Effect of normalization and phase angle calculations on continuous relative phase

Badminton lunge requires rapid coordination between the knee and ankle joints and it is accompanied by fast contact between the shoe’s sole and the floor. Phase angle analysis is a protocol with high resolution and relating to the coordination, but how the shoe’s sole would affect the lunge performance was not clear in terms of coordination. Thereby, the aim of this study was to applied phase angle analysis to insight the lunge process, then to disclose the effect of badminton shoe’s sole on the lunge skill performance. Eleven elite badminton players performed five left-forward maximum lunge trials with wearing Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). The motion capturing system was used to measure the knee and ankle kinematics information. The Phase Angle (PA), continuous relative phase (CRP) and variability of continuous relative phase (VCRP) between the knee and ankle joints were then calculated for both forward lunge phase and recovery phase in each of the three shoes. Current findings indicated that players wearing RHS had certain advantages on better movement coordination than other shoes, as indicated by better PA and CRP. The findings of this study would be helpful to understand the coordination of badminton lunges and explain the synergy between the lower extremity ankle and knee joint to minimize the possibility of injury in badminton. Furthermore, the coordination between the knee and ankle joints was greatly affected by the structure of the shoe heel design.

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Kinematic Displacement Analysis of a Double-Cardan-Joint Driveline

13th Design Automation Conference: Volume 2 — Robotics, Mechanisms, and Machine Systems ◽

10.1115/detc1987-0078 ◽

1987 ◽

Author(s):

I. S. Fischer ◽

R. N. Paul

Keyword(s):

Phase Angle ◽

Relative Phase ◽

Front Wheel ◽

Constant Input ◽

Computer Data ◽

Output Displacement ◽

Wheel Drive ◽

In Series ◽

The Difference ◽

Cardan Joint

Abstract The input-output displacement relations of two Cardan joints arranged in series on a driveline has been investigated in detail, including the effects of unequal joints angles, the phase angle between the two Cardan joints and also such manufacturing tolerance errors as non-rigth angle link lengths and offset joint axes. A combined Newton-Raphson and Davidson-Fletcher-Powell optimization algorithm using dual-number coordinate-transformation matrices was employed to perform the analysis. An experiment was conducted to validate the results of the analysis. The apparatus consisted of a double-Cardan-joint driveline whose rotations were measured by optical shaft encoders that were sampled by a computer data-acquisition system. The equipment was arranged so that the phase angle between the joints and the offset angles between the shafts at each of the two joints could be readily varied. The “relative phase angle”, the difference between the phase angle of the two joints and the angle between the planes defined by the input and intermediate and the intermediate and output shafts, was found to be the significant factor. If the offset angles at both Cardan joints are equal, the double-Cardan-joint driveline function as a constant-velocity coupling when the magnitude of the relative phase angle is zero. If the offset angles at the two Cardan joints are unequal, a condition prevailing in the important front-wheel-drive automobile steering column, then fluctuation in output velocity for a constant input velocity is minimized although not eliminated for zero relative phase angle.

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Stroke-affected upper extremity movement assessment via continuous relative phase analysis

Measurement ◽

10.1016/j.measurement.2017.06.011 ◽

2017 ◽

Vol 110 ◽

pp. 84-89 ◽

Cited By ~ 2

Author(s):

Kristina Daunoravičienė ◽

Jurgita Žižienė ◽

Jolanta Pauk ◽

Adam Idzkowski ◽

Inga Raudonytė ◽

...

Keyword(s):

Upper Extremity ◽

Phase Analysis ◽

Relative Phase ◽

Movement Assessment ◽

Continuous Relative Phase ◽

Upper Extremity Movement

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Variability in kinematic coupling assessed by vector coding and continuous relative phase

Journal of Biomechanics ◽

10.1016/j.jbiomech.2010.05.014 ◽

2010 ◽

Vol 43 (13) ◽

pp. 2554-2560 ◽

Cited By ~ 54

Author(s):

Ross H. Miller ◽

Ryan Chang ◽

Jennifer L. Baird ◽

Richard E.A. Van Emmerik ◽

Joseph Hamill

Keyword(s):

Relative Phase ◽

Vector Coding ◽

Kinematic Coupling ◽

Continuous Relative Phase

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Comparison of Lumbopelvic Coordination between Trunk Flexion and Extension

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1541931213601215 ◽

2016 ◽

Vol 60 (1) ◽

pp. 937-941

Author(s):

Jie Zhou ◽

Xiaopeng Ning

Keyword(s):

Relative Phase ◽

Sagittal Plane ◽

Influential Factor ◽

Coordination Pattern ◽

Trunk Flexion ◽

Flexion Extension ◽

Continuous Relative Phase ◽

Phase Variability ◽

Coordination Patterns ◽

Flexion And Extension

Lumbopelvic coordination describes the relative contributions of lumbar and pelvis to the total trunk flexion/extension motion, which has been identified as a major influential factor to spinal loading. The current study investigated the differences in lumbopelvic coordination between trunk flexion and extension. Thirteen subjects performed pace-controlled trunk flexion/extension motions in the sagittal plane while lumbopelvic continuous relative phase and phase variability were quantified. The results demonstrated that compared with trunk extension, lumbopelvic continuous relative phase and phase variability were 28% and 117% greater in trunk flexion motion, respectively, which indicated a more anti-phase and unstable coordination pattern. Quantifying these coordination patterns helps identifying abnormal patterns and serves as normative benchmarks during low back pain rehabilitation.

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On The Relationships Among Different Voltage Unbalance Definitions

10.31224/osf.io/6qdrx ◽

2021 ◽

Author(s):

Kshitij I Girigoudar ◽

Daniel K. Molzahn ◽

Line A. Roald

Keyword(s):

Power Quality ◽

Phase Angle ◽

Distribution Systems ◽

Relative Phase ◽

Energy Resources ◽

Distributed Energy ◽

Line Voltage ◽

Voltage Unbalance ◽

Power Injection ◽

Symmetrical Component

Growing penetrations of distributed energy resources (DERs) increase the power injection variability in distribution systems, which can result in power quality issues such as voltage unbalance. To measure unbalance, organizations such as IEC, NEMA and IEEE define phase unbalance in their power quality standards. However, the definitions in these different standards are not consistent, and voltages that are considered acceptable by one standard may violate good practices defined by another standard. To address this issue, this paper provides analytical comparisons of the most common voltage unbalance definitions, which are supplemented with numerical simulations. The analytical relationships suggest that it is possible to approximately bound the symmetrical-component-based voltage unbalance factor (which depends on the magnitude and relative phase angle) by limiting the line-to-line voltage unbalance, whereas applying line-to-ground voltage unbalance definitions neglects all information about phase angle offsets.

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PORTRAIT AND HILBERT TRANSFORM METHODS FOR EVALUATING CONTINUOUS RELATIVE PHASE BETWEEN LOWER-LIMB JOINTS IN THE ELDERLY DURING WALKING

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519421400388 ◽

2021 ◽

pp. 2140038

Author(s):

HYUK-JAE CHOI ◽

GYOOSUK KIM ◽

CHANG-YONG KO

Keyword(s):

Angular Velocity ◽

Hilbert Transform ◽

Lower Limb ◽

Cross Correlation ◽

Relative Phase ◽

The Elderly ◽

Transform Method ◽

Transform Methods ◽

Continuous Relative Phase ◽

The Hilbert Transform

In order to calculate the continuous relative phase (CRP) between joints, the portrait method based on the joint angle and angular velocity and the Hilbert transform method based on the analytical signal have been widely used. However, there are few comparisons of these methods. Therefore, the aim of this study is to quantitatively compare these methods by calculating the CRP in the lower-limb joints of the elderly during level free walking. Eighteen elderly female adults ([Formula: see text] year-old, [Formula: see text][Formula: see text]cm, [Formula: see text][Formula: see text]kg) wearing a Helen Hayes full-body marker set walked 10[Formula: see text]m on level ground at a self-selected velocity. The angles of the hip, knee, and ankle were measured. To calculate the CRP using the portrait method, the angular velocities were measured. Then, the phases between the angle and the angular velocity were calculated. To calculate the CRP using the Hilbert transform method, analytical signals were acquired. Then, the phases between the real and imaginary parts were calculated. A CRP was calculated as the difference between the phase in the proximal joint and the phase in the distal joint. To evaluate the similarity in the shape between the portrait and Hilbert transform methods, the cross-correlation was calculated. Bland–Altman plot analyses were performed to assess the agreement between these methods. For the root mean squares (RMSs) and standard deviations (SDs), a paired [Formula: see text]-test and the Pearson correlation between methods were evaluated. There were similarities in the in-phase or out-of-phase features and in the RMS and SD between the methods. Additionally, a higher cross-correlation and agreement between them were found. These results indicated the similarity between the portrait and Hilbert transform methods for the calculation of the CRP. Therefore, either method can be used to evaluate joint coordination.

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Phase Angle in Transient Regimes of Vortex-Induced Vibration: An Experimental Determination

Volume 9: 6th FSI, AE and FIV and N Symposium ◽

10.1115/pvp2006-icpvt-11-93858 ◽

2006 ◽

Cited By ~ 1

Author(s):

Andre´ Laneville ◽

Pierre-Olivier Dallaire

Keyword(s):

Experimental Determination ◽

Flow Velocity ◽

Phase Angle ◽

Vortex Shedding ◽

Relative Phase ◽

Circular Tube ◽

Oncoming Flow ◽

Transient Regimes ◽

Dimensionless Amplitude

This article deals with an experimental determination of the relative phase angle between the shedding of vortices and motion in the case of the Aeolian vibrations of a flexible circular tube. The objective is to compare and determine if the phase value of a transient regime differs from that measured in a steady vibrating state. For each mode of vortex shedding (Von Ka´rma´n, 2S and 2P), the results show that the value of the phase angle in the unsteady and steady regimes is relatively similar if an appropriate dependency is selected: in the cases of the 2P and 2S modes of vortex shedding, this dependency is either the dimensionless amplitude or the ratio of the velocity of the structure motion to the oncoming flow velocity; in the case of the Von Ka´rma´n regime, at the onset of the instability, the usual reduced velocity is a better dependent variable. The analysis of jumps occurring in the instruments output reveals a boundary between the Von Ka´rma´n and the 2P modes of vortex shedding.

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TWO-MODE ENTANGLEMENT VIA SUPERPOSITIONS OF TWO-MODE COHERENT STATES

Modern Physics Letters B ◽

10.1142/s0217984907013584 ◽

2007 ◽

Vol 21 (19) ◽

pp. 1253-1259 ◽

Cited By ~ 3

Author(s):

YUN-XIA PING ◽

BO ZHANG ◽

ZE CHENG ◽

QINFENG XU

Keyword(s):

Phase Angle ◽

Coherent States ◽

Relative Phase ◽

Superposition States ◽

Entanglement Criterion

Two-mode entanglement of superposition states from several two-mode coherent states is investigated according to the entanglement criterion.9 The dependence of entanglement on relative phase angle, coherent amplitude of each mode and phase angle is discussed. It is shown that under certain conditions the superposition states can exhibit entanglement properties.

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