scholarly journals 2D Video Analysis System to Analyze the Performance Model of Figure Roller Skating: A Pilot Study

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 155
Author(s):  
Cristian Romagnoli ◽  
Vincenzo Bonaiuto ◽  
Giorgio Gatta ◽  
Naomi Romagnoli ◽  
Anas Alashram ◽  
...  
Keyword(s):  
Video Analysis ◽  
Center Of Mass ◽  
Performance Model ◽  
Biomechanical Analysis ◽  
Knee Joints ◽  
Jump Height ◽  
Compensatory Strategy ◽  
Medium Level ◽  
Analysis System ◽  
High Level

Figure roller skating is a discipline composed of various movements which involve jumps, artistic figures and spins in a seamless program which has both technical and shapely difficult. A biomechanical analysis of a double salchow was performed using a 2D video analysis of one European and in two Italian roller skaters. On average, the high level (HL) roller skater showed a horizontal velocity of the center of mass higher than the average, especially in the prop stage, whereas the medium level (ML) and low level (LL) athletes reduced their velocity significantly. The spin angular velocity of the ML and LL skaters was always higher than of the HL. This phenomenon would seem to be a compensatory strategy for a lower jump height, with a reduced trunk-thigh angle and less thigh lever arm (coxo-femur/knee joints) during the take-off and landing phases of the double salchow jump.

scholarly journals Effect of Three Technical Arms Swings on The Elevation of the Center of Mass During a Standing Back Somersault

2014 ◽  
Vol 40 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Bessem Mkaouer ◽  
Monèm Jemni ◽  
Samiha Amara ◽  
Helmi Chaabène ◽  
Johnny Padulo ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Body Height ◽  
Force Plate ◽  
Three Dimensional ◽  
Movement Analysis ◽  
Vertical Displacement ◽  
Technical Performance ◽  
Risk Of Falls ◽  
Analysis System ◽  
High Level

Abstract Arms swing during standing back somersaults relates to three different “gymnastics schools”, each is considered “optimal” by its adepts. In the three cases, technical performance, elevation and safety differ. Therefore, the aim of this study was to compare the mechanical variables of three different arms swing techniques in the performance of a standing back tucked somersault. Five high-level male gymnasts (age: 23.17±1.61 yrs; body height: 1.65±0.05 m; body mass: 56.80±7.66 kg) randomly performed standing somersaults under three conditions, each following a different arms’ swing technical angle (270°, 180° and 90°). A force plate synchronized with a three dimensional movement analysis system was used to collect kinetic and kinematic data. Significant differences were observed between somersaults’ performance. The back somersault performed with 270° arms swing showed the best vertical displacement (up to 13.73%), while the back somersaults performed with 180° arms swing showed a decrease in power (up to 22.20%). The back somersault with 90° arms swing showed the highest force (up to 19.46%). Considering that the higher elevation of the centre of mass during the flight phase would allow best performance and lower the risk of falls, this study demonstrated that optimal arms’ swing technique prior to back tucked somersault was 270°.

scholarly journals Relationships Between Triathlon Performance and Pacing Strategy During the Run in an International Competition

2011 ◽  
Vol 6 (2) ◽  
pp. 183-194 ◽  
Author(s):  
Yann Le Meur ◽  
Thierry Bernard ◽  
Sylvain Dorel ◽  
Chris R. Abbiss ◽  
Gérard Honnorat ◽  
...  
Keyword(s):  
Video Analysis ◽  
Inverse Correlation ◽  
International Competition ◽  
Running Speed ◽  
Significant Inverse Correlation ◽  
Pacing Strategy ◽  
Pacing Strategies ◽  
The Mean ◽  
Analysis System ◽  
High Level

Purpose:The purpose of the present study was to examine relationships between athlete’s pacing strategies and running performance during an international triathlon competition.Methods:Running split times for each of the 107 finishers of the 2009 European Triathlon Championships (42 females and 65 males) were determined with the use of a digital synchronized video analysis system. Five cameras were placed at various positions of the running circuit (4 laps of 2.42 km). Running speed and an index of running speed variability (IRSVrace) were subsequently calculated over each section or running split.Results:Mean running speed over the frst 1272 m of lap 1 was 0.76 km-h–1 (+4.4%) and 1.00 km-h–1 (+5.6%) faster than the mean running speed over the same section during the three last laps, for females and males, respectively (P < .001). A significant inverse correlation was observed between RSrace and IRSVrace for all triathletes (females r = -0.41, P = .009; males r = -0.65, P = .002; and whole population -0.76, P = .001). Females demonstrated higher IRSVrace compared with men (6.1 ± 0.5 km-h–1 and 4.0 ± 1.4 km-h–1, for females and males, respectively, P = .001) due to greater decrease in running speed over uphill sections.Conclusions:Pacing during the run appears to play a key role in high-level triathlon performance. Elite triathletes should reduce their initial running speed during international competitions, even if high levels of motivation and direct opponents lead them to adopt an aggressive strategy.

A unified framework for automated person re-indentification

2020 ◽  
Vol 71 (7) ◽  
pp. 868-880
Author(s):  
Nguyen Hong-Quan ◽  
Nguyen Thuy-Binh ◽  
Tran Duc-Long ◽  
Le Thi-Lan
Keyword(s):  
Deep Learning ◽  
Video Analysis ◽  
Camera Network ◽  
Unified Framework ◽  
Person Detection ◽  
Practical Applications ◽  
Detection And Tracking ◽  
Analysis System ◽  
Bounding Boxes

Along with the strong development of camera networks, a video analysis system has been become more and more popular and has been applied in various practical applications. In this paper, we focus on person re-identification (person ReID) task that is a crucial step of video analysis systems. The purpose of person ReID is to associate multiple images of a given person when moving in a non-overlapping camera network. Many efforts have been made to person ReID. However, most of studies on person ReID only deal with well-alignment bounding boxes which are detected manually and considered as the perfect inputs for person ReID. In fact, when building a fully automated person ReID system the quality of the two previous steps that are person detection and tracking may have a strong effect on the person ReID performance. The contribution of this paper are two-folds. First, a unified framework for person ReID based on deep learning models is proposed. In this framework, the coupling of a deep neural network for person detection and a deep-learning-based tracking method is used. Besides, features extracted from an improved ResNet architecture are proposed for person representation to achieve a higher ReID accuracy. Second, our self-built dataset is introduced and employed for evaluation of all three steps in the fully automated person ReID framework.

scholarly journals Biomechanical analysis of a centralization procedure for extruded lateral meniscus after meniscectomy in porcine knee joints

2021 ◽  
Author(s):  
Yuji Kohno ◽  
Hideyuki Koga ◽  
Nobutake Ozeki ◽  
Junpei Matsuda ◽  
Mitsuru Mizuno ◽  
...  
Keyword(s):  
Lateral Meniscus ◽  
Biomechanical Analysis ◽  
Knee Joints ◽  
Porcine Knee

Urban network of China from the perspective of population mobility: Three-dimensional co-occurrence of nodes and links

2021 ◽  
pp. 0308518X2199781
Author(s):  
Xinyue Luo ◽  
Mingxing Chen
Keyword(s):  
Three Dimensional ◽  
Geographical Distance ◽  
Two Dimensional ◽  
Population Mobility ◽  
Urban Network ◽  
Urban Networks ◽  
Low Level ◽  
Medium Level ◽  
High Level ◽  
External Connections

The nodes and links in urban networks are usually presented in a two-dimensional(2D) view. The co-occurrence of nodes and links can also be realized from a three-dimensional(3D) perspective to make the characteristics of urban network more intuitively revealed. Our result shows that the external connections of high-level cities are mainly affected by the level of cities(nodes) and less affected by geographical distance, while medium-level cities are affected by the interaction of the level of cities(nodes) and geographical distance. The external connections of low-level cities are greatly restricted by geographical distance.

scholarly journals Transfer and generalization of learned manipulation between unimanual and bimanual tasks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Trevor Lee-Miller ◽  
Marco Santello ◽  
Andrew M. Gordon
Keyword(s):  
Learning Transfer ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Pressure Point ◽  
Torque Generation ◽  
Before And After ◽  
Object Center ◽  
High Level ◽  
Bimanual Grasping ◽  
Partial Learning

AbstractSuccessful object manipulation, such as preventing object roll, relies on the modulation of forces and centers of pressure (point of application of digits on each grasp surface) prior to lift onset to generate a compensatory torque. Whether or not generalization of learned manipulation can occur after adding or removing effectors is not known. We examined this by recruiting participants to perform lifts in unimanual and bimanual grasps and analyzed results before and after transfer. Our results show partial generalization of learned manipulation occurred when switching from a (1) unimanual to bimanual grasp regardless of object center of mass, and (2) bimanual to unimanual grasp when the center of mass was on the thumb side. Partial generalization was driven by the modulation of effectors’ center of pressure, in the appropriate direction but of insufficient magnitude, while load forces did not contribute to torque generation after transfer. In addition, we show that the combination of effector forces and centers of pressure in the generation of compensatory torque differ between unimanual and bimanual grasping. These findings highlight that (1) high-level representations of learned manipulation enable only partial learning transfer when adding or removing effectors, and (2) such partial generalization is mainly driven by modulation of effectors’ center of pressure.

Alchemy: Distributed financial quantitative analysis system with high‐level programming model

2021 ◽  
Author(s):  
Rong Gu ◽  
Zhixiang Zhang ◽  
Zhihao Xu ◽  
Zhaokang Wang ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Programming Model ◽  
Analysis System ◽  
High Level

scholarly journals Quality of colostral passive immunity and pattern of serum protein fluctuation in newborn calves

2003 ◽  
Vol 60 (3) ◽  
pp. 453-456 ◽  
Author(s):  
Patricia Pauletti ◽  
Raul Machado Neto ◽  
Irineu Umberto Packer ◽  
Raul Dantas D'Arce ◽  
Rosana Bessi
Keyword(s):  
Total Protein ◽  
Statistical Design ◽  
Extended Period ◽  
Experimental Period ◽  
Passive Immunity ◽  
Serum Total Protein ◽  
Non Linear ◽  
Medium Level ◽  
Group 2 ◽  
High Level

Immunity acquired by newborn animals is known as passive immunity, and for ruminants, antibody acquisition depends on the ingestion and absorption of adequate amounts of immunoglobulins from colostrum. This study relates different initial levels of acquired passive protection and serum total protein (TP) and immunoglobulin G (IgG). Serum immunoglobulin concentration and total protein were evaluated for female Holstein calves in the first sixty days of life. Animals were separated into three groups according to their initial level of passive immunity: group 1- animals with a low level of passive immunity (below 20 mg mL-1); group 2- animals with a medium level (between 20 and 30 mg mL-1), and group 3- animals with a high level (above 30 mg mL-1). Serum total protein was determined through the biuret method and IgG was determined by radial immunodiffusion. Data were analyzed as a completely randomized, split-plot statistical design. Fluctuation of the variables along the experimental period was determined through non-linear regression by the DUD method (PROC NLIN - Non Linear SAS). Animals with low antibody acquisition started to produce antibodies earlier, reflecting a compensatory synthesis. On the other hand, animals having adequate levels exhibited an extended period of immunoglobulin catabolism and the beginning of the endogenous phase was delayed. Regardless initial levels, the fluctuations in IgG contents occurred around adequate physiological concentrations, ranging from 20 to 25 mg mL-1.

scholarly journals A Fast and Effective Method to Identify Relevant Sets of Variables in Complex Systems

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1022
Author(s):  
Gianluca D’Addese ◽  
Martina Casari ◽  
Roberto Serra ◽  
Marco Villani
Keyword(s):  
Complex Systems ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Computational Cost ◽  
Graph Analysis ◽  
The Past ◽  
Medium Level ◽  
Micro Level ◽  
Gene Regulatory ◽  
High Level

In many complex systems one observes the formation of medium-level structures, whose detection could allow a high-level description of the dynamical organization of the system itself, and thus to its better understanding. We have developed in the past a powerful method to achieve this goal, which however requires a heavy computational cost in several real-world cases. In this work we introduce a modified version of our approach, which reduces the computational burden. The design of the new algorithm allowed the realization of an original suite of methods able to work simultaneously at the micro level (that of the binary relationships of the single variables) and at meso level (the identification of dynamically relevant groups). We apply this suite to a particularly relevant case, in which we look for the dynamic organization of a gene regulatory network when it is subject to knock-outs. The approach combines information theory, graph analysis, and an iterated sieving algorithm in order to describe rather complex situations. Its application allowed to derive some general observations on the dynamical organization of gene regulatory networks, and to observe interesting characteristics in an experimental case.

Sign in / Sign up

Export Citation Format

Share Document