Motion (Total 66078 Papers Found)

Motion (66078 Papers Found)
This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1) joint axis and position identi ...
The technique of particle image velocimetry is used to study the velocity field of turbulent Rayleigh-Bénard convection in an aspect-ratio-1 cylindrical cell filled with water. By measuring the two-dimensional (2D) velocity vector map in different vertical cross sections of the cell, we investigate the 3D structures and dynamics of turbulent thermal convection. The experiment reveals how thermal plumes synchronize their emissions and organize their motions spatially between the top and bottom p ...
Individual experience reveals that posterior foot placement enables one to stand up easily from a chair. However, the way in which foot placement affects this motion has not been investigated in detail. This study was performed to examine the effects of foot placement in the initial stage of the dynamics of standing up from a chair. Subjects wearing light-emitting diode markers and surface electrodes stood up from a chair over force plates, and ground reaction force, joint angle, and muscle acti ...
In this paper, we present a stereovision algorithm for real-time 6DoF ego-motion estimation, which integrates image intensity information and 3D stereo data in the well-known Iterative Closest Point (ICP) scheme. The proposed method addresses a basic problem of standard ICP, i.e. its inability to perform the segmentation of data points and to deal with large displacements. Neither a-priori knowledge of the motion nor inputs from other sensors are required, while the only assumption is that the s ...
We establish an almost sure scaling limit theorem for super-Brownian motion on R associated with the semi-linear equation ut = 1 2∆u + βu − αu2, where α and β are positive constants. In this case, the spectral theoretical assumptions that required in Chen et al (2008) are not satisfied. An example is given to show that the main results also hold for some sub-domains in R. AMS Subject Classifications (2000): Primary 60J80; Secondary 60F15 ...
This paper presents a model-based approach to cancel friction in the joints of the manipulators of a force-feedback telerobotic system. Friction compensation can improve the transparency of telerobotic systems, where transparency is quantified in terms of a match between the impedance of the environment and the impedance transmitted to the user. We used Dahl friction models to compensate for physical friction in the device. Experiments performed on a telerobotic system demonstrated that teleoper ...
The influence of different agitation speeds on alcoholic fermentation by free and immobilized cells of Saccharomyces cerevisiae in a co-culture with free cells of Aspergillus awamori was investigated. Starch hydrolysis and glucose, glucoamylase and alpha-amylase accumulation in the fermentation medium was affected by agitation speed. Maximum amounts of the enzymes were obtained at 150-200 rpm after 72 h where, maximum growth and glucose accumulations were noticed at 200-300 rpm. Alcohol producti ...
This paper presents an approach for optimal path planning on implicitly-defined configuration spaces such as those arising, for instance, when manipulating an object with two arms or with a multifingered hand. In this kind of situations, the kinematic and contact constraints induce configuration spaces that are manifolds embedded in higher dimensional ambient spaces. Existing sampling-based approaches for path planning on manifolds focus on finding a feasible solution, but they do not optimize t ...
In this paper, new tools for obstacle avoidance and path planning for underwater vehicles are presented. The authors' technique, based on a level set formulation of the path planning problem, extracts optimal paths from complex and continuous environments in a complete and consistent manner. Fast marching algorithm is known to be efficient for finding cost optimal path in mobile robotics because of its reliability, precision, and simple implementation. Fast marching algorithm originally propagat ...
Image motion estimation using the spatiotemporal approach has largely relied on the constant velocity assumption, and thus becomes inappropriate when the velocity of the imaged scene or the camera changes during the data acquisition time. Using a polynomial or a trigonometric polynomial model for the time variation of the image motion, spatiotemporal algorithms are developed in this paper to handle time-varying (but space-invariant) motion. Under these models, it is shown that time-varying image ...
A blimp is a small airship that has no metal framework and collapses when deflated. In the first part of this paper, dynamic modeling of small autonomous non rigid airships is presented, using the Newton-Euler approach. This study discusses the motion in 6 degrees of freedom since 6 independent coordinates are necessary to determine the position and orientation of this vehicle. Euler angles are used in the formulation of this model. In the second part of the paper, path planning is introduced. M ...
Coherent motions, which represent coherent movements of massive individual particles, are pervasive in natural and social scenarios. Examples include traffic flows and parades of people (cf. Figs 1a and 2a). Since coherent motions can effectively decompose scenes into meaningful semantic parts and facilitate the analysis of complex crowd scenes, they are of increasing importance in crowd-scene understanding and activity recognition. In this paper, we address the problem of detecting coherent mot ...
In the Cat with a penicillin motor focus, a transcortical reflex (RTC) can be triggered by stimulation of the muscle or the cutaneous branch of the radial nerve (DR - SR). We tried here to identify at a suprabulbar level, the proprioceptive pathway involved in triggering RTC. Cerebellar ablation did not modify the reflex. On the other hand reversibly inactivation of a rostral-dorso-medial part of VPL (VPLr) receiving short latency proprioceptive afferents, reversibly abolished the TRC elicited t ...
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  • 2015
In 1879 E. H. Hall observed that when an electrical current passes through a sample placed in a magnetic field, a potential proportional to the current and to the magnetic field is developed across the material in a direction perpendicular to both the current and to the magnetic field [1]. This effect is known as the Hall effect, and is the basis of many practical applications and devices such as magnetic field measurements, and position and motion detectors. ...
Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Lauri Viitasaari Name of the doctoral dissertation Integration in a Normal World: Fractional Brownian Motion and Beyond Publisher School of Science Unit Department of Mathematics and Systems Analysis Series Aalto University publication series DOCTORAL DISSERTATIONS 14/2014 Field of research Mathematics Manuscript submitted 12 November 2013 Date of the defence 28 February 2014 Permission to publish granted (date) 14 January 2014 ...
To duplicate human motion on the computer while retaining the individuality of the source, this paper discusses what the viewers focus on when they attempt to distinguish the identity of the source. In order to define the degree of similarity on motion, the data obtained by motion capture system are categorized using Self-Organizing maps, and the validity of the categorization is investigated to confirm the extent to which it is in agreement with the viewer's intuitive judgment. Human walking pa ...
This paper presents the effect of elastic motions on rigid body motions of a 3-PRR parallel manipulator with three flexible intermediate links. The intermediate links are modeled as Euler-Bernoulli beams with pinned-pinned boundary conditions based on the assumed mode method (AMM). Using Lagrange multipliers, the fully coupled equations of motions of the flexible parallel manipulator are developed by incorporating the rigid body motions with elastic motions as a non-separated quantity. The mutua ...
Automatic adjustments of muscle activity throughout the body are required for the maintenance of balance during human walking. One mechanism that is likely to contribute to this control is the heteronymous spinal excitation between human ankle dorsiflexors and knee extensors (CPQ-reflex). Here, we investigated the CPQ-reflex at different walking speeds (1–6 km/h) and stride frequencies (0.6–1.3 Hz) in healthy human subjects to provide further evidence of its modulation, and its role in ens ...
Smolt survival through the Columbia/Snake river hydrosystem and tributaries of the Snake River are evaluated with the XT-model, which describes predator-prey interactions in terms of migration distance and time, temperature, turbidity, and a random encounter velocity between predators and prey. In this formulation, smolt survival depends on both distance traveled and exposure time, and the importance of each depends on the amount and character of predator and prey motions. The model is used to a ...
Magnetic resonance is a wrell known tool for the investigation of atomic and molecular motions in solids and a large amount of work has been done in the past on this subject by studies of Zeeman (Ty/J spin-lattice relaxation time and dipolar line widths {To). More recently, the power of the NMR method has been still considerably improved bv the mea­ surements on rotating frame1,2 Tls and dipolar (jTh)) relaxation rates which are particularly sensi­ tive to extremely slowT spin motions in solid ...
For a Reactive Virtual Trainer(RVT), subtle timing and lifelikeness of motion is of primary importance. To allow for reactivity, movement adaptation, like a change of tempo, is necessary. In this paper we investigate the relation between movement tempo, its synchronization to verbal counting, time distribution, amplitude, and left-right symmetry of a clapping movement. We analyze motion capture data of two subjects performing a clapping exercise, both freely and timed by a metronome. Our finding ...
This paper proposes a novel hybrid formation control technique for a group of differentially driven wheeled mobile robots in the Leader-Follower framework. In the proposed method, the leader robot of the group plans its path of navigation by an artificial potential field and the follower robots plan their path in order to follow the leader robot by maintaining a particular formation employing the separation-bearing control   l   . Thus, the resulting control problem has been transfor ...
Motion analysis of human body is indispensable for design and evaluation of assistive technologies. Especially, on-site analyses, which are conducted not in experimental environments but in life circumstances, are important to develop truly beneficial assistive technologies. We developed a portable motion tracking system using high-accuracy AR markers. It enables easy measurement of 6-DOF (six degrees of freedom) motion of multiple tracking points by a single camera. The pose estimation errors a ...
The thermohydrodynamical picture of a charged Brownian particle. Abstract We study a charged Brownian gas with a non uniform bath temperature, and present a thermohydrodynamical picture. Expansion on the collision time probes the validity of the local equilibrium approach and the relevant thermodynamical variables. For the linear regime we present several applications (including some novel results). For the lowest nonlinear expansion and uniform bath temperature we compute the gradient correctio ...
In this paper, two cooperative communications schemes with inter-relay interference (IRI) management are proposed for wireless multi-user decode-and-forward (DF) relay networks. The schemes are based on a DF half-duplex (HD) relaying protocol and a relay selection method which maximizes the signal-to-noise ratio (SNR) of the second hop. To minimize the IRI, the first scheme [constellation real part (CRP)] uses a new transmission scheme based on the constellation real parts of the modulated signa ...
  • C. Alba, Paul LaStayo,
  • Journal of hand therapy : official journal of the American Society of Hand Therapists
  • 2001
After a surgical release of adhered nongliding tendons, early active mobilization is encouraged to prevent the reformation of unfavorable adhesions that would limit functional tendon excursion. These restricting adhesions can also occur in non-synovial regions, such as within the flexor mass in the forearm. A "myolysis," or release of muscle fibers from tethering adhesions, can be performed surgically to restore the muscle's gliding and lengthening properties. Postoperative management consists o ...
c 1998 SPIE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the SPIE. ABSTRACT We propose a new approach to spatial segmentation of video sequences that is based on motion attributes. The approach, similarly to some previous eeorts, ...
The light from historical supernovae could in principle still be visible as scattered-light echoes centuries after the explosion. The detection of light echoes could allow us to pinpoint the supernova event both in position and age and, most importantly, permit the acquisition of spectra to determine the ‘type’ of the supernova centuries after the direct light from the explosion first reached Earth. Although echoes have been discovered around some nearby extragalactic supernovae, targeted se ...
A robot may be at the risk of falling from a high place when it works in an unknown complex environment, so the attitude control ability of the robot in the air should be considered to reduce the damage caused by the wrong dropping posture. When a cat drops in the upside-down posture with zero angular momentum, it can always right itself and land on its feet safely. Inspired by this biological phenomenon, we studied the optimal falling trajectory for adjusting the attitude of the falling cat rob ...
In order to solve the limited energy and low throughput problems of the battery-powered wireless mesh network (WMN), an IEEE 802.11n based multi-radio multi-channel energy balancing and high throughput protocol (EBHT) for battery-powered emergency WMN is presented in this paper. EBHT optimizes the route path planning to achieve the energy balance by taking WMN nodes’ residual energy, client accessed condition and route paths’ link quality into account. It also assigns different high quality ...
Analyses of the inverse and forward positions of a 3-DOF parallel mechanism (PM) along with two rotational DOFs and one translational DOF are presented in this paper. The module of this 2-PRU-PRRU PM is created, and the Jacobian of the 2-PRU-PRRU PM is derived. Boundary, local, and combined singularities are identified based on the Jacobian. The workspace of the 2-PRU-PRRU PM is discussed according to the singularities and condition of a U-joint interference. The 2-PRU-PRRU PM has a simple struc ...
Baseball injuries from throwing and hitting generally occur as a consequence of the repetitive and high-energy motions inherent to the sport. Biomechanical studies have contributed to understanding the pathomechanics leading to injury and to the development of rehabilitation programs. Interval-based throwing and hitting programs are designed to return an athlete to competition through a gradual progression of sport-specific exercises. Proper warm-up and strict adherence to the program allows the ...
The purpose of this research is to construct an intelligent upper limb prosthesis control system that uses electromyogram (EMG) signals. The signal processing of EMG signals is performed using a linear multiple regression model that can learn parameters in a short time. Using this model, joint angles are predicted, and the motion pattern discrimination is conducted. Discriminated motions were grip, open, and chuck of a hand. Predicted joint angles were multi-finger angles corresponding to these ...
A PROBABILISTIC SEARCH ALGORITHM FOR PROTEIN-PROTEIN DOCKING Irina Hashmi, MS George Mason University, 2012 Thesis Director: Dr. Amarda Shehu Computational methods able to assist or complement wet-laboratory experiments in structural characterization of molecular assemblies promise to provide detailed insight into molecular interactions, drug-design, and biological function in the living and diseased cell. Methods that predict three-dimensional structures of protein-protein assemblies are abunda ...
The submacrogeometric (tolerance) variations of mechanical components have an important impact on product function. The problem of combining tolerance assignment in engineering design with tolerance control in manufacturing and quality assurance presents a continuing challenge to researchers. This paper illustrates the feasibility of using fractal-based methods for the problem of tolerance specification in engineering design. Error data are generated as a function of the fractal dimension using ...
We consider a classical model of matter–radiation interaction, in which the matter is represented by a system of infinitely many dipoles on a one– dimensional lattice, and the system is dealt with in the so–called dipole (i.e. linearized) approximation. We prove that there exist normal–mode solutions of the complete system, so that in particular the dipoles, though performing accelerated motions, do not radiate energy away. This comes about in virtue of an exact compensation which we pro ...
Objective of the methodology presented in this paper is to perform design space exploration on a high level of abstraction by applying high-level transformations. To realize a design loop which is close and settled on upper design levels, a high-level estimation step is integrated. In this paper, several estimation methodologies fixed on different states of the high-level synthesis process are examined with respect to their aptitude on controlling the transformational design space exploration pr ...
OBJECTIVE The purpose of this study was to evaluate trajectories of and predictors for changes in upper extremity (UE) function in women (n = 396) during the first year after breast cancer treatment. DESIGN Prospective, longitudinal assessments of shoulder range of motion (ROM), grip strength, and perceived interference of function were performed before and for 1 year after surgery. Demographic, clinical, and treatment characteristics were evaluated as predictors of postoperative function. R ...
Burger, Birgitta Move the way you feel: Effects of musical features, perceived emotions, and personality on music-induced movement Jyväskylä: University of Jyväskylä, 2013, 79 p. (Jyväskylä Studies in Humanities ISSN 1459-4323 (nid.), 1459-4331 (PDF); 215) ISBN 978-951-39-5465-9 (nid.) ISBN 978-951-39-5466-6 (PDF) Listening to music makes us move, ranging from barely visible movement like faint foot tapping to full-body dance movement. Such movements appear to be synchronized to the beat o ...
Limited capture range and the requirement to provide high quality initialisation for optimisation-based 2D/3D image registration methods can significantly degrade the performance of 3D image reconstruction and motion compensation pipelines. Challenging clinical imaging scenarios, which contain significant subject motion such as fetal in-utero imaging, complicate the 3D image and volume reconstruction process. In this paper we present a learning based image registration method capable of predicti ...
For any non-compact Riemannian manifold M of dimension n ≥ 2 we previously defined a function λM : M×M → R+ = R+∪{+∞] only dependent on the conformal structure of M , and proved that for a class of manifolds containing all the proper subdomains of R, λ 1 n M was a distance on M [F1, F2]. The case of a domain G of R has been the object of several investigations leading to estimations of λG[V1, . . . , V4] and to properties of the λG-Lipschitz mappings [FMV]. Then by considering the c ...
Extracting moving objects from their background or partitioning them have been one of the most prerequisite tasks for various computer vision applications such as surveillance, tracking, human machine interface, etc. Though many previous approaches have been working in a certain level, still they are not robust under various unexpected situation such as large illumination change. In this paper, we propose a motion segmentation method based on our robust illumination invariant optical flow estima ...
A Berkovits type action for pure spinors in even dimensions is considered. The equations of motion for pure spinors are investigated by using explicit parameterizations which solve the pure spinor constraints. For general interactions, the equations of motions are shown to be modified from the naive ones. The extra terms contain a particular projector ∆(λ, ω). If the interactions are restricted to the “ghost number” u(1) and the Lorentz so(p, q) current couplings, the action has a large ...
We show that the excitonic coupling in molecular crystals undergoes a very large fluctuation at room temperature as a result of the combined thermal motions of the nuclei. This observation dramatically affects the description of exciton transport in organic crystals and any other phenomenon (like singlet fission or exciton dissociation) that originates from an exciton in a molecular crystal or thin film. This unexpected result is due to the predominance of the short-range excitonic coupling mech ...
Background Pediatric cancer survivors after anthracycline therapy are at risk for left ventricular systolic dysfunction. Strain may be a more sensitive marker than left ventricular ejection fraction (LVEF). Feature tracking (FT) is a promising technique for strain measurement on cardiovascular magnetic resonance (CMR) images, but has limited validation vs. the gold standard of harmonic phase (HARP) imaging analysis. This study aimed to compare strain by FT and HARP on CMR images in pediatric can ...
Background Cardiac diffusion MRI (CDMRI) has the potential to identify acute myocardial ischemia and assess the chronic change of myofiber orientation after a myocardial infarction [1,2]. Cardiac motion and SNR limitations have been the primary challenges for the application of the technique in vivo. A few previous in vivo studies have demonstrated the feasibility of CDMRI in humans using diffusion-weighted (DW) EPI. However, these approaches suffer from inherently poor SNR efficiency in the cas ...
The method of regularized Stokeslets (MRS) uses a radially symmetric blob function of infinite support to smooth point forces and allow for evaluation of the resulting flow field. This is a common method to study swimmers at zero Reynolds number where the Stokeslet is the fundamental solution corresponding to the kernel of the single layer potential. Simulating the collective motion of N micro swimmers using the MRS results in at least N pair-wise interactions. Efficient simulation of a large nu ...
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  • 2017
Noise’ or random fluctuations characterize all physical systems in nature ranging from biology, botany, physiology, meteorology, astronomy, etc. The apparently irregular or chaotic fluctuations were considered as ‘noise’ in all fields except in astronomy, where the fluctuations from astronomical sources were referred to as signal. Noise and fluctuation has been a field of study since 1826 with the study of Brownian motion which indirectly confirmed the existence of atoms and molecules. The ...
STUDY DESIGN A human cadaveric biomechanical study comparing craniocervical fixation techniques. OBJECTIVE To quantitatively compare the biomechanical stability of a new technique for occipitocervical fixation using the occipital condyles with an established method for craniocervical spine fusion. SUMMARY OF BACKGROUND DATA Stabilization of the occipitocervical junction remains a challenge. The occiput does not easily accommodate instrumentation because of access and spatial constraints. In ...