Journal articles: 'Angular performance'

1

Hudson, Tracy D. "High-performance microfabricated angular rate sensor." Journal of Micro/Nanolithography, MEMS, and MOEMS 4, no. 4 (October 1, 2005): 043006. http://dx.doi.org/10.1117/1.2114787.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Edmonds, I. R., P. A. Jardine, and G. Rutledge. "Daylighting with angular-selective skylights: Predicted performance." Lighting Research and Technology 28, no. 3 (September 1, 1996): 122–30. http://dx.doi.org/10.1177/14771535960280030101.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Białecki, Gabriel, and Beata Pańczyk. "Performance analysis of Svelte and Angular applications." Journal of Computer Sciences Institute 19 (June 30, 2021): 139–43. http://dx.doi.org/10.35784/jcsi.2633.

Full text

Abstract:

The aim of this article is to check if the Svelte-based client part of a web application is more effective than the standard Angular approach. The article presents a comparison of page components rendering times on the basis of two test applications prepared in both frameworks. For the performance tests, scenarios were prepared in which the times of adding and removing a different number of page components were examined. Application tests were performed using the Selenium Webdriver package. The research results clearly showed that the new approach used for DOM manipulation (Svelte v.3.0) is more efficient than the standard solution used in Angular applications (v.10.2).

APA, Harvard, Vancouver, ISO, and other styles

4

Yu, Bing, and James G. Hay. "Angular Momentum and Performance in the Triple Jump: A Cross-Sectional Analysis." Journal of Applied Biomechanics 11, no. 1 (February 1995): 81–102. http://dx.doi.org/10.1123/jab.11.1.81.

Full text

Abstract:

The purposes of this study were (a) to determine the magnitude of the angular momentum elite triple jumpers possess during each of the three phases of a triple jump, and (b) to identify those components of the angular momentum that are closely related to the actual distance of the triple jump. Angular momentum about each of three orthogonal axes at the takeoff of each of the last stride, hop, step, and jump was computed from the smoothed 3-D coordinate data of 21 body landmarks and joint centers and normalized to body mass (mb) and standing height (hb). Linear and nonlinear regression analyses were conducted to examine the relationships between angular momenta and actual distance. The results suggested that the estimated optimum magnitude of this side-somersaulting angular momentum is 0.0069 mb hb2 kg · m2 · s-1 toward the side of the free leg, that the side-somersaulting angular momentum needed at the takeoff of the step should be obtained during the support phase of the hop; and that the change in the side-somersaulting angular momentum during the support phase of the step should be minimized.

APA, Harvard, Vancouver, ISO, and other styles

5

Schmidt, Edward M. "Angular Motion Effects on Kinetic Energy Projectile Performance." Journal of Spacecraft and Rockets 36, no. 2 (March 1999): 292–93. http://dx.doi.org/10.2514/2.7594.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Atkinson, Ron. "Angular performance of phase-optimized magneto-optic quadrilayers." Optical Engineering 32, no. 12 (1993): 3288. http://dx.doi.org/10.1117/12.151271.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Harnoy, A., and H. Rachoor. "Angular-Compliant Hydrodynamic Bearing Performance Under Dynamic Loads." Journal of Tribology 115, no. 3 (July 1, 1993): 342–47. http://dx.doi.org/10.1115/1.2921641.

Full text

Abstract:

The study is focused on a dynamically loaded composite bearing, consisting of a hydrodynamic journal bearing inside the internal race of a rolling-element bearing. In this combination, the hydrodynamic bearing has an angular-compliant sleeve with a restricted freedom of rotation around its axis. Under static loads, the improvement is primarily in a significant reduction of friction and wear during the starting and stopping. Under periodical loads, our analysis shows that the performance depends on two dimensionless design parameters. Below particular critical values of these parameters, the results show a considerable improvement, demonstrated by a reduction of the maximum eccentricity. However, above the critical values, the bearing becomes unstable. These results indicate the significance of incorporating this computer assisted computation for each design.

APA, Harvard, Vancouver, ISO, and other styles

8

Moody, M. Vol, Ho Jung Paik, and Edgar R. Canavan. "Principle and performance of a superconducting angular accelerometer." Review of Scientific Instruments 74, no. 3 (March 2003): 1310–18. http://dx.doi.org/10.1063/1.1539894.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Ross, Cameron, Peter Lambs, Paul McAlpine, Gavin Kennedy, and Chris Button. "Validation of gyroscope sensors for snow sports performance monitoring." International Journal of Computer Science in Sport 19, no. 1 (July 1, 2020): 51–59. http://dx.doi.org/10.2478/ijcss-2020-0004.

Full text

Abstract:

AbstractWearable sensors that can be used to measure human performance outcomes are becoming increasingly popular within sport science research. Validation of these sensors is vital to ensure accuracy of extracted data. The aim of this study was to establish the validity and reliability of gyroscope sensors contained within three different inertial measurement units (IMU). Three IMUs (OptimEye, I Measure U and Logger A) were fixed to a mechanical calibration device that rotates through known angular velocities and positions. RMS scores for angular displacement, which were calculated from the integrated angular velocity vectors, were 3.85° ± 2.21° and 4.34° ± 2.57° for the OptimEye and IMesU devices, respectively. The RMS error score for the Logger A was 22.76° ± 23.22°, which was attributed to a large baseline shift of the angular velocity vector. After a baseline correction of all three devices, RMS error scores were all below 3.90°. Test re-test reliability of the three gyroscope sensors were high with coefficient of variation (CV%) scores below 2.5%. Overall, the three tested IMUs are suitable for measuring angular displacement of snow sports manoeuvres after baseline corrections have been made. Future studies should investigate the accuracy and reliability of accelerometer and magnetometer sensors contained in each of the IMUs to be used to identify take-off and landing events and the orientation of the athlete at those events.

APA, Harvard, Vancouver, ISO, and other styles

10

Zhang, Zhi Yong, and Qing Kun Zhou. "Design and Analysis of a Novel Micro-Angular Vibration Testbed Driven by Voice Coil Actuator." Key Engineering Materials 522 (August 2012): 587–92. http://dx.doi.org/10.4028/www.scientific.net/kem.522.587.

Full text

Abstract:

The construction and the operating principle of the novel micro-angular vibration testbed (MAVT) are presented, the MAVT is designed to complete the angular performance testing for the micro sensor and parts such as MEMS-gyro, angular accelerometer. A systemic design procedure of the optimized flexure hinge and general voice coil actuator (VCA) to fine single-axis MAVT actuator are introduced for fast and precision actuation. A method for measuring frequency response function by means of a displacement sensor electric eddy current sensor is designed. To verify the performance of the designed MAVT, frequency response of the system are performed, the differential equation of the pull-tilting motion is established according to the Lagranges equation, the formula of the natural frequency is derived, and the model analysis of the MAVT is also carried out with the help of limited element analysis. The static stiffness experiments show that the angular stroke of the MAVT is 1° and preliminary tests performed on the closed-loop control system indicate that angular resolution of 1 can be achieved. Model experiments performed on the prototype of MAVT are presented and the theoretic result fits with the result of experiment (250Hz). For fast and precision actuation performances, design parameters are selected based on the dynamic model of VCA and flexure hinge, and design process is completed. The model results can be provided for the construction design of the MAVT. Conventional platforms of angular performance testing are bulky and costly. Analysis and experiments results indicate that the novel MAVT is an efficient platform to complete the angular performance testing for micro sensor and parts.

APA, Harvard, Vancouver, ISO, and other styles

11

Dao, Thanh Phong, and Shyh Chour Huang. "Optimization of Multiresponse Performance Measure in Slider-Rocker Compliant Mechanism Using Fuzzy-Taguchi Method." Advanced Materials Research 683 (April 2013): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amr.683.708.

Full text

Abstract:

This paper focuses on the application of fuzzy logic-Taguchi method for multi-objective optimization of the flexible segment in slider-rocker compliant mechanisms. The input parameters such as input torque and crank angular are optimized with considerations of the multiple performance measures as angular displacement and stress of the flexible segment. The results found that the input torque at level 3 of 60 Nm and crank angular at level 1 of 70 degrees are favorable parameters for compliant flapper mechanism. Based on analysis of variance (ANOVA), the results revealed that input crank angular is the most significant with hightest contribution of 48%.

APA, Harvard, Vancouver, ISO, and other styles

12

Yu, Bing, and James G. Andrews. "The Relationship between Free Limb Motions and Performance in the Triple Jump." Journal of Applied Biomechanics 14, no. 2 (May 1998): 223–37. http://dx.doi.org/10.1123/jab.14.2.223.

Full text

Abstract:

The purpose of this study was to investigate relationships between free limb motions and triple jump performance. The subjects were 13 elite male triple jumpers. Three-dimensional videographic data were collected using a direct linear transformation technique with panning cameras. Changes in the velocity of the whole body center of gravity (G), changes in the whole body angular momentum about G, changes in the velocity of G due to free limb motions, and changes in the whole body angular momentum about G due to free limb motions were determined for each of the three support phases. Free limb motions were associated with decreases in the forward horizontal velocity of G and increases in the vertical velocity of G and significantly influenced changes of the corresponding velocity components of G when the changes were large. The free limb motions also created some angular momentum components about G during each support phase but did not significantly influence the changes of the corresponding angular momentum components of the whole body. Neither the changes in the three velocity components of G nor the changes in the three angular momentum components of the whole body about G due to free limb motions were significantly related to the actual distance of the triple jump.

APA, Harvard, Vancouver, ISO, and other styles

13

Kishikawa, Hiroki, Noriyuki Sakashita, and Nobuo Goto. "Mode sorting performance for optical beams carrying orbital angular momentum suffering lateral displacement and angular deflection." Japanese Journal of Applied Physics 57, no. 8S2 (June 28, 2018): 08PB01. http://dx.doi.org/10.7567/jjap.57.08pb01.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Zheng, Peng, Duo Zuo, and Yuan Hui Wang. "Analysis of A/C Double Angular Milling Head’s Performance." Applied Mechanics and Materials 87 (August 2011): 55–58. http://dx.doi.org/10.4028/www.scientific.net/amm.87.55.

Full text

Abstract:

We design a set of milling head test series in order to test the properties of the A/C double angular milling head. The article gives the primary test method as a comprehensive test for the whole series’ property, precision, stiffness, and mechanical performance to make the milling head excellent property.

APA, Harvard, Vancouver, ISO, and other styles

15

Rivero Rodriguez, Nicolas F. "Performance Evaluation of a Low Cost Angular Positioning System." IEEE Latin America Transactions 4, no. 3 (May 2006): 184–91. http://dx.doi.org/10.1109/tla.2006.4472112.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Gómez-Iglesias, Antonio, and Miguel Cárdenas-Montes. "Performance evaluation of the three-point angular correlation function." Parallel Computing 76 (August 2018): 28–41. http://dx.doi.org/10.1016/j.parco.2018.04.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

KHALAF, K. A., and M. PARNIANPOUR. "A NORMATIVE DATABASE OF ISOKINETIC UPPER-EXTREMITY JOINT STRENGTHS: TOWARDS THE EVALUATION OF DYNAMIC HUMAN PERFORMANCE." Biomedical Engineering: Applications, Basis and Communications 13, no. 02 (April 25, 2001): 79–92. http://dx.doi.org/10.4015/s101623720100011x.

Full text

Abstract:

The objective of this study was to provide a normative database of dynamic upper-extremity (shoulder and elbow) joint strengths to fill the current void in literature for multidimensional strength capacity profiles. The isokinetic strength of the elbow and shoulder joints was tested for twenty normal males and females. The independent variables consisted of joint angular position, joint angular velocity, direction of exertion, and gender. The measured joint strength (torque, Nm) was the only defined dependent variable. The majority of existing joint strength prediction models and normative databases are static (isometric) in nature. The few available dynamic models are reported in the form of torque as a function of joint angle. Since joint strength is a function of both the joint angular position and angular velocity, descriptive models should take this interaction into consideration. The dynamic joint strengths of the subjects were studied using the KIN_COM 125E Plus. A second-order multiple regression analysis was used to model the dynamic 3-D strength surface response of each joint in each direction of exertion. Analysis of variance (ANOVA) with repeated measures design was used to test for the effects of gender, angular position, angular velocity, and direction on the dynamic strength of each joint, joint strength was significantly influenced by dynamic parameters such as the angular velocity. The interaction between angular position and velocity was highly significant. 3-D strength surface representation may be used as a "performance capacity envelope" to comprehensively characterize an individual's dynamic joint strength performance.

APA, Harvard, Vancouver, ISO, and other styles

18

Miller, Doris I., and Eric J. Sprigings. "Factors Influencing the Performance of Springboard Dives of Increasing Difficulty." Journal of Applied Biomechanics 17, no. 3 (August 2001): 217–31. http://dx.doi.org/10.1123/jab.17.3.217.

Full text

Abstract:

Major factors influencing the ability of divers to perform nontwisting springboard dives of increasing degree of difficulty were investigated. The analysis was based upon 49 dives (42 in pike and 7 in tuck) executed by male and female medalists in the 1996 Olympics. Videotapes were digitized to determine competitors’ vertical velocities and angular momenta at the beginning of dive flight. Centripetal force and resultant joint torque models were used to estimate the effort needed to perform multiple somersaulting dives. Increasing degree of difficulty by spinning in a pike rather than a tuck position for the same number of somersaults was associated with decreased vertical velocity at the start of dive flight, decreased angular velocity while somersaulting in a quasi-rigid position, and little change in centripetal force or related muscular effort. Increasing degree of difficulty by adding a somersault while rotating in a tuck rather than a pike position involved increases in vertical and angular velocities, a smaller increase in angular momentum, and notable increases in resultant joint torque and centripetal force. Sufficient muscular torque to maintain a compact spinning position was considered to be the major additional challenge facing divers making the transition from a 21/2 pike to a 31/2 tuck.

APA, Harvard, Vancouver, ISO, and other styles

19

HAYASHI, Tomohiko, Xianbing LIU, Kiyoshi YOSHIOKA, Kazuo YAMAZAKI, and Masahiko MORI. "Laser-CCD Based Measurement System for Angular Motion of Integrated Machine Tools(Evaluation of machine tool performance)." Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 2005.1 (2005): 85–90. http://dx.doi.org/10.1299/jsmelem.2005.1.85.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Chung, J. "Effect of gravity and angular velocity on an automatic ball balancer." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 219, no. 1 (January 1, 2005): 43–51. http://dx.doi.org/10.1243/095440605x8333.

Full text

Abstract:

The effects of gravity and an angular velocity profile on the performance of an automatic ball balancer (ABB) are studied in this paper. In order to investigate these effects, a physical model of a Jeffcott rotor with an ABB is adopted in this study, in which gravity as well as the angular acceleration is considered. With the polar coordinates, the non-linear equations of motion are derived by using Lagrange's equation. These equations include gravity, the angular acceleration, and the angular jerk. Based on the equations derived, time responses are computed by using the generalized α method. The effects of gravity on the balancing performance are analysed. For various angular velocity profiles, the ABB performance is also evaluated. The analysis of results shows that the balancing of the rotor with an ABB can be achieved regardless of gravity. It is also shown that a smooth velocity profile results in less vibration compared with a non-smooth velocity profile.

APA, Harvard, Vancouver, ISO, and other styles

21

Ji, Xue Wu, Ning Sun, and Ya Hui Liu. "Inertia Compensation of EPS Based on Kalman Filtering." Advanced Materials Research 588-589 (November 2012): 509–12. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.509.

Full text

Abstract:

The dynamic performance of an electric power steering system (EPS) is deteriorated by the inertia of assistant motor embodied in EPS. To compensate the effect of motor inertia and improve the dynamic performance of EPS, the angular acceleration of the motor rotor is needed. However, the angular acceleration cannot be derived by differentiating the rotor angle signal of the permanent magnet synchronous motor (PMSM) directly, for the noise will be amplified. This paper attempts to get motor angular acceleration signal through Kalman filtering method and the angular acceleration signal acquired by this method is calibrated with high precision encoder, furthermore, the signal is verified though simulation and experiment of inertia compensation control. All the calibration results and simulation and experiment results of inertia compensation control show that the angular acceleration acquired through Kalman filtering method is available for the realization of motor inertia compensation control and can achieve the purpose of improving the dynamic performance of the steering system.

APA, Harvard, Vancouver, ISO, and other styles

22

Enoch, Sharmini, Ifiok Otung, Naeem Azeemi, and M. A. Habli. "Performance Evaluation of Angular Separation on Cell Site Diversity Gain." GIS Business 14, no. 6 (December 5, 2019): 717–27. http://dx.doi.org/10.26643/gis.v14i6.15127.

Full text

Abstract:

There have been remarkable advancements in the field of broadband wireless access (BFWA) technologies. These technologies operate in microwave frequencies where rain attenuation is the most important factor leading to signal impairments. The use of cell site diversity (CSD) can help in overcoming the signal fading. During the event of rain, when the signal level falls below a particular threshold, the subscriber station switches to another base station in the coverage area. The CSD gain bears strong correlation with the angular separation between the various base stations. This paper analyses the effects of CSD gain on angular separation.

APA, Harvard, Vancouver, ISO, and other styles

23

Neagoe, Mircea, Maria M. Vatasescu, Radu G. Saulescu, and Nora Creanga. "On New High Performance Systems with Linear Actuators for Diurnal Orientation of PV Platforms." Applied Mechanics and Materials 162 (March 2012): 214–23. http://dx.doi.org/10.4028/www.scientific.net/amm.162.214.

Full text

Abstract:

The paper presents new mechatronic systems used to perform the diurnal orientation of photovoltaic (PV) platforms, aiming to achieve high angular strokes and also low cost, high precision, constructive simplicity and relative low pressure angles. Starting from the disadvantages of the existing tracking mechanism identified in the literature (patents, scientific articles, market documentation, etc.), new high performance linkages and gear mechanisms driven by linear actuators are proposed in the paper. Hence, four new tracking mechanisms, achieving high angular strokes (over 180o), are described: a) quadrilateral type, b) rhombus type, c) slider-crank type, and d) linkage with gears type. These mechanisms are designed especially for concentrating PV systems, which require high orientation precision on the entire angular stroke.

APA, Harvard, Vancouver, ISO, and other styles

24

Avellar, Letícia, Arnaldo Leal-Junior, Carlos Marques, and Anselmo Frizera. "Performance Analysis of a Lower Limb Multi Joint Angle Sensor Using CYTOP Fiber: Influence of Light Source Wavelength and Angular Velocity Compensation." Sensors 20, no. 2 (January 7, 2020): 326. http://dx.doi.org/10.3390/s20020326.

Full text

Abstract:

This paper presents the analysis of an intensity variation polymer optical fiber (POF)-based angle sensor performance, i.e., sensitivity, hysteresis and determination coefficient ( R 2 ), using cyclic transparent optical polymer (CYTOP) fiber. The analysis consisted of two approaches: influence of different light source central wavelengths (430 nm, 530 nm, 660 nm, 870 nm and 950 nm) and influence of different angular velocities ( 0.70 rad/s, 0.87 rad/s, 1.16 rad/s, 1.75 rad/s and 3.49 rad/s). The first approach aimed to select the source which resulted in the most suitable performance regarding highest sensitivity and linearity while maintaining lowest hysteresis, through the figure of merit. Thereafter, the analysis of different angular velocities was performed to evaluate the influence of velocity in the curvature sensor performance. Then, a discrete angular velocity compensation was proposed in order to reduce the root-mean-square error (RMSE) of responses for different angular velocities. Ten tests for each analysis were performed with angular range of 0 ∘ to 50 ∘ , based on knee and ankle angle range during the gait. The curvature sensor was applied in patterns simulating the knee and ankle during the gait. Results show repeatability and the best sensor performance for λ = 950 nm in the first analysis and show high errors for high angular velocities ( w = 3.49 rad/s) in the second analysis, which presented up to 50 % angular error. The uncompensated RMSE was high for all velocities ( 6.45 ∘ to 12.41 ∘ ), whereas the compensated RMSE decreased up to 74 % ( 1.67 ∘ to 3.62 ∘ ). The compensated responses of application tests showed maximum error of 5.52 ∘ and minimum of 1.06 ∘ , presenting a decrease of mean angular error up to 30 ∘ when compared with uncompensated responses.

APA, Harvard, Vancouver, ISO, and other styles

25

Liu, Changwu, Haowen Wang, and Chen Jiang. "High-order derivative fusion estimation of rotorcraft angular rate." Aircraft Engineering and Aerospace Technology 93, no. 2 (March 19, 2021): 347–53. http://dx.doi.org/10.1108/aeat-09-2020-0203.

Full text

Abstract:

Purpose The paper aims at developing a novel algorithm to estimate high-order derivatives of rotorcraft angular rates to break the contradiction between bandwidth and filtering performance because high-order derivatives of angular rates are crucial to rotorcraft control. Traditional causal estimation algorithms such as digital differential filtering or various tracking differentiators cannot balance phase-lead angle loss and high-frequency attenuation performance of the estimated differentials under the circumstance of strong vibration from the rotor system and the rather low update rate of angular rates. Design/methodology/approach The algorithm, capable of estimating angular rate derivatives to maximal second order, fuses multiple attitude signal sources through a first-proposed randomized angular motion maneuvering model independent of platform dynamics with observations generated by cascaded tracking differentiators. Findings The maneuvering flight test on 5-kg-level helicopter and the ferry flight test on 230-kg-level helicopter prove such algorithm is feasible to generate higher signal to noise ratio derivative estimation of angular rates than traditional differentiators in regular flight states with enough bandwidth for flight control. Research limitations/implications The decrease of update rate of input attitude signals will weaken the bandwidth performance of the algorithm and higher sampling rate setting is recommended. Practical implications Rotorcraft flight control researchers and engineers would benefit from the estimation method when implementing flight control laws requiring angular rate derivatives. Originality/value A purely kinematic randomized angular motion model for flight vehicle is first established, combining rigid-body Euler kinematics. Such fusion algorithm with observations generated by cascaded tracking differentiators to estimate angular rate derivatives is first proposed, realized and flight tested.

APA, Harvard, Vancouver, ISO, and other styles

26

He, Qiong, Ling Tong, Lingyun Huang, Jing Liu, Yinran Chen, and Jianwen Luo. "Performance optimization of lateral displacement estimation with spatial angular compounding." Ultrasonics 73 (January 2017): 9–21. http://dx.doi.org/10.1016/j.ultras.2016.08.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Tang, Bo, Kun-Yi Guo, Jian-Ping Wang, and Xin-Qing Sheng. "Resolution Performance of the Orbital-Angular-Momentum-Based Imaging Radar." IEEE Antennas and Wireless Propagation Letters 16 (2017): 2975–78. http://dx.doi.org/10.1109/lawp.2017.2756094.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Quan, Shaohui. "Compact Range Performance Evaluation Using Aperture Near-Field Angular Spectrums." IEEE Transactions on Antennas and Propagation 61, no. 5 (May 2013): 2474–81. http://dx.doi.org/10.1109/tap.2013.2240646.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Taladriz, Sonia, Blanca de la Fuente-Caynzos, and Raúl Arellano. "Analysis of angular momentum effect on swimming kick-start performance." Journal of Biomechanics 49, no. 9 (June 2016): 1789–93. http://dx.doi.org/10.1016/j.jbiomech.2016.04.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Chanchangi, Yusuf N., Aritra Ghosh, Senthilarasu Sundaram, and Tapas K. Mallick. "Angular dependencies of soiling loss on photovoltaic performance in Nigeria." Solar Energy 225 (September 2021): 108–21. http://dx.doi.org/10.1016/j.solener.2021.07.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Askari, Sina, Mohammad Asadian, and Andrei Shkel. "Performance of Quad Mass Gyroscope in the Angular Rate Mode." Micromachines 12, no. 3 (March 4, 2021): 266. http://dx.doi.org/10.3390/mi12030266.

Full text

Abstract:

In this paper, the characterization and analysis of a silicon micromachined Quad Mass Gyroscope (QMG) in the rate mode of operation are presented. We report on trade-offs between full-scale, linearity, and noise characteristics of QMGs with different Q-factors. Allan Deviation (ADEV) and Power Spectral Density (PSD) analysis methods were used to evaluate the performance results. The devices in this study were instrumented for the rate mode of operation, with the Open-Loop (OL) and Force-to-Rebalance (FRB) configurations of the sense mode. For each method of instrumentation, we presented constraints on selection of control parameters with respect to the Q-factor of the devices. For the high Q-factor device of over 2 million, and uncompensated frequency asymmetry of 60 mHz, we demonstrated bias instability of 0.095∘/hr and Angle Random Walk (ARW) of 0.0107∘/hr in the OL mode of operation and bias instability of 0.065∘/hr and ARW of 0.0058∘/hr in the FRB mode of operation. We concluded that in a realistic MEMS gyroscope with imperfections (nearly matched, but non-zero frequency asymmetry), a higher Q-factor would increase the frequency stability of the drive axis resulting in an improved noise performance, but has challenges in implementation of digital control loops.

APA, Harvard, Vancouver, ISO, and other styles

32

Przywara, Artur, Francesco Santoro, Artur Kraszkiewicz, Anna Pecyna, and Simone Pascuzzi. "Experimental Study of Disc Fertilizer Spreader Performance." Agriculture 10, no. 10 (October 12, 2020): 467. http://dx.doi.org/10.3390/agriculture10100467.

Full text

Abstract:

We report the experimental results of tests aimed at assessing the effects of different settings on the mean radius of mineral fertilizer distribution using a disc fertilizer spreader. Our aim was to improve the performance of fertilizer distribution in sustainable agriculture. Three types of mineral fertilizers with different physical characteristics, commonly used in agriculture, were considered: urea, calcium ammonium nitrate and ammonium sulfate. A complete randomization method based on a four-factor experimental model was used to study the influence of the functional and operational parameters on the mean radius of fertilizer spread. Fixed model analysis of variance showed that fertilizer type, vane configuration and disc angular velocity explained 91.74% of the variance of the spread mean radius, while linear multiple regression analysis highlighted that the fertilizer dust fraction and disc angular velocity had an overall effect of 82.72%, the former showing an inverse correlation as high as 72.77%.

APA, Harvard, Vancouver, ISO, and other styles

33

Bussmann, Allan James de Castro, Márcia Greguol, Emanuel Messias Oliveira de Carvalho, and Felipe Arruda Moura. "Evaluation of the propulsion technique and motor performance of wheelchair basketball players." Revista Brasileira de Educação Física e Esporte 33, no. 2 (May 29, 2019): 313–22. http://dx.doi.org/10.11606/issn.1981-4690.v33i2p313-322.

Full text

Abstract:

The objective of this study was to evaluate the propulsion technique of wheelchairs basketball athletes. The group of study was formed for 11 athletes practicing, the modality studied, with an average age of 30.27 ± 6.51 years. The sample was divided in two groups (faster, slowest) according to the performance in the agility and speed tests. To analyze the angular kinematics of the upper limbs, each person performed threeattempts to “round trip” in a distance of 5 meters. The results indicate a strong positive association between the results obtained in the speed and agility tests (r = 0.83; p = 0.002) and negative between speed test time and sports practice time (r = −0.68; p = 0.02). For the analysis of angular behavior significant difference was observed (p = 0.02), only in the variable maximum angle of the left elbow and the faster group presentedthe highest values. The angular behavior analyzes during all the movement, present significant difference at some point of the cycle, for the variables abduction angle on the left shoulder, absolute angle of the right and left forearm, absolute angles of the shoulder in the sagittal plane left and right, maximum angle of the right and left elbow. The results indicate that the athletes present specific characteristics of propulsion, andthat some angular movement characteristics, as a smaller angle of shoulder abduction during early stages of the propulsion, influence the performance in the speed test.

APA, Harvard, Vancouver, ISO, and other styles

34

Bussmann, Allan James de Castro, Márcia Greguol, Emanuel Messias Oliveira de Carvalho, and Felipe Arruda Moura. "Evaluation of the propulsion technique and motor performance of wheelchair basketball players." Revista Brasileira de Educação Física e Esporte 33, no. 2 (May 29, 2019): 313–22. http://dx.doi.org/10.11606/1807-5509201900020313.

Full text

Abstract:

The objective of this study was to evaluate the propulsion technique of wheelchairs basketball athletes. The group of study was formed for 11 athletes practicing, the modality studied, with an average age of 30.27 ± 6.51 years. The sample was divided in two groups (faster, slowest) according to the performance in the agility and speed tests. To analyze the angular kinematics of the upper limbs, each person performed threeattempts to “round trip” in a distance of 5 meters. The results indicate a strong positive association between the results obtained in the speed and agility tests (r = 0.83; p = 0.002) and negative between speed test time and sports practice time (r = −0.68; p = 0.02). For the analysis of angular behavior significant difference was observed (p = 0.02), only in the variable maximum angle of the left elbow and the faster group presentedthe highest values. The angular behavior analyzes during all the movement, present significant difference at some point of the cycle, for the variables abduction angle on the left shoulder, absolute angle of the right and left forearm, absolute angles of the shoulder in the sagittal plane left and right, maximum angle of the right and left elbow. The results indicate that the athletes present specific characteristics of propulsion, andthat some angular movement characteristics, as a smaller angle of shoulder abduction during early stages of the propulsion, influence the performance in the speed test.

APA, Harvard, Vancouver, ISO, and other styles

35

Aldeman, Matthew R., and Ganesh Raman. "Experimental determination of the effects of boundary reflection on the angular resolution of microphone arrays." Building Acoustics 25, no. 3 (April 17, 2018): 249–86. http://dx.doi.org/10.1177/1351010x18768746.

Full text

Abstract:

The Rayleigh criterion has long been considered the standard criterion for angular resolution of imaging systems, including microphone arrays. However, advanced beamforming methods have been developed in the past 20 years that have dramatically improved the angular resolution of microphone array systems. In this investigation, the angular resolution performance of three scaled microphone arrays and one alternative array geometry were tested with both approximately free-field and reflective boundary conditions. All of the arrays were subjected to a thorough regimen of testing with broadband acoustic sources. Beamforming analysis was performed with the Delay-and-Sum, TIDY, DAMAS, DAMAS2, and CLEAN-SC algorithms. The Delay-and-Sum algorithm is shown to offer the lowest angular resolution performance because it does not separate the acoustic source map from the point spread function of the array. The DAMAS algorithm offers the greatest angular resolution because it numerically deconvolutes the acoustic source map from the point spread function. However, deconvolution-based algorithms (DAMAS and DAMAS2) were the most negatively affected by boundary reflection effects. The logarithmic spiral array is shown to offer versatile performance across a wide range of frequencies, while an alternative quasi-periodic array yields results that are highly frequency-dependent. It is demonstrated that this is because of gaps in the source-to-element differences coverage, and the gaps in coverage correspond to half-wavelengths of frequency bands with significantly lower angular resolution performance.

APA, Harvard, Vancouver, ISO, and other styles

36

Kwon, Young-Hoo, Virginia L. Fortney, and In-Sik Shin. "3-D Analysis of Yurchenko Vaults Performed by Female Gymnasts During the 1988 Seoul Olympic Games." International Journal of Sport Biomechanics 6, no. 2 (May 1990): 157–76. http://dx.doi.org/10.1123/ijsb.6.2.157.

Full text

Abstract:

Two of the most frequently performed vaults in the 1988 Olympic Games in Seoul were selected for 3-D cine-photogrammetry analysis: the Yurchenko layout with full twist and the Yurchenko layout. The performances included 20 vaults with the highest performance scores: 10 Yurchenko layout with Ml twist (YLF) and 10 Yurchenko layout (YL) vaults, which were performed in the women’s team optional competitions. The YLFgroup earned higher performance scores than the YLgroup. Average vaulting times were similar for the groups, but the YLFgroup showed shorter board and horse contact times and longer postflight times. The projectile motion variables were critical for better performance in the YLFgroup. Higher vertical velocity at horse takeoff was achieved mainly by minimizing its (Vv) loss during horse contact. The YLgroup showed the importance of angular momentum for better performance, with the normalized angular momentum during postflight being the critical variable for the YLvault.

APA, Harvard, Vancouver, ISO, and other styles

37

Li, Z. "On the angular correction of satellite radiation measurements: The performance of ERBE angular dependence model in the Arctic." Theoretical and Applied Climatology 54, no. 3-4 (1996): 235–48. http://dx.doi.org/10.1007/bf00865166.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Zhu, Xian Hua, and Jian Ming Huang. "Weaken Polygon Effect and Improve Chain Drive Performance." Applied Mechanics and Materials 246-247 (December 2012): 159–63. http://dx.doi.org/10.4028/www.scientific.net/amm.246-247.159.

Full text

Abstract:

analyzes the polygonal effect of the chain drives by analyzing the chain velocity and angular velocity change of driven sprocket. In order to abate polygon effect and improve the performance of chain transmission, advanced production technology should be adopted.

APA, Harvard, Vancouver, ISO, and other styles

39

Rao, Jinhui, Taihui Zhang, Honglei An, and Hongxu Ma. "Discretized Mid-Value CLVI-PDNN Based Redundancy Resolution for Single Leg of Quadruped Robot." Mathematical Problems in Engineering 2019 (June 24, 2019): 1–13. http://dx.doi.org/10.1155/2019/5071254.

Full text

Abstract:

The two most important performance indicators of quadruped robot are load capacity and walking speed, and these performance indicators of the whole robot finally reflect on the joint torques and angular velocities. To satisfy different requirements of walking speed and load capacity when quadruped robots implement different tasks, the joint torques and angular velocities need to be balanced with physical constraints of the joints. A single leg with redundant DOF (degree of freedom) could optimize the distribution of joint torques or angular velocities based on different performance requirements. This paper presents a kind of new recurrent neural networks taking joint torques and angular velocities simultaneously into consideration and proposes mid-value CLVI-PDNN to achieve the optimal joint torques and angular velocities with physical constraints of the mechanism as described in our previous paper. Because the continuous mid-value CLVI-PDNN has difficulty in real-time operation because of too much calculation workload, two kinds of methods are proposed to discretize the mid-value CLVI-PDNN for application on computer or digital circuit. The simulation results demonstrate the efficacy of the algorithm proposed in this paper.

APA, Harvard, Vancouver, ISO, and other styles

40

Tang, Chuanye, and Xiyuan Chen. "A Generalized Coning Correction Structure for Attitude Algorithms." Mathematical Problems in Engineering 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/614378.

Full text

Abstract:

A new coning correction structure is presented for attitude update coning correction. Different from the previous rate-based and increment-based coning correction structures, the new structure contains cross-product of angular rates, cross-product of angular increments, and cross-product of angular rate and increment (an angular increment may be approximated from angular rate samples). Two types of optimization methods including time Taylor-series method and frequency Taylor-series method were utilized to design the structure coefficients including the uncompressed and the compressed. Two types of algorithm error models including one applicable to coning environments and the other two applicable to maneuver environments were defined and used for analyzing or evaluating the algorithm performance. The derivation procedure of a rotation vector magnitude extraction method is included. Analysis and simulation results indicate that the new structure-based algorithm with the compressed coefficients designed by using frequency Taylor-series method gives a superior algorithm performance in coning environments and maneuver environments.

APA, Harvard, Vancouver, ISO, and other styles

41

Lin, WY, YH Tsai, and KM Hsiao. "Optimum variable input speed for kinematic performance of Geneva mechanisms using teaching-learning-based optimization algorithm." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 10 (December 15, 2015): 1871–83. http://dx.doi.org/10.1177/0954406215623307.

Full text

Abstract:

An optimum design of variable input speed for the Geneva mechanism is aimed at improving the kinematic performance of the traditional Geneva mechanism by eliminating infinite angular jerks and reducing the peak angular acceleration of the Geneva wheel during the indexing motion. The normalized angular velocity and acceleration of the Geneva wheel corresponding to the normalized time are introduced. A polynomial function of the normalized time is used to describe the normalized angular position of the crank, and therefore, the corresponding polynomial coefficients are considered as the design variables. The optimum design task is very specialized and difficult to solve with some evolutionary and swarm optimization methods because of the extremely large range for the value of the design variable, arising from the utilization of a higher order polynomial for the normalized time parameter with a value between 0 and 1. A new evolutionary algorithm termed teaching-learning-based optimization comprises a teacher phase and a learner phase. In the teacher phase, the entire population can be gradually shifted to a more promising region, which may be very far from the relatively small initial region. The obtained optimal results are compared with those obtained using the length-adjustable deriving link method discussed in the literature. The findings show that the difference in the effectiveness of the variable input speed method and the length-adjustable driving link method for the reduction of the peak angular acceleration of the Geneva wheel is small.

APA, Harvard, Vancouver, ISO, and other styles

42

Laugier, Romain, Frantz Martinache, Nick Cvetojevic, David Mary, Alban Ceau, Mamadou N’Diaye, Jens Kammerer, Julien Lozi, Olivier Guyon, and Coline Lopez. "Angular differential kernel phases." Astronomy & Astrophysics 636 (April 2020): A21. http://dx.doi.org/10.1051/0004-6361/201937121.

Full text

Abstract:

Context. To reach its optimal performance, Fizeau interferometry requires that we work to resolve instrumental biases through calibration. One common technique used in high contrast imaging is angular differential imaging, which calibrates the point spread function and flux leakage using a rotation in the focal plane. Aims. Our aim is to experimentally demonstrate and validate the efficacy of an angular differential kernel-phase approach, a new method for self-calibrating interferometric observables that operates similarly to angular differential imaging, while retaining their statistical properties. Methods. We used linear algebra to construct new observables that evolve outside of the subspace spanned by static biases. On-sky observations of a binary star with the SCExAO instrument at the Subaru telescope were used to demonstrate the practicality of this technique. We used a classical approach on the same data to compare the effectiveness of this method. Results. The proposed method shows smaller and more Gaussian residuals compared to classical calibration methods, while retaining compatibility with the statistical tools available. We also provide a measurement of the stability of the SCExAO instrument that is relevant to the application of the technique. Conclusions. Angular differential kernel phases provide a reliable method for calibrating biased observables. Although the sensitivity at small separations is reduced for small field rotations, the calibration is effectively improved and the number of subjective choices is reduced.

APA, Harvard, Vancouver, ISO, and other styles

43

Doyle, P. F. "Performance of alternative methods of bank protection." Canadian Journal of Civil Engineering 19, no. 6 (December 1, 1992): 1049–61. http://dx.doi.org/10.1139/l92-125.

Full text

Abstract:

The durability of several common bank protection methods used as less expensive or environmentally acceptable alternatives to toe-trenched angular rock riprap has been documented during the 1980s at seven typical bank erosion sites in British Columbia. Since the sites were uncontrolled examples of actual river training works in operation, natural events hindered a precise comparison of each scheme with toe-trenched angular rock riprap protection. However, of the four alternatives investigated – gravel dykes, tree revetments, riprap with toe apron, and semi-round riprap – all but semi-round riprap performed less than satisfactorily over the years of observation. Documentation of performance is sufficient to conclude that on steep gravel-bed rivers, gravel dykes do not endure; tree revetments require constant maintenance and will not endure large floods, unless extremely well-constructed; toe aprons are not as reliable as toe trenches for the same volume of rock; and well-placed, large semi-round rock performs well under moderately severe attack. Key words: erosion, bank protection, channel stability, river training structures, gravel-bed.

APA, Harvard, Vancouver, ISO, and other styles

44

Li, Jianjun. "Angular Response of Magnetostrictive Thin Films." Journal of Nanomaterials 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/940272.

Full text

Abstract:

The magnetostrictions of the single TbFe layer and coupled Py/TbFe2bilayers were measured by using laser deflectometry. The dependences of the magntostriction performance on the driving magnetic field direction have been investigated. The relationship studies between the saturation bending angle and torsion angle of the single layer with perpendicular anisotropy and coupled bilayers with in-plane uniaxial anisotropy have been conducted. Interesting “jump” reflecting the spin dynamics is observed in the magnetostriction loops of the coupled bilayers.

APA, Harvard, Vancouver, ISO, and other styles

45

Nguyen, Vanliem, Zhenpeng Wu, Beiping Zhang, and Zhang Jian Run. "Vibration Analysis and Control of a Vibration Screed System for Asphalt Pavers." International Journal of Acoustics and Vibration 25, no. 3 (September 30, 2020): 363–72. http://dx.doi.org/10.20855/ijav.2020.25.31649.

Full text

Abstract:

To reduce shaking of a vibration screed system (VSS) and improve the paving performance of an asphalt paver (AP), the root-mean-square (RMS) acceleration responses at points on the front and rear screed floors are analyzed via an experimental method. A 3D nonlinear dynamic model of the VSS is also built to evaluate the influence of the dynamic parameters of the VSS on the compression efficiency, paving quality, and working stability of the AP based on the objective functions of the vertical, pitching, and rolling RMS values at the centre of gravity of the screed. The angular deviations, $alpha$ and $gamma$, of the tamper are then controlled to improve the paving performance. The research results show that the excitation frequency, $f_{t}$, and both angular deviations, $alpha$ and $gamma$, of the tamper strongly affect the paving performance. The compression efficiency is quickly enhanced, while both paving quality and working stability are significantly reduced with increasing the excitation frequency $f_{t}$ and reducing the angular deviations. $alpha$ and $gamma$. and vice versa. Additionally, the screed shaking and paving performance of the AP are remarkably improved by control of the angular deviations, $alpha$ and $gamma$, under different working conditions.

APA, Harvard, Vancouver, ISO, and other styles

46

Aktaş, Yakup. "Relationship Between Isokinetic Leg Strength and Dynamic Balance Performance of Elite Male Volleyball Players." Journal of Education and Training Studies 7, no. 7 (June 17, 2019): 138. http://dx.doi.org/10.11114/jets.v7i7.4328.

Full text

Abstract:

Objective: This study aims at analysing the relationship between isokinetic leg strength and dynamic balance performances of MSK Urfa male volleyball players that play in Turkey Volleyball League of Swashbucklers.Materials and Methods: 13 voluntary volleyball players that played in MSK Urfa being a team in League of Swashbucklers in 2016-2017 season participated in the study. Bioelectric Impedance Measurement Device (Tanita MC 180) was used to measure body composition of volleyball players. Isokinetic dynamometer (IsoMed 2000 GmbH, Germany) was used to measure their isokinetic leg strength. Tecnobody Prokin device was used to measure their dynamic balance performance. The relationship between isokinetic leg strength and dynamic balance performance was determined by Spearman correlation analysis and the significance level was accepted as p <0.05.Findings: According to the data obtained from the study, there was no statistically significant relationship between the dynamic balance performance of volleyball players and the bilateral differences of quadriceps and hamstring muscles at the angular velocity of 60°/s (p>0,05); but there was statistically significant relationship between the bilateral differences of quadriceps and hamstring muscles at the angular velocity of 120°/s (p<0,05).There was no statistically significant relationship between dynamic balance performance and Hamstring/Quadriceps (H/Q) force ratio of dominant and non-dominant leg at angular velocity of 60°/s and 120°/s (p> 0.05).As a result; it was observed that the bilateral differences of hamstring and quadriceps muscles of volleyball players at 120°/s velocity affected their dynamic balance performance; but H/Q ratio at 60°/s and 120°/s velocity did not affect their dynamic balance performance.

APA, Harvard, Vancouver, ISO, and other styles

47

Robinson, Richard, and Phillip Gribble. "Kinematic Predictors of Performance on the Star Excursion Balance Test." Journal of Sport Rehabilitation 17, no. 4 (November 2008): 347–57. http://dx.doi.org/10.1123/jsr.17.4.347.

Full text

Abstract:

Context:The Star Excursion Balance Test (SEBT) is composed of 8 reaching directions that are potentially measuring the same functional component, leading to the suggestion that the number of reach directions could be reduced without compromising the assessment of dynamic postural control.Objective:To determine whether the relationship of stance-leg angular displacement on normalized reach distance is a source of dynamic-postural-control measurement redundancy.Design:Single-session within-subjects design.Setting:Athletic training research laboratory.Participants:10 women and 10 men.Interventions:None.Main Outcome Measures:Normalized reach distance and angular displacement at the knee and hip.Results:Stepwise regression revealed that hip flexion and knee flexion, separately and in combination, accounted for 62% to 95% of the variance in reach distances.Conclusion:Similarity in lower extremity function could account for the previously observed measurement redundancy in the SEBT.

APA, Harvard, Vancouver, ISO, and other styles

48

Hamzah, Nor Hazadura, Sazali Yaacob, Ahmad Kadri Junoh, and Mohd Zamri Hasan. "The study of particle filter for satellite angular rate estimation without rate sensor measurement." MATEC Web of Conferences 150 (2018): 06010. http://dx.doi.org/10.1051/matecconf/201815006010.

Full text

Abstract:

This paper studies particle filter algorithm to estimate the angular rate of a satellite without the rate sensor measurements. In this work, the performance of the algorithm is studied in terms of capability to estimate the angular rate by using the Euler angles attitude information only. The effects of the number of particles on the algorithm performance are also investigated in terms of accuracy and computational aspects. The performance of the particle filter algorithm is verified using real flight data of Malaysian satellite.

APA, Harvard, Vancouver, ISO, and other styles

49

She, Feng, Hsiao Hwa Chen, and Hongyang Li. "Joint Angular and Time Diversity of Multi-Antenna CDMA Systems in Wireless Fading Channels." International Journal of Wireless Networks and Broadband Technologies 1, no. 1 (January 2011): 1–14. http://dx.doi.org/10.4018/ijwnbt.2011010101.

Full text

Abstract:

In this paper, a multi-antenna based receiver structure for direct sequence code division multiple access (DS/CDMA) system is proposed. The proposed scheme exploits the excellent time resolution of a CDMA RAKE receiver and uses an antenna array beamforming structure to resolve multipath returns in both angular and time domains. A much higher diversity gain than that based only on the time domain diversity can be achieved. This work suggests a new space-time diversity paradigm, namely angular-time diversity, which differs from traditional Alamouti-type space-time coded schemes. The impairments caused by multipath and multiuser interference are analyzed. The performance of the proposed receiver in multipath fading channel is explicitly evaluated. An expression for uncoded system bit error probability is derived. Simulation results show the performance improvement in terms of BER due to the use of multi-antenna in the receiver, and the results illustrate that the multi-antenna based receiver works effectively in resolving multipaths in both angular and time domains to achieve performance improvement due to angular and time diversity gain provided by the multi-antenna system.

APA, Harvard, Vancouver, ISO, and other styles

50

Wakahara, Taku, Hiroaki Kanehisa, Yasuo Kawakami, Tetsuo Fukunaga, and Toshimasa Yanai. "Relationship Between Muscle Architecture and Joint Performance During Concentric Contractions in Humans." Journal of Applied Biomechanics 29, no. 4 (August 2013): 405–12. http://dx.doi.org/10.1123/jab.29.4.405.

Full text

Abstract:

The purpose of this study was to examine the relationship between muscle architecture of the triceps brachii (TB) and joint performance during concentric elbow extensions. Twenty-two men performed maximal isometric and concentric elbow extensions against various loads. Joint torque and angular velocity during concentric contractions were measured, and joint power was calculated. Muscle length, cross-sectional areas, and volume of TB were measured from magnetic resonance images. Pennation angle (PA) of TB at rest was determined by ultrasonography. The PA was significantly correlated with the maximal isometric torque (r= .471), but not to the torque normalized by muscle volume (r= .312). A significant correlation was found between PA and the angular velocity at 0 kg load (r= .563), even when the angular velocity was normalized by the muscle length (r= .536). The PA was significantly correlated with the maximal joint power (r= .519), but not with the power normalized by muscle volume (r= .393). These results suggest that PA has a positive influence on the muscle shortening velocity during an unloaded movement, but does not have a significant influence on the maximum power generation in untrained men.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Angular performance'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles