural Analysis of Mechanism with Compound Hinges in Ordinal Single Opened Chain Theory." Advanced Materials Research 418-420 (December 2011): 2050–54. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.2050.
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The coupling degree and structure factor of mechanism are the important parameters for the research of principle of mechanism structure, kinematics and dynamics in the ordinal single opened chain method, This article presents the algorithm of coupling degree for the kinematic chain with compound hinges on the basis of that for the kinematic chain without compound hinges and the dual-color topology graph, through which the mechanism with compound hinges can be decomposed into basic kinematic chains, the correctness of the algorithm has been verified by the practical example.
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Zhang, Dan Dan. "Dynamics Analysis of Manipulator in the Hot Line." Advanced Materials Research 989-994 (July 2014): 3079–83. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.3079.
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The high voltage transmission lines exposed for a long time are often broken down, thus, The manipulator arm of robot in the hot line was designed, The design is reasonable through kinematical analysis. First, make sure of the connecting rod coordinates and the connecting rod's D-H parameters. Matlab was used to draw 3D model of manipulator. Use functions in the Robotics Toolbox to solve kinematics analysis.
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Bardan, Eytan, Mark Kern, Ronald C. Arndorfer, Candy Hofmann, and Reza Shaker. "Effect of aging on bolus kinematics during the pharyngeal phase of swallowing." American Journal of Physiology-Gastrointestinal and Liver Physiology 290, no. 3 (March 2006): G458—G465. http://dx.doi.org/10.1152/ajpgi.00541.2004.
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Swallowing difficulty is a common complaint in the elderly and, although there are data for the biomechanics of liquid swallows, little is known about solid bolus motion, or kinematics, in the elderly. The aims of this study were as follows: 1) to characterize and compare solid and liquid bolus kinematics in the elderly and compare the findings with those in young subjects and 2) to correlate bolus kinematics and dynamics. Concurrent manometric-fluoroscopic techniques were used to study eight young and eight elderly subjects. The subjects performed four swallows each of 0.2-cm-diameter solid barium pellets and 5 ml of liquid barium during sagittal fluoroscopy and six-channel pharyngoesophageal manometry. Images were digitized for analysis of kinematic properties such as velocity and acceleration. Dynamic pressures were recorded and coordinated with kinematic events. Image analysis showed that velocity varied as the pellet passed through the hypopharynx, pharynx, and upper esophageal sphincter. In young subjects, pellet kinematics were characterized by two zones of pellet acceleration: one over the tongue base and another as the pellet passed through the upper esophageal sphincter. Although the elderly showed a similar zone of acceleration over the base of the tongue, the second zone of pellet acceleration was not seen. Decreasing pressure gradients immediately distal to the position of the solid pellet and liquid bolus characterized dynamics for all subjects. This decreasing pressure gradient was significantly larger in elderly than in young subjects. Bolus kinematics and dynamics were significantly altered among elderly compared with young subjects. Among these differences were the absence of hypopharyngeal bolus acceleration and a significant increase in the transsphincteric pressure gradient in the elderly.
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Müller, Andreas. "On the terminology and geometric aspects of redundant parallel manipulators." Robotica 31, no. 1 (April 20, 2012): 137–47. http://dx.doi.org/10.1017/s0263574712000173.
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SUMMARYParallel kinematics machines (PKMs) can exhibit kinematics as well as actuation redundancy. While the meaning of kinematic redundancy has been already clarified for serial manipulators, actuation redundancy, which is only possible in PKMs, is differently classified in the literature. In this paper a consistent terminology for general redundant PKM is proposed. A kinematic model is introduced with the configuration space (c-space) as central part. The notion of kinematic redundancy is recalled for PKM. C-space, output, and input singularities are distinguished. The significance of the c-space geometry is emphasized, and it is pointed out geometrically that input singularities can be avoided by redundant actuation schemes. In order to distinguish different actuation schemes of PKM, a nonlinear control system is introduced whose dynamics evolves on c-space. The degree of actuation (DOA) is introduced as the number of independent control vector fields, and PKMs are classified as full-actuated and underactuated machines. Relating this DOA to degree of freedom allows to classify the actuation redundancy.
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Dipietro, Laura, Howard Poizner, and Hermano I. Krebs. "Spatiotemporal Dynamics of Online Motor Correction Processing Revealed by High-density Electroencephalography." Journal of Cognitive Neuroscience 26, no. 9 (September 2014): 1966–80. http://dx.doi.org/10.1162/jocn_a_00593.
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The ability to control online motor corrections is key to dealing with unexpected changes arising in the environment with which we interact. How the CNS controls online motor corrections is poorly understood, but evidence has accumulated in favor of a submovement-based model in which apparently continuous movement is segmented into distinct submovements. Although most studies have focused on submovements' kinematic features, direct links with the underlying neural dynamics have not been extensively explored. This study sought to identify an electroencephalographic signature of submovements. We elicited kinematic submovements using a double-step displacement paradigm. Participants moved their wrist toward a target whose direction could shift mid-movement with a 50% probability. Movement kinematics and cortical activity were concurrently recorded with a low-friction robotic device and high-density electroencephalography. Analysis of spatiotemporal dynamics of brain activation and its correlation with movement kinematics showed that the production of each kinematic submovement was accompanied by (1) stereotyped topographic scalp maps and (2) frontoparietal ERPs time-locked to submovements. Positive ERP peaks from frontocentral areas contralateral to the moving wrist preceded kinematic submovement peaks by 220–250 msec and were followed by positive ERP peaks from contralateral parietal areas (140–250 msec latency, 0–80 msec before submovement peaks). Moreover, individual subject variability in the latency of frontoparietal ERP components following the target shift significantly predicted variability in the latency of the corrective submovement. Our results are in concordance with evidence for the intermittent nature of continuous movement and elucidate the timing and role of frontoparietal activations in the generation and control of corrective submovements.
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Khang, Nguyen Van, Nguyen Phong Dien, Nguyen Van Vinh, and Tran Hoang Nam. "Inverse kinematic and dynamic analysis of redundant measuring manipulator BKHN-MCX-04." Vietnam Journal of Mechanics 32, no. 1 (June 1, 2010): 15–26. http://dx.doi.org/10.15625/0866-7136/32/1/313.
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This paper deals with the problem of inverse kinematics and dynamics of a measuring manipulator with kinematic redundancy which was designed and manufactured at Hanoi University of Technology for measuring the geometric tolerance of surfaces of machining components. A comparison between the calculation result and the experimental measurement is also presented.
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Sfarti, A. "Tachyon – A Non-Existent Particle." European Journal of Applied Physics 3, no. 2 (March 15, 2021): 1–2. http://dx.doi.org/10.24018/ejphysics.2021.3.2.56.
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In a 1967 paper [1], G. Feinberg conjectured about the possibility of “faster-than-light” particles. In the current note we prove his conjecture to be false by showing that he missed several key counter-arguments to their existence. We explain why the existence of tachyons contradicts both relativistic kinematics and relativistic dynamics. Our paper is divided in two sections: the kinematic counter-arguments and the dynamics counter-arguments.
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Coccato, Lodovico. "Planetary nebulae as kinematic tracers of galaxy stellar halos." Proceedings of the International Astronomical Union 12, S323 (October 2016): 271–78. http://dx.doi.org/10.1017/s1743921317000564.
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AbstractThe kinematic and dynamical properties of galaxy stellar halos are difficult to measure because of the faint surface brightness that characterizes these regions. Spiral galaxies can be probed using the radio Hiemission; on the contrary, early-type galaxies contain less gas, therefore alternative kinematic tracers need to be used. Planetary nebulae (PNe) can be easily detected far out in the halo thanks to their bright emission lines. It is therefore possible to map the halo kinematics also in early-type galaxies, typically out to 5 effective radii or beyond. Thanks to the recent spectroscopic surveys targeting extra-galactic PNe, we can now rely on a few tens of galaxies where the kinematics of the stellar halos are measured. Here, I will review the main results obtained in this field in the last decades.
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Made Kartika Wijayanti, Ni, Mochamad Ikbal Arifyanto, and Nur Annisa. "Search for Stellar Streams in The Galactic Halo From Gaia DR2, GALAH DR2, RAVE DR5 and LAMOST DR4 Data." EPJ Web of Conferences 240 (2020): 07012. http://dx.doi.org/10.1051/epjconf/202024007012.
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Stellar streams are stars which are trapped in the same potensial caused by dynamical resonance or tidal force. We aim to analyze kinematic sub- structures (streams) in the Galactic halo by V vs √ U2+ 2V 2 planes of Arifyanto & Fuchs. We crossmatched data from Gaia DR2, GALAH DR2, RAVE DR5 and LAMOST DR4 based on positions. We have 3D kinematics and metallicity data of halo stars selected from kinematics criteria from ratio of probability of thick disk (TD) over halo (H) less than 0.01. Substructures are detected by using wavelet transformation and corrected using 15 Monte Carlo simulations. We obtained four kinematic structures on V vs √U2 + 2V 2 plane which two of them are associated to BB17-1 and BB17-2 streams. All the streams had a high probability from the extragalactic origin.
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Kecskés, István, Ervin Burkus, Fülöp Bazsó, and Péter Odry. "Model validation of a hexapod walker robot." Robotica 35, no. 2 (August 17, 2015): 419–62. http://dx.doi.org/10.1017/s0263574715000673.
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SUMMARYOur complete dynamical simulation-model realistically describes the real low-cost hexapod walker robot Szabad(ka)-II within prescribed tolerances under nominal load conditions. This validated model is novel, described in detail, for it includes in a single study: (a) digital controllers, (b) gearheads and DC motors, (c) 3D kinematics and dynamics of 18 Degree of Freedom (DOF) structure, (d) ground contact for even ground, (e) sensors and battery model. In our model validation: (a) kinematical-, dynamical- and digital controller variables were simultaneously compared, (b) differences of measured and simulated curves were quantified and qualified, (c) unknown model parameters were estimated by comparing real measurements with simulation results and applying adequate optimization procedures. The model validation helps identifying both model's and real robot's imperfections: (a) gearlash of the joints, (b) imperfection of approximate ground contact model, (c) lack of gearhead's internal non-linear friction in the model. Modeling and model validation resulted in more stable robot which performed better than its predecessors in terms of locomotion.
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Kalani, Hadi, and Alireza Akbarzadeh. "Parameter Optimization of a Snake Robot Using Taguchi Method." Applied Mechanics and Materials 110-116 (October 2011): 4220–26. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.4220.
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In this paper, performance of a 16 link snake robot in serpentine locomotion is investigated. Key kinematics and dynamics parameters are identified. The aim of this paper is to minimize average power consumption per unit distance traveled. Dynamic and kinematics equations of snake robot are used to perform simulation and obtain results. Key kinematics parameters are identified. Taguchi method is utilized and orthogonal array table is constructed. ANOVA technique is used to analyze the statistical significance of kinematic and dynamic parameters. Taguchi method is used to determine optimum parameter settings effecting performance of snake robot. Finally, the snake robot is modeled in WEBOTS software and forward motion is obtained.
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Zhou, Wan Chun, and Dong Min Liu. "The Creative Design of Injector Clamping Mechanism." Advanced Materials Research 418-420 (December 2011): 2166–69. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.2166.
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Abstract. Analysis of a certain topological structure characteristics of clamping mechanism of injection machine, according to general principles, converts it into only containing Deputy General of the connecting rod and rotating chain. Bodies comprehensive theory of numbers after distribution combined with rod classes are general Atlas of kinematic chain. After identifying design constraints, on the redistribute members and turn the pair, you can get all man foot design requirements of viable specific Atlas of kinematic chains. Then every possible specific kinematic chain materialized to the schematic diagram of mechanism. Designers are on this basis through the kinematics and dynamics analysis to determine the best new clamping mechanism of injection machine.
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Giorgi, Giuseppe, Josh Davidson, Giuseppe Habib, Giovanni Bracco, Giuliana Mattiazzo, and Tamás Kalmár-Nagy. "Nonlinear Dynamic and Kinematic Model of a Spar-Buoy: Parametric Resonance and Yaw Numerical Instability." Journal of Marine Science and Engineering 8, no. 7 (July 9, 2020): 504. http://dx.doi.org/10.3390/jmse8070504.
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Mathematical models are essential for the design and control of offshore systems, to simulate the fluid–structure interactions and predict the motions and the structural loads. In the development and derivation of the models, simplifying assumptions are normally required, usually implying linear kinematics and hydrodynamics. However, while the assumption of linear, small amplitude motion fits traditional offshore problems, in normal operational conditions (it is desirable to stabilize ships, boats, and offshore platforms), large motion and potential dynamic instability may arise (e.g., harsh sea conditions). Furthermore, such nonlinearities are particularly evident in wave energy converters, as large motions are expected (and desired) to enhance power extraction. The inadequacy of linear models has led to an increasing number of publications and codes implementing nonlinear hydrodynamics. However, nonlinear kinematics has received very little attention, as few models yet consider six degrees of freedom and large rotations. This paper implements a nonlinear hydrodynamic and kinematic model for an archetypal floating structure, commonplace in offshore applications: an axisymmetric spar-buoy. The influence of nonlinear dynamics and kinematics causing coupling between modes of motion are demonstrated. The nonlinear dynamics are shown to cause parametric resonance in the roll and pitch degrees of freedom, while the nonlinear kinematics are shown to potentially cause numerical instability in the yaw degree of freedom. A case study example is presented to highlight the nonlinear dynamic and kinematic effects, and the importance of including a nominal restoring term in the yaw DoF presented.
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Pensabene, A., S. Carniani, M. Perna, G. Cresci, R. Decarli, R. Maiolino, and A. Marconi. "The ALMA view of the high-redshift relation between supermassive black holes and their host galaxies." Astronomy & Astrophysics 637 (May 2020): A84. http://dx.doi.org/10.1051/0004-6361/201936634.
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Context. The existence of tight correlations between supermassive black holes (BHs) and their host galaxies’ properties in the local Universe suggests a closely linked evolution. Investigating these relations up to the high redshifts (z ≳ 6) is crucial in order to understand the interplay between star formation and BH growth across the cosmic time and to set constraints on galaxy formation and evolution models. In this work, we focus on the relation between BH mass (MBH) and the dynamical mass (Mdyn) of the host galaxy. Aims. Previous works suggest an evolution of the MBH−Mdyn relation with redshift indicating that BH growth precedes the galaxy mass assembly during their co-evolution at z > 3. However, dynamical galaxy masses at high redshift are often estimated through the virial theorem, thus introducing significant uncertainties. Within the scope of this work, our aim is to study the MBH−Mdyn relation of a sample of 2 < z < 7 quasars by constraining their galaxy masses through a full kinematical modelling of the cold gas kinematics, thus avoiding all possible biases and effects introduced by the rough estimates usually adopted so far. Methods. For this purpose, we retrieved public observations of 72 quasar host galaxies observed in [CII]158 μm or CO transitions with the Atacama Large Millimeter Array (ALMA). We then selected those quasars whose line emission is spatially resolved, and performed a kinematic analysis on ALMA observations. We estimated the dynamical mass of the systems by modelling the gas kinematics with a rotating disc, taking into account geometrical and instrumental effects. Our dynamical mass estimates, combined with MBH obtained from literature and our own new CIVλ1550 observations allowed us to investigate the MBH/Mdyn in the early Universe. Results. Overall, we obtained a sample of ten quasars at z ∼ 2−7, in which line emission is detected with high S/N (≳5−10) and the gas kinematics are spatially resolved and dominated by ordered rotation. The estimated dynamical masses place six out of ten quasars above the local relation yielding to MBH/Mdyn ratios ∼10× higher than those estimated in low-z galaxies. On the other hand, we found that four quasars at z ∼ 4−6 have dynamical-to-BH-mass ratios consistent with what is observed in early-type galaxies in the local Universe.
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Sun, Shu Hua. "Study on the 4-PTT Variable Topology Parallel Chinese Massage Manipulator." Applied Mechanics and Materials 215-216 (November 2012): 33–36. http://dx.doi.org/10.4028/www.scientific.net/amm.215-216.33.
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In the paper, virtual prototype parallel chinese massage manipulator was designed based on the technique kinematics and dynamics analysis in Chinese massage technique and on the 4-PTT variable topology parallel mechanism.At the same time, for an example the pushing method,simulation analysis for the kinematic and dynamic of the virtual prototype were studied.
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Xia, Guang Lan, Xing Wei Hu, Bao Lin Yin, and Feng Yu. "Kinematic Analysis of 4-UPU Parallel Mechanism Based on Influence Coefficient." Applied Mechanics and Materials 741 (March 2015): 691–96. http://dx.doi.org/10.4028/www.scientific.net/amm.741.691.
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Mechanism kinematic influence coefficient deeply reflects the essence of the kinematics and dynamics mechanism, analysis of the problems of many institutions can use the influence coefficient of clear and clearly expressed. In this paper, with less degree of freedom parallel mechanism as the research object, through the virtual mechanism method to derive one or two order influence coefficient matrix, based on the analysis of the mechanism and influence of speed and acceleration coefficient matrix. Finally, the precision of the method for solving the kinematics is proved by examples of numerical analysis.
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Drewniak, J., and S. Zawiślak. "Kinematical and dynamical analysis of closed kinematic chains using graphs and contour equations." PAMM 9, no. 1 (December 2009): 547–48. http://dx.doi.org/10.1002/pamm.200910246.
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Kosbolov, Serikbay, Yerlan Yeleukulov, Alfiya Atalykova, Algazy Zhauyt, Gulsara Yestemessova, and Saltanat Yussupova. "Dynamics and rigidity of a manipulator with three DOFs." MATEC Web of Conferences 226 (2018): 01020. http://dx.doi.org/10.1051/matecconf/201822601020.
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The problem of dynamic elastic four-link initial kinematic chain (IKC) of the load-bearing manipulator, which is the basis for various modifications are considered. Using the Lagrange operator for this system, equations of motion in matrix form are obtained. To determine the potential energy of an elastic four-link IKC manipulator, we use the formula for the elastic potential energy of a rectilinear homogeneous rod of length l. The cross-section of the rod is considered annular or circular. Solving the system of linear equations of motion on a computer using the ADAMS program, the results of the movement of links and cargo were obtained. Kinematics and dynamics are presented for a generic 3 DOFs Initial Kinematic Chain; with anthropometric data and the dynamics equations, simulations were performed to understand its behavior.
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Sosa-Méndez, Deira, Esther Lugo-González, Manuel Arias-Montiel, and Rafael A. García-García. "ADAMS-MATLAB co-simulation for kinematics, dynamics, and control of the Stewart–Gough platform." International Journal of Advanced Robotic Systems 14, no. 4 (July 1, 2017): 172988141771982. http://dx.doi.org/10.1177/1729881417719824.
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The mechanical structure known as Stewart–Gough platform is the most representative parallel robot with a wide variety of applications in many areas. Despite the intensive study on the kinematics, dynamics, and control of the Stewart–Gough platform, many details about these topics are still a challenging problem. In this work, the use of automatic dynamic analysis of multibody systems software for the kinematic and dynamic analysis of the Stewart–Gough platform is proposed. Moreover, a co-simulation automatic dynamic analysis of multibody systems (ADAMS)-MATLAB is developed for motion control of the Stewart–Gough platform end-effector. This computational approach allows the numerical solution for the kinematics, dynamics, and motion control of the Stewart–Gough platform and a considerable reduction on the analytical and programming effort. The obtained results in the three topics (kinematics, dynamics, and control) are validated by comparing them with analytical results reported in the literature. This kind of computational approach allows for the creation of virtual prototypes and saves time and resources in the development of Stewart–Gough platform-based robots applications.
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Melluso, Maurizio. "A Theoretical and Experimental Approach of Fuzzy Adaptive Motion Control for Wheeled Autonomous Nonholonomic Vehicles." ISRN Robotics 2013 (October 21, 2013): 1–18. http://dx.doi.org/10.5402/2013/621067.
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A new fuzzy adaptive control is applied to solve a problem of motion control of nonholonomic vehicles with two independent wheels actuated by a differential drive. The major objective of this work is to obtain a motion control system by using a new fuzzy inference mechanism where the Lyapunov stability can be ensured. In particular the parameters of the kinematical control law are obtained using a fuzzy mechanism, where the properties of the fuzzy maps have been established to have the stability above. Due to the nonlinear map of the intelligent fuzzy inference mechanism (i.e., fuzzy rules and value of the rule), the parameters above are not constant, but, time after time, based on empirical fuzzy rules, they are updated in function of the values of the tracking errors. Since the fuzzy maps are adjusted based on the control performances, the parameters updating ensures a robustness and fast convergence of the tracking errors. Also, since the vehicle dynamics and kinematics can be completely unknown, dynamical and kinematical adaptive controllers have been added. The proposed fuzzy controller has been implemented for a real nonholonomic electrical vehicle. Therefore, system robustness and stability performance are verified through simulations and experimental studies.
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Manchado, Arturo, Guillermo García-Segura, and You-Hua Chu. "Kinematical study of the wind-blown bubble NGC 6888." Symposium - International Astronomical Union 193 (1999): 366–67. http://dx.doi.org/10.1017/s0074180900205767.
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A detailed kinematical analysis of wind-blown bubble ring nebula NGC 6888 swept-up by the wind of the Wolf-Rayet star WR 136, combining high resolution echelle [O III] spectra, high resolution HST imaging and high resolution ground base imaging, is presented. The kinematics is compared to new theoretical models for the dynamics of WR bubbles based on a three-winds scenario. The actual visible nebula is formed by the red supergiant wind swept-up by the fast WR wind. We conclude that the intringuing filamentary morphology, mainly formed by clumps, tails and ripples are explained by the actuation of Vishniac instabilities on the swept-up shell during the expansion of a red supergiant wind, as predicted by the gas dynamical simulations. The kinematics confirm that NGC 6888 is actually on a breakout process at the NW side, as derived from the blowouts. The blowouts are formed by shocked gas which is directly interacting with the cavity formed by the main sequence wind. The fact that these blowouts are bounded by shocks suggests that the cooling is efficient in a main sequence bubble during the evolution.
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Hedrick, Tyson L., and Alice K. Robinson. "Within-wingbeat damping: dynamics of continuous free-flight yaw turns in Manduca sexta." Biology Letters 6, no. 3 (February 24, 2010): 422–25. http://dx.doi.org/10.1098/rsbl.2010.0083.
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Free-flight body dynamics and wing kinematics were collected from recordings of continuous, low-speed, multi-wingbeat yaw turns in hawkmoths ( Manduca sexta ) using stereo videography. These data were used to examine the effects of rotational damping arising from interactions between the body rotation and flapping motion (flapping counter-torque, FCT) on continuous turning. The moths were found to accelerate during downstroke, then decelerate during upstroke by an amount consistent with FCT damping. Wing kinematics related to turning were then analysed in a simulation of hawkmoth flight; results were consistent with the observed acceleration–deceleration pattern. However, an alternative wing kinematic which produced more continuous and less damped accelerations was found in the simulation. These findings demonstrate that (i) FCT damping is detectable in the dynamics of continuously turning animals and (ii) FCT-reducing kinematics do exist but were not employed by turning moths, possibly because within-wingbeat damping simplifies control of turning by allowing control systems to target angular velocity rather than acceleration.
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Steffen, Wolfgang. "Dynamical modeling and the interactions with the ISM." Proceedings of the International Astronomical Union 7, S283 (July 2011): 168–75. http://dx.doi.org/10.1017/s1743921312010897.
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AbstractThis paper is a review of some of the recent modeling efforts to improve our understanding of structure formation and evolution of planetary nebulae including their interaction with the interstellar medium. New propositions have been made for the formation mechanism of multi-polar PNe and PPNe. These mechanisms are based on the central engine with interacting binary stars or hole producing instabilities in expanding shock waves leading to illumination effects from the central star that change the appearance of the nebula. Furthermore, there has been a lot of progress in the observation and 3D modeling of the kinematics, which is key to the understanding of the dynamics. Extensive observational catalogs are coming online for the kinematics, as well as some very detailed proper motion measurements have been made. New techniques for morpho–kinematic 3D modeling help to make the interpretation of kinematic data more reliable and detailed. In addition to individual pointed observations, new surveys have lead to the discovery of many PNe that show clear signs of interaction with the interstellar medium. Systematic hydrodynamic models of the interaction have produced a general scheme for the observed structure that results from the interaction of an evolving planetary nebula with the ISM. Detailed modeling of the dust-gas dynamics during the interaction with the ISM have produced interesting predictions for future IR observations. Detailed models were worked out for the structure of the bowshock and tail of Mira that was recently discovered in the UV.
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McNeil, Emily, Magda Arnaboldi, Ortwin Gerhard, Kenneth Freeman, Payel Das, and Lodovico Coccato. "JD1-The Planetary Nebulae and the Dynamics of NGC 1399." Proceedings of the International Astronomical Union 5, H15 (November 2009): 66. http://dx.doi.org/10.1017/s1743921310008215.
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Dynamical models of galaxies are limited by the paucity of kinematic data at large radii. Beyond the feasible limit of integrated-light spectroscopy, we rely on discrete tracers such as planetary nebulae and globular clusters. We describe a large (~200) sample of planetary nebula (PN) velocities in the outer regions of the cD elliptical NGC 1399. These data were obtained with a counter-dispersed slitless-spectroscopy technique which traces the kinematics to about 60 kpc (McNeil et al., 2009).
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Ciortan, Marinela, Liliana Luca, and Alin Stancioiu. "Study on a Gripping Biomechanism Represented by the Human Dento-Maxillary Apparatus." Applied Mechanics and Materials 332 (July 2013): 515–20. http://dx.doi.org/10.4028/www.scientific.net/amm.332.515.
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In this paper presents the gripping biomechanism of the dento-maxillary apparatus. Here are some important studies conducted worldwide on the structure, kinematics and dynamics of biomechanism. In the paper the authors present their experimental research conducted to determine the movements made by the biomechanism. Using data obtained from video films, and radiographs we identified in detail the permitted movements of temporomandibular joint. The kinematic equivalent diagram of mechanism was established. The kinematic calculations performed but not presented due to lack of space in the paper showed that the mechanism is optimal for the required movements.
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Mitnitski, Arnold B. "Kinematic models cannot provide insight into motor control." Behavioral and Brain Sciences 20, no. 2 (June 1997): 318–19. http://dx.doi.org/10.1017/s0140525x97371441.
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In Plamondon & Alimi's target article, a bell-shaped velocity profile typically observed in fast movements is used as a basis for the “kinematic theory” of motor control. In our opinion, kinematics is a necessary but insufficient ground for a theory of motor control. Relationships between different kinematic characteristics are an emergent property of the system dynamics controlled by the brain in a specific way. In particular, bell-shaped velocity profiles with or without additional waves are a trivial consequence of shifts in the equilibrium state of the system as suggested, for example, in the λ-model of motor control.
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Pfister, F. "Bernoulli Numbers and Rotational Kinematics." Journal of Applied Mechanics 65, no. 3 (September 1, 1998): 758–63. http://dx.doi.org/10.1115/1.2789120.
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The representation of rotation operators in the form of infinite tensor power series, R = exp(Ψˆ), has been found to be a valuable tool in multibody dynamics and nonlinear finite element analysis. This paper presents analogous formulations for the kinematic differential equations of the Euler-vector Ψ and elucidates their connection to Bernoulli-numbers. New power series such as the Bernoulli- and the Gibbs series are shown to provide compact expressions and a simple means for understanding and computing some of the fundamental formulae of rotational kinematics. The paper includes an extensive literature review, discussions of isogonal rotations, and a kinematic singularity measure.
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Wang, Baofang, Chen Qian, and Qingwei Chen. "A Dynamics Controller Design Method for Car-like Mobile Robot Formation Control." MATEC Web of Conferences 160 (2018): 06003. http://dx.doi.org/10.1051/matecconf/201816006003.
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A dynamics controller design method based on characteristic model is proposed for the formation control problem of car-like mobile robots. Only kinematics controller is not enough for some cases such as the environment is rugged, and the dynamics parameters of the robot are time-varying. Simulation results show that the proposed method can improve the responding speed of the mobile robots and maintain high formation accuracy. First, we obtain the kinematic error state equations according to the leader-follower method. A kinematics controller is designed and the stability is proved by Lyapunov theory. Then the characteristic model of the dynamics inner loop is established. A sliding mode controller is designed based on the second order discrete model, and the stability of the closed-loop system is analyzed. Finally, simulations are designed in MATLAB and Microsoft Robotics Developer Studio 4 (MRDS) to verify the effectiveness of the proposed method.
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Zanganeh, Kourosh E., Rosario Sinatra, and Jorge Angeles. "Kinematics and dynamics of a six-degree-of-freedom parallel manipulator with revolute legs." Robotica 15, no. 4 (July 1997): 385–94. http://dx.doi.org/10.1017/s0263574797000477.
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This paper presents the kinematics and dynamics of a six-degree-of-freedom platform-type parallel manipulator with six revolute legs, i.e. each leg consists of two links that are connected by a revolute joint. Moreover, each leg is connected, in turn, to the base and moving platforms by means of universal and spherical joints, respectively. We first introduce a kinematic model for the manipulator under study. Then, this model is used to derive the kinematics relations of the manipulator at the displacement, velocity and acceleration levels. Based on the proposed model, we develop the dynamics equations of the manipulator using the method of the natural orthogonal complement. The implementation of the model is illustrated by computer simulation and numerical results are presented for a sample trajectory in the Cartesian space.