Changes In Direction Of Motion Research Articles

A fresh look at Gulf of Mexico tectonics: Testing rotations and breakup mechanisms from the perspective of seismically constrained potential-fields modeling and plate kinematics

Interpretation of recent, high-quality seismic data in the Gulf of Mexico (GOM) has led to competing hypotheses regarding the basin’s rift to drift transition. Some studies suggest a fault-controlled mechanism that ultimately results in mantle exhumation prior to seafloor spreading. Others suggest voluminous magmatic intrusion accommodates the terminal extension phase and results in the extrusion of volcanic seaward dipping reflectors (SDRs). Whereas it has been generally accepted that the plate motions between the rift and drift phases of the GOM are nearly perpendicular to each other, it has not been greatly discussed if the breakup mechanism plays a role in accommodating the transition in plate motion. We have developed a plate kinematic and crustal architecture hypothesis to address the transition from rift to drift in the GOM. We support the proposition of a fault-controlled breakup mechanism, in which slip on a detachment between the crust and mantle may have exhumed the mantle. However, we stress that this mechanism is not exclusive of synrift magmatism, though it does imply that SDRs observed in the GOM are not in this case indicative of a volcanic massif separating attenuated continental and normal oceanic crust. We support our hypothesis through a geometrically realistic 2D potential field model, which includes a magnetic seafloor spreading model constrained by recent published seismic data and analog rock properties. The 2D model suggests that magnetic anomalies near the continent-ocean transition may be related to removal of the lower continental crust during a phase of hyperextension prior to breakup, ending in mantle exhumation. The kinematics of breakup, derived from recent satellite gravity data and constrained by our spreading model and the global plate circuit, suggests that this phase of hyperextension accommodated the change in plate motion direction and a diachronous breakup across the GOM.

Similar Biomechanics During Change Of Direction In Adolescents With Contact Versus Non-contact Acl Injury

PURPOSE: Patients who sustain non-contact (N-CON) anterior cruciate ligament (ACL) injuries may be predisposed to injury due to deficient biomechanics. In contrast, patients who sustain contact (CON) ACL injuries may be injured due to unlucky trauma rather than poor biomechanics. This study compared biomechanics during change of direction movements between patients with CON vs. N-CON ACL injury mechanisms. We hypothesized that patients with CON ACL injury would have better biomechanics (greater shock absorption and less dynamic limb valgus) than patients with N-CON ACL injury. METHODS: 15 patients age 10-18 years with CON ACL injury (4 female; mean age 15.5, SD 2.1) and 94 with N-CON ACL injury (11 female; mean age 15.6, SD 1.9) underwent motion analysis 6-12 months (mean 7.5, SD 1.3) after ACL reconstruction (ACLR). Subjects performed forward-backwards and lateral change of direction tasks. 3D kinematic and kinetic variables reflecting dynamic limb valgus (frontal and transverse plane) and shock absorption (sagittal plane) were compared between patients who had CON and N-CON injury mechanisms using 2-tailed t-tests. RESULTS: No significant differences were observed between the CON and N-CON groups (Table). CONCLUSION: The CON injury group did not have better biomechanics than the N-CON group. This may be due to both groups engaging in similar rehabilitation programs. Alternatively, the CON injury group may have had similar pre-injury biomechanics to the N-CON group but happened to suffer a contact injury. These results suggest that all patients post-ACLR have potentially modifiable risk factors for re-injury and should have their biomechanics evaluated so any deficiencies can be rectified prior to return to sport regardless of injury mechanism.Table: Comparison of kinematics and kinetics between contact and non-contact ACL injury groupsExternal moments are reported. Angles are expressed in degrees, moments in N/kg, energy absorption in J/kg.

Importance of Visual Information at Change in Motion Direction on Depth Perception From Monocular Motion Parallax

This article demonstrates the importance of visual information on depth perception from monocular motion parallax presented at the time of change in the motion direction of head and stimulus movements. In head-tracking systems, a longer delay time between the head and stimulus movements degrades the depth perception from the monocular motion parallax. Because this delay is noticeable at this time, we hypothesized that the visual information given at the time of the direction change plays a critical role in the depth perception from motion parallax. We evaluated depth perception from monocular motion parallax with and without a visual stimulus at the time of the motion direction change to confirm our hypothesis and clarified that stable and unambiguous depth can be perceived by presenting the change of the stimulus motion direction. We also demonstrated that it is the change in motion direction itself that is important rather than the temporal stop between deceleration and acceleration of the stimulus motion.

Attention amplifies neural representations of changes in sensory input at the expense of perceptual accuracy

Attention enhances the neural representations of behaviorally relevant stimuli, typically by a push–pull increase of the neuronal response gain to attended vs. unattended stimuli. This selectively improves perception and consequently behavioral performance. However, to enhance the detectability of stimulus changes, attention might also distort neural representations, compromising accurate stimulus representation. We test this hypothesis by recording neural responses in the visual cortex of rhesus monkeys during a motion direction change detection task. We find that attention indeed amplifies the neural representation of direction changes, beyond a similar effect of adaptation. We further show that humans overestimate such direction changes, providing a perceptual correlate of our neurophysiological observations. Our results demonstrate that attention distorts the neural representations of abrupt sensory changes and consequently perceptual accuracy. This likely represents an evolutionary adaptive mechanism that allows sensory systems to flexibly forgo accurate representation of stimulus features to improve the encoding of stimulus change.

Development and Evaluation of Maze-Like Puzzle Games to Assess Cognitive and Motor Function in Aging and Neurodegenerative Diseases.

There is currently a need for engaging, user-friendly, and repeatable tasks for assessment of cognitive and motor function in aging and neurodegenerative diseases. This study evaluated the feasibility of a maze-like Numberlink puzzle game in assessing differences in game-based measures of cognition and motor function due to age and neurodegenerative diseases. Fifty-five participants, including young (18–31 years, n = 18), older (64–79 years, n = 14), and oldest adults (86–98 years, n = 14), and patients with Parkinson’s (59–76 years, n = 4) and Huntington’s disease (HD; 35–66 years, n = 5) played different difficulty levels of the Numberlink puzzle game and completed usability questionnaires and tests for psychomotor, attentional, visuospatial, and constructional and executive function. Analyses of Numberlink game-based cognitive (solving time and errors) and motor [mean velocity and movement direction changes (MDC)] performance metrics revealed statistically significant differences between age groups and between patients with HD and older adults. However, patients with Parkinson’s disease (PD) did not differ from older adults. Correlational analyses showed significant associations between game-based performance and movement metrics and performance on neuropsychological tests for psychomotor, attentional, visuospatial, and constructional and executive function. Furthermore, varying characteristics of the Numberlink puzzle game succeeded in creating graded difficulty levels. Findings from this study support recent suggestions that data from a maze-like puzzle game provide potential “digital biomarkers” to assess changes in psychomotor, visuoconstructional, and executive function related to aging and neurodegeneration. In particular, game-based movement measures from the maze-like puzzle Numberlink games are promising as a tool to monitor the progression of motor impairment in neurodegenerative diseases. Further studies are needed to more comprehensively establish the cognitive validity and test–retest reliability of using Numberlink puzzles as a valid cognitive assessment tool.

Hand dexterity assessment based on mouse pointer trajectory measurements in children with learning disabilities

We present an investigation of the systematic differences in upper limb motor skills between children with learning disabilities (LDs) and children without LDs. The study comprised point-and-click experiments, one-dimensional (1D), and two-dimensional (2D), conducted with mouse and joystick. Eighty (80) children with LDs and forty-six (46) children without LDs participated in the experiments. We utilized our input device evaluation application (IDEA) system to track the mouse pointer and calculate ten trajectory parameters: movement time, index of difficulty, throughput, movement variability, missed clicks, movement direction change, target re-entry, movement offset, task axis crossing, and movement error. The statistical analysis of the mouse pointer trajectory parameters using the hierarchical logistic regression model detected the children with LDs with a 70% success rate in the 2D experiment with the mouse.

Development of Point-to-Point Path Control in Actuator Space for Hydraulic Knuckle Boom Crane

This paper presents a novel method for point-to-point path control for a hydraulic knuckle boom crane. The developed path control algorithm differs from previous solutions by operating in the actuator space instead of the joint space or Cartesian space of the crane. By operating in actuator space, almost all the parameters and constraints of the system become either linear or constant, which greatly reduces the complexity of both the control algorithm and path generator. For a given starting point and endpoint, the motion for each actuator is minimized compared to other methods. This ensures that any change in direction of motion is avoided, thereby greatly minimizing fatigue, jerky motion, and energy consumption. However, where other methods may move the tool-point in a straight line from start to end, the method in actuator space will not. In addition, when working in actuator space in combination with pressure-compensated control valves, there is no need for linearization of the system or feedback linearization due to the linear relationship between the control signal and the actuator velocities. The proposed solution has been tested on a physical system and shows good setpoint tracking and minimal oscillations.

Hydrochronology of a proposed deep geological repository for low- and intermediate-level nuclear waste in southern Ontario from U–Pb dating of secondary minerals: response to Silurian and Cretaceous events

A record of fluid flow has been documented within a Paleozoic carbonate platform sequence by U–Pb dating of calcite in veins and vugs from rock core sampled through a shallowly dipping sequence of sedimentary rocks beneath the Bruce nuclear site, Ontario, Canada. Secondary calcite from >650 m deep Ordovician carbonate rocks yields a Silurian age of 434 ± 5 Ma possibly related to infiltration of seawater from overlying evaporitic basins as well as hydrothermal solutions that infiltrated from below. In contrast, near-surface Devonian rocks mostly give vein infill ages over the range of 80–100 Ma with evidence for younger infill down to 50 Ma. Vein calcite samples previously dated from surface outcrops of Ordovician carbonate exposed up to 500 km to the east yielded similar U–Pb ages. Coincidence of near-surface vein calcite ages indicates widespread vein emplacement synchronous with a change in direction of motion of the North American plate as well as possible erosional unroofing following passage of the region over the Great Meteor hotspot approximately 125 Myr ago. Deeper carbonate formations have remained apparently impermeable to post-Paleozoic disturbance despite these perturbations.

Effects of second-generation and indoor sports surfaces on knee joint kinetics and kinematics during 45° and 180° cutting manoeuvres, and exploration using statistical parametric mapping and Bayesian analyses

The aim of the current investigation was to examine the influence of second-generation (2G) and indoor surfaces on knee joint kinetics, kinematics, frictional and muscle force parameters during 45° and 180° change of direction movements using statistical parametric mapping (SPM) and Bayesian analyses. Twenty male participants performed 45° and 180° change of direction movements on 2G and indoor surfaces. Lower limb kinematics were collected using an eight-camera motion capture system, and ground reaction forces were quantified using an embedded force platform. ACL, patellar tendon and patellofemoral loading, was examined via a musculoskeletal modelling approaches, and the frictional properties of the surfaces were examined using ground reaction force information. Differences between surfaces were examined using SPM and Bayesian analyses. Both SPM and Bayesian analyses showed that ACL loading parameters were greater in the 2G condition in relation to the indoor surface. Conversely, SPM and Bayesian analyses confirmed that patellofemoral/patellar tendon loading alongside the coefficient of friction and peak rotational moment were larger in the indoor condition compared to the 2G surface. This study indicates that the indoor surface may improve change of direction performance owing to enhanced friction at the shoe--surface interface but augment the risk from patellar tendon/patellofemoral injuries, whereas the 2G condition may enhance the risk from ACL pathologies.

Using approximate Bayesian inference for a "steps and turns" continuous-time random walk observed at regular time intervals.

The study of animal movement is challenging because movement is a process modulated by many factors acting at different spatial and temporal scales. In order to describe and analyse animal movement, several models have been proposed which differ primarily in the temporal conceptualization, namely continuous and discrete time formulations. Naturally, animal movement occurs in continuous time but we tend to observe it at fixed time intervals. To account for the temporal mismatch between observations and movement decisions, we used a state-space model where movement decisions (steps and turns) are made in continuous time. That is, at any time there is a non-zero probability of making a change in movement direction. The movement process is then observed at regular time intervals. As the likelihood function of this state-space model turned out to be intractable yet simulating data is straightforward, we conduct inference using different variations of Approximate Bayesian Computation (ABC). We explore the applicability of this approach as a function of the discrepancy between the temporal scale of the observations and that of the movement process in a simulation study. Simulation results suggest that the model parameters can be recovered if the observation time scale is moderately close to the average time between changes in movement direction. Good estimates were obtained when the scale of observation was up to five times that of the scale of changes in direction. We demonstrate the application of this model to a trajectory of a sheep that was reconstructed in high resolution using information from magnetometer and GPS devices. The state-space model used here allowed us to connect the scales of the observations and movement decisions in an intuitive and easy to interpret way. Our findings underscore the idea that the time scale at which animal movement decisions are made needs to be considered when designing data collection protocols. In principle, ABC methods allow to make inferences about movement processes defined in continuous time but in terms of easily interpreted steps and turns.

Flip motion of solitary wave in an Ising-type Vicsek model.

An Ising-type Vicsek model is proposed for collective motion and sudden direction change in a population of self-propelled particles. Particles move on a linear lattice with velocity +1 or -1 in the one-dimensional model. The probability of the velocity of a particle at the next step is determined by the number difference of the right- and left-moving particles at the present lattice site and its nearest-neighboring sites. A solitary wave appears also in our model similarly to previous models. In some parameter range, the moving direction of the solitary wave sometimes changes rather suddenly, which is like the sudden change of direction of a flock of birds. We study the average reversal time of traveling direction numerically and compare the results with a mean-field theory. The one-dimensional model is generalized to a two-dimensional model. Flip motion of a bandlike soliton is observed in the two-dimensional model.

Changes (but not differences) in motion direction fail to capture attention

In this study we investigated under what conditions motion direction changes pop out in continuously moving target/distractor environments. Participants were presented with vertically oriented Gabor patches whose carrier components drifted at a constant speed from left to right and then reversed direction. On any given trial, one of these elements was nominated as the target and the remaining elements were distractors. Distractor elements all changed direction simultaneously. The distractors either moved in a homogeneous manner (i.e. all moved in the same direction), or in a heterogeneous manner (i.e. direction was randomized). The target moved with a similar spatio-temporal trajectory as the distractors from left to right (or vice versa), but changed direction asynchronously with respect to the distracting elements. The participants’ task was to locate this deviant (target) Gabor patch. We show that a motion direction change pops out (as indicated by the absence of a set size effect) when the surrounding distractors move in a homogeneous direction. When the distractors moved in heterogenous directions, a similar pop out effect was observed when the set size was small (≤5 elements), but not when it was large. This suggests that motion direction changes capture attention only when the change results in a unique direction of motion. Consistent with this finding we also show that a moving target (without direction change) captures attention in cases in which all distractors recently changed direction. This corroborates the idea that, in addition to direction cues, the temporal uniqueness of a change in an object’s direction (or absence, thereof) relative to surrounding objects is a cue capable of capturing attention.

Bilateral And Split Stance Isometric Midthigh Pulls Can Equally Predict Change Of Direction Ability

The isometric midthigh pull (IMTP) has been shown to be able to predict change of direction (COD) ability. This is of interest for sports that require COD movements, as it could potentially be used to identify standout athletes in their respective sports. However, no literature to our knowledge has assessed split stance isometric midthigh pull (SSIMTP) as a predictor of COD ability compared to the IMTP. PURPOSE: The purpose of this study was to determine whether SSIMTP is a better predictor of COD ability than the IMTP. METHODS: Seventeen (12M and 5F) university aged adults participated in the following study. Mean height, weight, and age were 176±8.6cm, 172±24.2kg, and 22±3 years, respectively. Participants completed two sessions randomized in order that were two to five days apart; four trials of the SSIMTP (two trials per lead leg) and the other session involved two trials of the IMTP. Each day also consisted of four trials of the 505-agility test. Two trials involved pivoting off of the left foot and two trials pivoting off of the right foot, which was randomized in order. RESULTS: All results are Pearson Correlation Coefficients presented with their respective p-value. The combined peak force (PF) of the IMTP and the best 505-agility time for the left and right foot had r values of -0.648 (p<0.09) and -0.464 (p<0.08), respectively. The r values during the SSIMTP condition were -0.722 (p=0.02) and -0.462 (p=0.07) when the left leg is the lead leg and COD to the left and when the right leg is the lead leg and COD to the right, respectively. CONCLUSION: The main finding of this study is that the combined PF produced during the IMTP and the PF produced by the lead leg during the SSIMTP can both uniformly predict COD. For the SSIMTP condition, a significant strong inverse correlation exists between left COD ability and left leg when it is forward and a moderate inverse correlation between right COD ability and the right leg when it is forward. For the IMTP condition, there is a strong inverse correlation between the combined PF and COD ability to the left and moderate inverse correlation between the combined PF and COD to the right. Previous literature has found correlations between IMTP and COD ability anywhere between -0.47 to -0.89.

Impact of Gln94Glu mutation on the structure and function of protection of telomere 1, a cause of cutaneous familial melanoma

Protection of telomere 1 (POT1) is a key component of shelterin complex, essential for maintaining telomere length and its regulation. It consists of N-terminal domain (residues 1–299), which interacts with telomeric ssDNA, and the C-terminal domain (residues 320–634) that binds to the tripeptidyl-peptidase I (TPP1). A large number of naturally occurring mutations in the POT1 gene are associated with glioma, cardiac angiosarcoma and cutaneous familial melanoma (FM). In particular, Q94E mutation disrupts the interaction of POT1 with telomeric DNA which subsequently enhances telomere uncapping and elongation and promotes the development of cutaneous familial melanoma. To understand the underlying mechanism of familial melanoma developed by Q94E-mutation, we have performed extensive structure analysis of WT and mutant protein followed by molecular dynamics simulations. Q94E mutation causes a dramatic change in the structure and stability of POT1 protein. A considerable decrease in the flexibility, fluctuation and solvent accessibility of Q94E was observed in comparison to the WT, indicating overall destabilization of protein. Essential dynamics and Anisotropic Network Mode analysis have quantified a significant change in direction and magnitude of conformational motion in Q94E mutant compared to WT. A significant loss of frustration due to Q94E mutation was also observed. Our findings indicate the loss of protein stability and dynamics of POT1 protein by Q94E mutation may be associated with the familial melanoma.AbbreviationsANManisotropic network modeEDessential dynamicsFMfamilial melanomaMDmolecular dynamicsPOT1protection of telomere 1Rgradius of gyrationRMSDroot-mean-square deviationRMSFroot-mean-square fluctuationsSASAsolvent accessible surface areaSIFTsorting Intolerant from TolerantTPP1tripeptidyl-peptidase IWTwild typeCommunicated by Ramaswamy H. Sarma

Multi-target tracking by non-linear motion patterns based on hierarchical network flows

We propose a multi-target tracking method for pedestrians, through locating them and maintaining their identities to make their individual trajectories. In most existing data association-based tracking approaches, the motion information in the affinity model is always linear, but the motion of target is non-linear in real-world surveillance video, especially when there is occlusion. This paper proposes a global optimization method based on hierarchical network flows with a non-linear motion model to track multiple targets. In our method, each node in network represents a tracklet, and each edge represents the likelihood of neighboring tracklets belonging to the same trajectory measured by affinity score that we proposed, it differs from other network flow formulation whose nodes represent detection responses. A non-linear motion map is used for explaining non-linear motion pattern between neighboring tracklets and getting motion affinity when there are time gaps. We evaluate our approach on 2DMOT2015, MOT16 database, and several real surveillance videos. Experimental results demonstrate that the proposed method can achieve continuous tracking trajectories under the case of motion direction changes and complete occlusions.

Assessment of a Novel Algorithm to Determine Change-of-Direction Angles While Running Using Inertial Sensors.

Balloch, AS, Meghji, M, Newton, RU, Hart, NH, Weber, JA, Ahmad, I, and Habibi, D. Assessment of a novel algorithm to determine change-of-direction angles while running using inertial sensors. J Strength Cond Res 34(1): 134-144, 2020-The ability to detect and quantify change-of-direction (COD) movement may offer a unique approach to load-monitoring practice. Validity and reliability of a novel algorithm to calculate COD angles for predetermined COD movements ranging from 45 to 180° in left and right directions was assessed. Five recreationally active men (age: 29.0 ± 0.5 years; height: 181.0 ± 5.6 cm; and body mass: 79.4 ± 5.3 kg) ran 5 consecutive predetermined COD trials each, at 4 different angles (45, 90, 135, and 180°), in each direction. Participants were fitted with a commercially available microtechnology unit where inertial sensor data were extracted and processed using a novel algorithm designed to calculate precise COD angles for direct comparison with a high-speed video (remotely piloted, position-locked aircraft) criterion measure. Validity was assessed using Bland-Altman 95% limits of agreement and mean bias. Reliability was assessed using typical error (expressed as a coefficient of variation [CV]). Concurrent validity was present for most angles. Left: (45° = 43.8 ± 2.0°; 90° = 88.1 ± 2.0°; 135° = 136.3 ± 2.1°; and 180° = 181.8 ± 2.5°) and Right: (45° = 46.3 ± 1.6°; 90° = 91.9 ± 2.2°; 135° = 133.4 ± 2.0°; 180° = 179.2 ± 5.9°). All angles displayed excellent reliability (CV < 5%) while greater mean bias (3.6 ± 5.1°, p < 0.001), weaker limits of agreement, and reduced precision were evident for 180° trials when compared with all other angles. High-level accuracy and reliability when detecting COD angles further advocates the use of inertial sensors to quantify sports-specific movement patterns.

As if by Magic: An Abrupt Change in Motion Direction Induces Change Blindness

Magicians claim that an abrupt change in the direction of movement can attract attention, allowing them to hide their method for a trick in plain sight. In three experiments involving 43 total subjects, we tested this claim by examining whether a sudden directional change can induce change blindness. Subjects were asked to detect an instantaneous orientation change of a single item in an array of Gabor patches; this change occurred as the entire array moved across the display. Subjects consistently spotted the change if it occurred while the array moved along a straight path but missed it when it occurred as the array changed direction. This method of inducing change blindness leaves the object in full view during the change; requires no additional distractions, visual occlusion, or global transients; and worked in every subject tested here. This phenomenon joins a body of magic-inspired work that yields insights into perception and attention.

DIFFERENCES IN AGILITY AND EXPLOSIVE POWER OF BASKETBALL PLAYERS IN RELATION TO THEIR POSITIONS ON THE TEAM

Basketball is a sports game which consists of rapid changes in direction of movement, sudden stopping and starting for driving and dribbling and a great number of jumps. The various positions on a basketball team precisely determine the requirements for specific forms of movement, even though contemporary basketball strives for all players in all positions to possess the aforementioned abilities. A sample of 15 male basketball players, divided into three groups of five players each, based on their positions on the team, including the guard, forward and center position, was used to determine differences in agility (Agility T Test, Hexagon Agility Тest, Illinois Agility Test и Lane Agility Drill) and explosive power (the Squat jump, Countermovement Jump, Drop Jump and One-legged Counter Movement Jump). To determine the differences between the basketball players in relation to their positions on the team, the ANOVA analysis for independent samples was used as was a post-hoc analysis. The research results have indicated that there is a difference between the guard position compared to the forward and center position.

Design and evaluation of sensorized robot for minimally vascular interventional surgery

Remote-controlled vascular interventional robots (RVIRs) are being developed to reduce the occupational risk of the intervening physician, such as radiation, chronic neck and back pain, and increase the accuracy and stability of surgery operation. The collision between the catheter/guidewire tip and blood vessels during the surgery practice is important for minimally invasive surgery because the success of the surgery mainly depends on the detection of collisions. In this study, we propose a novel sensing principle and fabricate a sensorized RVIR. The proposed sensorized RVIR can accurately detect force and reconstruct force feedback. The performance of the proposed sensorized RVIR is evaluated through experiments. The experiment results show that it can accurately measure static force and time-varying force. Subtle force changes caused by changes of movement direction in surgeries can also be detected. In addition, the proposed sensorized RVIR has higher operation efficiency than our previous prototype.

Precise 3D Baseball Pitching Trajectory Estimation Using Multiple Unsynchronized Cameras

We developed a method for the precise estimation of the 3D trajectory of a baseball by modeling the movement of the baseball and estimating the capture delay, using multiple unsynchronized cameras. To develop the proposed algorithm, we mimicked the real-world process of capturing a baseball in simulation space, and analyzed the capture process using a multiple unsynchronized camera system. We represented the movement of the baseball using a piece-wise spline model, and predicted the position of the baseball in the subframes in a manner which is robust to position error and change in direction of movement of the baseball. This method accurately predicts the baseball position over time by modeling the movement of the baseball in a real baseball game environment, and improves the accuracy of the reconstructed 3D baseball trajectories. We defined an objective function to estimate the capture delay, and estimate the optimal capture delay parameter using non-linear optimization method. In addition, we evaluated the performance of the proposed method in simulation space and in a real-world situation. The experimental results show that the proposed method can estimate a 3D baseball trajectory precisely using a multiple unsynchronized camera system and is robust to variations in capture delay, both in the simulation space and in real-world situations.