Achievements of female athletes in different disciplines of ketlebell lifting at the present stage

The article is devoted to the study of the current state of female athletes’ training in ketlebell lifting. The dynamics of fulfillment of standards of the master of sports of Ukraine by female athletes in all disciplines of ketlebell lifting in the period from 2016 to 2021 is analyzed. Female athletes (women aged 18-35 years) of national teams of regions of Ukraine in weight categories up to 58 kg, up to 63 kg, up to 68 kg and over 68 kg took part in the study. The protocols of the championships of Ukraine for the specified period were analyzed. Research methods: theoretical analysis and generalization of scientific and methodical literature and documentary method (study of competition protocols). It was found that in the snatch for the period under study the standard of the master of sports obeyed only three athletes, but in the jerk and long cycle no one female athletes have not fulfill the standarts. In addition, in a snatch with an arbitrary change of hands for 12 minutes (R-12), which was introduced in 2019 to attract more women to ketlebell lifting and popularize ketlebell lifting among women, in three years the standard of master of sports obeyed 27 female athletes. This allows us to say that at the present stage of development of ketlebell lifting there is a high level of preparedness of female athletes in the discipline of R-12 and the popularity of exercises with ketlebells among women. The need to improve the training process of female athletes in other disciplines of ketlebell lifting was also confirmed.

The effectiveness of athletes’ training in the snatch with an arbitrary change of hands without placing the kettlebell on the platform

The article examines the current state of athletes’ training process in the snatch with an arbitrary change of hands without placing the kettlebell on the platform for 12 minutes. The dynamics of the fulfillment of the standard of the Master of Sports of Ukraine in the snatch with an arbitrary change of hands without placing the kettlebell on the platform for 12 minutes by male and femail athletes by weight categories in 2019 was nalyzed and a comparative analysis was carried out with other disciplines of kettlebell lifting. The results of athletes (men aged 18–40 and women 18–35 years old) of the teams of regions of Ukraine of different weight categories (men: up to 63 kg, up to 68 kg, up to 73 kg, up to 78 kg, up to 85 kg, up to 95 kg, over 95 kg; women: up to 58 kg, up to 63 kg, up to 68 kg, over 68 kg) were studied. Research methods: theoretical analysis and generalization of scientific and methodical literature, documentary method (study of competition protocols), methods of mathematical statistics. It was found that the number of athletes who first met the standard of the Master of Sports of Ukraine in 2019 in the snatch with an arbitrary change of hands is 5 people (3 men, 2 women); in biathlon – 7 men; in long cycle – 4 men, in classic snatch – 1 woman. It was revealed that in biathlon much more athletes fulfill the standard of the Master of Sports of Ukraine than in the snatch with an arbitrary change of hands, which indicates the insufficient efficiency of the system of training athletes in the snatch with an arbitrary change of hands without placing the kettlebell on the platform and the need for its improvement.

Nonparametric Counterfactual Predictions in Neoclassical Models of International Trade

We develop a methodology to construct nonparametric counterfactual predictions, free of functional form restrictions on preferences and technology, in neoclassical models of international trade. First, we establish the equivalence between such models and reduced exchange models in which countries directly exchange factor services. This equivalence implies that, for an arbitrary change in trade costs, counterfactual changes in the factor content of trade, factor prices, and welfare only depend on the shape of a reduced factor demand system. Second, we provide sufficient conditions under which estimates of this system can be recovered nonparametrically. Together, these results offer a strict generalization of the parametric approach used in so-called gravity models. Finally, we use China's recent integration into the world economy to illustrate the feasibility and potential benefits of our approach. (JEL C51, D51, F11, F14, O19, P33)

Affine connection form of Regge calculus

Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein–Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the three-simplices which play the role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4, R) of the connection matrices. As a result, we have some action invariant w.r.t. arbitrary change of coordinates of the vertices (and related GL(4, R) transformations in the four-simplices). Excluding GL(4, R) connection from this action via the equations of motion we have exactly the Regge action for the considered spacetime.

An Inverse Heat Transfer Approach to Mitigating Sources of Experimental Error in Transient Heat Transfer Experiments

The Inverse Flux Solver for Arbitrary Waveforms (IFSAW) algorithm is a transient, simultaneous solution of time resolved adiabatic effectiveness, η(t), and heat transfer coefficient, h(t). Numerical simulations showed IFSAW maintained its high accuracy despite two experimental sources of error typically found when using a transient heat transfer method. The traditional transient method involves exposing a film cooled wind tunnel model at uniform temperature to a step change in freestream temperature. The experimental design results in nearly one-dimensional heat transfer and allows the surface to be modeled as semi-infinite. Typically, the surface temperature history is correlated to an analytical solution to the governing heat transfer equation (yielding η and h), but the required temperature step change is impossible to achieve in a laboratory. This paper first analyzed the error introduced by imperfect step changes and evaluated an alternative methodology, IFSAW, requiring only an arbitrary change in freestream temperature occurring at any rate. Secondly, severe error in h (found in locations where η is near unity because the surface temperature changes little from the initial temperature) was shown to be mitigated using IFSAW combined with a gradual change in coolant temperature at any point during measurement. With both complications, IFSAW maintains its ability to determine periodic η(t) and h(t) waveforms. In these ways, IFSAW is shown to be superior to the legacy transient method.

Sensitivity of Perturbation Variance and Fluxes in Turbulent Jets to Changes in the Mean Jet

Synoptic-scale eddy variance and fluxes of heat and momentum in midlatitude jets are sensitive to small changes in mean jet velocity, dissipation, and static stability. In this work the change in the jet producing the greatest increase in variance or flux is determined. Remarkably, a single jet structure change completely characterizes the sensitivity of a chosen quadratic statistical quantity to modification of the mean jet in the sense that an arbitrary change in the jet influences a chosen statistical quantity in proportion to the projection of the change on this single optimal structure. The method used extends previous work in which storm track statistics were obtained using a stochastic model of jet turbulence.

ON RELATION BETWEEN WEYL AND KONTSEVICH QUANTUM PRODUCTS: DIRECT EVALUATION UP TO THE ℏ3-ORDER

In his celebrated paper Kontsevich has proved a theorem which manifestly gives a quantum product (deformation quantization formula) and states that changing coordinates leads to gauge equivalent star products. To illuminate his procedure, we make an arbitrary change of coordinates in the Weyl (Moyal) product and obtain the deformation quantization formula up to the third order. In this way, the Poisson bivector is shown to depend on ℏ and not to satisfy the Jacobi identity. It is also shown that the values of coefficients in the formula obtained follow from associativity of the star product.

Magneto-acoustic surface waves on current sheets

The theory of linear magneto-acoustic surface waves is investigated for current sheets across which the magnetic field has an arbitrary change of direction: in the first place discontinuously, and in the second place via a narrow transition region in which the magnetic field rotates with constant amplitude, so that the gas pressure remains constant. It is found that the effect of non-zero pressure is to eliminate the surface wave for certain angles of propagation and to allow the existence of an additional, slower, surface wave for other angles of propagation. The resonance damping of the surface waves when the current sheet is of small non-zero width is considered, and it is found that Alfvénresonance damping always occurs, as well as (for high β and certain angles of propagation) compressive- or cusp-resonance damping.

ON SIGNATURE CHANGE IN p-ADIC SPACE-TIMES

Change of signature by linear coordinate transformations in p-adic space-times is considered. It is shown that there exists arbitrary change of trivial signature in [Formula: see text] for all n≥1 if p≡1( mod 4). In other cases it is possible to change only even number of the signs of the signature. We suggest new concept of signature with respect to distinct quadratic extensions of ℚp. If space-time dimension is restricted to four there is no signature change.