PERFORMANCE ANALYSIS AND PROBABILITIES BY GENDER IN JUDO: COMBAT PHASES, TECHNIQUES AND BIOMECHANICAL LEVERS

The aim of the current study was to compare and verify factors associated with gender in combat phases, techniques and biomechanical leversused during judo matches, and performance probabilities in those same matches. We evaluated high-level judo athletes from each weight division who qualified for the Olympic Games. 773 male and 638 female bouts were analyzed based on the motor actions during approach, gripping, attack, defense, groundwork and biomechanics of techniques. The current results demonstrated significant differences between male and female bouts in pause frequencies [7(4;12); 9(4;13); p≤0.05], and approach with displacements [1(0; 6); 3(0;9); p≤0.05]. Female athletes used higher frequencies of techniques with different biomechanical levers for attacks (i.e. trunk leg lever attempts; waist lever variable attempts, waist lever variable effective and attempts, and maleolo lever effective and attempts; p≤0.05), while men used more variations of gripping (i.e. left collar, left collar and sleeve, both collars, right sleeve, left sleeve and both sleeves; p≤0.05) and groundwork attacks (i.e. Osae-waza, kansetsu-waza and shime-waza attempts; p≤0.05). The regression analysis demonstrated that female performance probabilities are associated positively with the use of Osae-waza, Variable/medium length attempted and scored, Arm/foot lever, Minimum lever attempted and scored and negatively with the grip on both collars, while male performance probabilities are associated positively with the use of Variable/medium length scored, Arm/foot lever scored, Minimum lever attempted and negatively with the grip on the right sleeve. The present data can be applied by coaches and athletes to elaborate the training programs focused on competitive strategies that increase the chances of winning.

The Evolution of Inhomogeneous Wave Statistics through a Variable Medium

The interaction of ocean waves with variable currents and topography in coastal areas can result in inhomogeneous statistics because of coherent interferences, which affect wave-driven circulation and transport processes. Stochastic wave models, invariably based on some form of the radiative transfer equation (or action balance), do not account for these effects. The present work develops and discusses a generalization of the radiative transfer equation that includes the effects of coherent interferences on wave statistics. Using multiple scales, the study approximates the transport equation for the (complete) second-order wave correlation matrix. The resulting model transports the coupled-mode spectrum (a form of the Wigner distribution) and accounts for the generation and propagation of coherent interferences in a variable medium. The authors validate the model through comparison with analytic solutions and laboratory observations, discuss the differences with the radiative transfer equation and the limitations of this approximation, and illustrate its ability to resolve coherent interference structures in wave fields such as those typically found in refractive focal zones and around obstacles.

Mechanical Behavior of Fracture Filled with Variable Medium

Filled fracture is a fracture in which sands or other materials occupy some void spaces. This study uses well-controlled laboratory experiments to investigate mechanical behavior of fracture filled with variable medium by means of normal compression and lateral restraint. A large number of stress-strain data are obtained. The mechanical behavior of filled fracture with variable medium can be divided into three phases: rheological phase, compaction phase and linear elastic phase. At the beginning of the experiment, the filled fracture is in the ideal plastic flow state. The overall strength of filled fracture increase with finite deformation and normal stress increasing, and show linear elastic characters. Based on the experiment results and characteristics, the mechanical behavior model of fracture filled with variable medium is constructed, and also its mechanism is analyzed.