APPLICATION OF SIMULATION TO FREESTYLE AERIAL SKIING

The aim of this study was to use a computer simulation model of aerial movement to investigate the ability of asymmetrical arm movements to initiate twist in the flight phase of a triple layout somersault in the aerials event of freestyle skiing. Three arm movements were analysed resulting in triple somersaults with four and five twists together with lead up movements with one twist less. It is concluded that four twists can be initiated during flight using two phases of asymmetrical arm movement and that the production of five twists requires three phases of asymmetrical arm movement

APPLICATIONS OF MODELLING TO THE IMPROVEMENT OF SPORTS TECHNIQUE

Models of high jumping, high bar circling, swinging on rings, tumbling, diving, twisting and balancing can give insight into the mechanics of these movements and provide a basis for coaching in order to improve performance. Such models can also be used to investigate the viability of new movements or new techniques. Training aids based on models of sports movements have the potential to speed learning and enable athletes to reach new levels of achievement

A CASE STUDY ON THE EFFECTS OF THE UPPER ARM DEFINITION ON SHOULDER AND ELBOW KINEMATICS DURING THE BADMINTON SMASH

The aim of this case study was to identify the effect of the upper arm definition on shoulder and elbow kinematics during the badminton smash. A method was proposed that corrects the false external rotation when using the shoulder-elbow-wrist plane based on the carrying angle (ISB-2C) and compared to ISB recommendations for defining the upper arm (ISB-1 and ISB-2). Differences were found in shoulder and elbow kinematics, in particular angular velocities. Both magnitude and the time history of the angular velocity were affected. In particular, use of the medial and lateral epicondyles was unable to detect a reasonable signal for pronation/supination. ISB-2C reduces some of the problems associated with ISB-1 and ISB-2 e.g. soft-tissue artifact, proximity of medial and lateral epicondyles to the humeral longitudinal axis and false external rotation caused by the carrying angle

WHICH JOINT ANGLE CHANGES HAVE MOST EFFECT ON BALL RELEASE SPEED IN OVERARM THROWING?

An eight-segment angle-driven simulation model of the trunk and upper limbs plus ball was developed to determine which joint angle changes have most influence on ball release speed. 15 overarm throwing trials were recorded, and the joint angle time histories of each trial were input into the simulation model. Systematically replacing specific joint angle time histories with a constant value and observing the effect on ball release speed showed that overarm throwing was most sensitive to trunk extension/flexion, trunk ext./internal rotation, scapula ext./internal rotation, upper arm flexion/extension, upper arm add/abduction, upper arm ext./internal rotation and forearm extension/flexion. During coaching or performance, attention should be focused on these angles because any changes could have a substantial effect on the ball release speed

ADJUSTMENT IN THE FLIGHT PHASE OF 1M SPRINGBOARD FORWARD PIKE DIVES

The aim of this study was to investigate the variability in 1m springboard forward pike dives (101B). Variability of body orientation angle at takeoff and water entry together with joint angle time histories of 15 forward pike dives, performed by an international diver, were determined using video analysis. A computer simulation model was used to investigate the effects of initial conditions variability and flight phase configuration variability on outcome (orientation at entry) variability. It was found that the variation in the simulated orientation at entry arising from variability in the initial conditions was greater than the actual variation. This indicates that the diver used feedback correction to make adjustments during flight to reduce the variability of his entry angle

ATP induced MUC5AC release from human airways in vitro.

BACKGROUND: Chronic airway diseases are often associated with marked mucus production, however, little is known about the regulation of secretory activity by locally released endogenous mediators. AIM: This investigation was performed to determine the release of MUC5AC mucin from human bronchial preparations using the purinergic agonists adenosine 5'-triphosphate (ATP) and uridine 5'-triphosphate (UTP). METHODS: Immunohistochemical and immunoradiometric assays (IRMA) were used to detect the MUC5AC mucin. Immunohistochemical analysis were performed using individual 1-13 M1 and 21 M1 MAbs recognizing a recombinant M1 mucin partially encoded by the MUC5AC gene. IRMA measurments were performed using a mixture of eight anti-M1 mucin MAbs (PM8), which included both 1-13 M1 and 21 M1 MAbs. Lysozyme and protein were also measured in the biological fluids derived from human bronchial preparations obtained from patients who had undergone surgery for lung carcinoma. RESULTS: The anti-M1 monoclonal antibodies labelled epithelial goblet cells. After challenge of human bronchial preparations with ATP, the goblet cells exhibited less staining. In contrast, UTP did not alter the immunolabelling of goblet cells. MUC5AC mucin in the bronchial fluids derived from ATP-challenged preparations was increased while UTP had no effect on release. ATP did not alter either the quantities of lysozyme or protein detected in the biological fluids. CONCLUSION: These results suggest that ATP may regulate epithelial goblet cell secretion of MUC5AC mucin from human airways in vitro

ADJUSTMENT IN THE TAKEOFF PHASE OF 1-M SPRINGBOARD FORWARD DIVES

The aim of this study was to investigate whether any adjustment is made during the board contact phase of 1-m springboard forward dives. Variability of body orientation angle at landing from hurdle (touchdown) and at takeoff together with joint angle time histories of 15 forward pike dive takeoffs, performed by an international diver, were determined using video analysis. A computer simulation model of a diver and springboard was used to determine the effects of perturbations of initial conditions on takeoff variability. The variation at takeoff obtained in the simulation outcome was much greater than in the actual performance, indicating that the diver made adjustments during the board contact phase. The diver varied his body configuration during the board recoil phase to adjust his body orientation, leading to low variability at takeoff

Multi-Objective Tradeoffs in the Design Optimization of a Brushless Permanent-Magnet Machine With Fractional-Slot Concentrated Windings

In this paper, a robust parametric model of a brushless permanent magnet machine with fractional-slot concentrated windings, which was developed for automated design optimization is presented. A computationally efficient finite-element analysis method was employed to estimate the dq-axes inductances, the induced voltage and torque ripple waveforms, and losses of the machine. A method for minimum effort calculation of the torque angle corresponding to the maximum torque per ampere load condition was developed. A differential evolution algorithm was implemented for the global design optimization with two concurrent objectives of minimum losses and minimum material cost. An engineering decision process based on the Pareto-optimal front for 3,500 candidate designs is presented together with discussions on the tradeoffs between cost and performance. One optimal design was finally selected, prototyped and successfully tested

NiGe on Ge(001) by reactive deposition epitaxy: An in situ ultrahigh-vacuum transmission-electron microscopy study

We use an ultrahigh-vacuum transmission-electron microscopy, equipped with an electron-beam evaporator directed at a heating stage in the pole piece, to follow the reaction pathway of Ni on Ge(001) substrate at 300 °C. Using reactive deposition, we illustrate that epitaxial orthorhombic NiGe (a = 5.381 Åa=5.381Å, b = 3.428 Åb=3.428Å, and c = 5.811 Åc=5.811Å) phase can be grown directly without the initial formation of metal-rich Ni2GeNi2Ge phase. The epitaxial orientation of the NiGe islands and the underlying Ge(001) substrate were found to be NiGe(01)//Ge(001)NiGe(1¯01)∕∕Ge(001) and NiGe[010]//Ge[110]NiGe[010]∕∕Ge[110].Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87854/2/201908_1.pd