scholarly journals Hammer Throw: A Pilot Study for a Novel Digital-Route for Diagnosing and Improving Its Throw Quality

2020 ◽  
Vol 10 (6) ◽  
pp. 1922 ◽  
Author(s):  
Bingjun Wan ◽  
Yuanyuan Gao ◽  
Ye Wang ◽  
Xiang Zhang ◽  
Hua Li ◽  
...  
Keyword(s):  
National Level ◽  
Biofeedback Training ◽  
Dominant Factor ◽  
Measurement Unit ◽  
College Level ◽  
Camera System ◽  
Joint Coordination ◽  
Wire Tension ◽  
Muscle Groups ◽  
Trunk Tilt

The world record of the hammer throw has not been broken since 1986. This stagnation is multifactorial. One dominant factor could be the lack of evidence-based scientific/biofeedback training. This study aims to identify key parameters influencing throw quality and structure a new digital method for biofeedback training. Wire-tension measurement and 3D motion capture technology (VICON 12-camera system) were applied in quantifying and comparing throws of a national-level and a college-level athlete. Our results reveal that multi-joint coordination influences heavily on wire-tension generation. Four phases, i.e., initiation, transition, turns, and throw, play various roles in evaluating the quality of a throw. Among them, the transition, the third turn, and the throw display explosive/rapid increases of tension. For improving the effectiveness of the skill, the whip-like control and proper SSC (stretch-shortening cycle) of muscle groups involved should be established through years of training. Furthermore, our study unveils that quick and complex full-body control could be quantified and characterized by four key parameters: wire-tension, hand- and hip-height, and trunk tilt. Hence, a wearable digital device with tension and three Inertial Measurement Unit (IMU) sensors would have great potential in realizing real-time biomechanical feedback training in practice for evaluating and improving the efficiency of various training programs.

scholarly journals Kinematic Characteristics of National and College Level Weightlifters during the Snatch Technique Using Wearable Inertial Sensors

2021 ◽  
Vol 10 (1) ◽  
pp. 22
Author(s):  
Munkhbat Tumurbaatar ◽  
Batbayar Khuyagbaatar ◽  
Yoon Hyuk Kim ◽  
Ganbat Danaa
Keyword(s):  
Inertial Sensors ◽  
National Level ◽  
Knee Joints ◽  
Measurement Unit ◽  
College Level ◽  
Training Strategy ◽  
National Team ◽  
Camera Systems ◽  
Kinematic Characteristics ◽  
Wearable Inertial Sensors

Weightlifting performance is strongly dependent on technique, explosive strength, and flexibility. There are two major lifts involved in competition: the snatch and the clean and jerk, and the snatch is the most technical component of the weightlifting competition. Most technical analyses have previously been performed using either video analysis or conventional optical camera systems. However, few studies have investigated the kinematic characteristics of the weightlifters using inertial measurement unit (IMU) sensors. In this study, we investigated the joint kinematics of the trunk, shoulder, elbow, hip, and knee as well as the main phases during the snatch technique for national and college level weightlifters using multiple IMU sensors. Seven female Mongolian weightlifters (three national level and four college level) participated. Each participant performed three snatch attempts at 70% of their one-repetition maximum. The joint angles were calculated using three-axis acceleration and three-axis gyroscope data from the IMU sensors. The six main phases of the snatch technique were defined based on knee flexion. All parameters were compared between the national and college level weightlifters. The national team showed a higher elbow range of motion and a greater extension of the hip and knee joints at the second pull compared with college-level athletes. In addition, the college team did not exhibit the transition phase, and the proportion of the turnover phase was larger. This study provides a kinematic difference between the two different level weightlifters, which may help coaches and athletes to improve their training strategy and weightlifting performance.

scholarly journals A study on the improvement of basic general mathematics according to changes in the basic mathematical ability of first-year college students in the fields of science and engineering

2021 ◽  
Vol 15 (5) ◽  
pp. 85-95
Author(s):  
Hye Yoon Choi ◽  
Sang Kil Shim
Keyword(s):  
Mathematics Education ◽  
Mathematics Curriculum ◽  
National Level ◽  
Academic Ability ◽  
Mathematical Ability ◽  
Policy Support ◽  
First Year ◽  
College Level ◽  
Science And Engineering ◽  
Ability Test

The objective of this study is to examine changes in the Mathematics Curriculum and the College Scholastic Ability Test that affect the changes in the Basic Mathematical Ability of students enrolled in Science and Engineering departments and to compare and analyze the educational contents of basic general mathematics completed by first-year students in science and engineering fields in order to provide improvement plans for basic general mathematics. In Korea, whenever the mathematics curriculum is revised, the content covered in the previous curriculum is deleted or weakened in order to optimize the educational content, and ‘Calculus’ and ‘Geometry’ are required for science and engineering students to choose in the college scholastic ability test. Thus, the basic academic ability of mathematics is lowered, and it is difficult to complete the basic general mathematics taught in the first year of university. In order to solve this problem, it is necessary to analyze the mathematics and curriculum to include deleted or weakened contents in the university's basic general mathematics, to understand the students' basic academic ability in mathematics, and to operate basic general mathematics by level or operate basic mathematics courses. In addition, when revising the mathematics both in curriculum and the university scholastic ability test, the opinions of professors in charge of basic general mathematics education at universities should be sufficiently reflected to minimize changes in key factors for students to complete basic general mathematics, and it is necessary to provide policy support at the national level for the development and operation of the curriculum for general mathematics education at a college level.

Comparison of UGV Position Estimation Equipped With GNSS-RTK and GPS Using EKF

2020 ◽  
Author(s):  
Hesham Ismail ◽  
Thani Althani ◽  
Mohammed Minhas Anzil ◽  
Prashanth Subramaniam
Keyword(s):  
Extreme Temperature ◽  
Processing Technique ◽  
Position Estimation ◽  
Image Processing Technique ◽  
Measurement Unit ◽  
Unmanned Ground Vehicle ◽  
Camera System ◽  
Ground Vehicle ◽  
Positioning Device ◽  
Global Navigation Satellite

Abstract Site assessments for bifacial Photovoltaic (PV) installation are quite challenging to conduct manually due to the area size and the extreme temperature conditions at desert sites. We designed and built an autonomous Unmanned Ground Vehicle (UGV) fitted with a Global Navigation Satellite Network-System Real-Time Kinematic (GNSS-RTK) positioning device, an Inertial Measurement Unit (IMU), encoder to improve and aid site assessments in desert condition. Sandy terrains deserts are challenging for UGV’s because they increase the likelihood of wheel slippage due to reduced traction. Sensor details such as IMU, GNSS-RTK, and encoder should be taken into consideration to account for the errors that the desert terrains pose. This study compared the Extended Kalman Filter (EKF) for standard GPS & GNSS-RTK to verify which performs better for the UGV’s position estimation. The estimated UGV’s position from the kinematics model and EKF are validated using a drone camera system that uses an image processing technique to verify the UGV’s position with the help of the visible reference cones. Throughout the experiments, the GNSS-RTK performed better than GPS. Also, the EKF performed as well as the GNSS-RTK by trusting it more than the encoder/gyroscope reading.

Dispersion reduction of artillery rockets guided by flight path steering method

2016 ◽  
Vol 120 (1225) ◽  
pp. 435-456 ◽  
Author(s):  
S. Mandić
Keyword(s):  
Measurement Errors ◽  
Flight Path ◽  
Guidance System ◽  
Lateral Acceleration ◽  
Dominant Factor ◽  
Measurement Unit ◽  
Impact Point ◽  
Angle Correction ◽  
Flight Path Angle ◽  
The Impact

ABSTRACTArtillery rockets are sensitive to disturbances (total impulse variation, wind, thrust misalignment, etc.). As the range of ground-to-ground rockets increases, the accuracy of free flight rockets decreases. Requirements for the increase of the range and minimisation of the impact point dispersions can be solved by adding guidance and control systems to rockets. Based on the differences between the measured flight parameters and the calculated parameters for the nominal trajectory, the flight path angle correction algorithm is obtained by adding the correction to the nominal value. The flight path steering guidance system with lateral acceleration autopilot in the inner loop, is used for the guidance of hypothetical artillery rockets. The guidance algorithm given in this paper eliminates the time correction due to rocket velocity variations. Efficiency of the proposed algorithm is illustrated by numerical simulation. There is no practical influence of the external disturbances on impact point dispersion. It is also shown that the measurement errors of the inertial measurement unit are the dominant factor affecting impact point dispersion of artillery rockets modified by adding a guidance system based on the flight path steering method.

The carbon footprint of an Australian satellite haemodialysis unit

2013 ◽  
Vol 37 (3) ◽  
pp. 369 ◽  
Author(s):  
Allan E. K. Lim ◽  
Anthony Perkins ◽  
John W. M. Agar
Keyword(s):  
Water Use ◽  
Carbon Footprint ◽  
Water Consumption ◽  
National Level ◽  
Healthcare Providers ◽  
The State ◽  
Measurement Unit ◽  
Target Setting ◽  
Local Factors ◽  
The Impact

Objectives. This study aimed to better understand the carbon emission impact of haemodialysis (HD) throughout Australia by determining its carbon footprint, the relative contributions of various sectors to this footprint, and how contributions from electricity and water consumption are affected by local factors. Methods. Activity data associated with HD provision at a 6-chair suburban satellite HD unit in Victoria in 2011 was collected and converted to a common measurement unit of tonnes of CO2 equivalents (t CO2-eq) via established emissions factors. For electricity and water consumption, emissions factors for other Australian locations were applied to assess the impact of local factors on these footprint contributors. Results. In Victoria, the annual per-patient carbon footprint of satellite HD was calculated to be 10.2 t CO2-eq. The largest contributors were pharmaceuticals (35.7%) and medical equipment (23.4%). Throughout Australia, the emissions percentage attributable to electricity consumption ranged from 5.2% to 18.6%, while the emissions percentage attributable to water use ranged from 4.0% to 11.6%. Conclusions. State-by-state contributions of energy and water use to the carbon footprint of satellite HD appear to vary significantly. Performing emissions planning and target setting at the state level may be more appropriate in the Australian context. What is known about the topic? Healthcare provision carries a significant environmental footprint. In particular, conventional HD uses substantial amounts of electricity and water. In the UK, provision of HD and peritoneal dialysis was found to have an annual per-patient carbon footprint of 7.1 t CO2-eq. What does this paper add? This is the first carbon-footprinting study of HD in Australia. In Victoria, the annual per-patient carbon footprint of satellite conventional HD is 10.2 t CO2-eq. Notably, the contributions of electricity and water consumption to the carbon footprint varies significantly throughout Australia when local factors are taken into account. What are the implications for practitioners? We recommend that healthcare providers consider local factors when planning emissions reduction strategies, and target setting should be performed at the state, as opposed to national, level. There is a need for more comprehensive and current emissions data to enable healthcare providers to do so.

scholarly journals KONTRIBUSI SEKTOR PERTANIAN PADA PERTUMBUHAN EKONOMI DI PROVINSI JAWA BARAT

Agro Ekonomi ◽  
2016 ◽  
Vol 26 (2) ◽  
pp. 206 ◽  
Author(s):  
Wiwin Widianingsih ◽  
Any Suryantini ◽  
Irham Irham
Keyword(s):  
Agricultural Sector ◽  
National Level ◽  
Dominant Factor ◽  
Food Crop ◽  
Location Quotient ◽  
The West ◽  
West Java ◽  
Agriculture Sector ◽  
Dynamic Location ◽  
Typology Analysis

This study aims to know the trend of GDRP of agricultural sector in West Java Province, sector and sub-sector of agriculture which has a role as a leading sector in West Java Province and each district in this province, the factors that affect the economic growth of agriculture sector in the West Java Province, and the growth typology of the agricultural sector in West Java Province. The method that used for this study are Trend analysis, Location Quotient (LQ), Dynamic Location Quotient (DLQ), Shift-Share, and Klassen Typology. Theresults showed that the trend of agriculture sector/sub-sectors’ GDRP value were significantly increased and the trend of agriculture sector/sub-sectors’ GDRP contribution were significantly decreased over the period  year 2003-2012. The agricultural sector is a leading sector for West Java Province and most of its districts. Food crop and the horticultural sub-sector is a leading sector for West Java Province and some districts in this province. The growth of the national economy is the dominant factor affecting the growth of the sector/subsector of agriculture in West Java Province. The competitive advantage (competitiveness) of forestry sub-sector was higher than the same sub-sector in other areas at national level. Food crops and horticultural sub-sector and livestock sub-sector were advanced  ut depressed sub-sector. Forestry sub-sectors was categorized in developing sub-sector. The agriculture sector, plantation and fisheries sub-sector were categorized in lagging development. Based on LQ, DLQ and Klassen Typology analysis, the results showed that there was a consistent result that were the forestry sub-sector categorized in a leading sub-sector in the future, f ood crops and horticulture sub-sector categorized in leading sub-sector along year 2003-2012. While sector of agriculture, plantation and fisheries sub-sector categorized in the lagged development sectors.  

Decision Making in Elite White-Water Athletes Paddling on a Kayak Ergometer

2009 ◽  
Vol 31 (4) ◽  
pp. 554-565 ◽  
Author(s):  
Karen Davranche ◽  
Danny Paleresompoulle ◽  
Rémy Pernaud ◽  
Julie Labarelle ◽  
Thierry Hasbroucq
Keyword(s):  
Decision Making ◽  
Simon Task ◽  
National Level ◽  
Upper Body ◽  
Maximal Heart Rate ◽  
Moderate Exercise ◽  
Direct Response ◽  
White Water ◽  
Muscle Groups ◽  
Different Response

The present study investigated the effects of acute paddling on performance in a typical decision-making task. It was aimed at assessing whether the effects of moderate exercise can be replicated using the feet as response effectors when physical exercise essentially solicits upper-body muscles. Twelve national-level paddling athletes performed a Simon task while paddling at a moderate (75% of maximal heart rate, HRmax) and at very light (40% of HRmax) intensities. The results showed that the effects of moderate exercise can be generalized to exercises involving different response effectors and upper-body muscle groups. They suggest (1) that the activation-suppression hypothesis (Ridderinkhof, 2002) holds when the task is performed with the feet, and (2) that moderate exercise speeds up reaction time and impairs the suppression of direct response activation.

scholarly journals Obtaining Vital Distances Using Wearable Inertial Measurement Unit for Real-Time, Biomechanical Feedback Training in Hammer-Throw

2018 ◽  
Vol 8 (12) ◽  
pp. 2470 ◽  
Author(s):  
Ye Wang ◽  
Hua Li ◽  
Bingjun Wan ◽  
Xiang Zhang ◽  
Gongbing Shan
Keyword(s):  
Real Time ◽  
Inertial Measurement Unit ◽  
Lower Limbs ◽  
Measurement Unit ◽  
Wearable System ◽  
Inertial Measurement ◽  
Wire Tension ◽  
Feedback Training ◽  
Control Patterns ◽  
Tracking Device

The hammer throw is one of the regular track and field competitions, but unlike other events, it has not seen a new world record for over three decades. The standstill may be caused by the lack of scientifically based training. In our previous work, we have developed a wireless/wearable device for the wire tension measurement in order to develop real-time biomechanical feedback training. In this paper, we show the improvement of our wearable system by adding two sensors for tracking of two vital vertical distances. The paper describes the details related to the development of turning an inertial measurement unit into a tracking device for the dynamic distances. Our preliminary data has shown that the dynamic data of the hip and wrist could be used for revealing the coordination between the upper and the lower limbs during a throw. In conjunction with wearable wire-tension measurement, various motor control patterns employed for hammer throwing could be demystified. Such real-time information could be valuable for hammer-throw learning and optimization. Further studies are required to verify the potentials of the wearable system for its efficiency and effectiveness in coaching practice.

scholarly journals Use of IMU in Differential Analysis of the Reverse Punch Temporal Structure in Relation to the Achieved Maximal Hand Velocity

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4148
Author(s):  
Stefan Marković ◽  
Anton Kos ◽  
Vesna Vuković ◽  
Milivoj Dopsaj ◽  
Nenad Koropanovski ◽  
...  
Keyword(s):  
Motion Tracking ◽  
Performance Indicator ◽  
Temporal Structure ◽  
National Level ◽  
Vertical Movement ◽  
Measurement Unit ◽  
Maximal Velocity ◽  
Differential Analysis ◽  
Discrete Movements ◽  
Additional Information

To achieve good performance, athletes need to synchronize a series of movements in an optimal manner. One of the indicators used to monitor this is the order of occurrence of relevant events in the movement timeline. However, monitoring of this characteristic of rapid movement is practically limited to the laboratory settings, in which motion tracking systems can be used to acquire relevant data. Our motivation is to implement a simple-to-use and robust IMU-based solution suitable for everyday praxis. In this way, repetitive execution of technique can be constantly monitored. This provides augmented feedback to coaches and athletes and is relevant in the context of prevention of stabilization of errors, as well as monitoring for the effects of fatigue. In this research, acceleration and rotational speed signal acquired from a pair of IMUs (Inertial Measurement Unit) is used for detection of the time of occurrence of events. The research included 165 individual strikes performed by 14 elite and national-level karate competitors. All strikes were classified as slow, average, or fast based on the achieved maximal velocity of the hand. A Kruskal–Wallis test revealed significant general differences in the order of occurrence of hand acceleration start, maximal hand velocity, maximal body velocity, maximal hand acceleration, maximal body acceleration, and vertical movement onset between the groups. Partial differences were determined using a Mann–Whitney test. This paper determines the differences in the temporal structure of the reverse punch in relation to the achieved maximal velocity of the hand as a performance indicator. Detecting the time of occurrence of events using IMUs is a new method for measuring motion synchronization that provides a new insight into the coordination of articulated human movements. Such application of IMU can provide additional information about the studied structure of rapid discrete movements in various sporting activities that are otherwise imperceptible to human senses.

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