Repeatability of Mae-Geri-Keage in Traditional Karate: A Three-Dimensional Analysis with Black-Belt Karateka

2002 ◽  
Vol 95 (2) ◽  
pp. 433-444 ◽  
Author(s):  
Chiarella Sforza ◽  
Michela Turci ◽  
Gian Piero Grassi ◽  
Yuri F. Shirai ◽  
Giuliano Pizzini ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Dimensional Analysis ◽  
Horizontal Plane ◽  
Body Shape ◽  
Three Dimensional ◽  
Black Belt ◽  
Spatial Coordinates ◽  
Standard Deviations ◽  
Lower Variability

In karate, performance also depends on a correct body shape, and the repeatability of standardized movements conditions the effectiveness of techniques. The execution of mae-geri-keage (frontal snap kick) was studied in 13 karateka (1st–5th dan). The 3D trajectories of 13 body landmarks were analyzed by an optoelectronic instrument while each karateka performed 10 repetitions of the movement. For each karateka and repetition, the standard deviations of the spatial coordinates x, y, z for each landmark were computed. A total standard deviation of the single participant was also calculated. Two experienced karateka performed with the best repeatability (smaller standard deviation) while executing the studied kick. Generally, the best repeatability was observed in the horizontal plane. The lower variability was observed in hips and head. Ankle and knee of the dominant limb had the worse. The method could detect athletes particularly gifted for the discipline. Moreover, it could help in the identification of those parts of body that do not repeat the movement with the desired precision.

scholarly journals Transverse Asymmetries of the Maxilla Even in Healthy and Apparently Symmetrical Subjects

2021 ◽  
Vol 18 (2) ◽  
pp. 446
Author(s):  
Giuseppe Currò ◽  
Giuseppa Bilello ◽  
Pietro Messina ◽  
Giuseppe Alessandro Scardina
Keyword(s):  
Environmental Factors ◽  
Dimensional Analysis ◽  
Horizontal Plane ◽  
Orthodontic Treatment ◽  
Treatment Plan ◽  
Three Dimensional ◽  
The Other ◽  
Careful Study ◽  
Morphological Parameters ◽  
Bone Segment

In the formulation of an orthodontic treatment plan, the three-dimensional analysis of the dental arches represents a fundamental moment for the evaluation of all the morphological parameters necessary in order to have a correct and complete diagnosis. In this regard, the study of the dental arches on the horizontal plane is sometimes neglected or not thorough enough. When evaluating the transverse dimensions of the dental upper arche, the presence of an asymmetry is frequently found, and it means that an hemiarch is larger than the other. Furthermore, any variation in one of the three planes of space always involves an alteration also on the other two planes in order to have compensation. The morphology of a bone segment depends on various factors, mainly genetical, acquired and environmental. Regarding the environmental factors, the function determines the morphology, but this in turn determines the function. In the case of unilateral mastication, the upper maxilla will be asymmetrical, so growing patients will have compensation on other skull bones. From these considerations arises the need for a careful study of the horizontal plane of the maxilla in the presence of a malocclusion during diagnostic evaluations. These asymmetries, however, must be evaluated and quantified in the diagnostic phase in order to formulate a correct plan of treatment. The aim of this work is to demonstrate that there are almost always transverse asymmetries of the maxilla, albeit of a slight entity, even in healthy and apparently symmetrical subjects.

scholarly journals The Effect of the Selection of Three-Dimensional Random Numerical Soil Models on Strip Foundation Settlements

2021 ◽  
Vol 11 (16) ◽  
pp. 7293
Author(s):  
Kamil Żyliński ◽  
Karol Winkelmann ◽  
Jarosław Górski
Keyword(s):  
Standard Deviation ◽  
Random Field ◽  
Three Dimensional ◽  
Gaussian Model ◽  
Random Variables ◽  
Fe Model ◽  
Strip Foundation ◽  
Mean Values ◽  
Standard Deviations ◽  
Selection Of

This paper delivers a probabilistic attempt to prove that the selection of a random three-dimensional finite element (FE) model of a subsoil affects the computed settlements. Parametric analysis of a random soil block is conducted, assuming a variable subsoil Young’s modulus in particular finite elements. The modulus is represented by a random field or different-sized sets of random variables; in both cases, the same truncated Gaussian model is assumed. Mean values and standard deviations of random soil settlement are estimated by a Monte Carlo simulation procedure. With regard to the adopted FE model, the estimated settlement mean values do not vary significantly, but standard deviations do strongly. Similarities also appear in the diagrams of random field correlation length versus settlement standard deviation and the diagrams displaying a total number of model random variables versus settlement standard deviation. Thus, relevant single random variable models represent the random field approach well with regard to settlement parameter estimation. This remark is verified upon a settlement analysis of a three-dimensional FE model of a hypothetical strip foundation. Following the preliminary model observations, various probabilistic geotechnical analyses may be supported, e.g., continuous footing design, slope stability analysis, and foundation reliability assessment.

In situ investigation of the primary recrystallization of alpha titanium in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 634-635
Author(s):  
S. Naka ◽  
R. Penelle ◽  
R. Valle
Keyword(s):  
Dimensional Analysis ◽  
Texture Evolution ◽  
Cold Work ◽  
Three Dimensional ◽  
Primary Recrystallization ◽  
Thin Foils ◽  
In Situ Investigation ◽  
Grain Growth Model ◽  
Alpha Titanium

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.

On the sensibility of the Pairs Trading strategy: the case of the FTS stock market index

2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Ainhoa Fernández-Pérez ◽  
María de las Nieves López-García ◽  
José Pedro Ramos Requena
Keyword(s):  
Standard Deviation ◽  
Stock Market ◽  
Trading Strategy ◽  
Stock Market Index ◽  
Pairs Trading ◽  
Empirical Application ◽  
Statistical Arbitrage ◽  
Market Index ◽  
Standard Deviations ◽  
Using Data

In this paper we present a non-conventional statistical arbitrage technique based in varying the number of standard deviations used to carry the trading strategy. We will show how values of 1 and 1,2 in the standard deviation provide better results that the classic strategy of Gatev et al (2006). An empirical application is performance using data of the FST100 index during the period 2010 to June 2019.

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