Search results for "Cycle time"
showing 6 items of 6 documents
Effects of Gliding Properties of Cross-Country Skis on the Force Production during Skating Technique in Elite Cross-Country Skiers
2013
The aim of the present study was to examine how different gliding conditions of skis affect performance, cycle characteristics and leg and pole force production during V2 skating. Ten elite skiers skied on 100 m uphill (4°) at three different constant speeds (4.0, 4.8 and 5.6 m/s) and maximum speed using two differently prepared skating skis (fast and slow ski). With the slow ski, maximum speed was 6.4 % slower than with the fast ski. With constant speeds, cycle time got shorter due to a decrease in the recovery time of the leg and pole. Peak pole force and average cycle force increased as well as lateral leg forces while there were no changes in the vertical leg forces. A strategy for how…
Numerical and Experimentical Study of Motion Control Using Pressure Feedback
2013
This paper is concerned with the inherent oscillatory nature of pressure compensated motion control of a hydraulic cylinder subjected to a negative load and suspended by means of an overcenter valve. A pressure feedback scheme that indirectly eliminates the oscillations is investigated. The indirect control scheme utilizes pressure feedback to electronically compensate the metering-out allowing for the removal of the compensator and, subsequently, elimination of the oscillations. The suggested electronic compensation scheme is implemented and examined in a single degree-of-freedom test rig actuated by means of a double acting hydraulic cylinder. The control scheme is compared with other con…
Exercise respiratory cycle time components in patients with emphysema
2012
Background: We have recently demonstrated that in patients with COPD the severity of emphysema (E) measured by high resolution computed tomography (HRCT) correlated with: ratio VTpeak/FEV1; VE/VCO2 slope and PETCO2 values at peak exercise. The aim of this study was to further investigate if exercise respiratory cycle time components correlated with % of E measured by HRCT. Method: Twelve patients (age = 65±8 yrs; FEV1 = 55±17%pred) with moderate to severe E (quantified by lung HRCT as % voxels 50% and <50%), we observed that patients with higher % of E had longer TeM (TeM: 1,72±0,26sec vs 1,34±0,27sec, p = 0,005) and TeM-end. A good linear correlation has been observed also between TeM and …
Mental Toughness Moderates Social Loafing in Cycle Time-Trial Performance
2016
The purpose of this study was to determine if mental toughness moderated the occurrence of social loafing in cycle time-trial performance.Twenty-seven men (Mage = 17.7 years, SD = 0.6) completed the Sport Mental Toughness Questionnaire prior to completing a 1-min cycling trial under 2 conditions: once with individual performance identified, and once in a group with individual performance not identified. Using a median split of the mental toughness index, participants were divided into high and low mental toughness groups. Cycling distance was compared using a 2 (trial) × 2 (high-low mental toughness) analysis of variance. We hypothesized that mentally tough participants would perform equall…
Changes in performance and poling kinetics during cross-country sprint skiing competition using the double-poling technique
2013
In this study, changes in skiing performance and poling kinetics during a simulated cross-country sprint skiing competition were investigated. Twelve elite male cross-country skiers performed simulated sprint competition (4 x 1,150 m heat with 20 min recovery between the heats) using the double-poling technique. Vertical and horizontal pole forces and cycle characteristics were measured using a force plate system (20-m long) during the starting spurt, racing speed, and finishing spurt of each heat. Moreover, heat and 20-m phase velocities were determined. Vertical and horizontal pole impulses as well as mean cycle length were calculated. The velocities of heats decreased by 2.7 +/- 1.7% (p …
Minimizing the cycle time in serial manufacturing systems with multiple dual-gripper robots
2006
Robots are being used more and more extensively as material-handling systems for automated manufacturing systems. This is especially true for dual-gripper robots whose in-process buffer (the robot's second gripper) constitutes a further element of flexibility. When the number of stations to be served is high and the set of activities the robot must execute is great, the system throughput may depend on robot capability rather than on process times. In such conditions, the use of several robots leads to an increase in system productivity. Obviously, the design and the management of such a handling system becomes more complex: the minimum number of robots required, the work stations to be serv…