• Journal of the Korean Applied Science and Technology
• /
• v.38 no.3
• /
• pp.727-734
• /
• 2021

The purpose of this study was to analyze correlation between kinematic variables and ground slope perception ability during golf putting. 16 collegiate golfers were participated. To collect and analyze the kinematic data of putter head, SAMPutt lab was used(70 Hz). It was performed Pearson's correlation analysis using SPSS. The level of significance was at .05. As a results, right was correlated with backswing in flat. Toe-up was correlated with follow-through and left was correlated with aim, backswing, impact, follow-through, and loft in slice 1°. Toe-down was correlated with aim, backswing, impact in slice 2°. Toe-up was correlated with follow-through in hook 2°. In conclusion, it is important to improve the putting stroke through repetitive ground slope perception training.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.3
• /
• pp.11-21
• /
• 2007

The purpose of this study was to examine the differences of kinematics and muscle activities depending on the changes of angle approaching balls during backhand drive in squash. The results are as follows. Stride time took the longest at AD2 and step lengths were the biggest at AD1 of left foot contact and right foot contact and AD2 of impact and follow-through. The center of gravity and the speed of racket head were the highest at AD3 and at AD2. Angle of shoulder joint were the biggest at AD1 of left foot contact, right foot contact and impact and AD3 of follow-through. Angle of elbow joint were the biggest at AD3 of left foot contact, right foot contact and follow-through and AD2 of impact. Angle of pelvis joint were the biggest at AD2 of left foot contact, AD1 of right foot contact and AD3 of impact and follow-through. Angle of knee joint were the biggest at AD2 of left foot contact, AD1 of right foot contact and AD3 of impact and follow-through. Angle of ankle joint were the biggest at AD1 of left foot contact and AD3 of right foot contact, impact and follow-through. According to the analysis results of triceps brachii, latissimus dorsi, brachioradialis muscle and flexor carpi ulnaris muscle activities were high at AD1 of all phases. Analysis results of vastus lateralis, vastus medialis, tibialis anterior and gastrocnemius medial muscle activities were high at AD2 of phase1 and phase3. Those of vastus lateralis, vastus medialis and tibialis anterior, gastrocnemius medial were high at AD3 of Phase 2 and AD1 of phase2.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.3
• /
• pp.301-309
• /
• 2015

Objective : The purpose of this study was to describe the correlation between the activity of the muscles of upper and lower limbs of a golf driver swing according to shoulder injury. Method : The subjects were 18 professional golfers (7 male in KPGA and 11 female in KLPGA). Using surface electromyography, we evaluated muscle activities during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the left Deltoid(MD), Triceps Brachii(TB), Pectoralis(PM), Trapezius(UT), Rectus Femoris(RF), Vastus Medialis Obilique(VMO), Biceps Femoris(BF), Gastrocnemius(GCM) muscles during the golfer's swing. The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. Results : The results can be summarized as follows: MD, VMO had statistically significant difference in take away phases, GCM had statistically significant difference in acceleration phases, MD, PM, VMO had statistically significant difference in early follow through phases, PM had statistically significant difference in late follow through phases, Conclusion : Muscle activity of the 8 muscles(Deltoid, Triceps Brachii, Pectoralis, Trapezius, Rectus Femoris, Vastus Medialis Obilique, Biceps Femoris, Gastrocnemius) along the shoulder damage or absence of has shown that they are organically connected to each of the phases.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.4
• /
• pp.67-74
• /
• 2005

The purpose of this study is to compare and analyze the muscle activations between the professional golfers without low back pain symptom and the professional golfers with low back pain symptom, and so identify the stress related to golf swings, and provide the basic data to minimize the low back pain and the injury risk. Using surface electrode electromyography, we evaluated muscle activity in 6 male professional golfers during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the Abdominal Oblique, Elector Spinae, Rectus Abdominis, Gluteus Maximus muscles during the golfer's swing. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. we observed patterns of trunk muscle activity throughout five phases of the golf swing. The results can be summarized as follows: RES(Right Elector Spinae) had statistically significant difference in take away phase, LGM(Left Gluteus Maximus), LRA(Left Rectus Abdominis), LOA(Left Oblique Abdominal) had statistically significant difference in forward swing phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus), ROA(Right Oblique Abdominal) had statistically significant difference in acceleration phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in early follow-through phase, LES(Left Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in late follow through phase.

• Journal of Preventive Medicine and Public Health
• /
• v.42 no.4
• /
• pp.261-266
• /
• 2009

Objectives : The aim of this study is to examine the cognitive function change related to aging, the incidence of cognitive impairment, and the association between apolipoprotein E polymorphism and cognitive impairment through a follow-up of the elderly with normal cognitive ability at baseline. Methods : Two hundred and fifteen subjects aged 65 and over were surveyed in February, 1998 (baseline survey), and their cognitive function was assessed again in 2003 1st follow-up) and the once again in 2006 (2nd follow-up). Ninety one subjects completed all surveys up through the 2nd follow-up and their cognitive function scores using MMSE-K (Korean Version of the Mini-Mental State Examination) and the distribution of apolipoprotein E allele were analyzed. Results : The cognitive function scores decreased with aging and the difference between baseline and the 2nd follow-up scores of the study increased with the age group. The incidence rate of cognitive impairment through an 8-year follow-up was 38.5% and higher in older age groups. Age was the only significant factor for incidence of cognitive impairment, but there was no significant association between apolipoprotein E genotype and incidence of cognitive impairment. Conclusions : The cognition of the elderly decreased with aging and the association of apolipoprotein E genotype with incidence of cognitive impairment was not significant in this study. To confirm the association between apolipoprotein E polymorphism and incidence of cognitive impairment further studies will be needed.

• Safety and Health at Work
• /
• v.13 no.1
• /
• pp.104-111
• /
• 2022

Background: The IMPPAC cohort (Implications of the COVID-19 pandemic on psychosocial aspects and work ability among Brazilian workers) seeks to understand the impact of the pandemic on Brazilian workers. This article describes the occupational profile, psychosocial aspects, and work ability determined during the baseline and follow-up measurements of the cohort. Methods: Workers were invited to participate through media advertisements, social networks, and emails. From June to September 2020, 1211 workers were included in the cohort. Follow-up measurements finished on October 2021 with 633 workers. Data were collected through standardized questionnaires using Google Forms. Psychosocial aspects were assessed using the COPSOQ II-Br. Work ability was assessed using the Work Ability Index (WAI). Results: At baseline and follow-up, high proportion of workers were in the risk zone with regard to work pace, emotional work demands, influence on work, work-family conflict, burnout, and stress. Approximately 75% of the workers reported good to excellent work ability at baseline and follow-up. Conclusion: The occupational profile, psychosocial aspects, and work ability of Brazilian workers from the IMPPAC cohort were described. Psychosocial aspects and WAI were similar at baseline and follow-up.

• Journal of the Korean Institute of Navigation
• /
• v.5 no.2
• /
• pp.49-58
• /
• 1981

One of the main purposes of the marine gyrocompass follow-up system is to preserve the sensitive part from the wandering error due to the frictional or torsional torque around the vertical axis. This error can be diminished through the rapid follow-up action, which minimizes the relative azimuthal angular displacement between the sensitive and follow-up parts and shortens the duration of the same displacement. But an excessive rapidity of the follow-up action would result in a sustained oscillation to the system. Therefore, to design a new type of the follow-up system, the theoretical annlysis of the problems concerned should be studied systematically by introducing the control theory. This paper suggest a concrete procedure for the optimal adjustment of the gyrocompass follow-up system, utilizing the mathematic model and the stability informations formerly investiaged by the author. For theoptimal determination of the adjustable paramfter K, the performance index(P.I.), ITSE(Intergral of the Time multiplied by the Squared Error) is proposed, namely, P.I. = $\int_{0}^{\infty} t \cdot e^{2}(t)dt$ where t is time and e(t) means control error. Then, the optimal parameter minimizing the performance index is calculated by means of Parseval's theorem and numerical computation, and the validity of the obtained optimal value of the parameter Ka is examined and confirmed through the simulations and experiments. By using, the proposed method, the optimal adjustment can be performed deterministically. But, this can not be expected in the conventional frequency domain analysis. While the Mps of the original system vary to the extent of from 0.98 to 46.27, Mp of the optimal system is evaluated as 1.1 which satisfies the generally accepted frequency domain specification.

• Korean Journal of Applied Biomechanics
• /
• v.12 no.1
• /
• pp.173-191
• /
• 2002

The purpose of this study was defined efficient throw motion pattern to obtain the quantitative data and to achieve successful bowling through kinetic - kinematic variables on the throw motion. Subject of group composed of three groups : Higher bowlers who are two representative bowlers with 200 average points and one pro-bowler. Middle bowlers who are three common persons with 170 average points. Lower bowler who are three common persons with 150 average points. Motion analysis on throw motion in three groups respectively has been made through three-dimension cinematography using DLT method. Two high-speed video camera at operating 180 frame per secondary. One-way ANOVA has been used to define variable relations. Analyzed result and conclusion are the following : The displacement of back of the hand must have wider difference of each right-left displacement to increase the spin of the ball. In high bowlers group, difference between the front-rear position of back of the hand in case of success and that in case of failure in follow throw is 0.17m. That is to say, momentum in case of success come to increase greatly, compared with that in case of failure. To increase the spin of the ball, the potential difference should be narrower in follow through. In case of the high bowlers, the velocity of the front-rear direction of the back of the hand has been the fastest both in release and follow through, compared with those in other groups, which has contributed to increasing the spin force of the ball. The orders in the resultant velocity of the back of the hand has shown the this : the finger tip$\rightarrow$the back of the hand$\rightarrow$wrist.These orders made the proximal segment support the distal segment. The distal segment has provided the condition to accelerate the velocity. In case of failure, the suddenly increased velocity has caused the failure in the follow through. Acutely flexing the angle of the back of the hand has contributed to lifting to increase the spin of the ball.

• Journal of Korean Society of Rural Planning
• /
• v.28 no.4
• /
• pp.55-67
• /
• 2022

In this study, the village development promotion system was reorganized for Gimhae-si, and improvement plans and post-operation management plans were prepared through expert surveys. Through the Village Development Project, the landscape and environment of the village were improved, and the village and residents were positively changed. The Village Development Project laid the foundation for regional revitalization, giving the next generation hope for the sustainable development of the village. While maintaining the framework of the existing Rural Development Projects guidelines through case analysis of other regions, we operate educational programs for each stage by reflecting regional characteristics, and utilize and communicate with intermediate support organizations, systematically operate, and actively intervene by Eup·Myeon administration. In addition, as a follow-up management program, various follow-up management programs were being operated, such as support for capacity building such as consulting, as well as facility maintenance and support for village managers. As a result of the expert survey to review the adequacy of the improvement plan, the improvement plan derived from the overall average of 4.28 points and the standard deviation of 0 to 0.94 points for the process is judged to be appropriate. In particular, the item of 'self-reliance stage follow-up management' was very important as all experts responded with 5 points. By establishing the village development performance goals, we tried to check whether the qualitative/quantitative goals were achieved by year, and to secure quantified status data in response to changes such as resetting performance goals or adding new performance indicators. In this study, in order to improve the capacity to achieve regional development in response to the rural agreement, we prepared our own sustainable village development promotion system, governance establishment, and follow-up management plan. In addition, it is expected to be used as a reference material for the selection of new districts and the follow-up management of completed districts by establishing the village development goals.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.4
• /
• pp.375-381
• /
• 2011

This paper deals with the improvement of visual path following through velocity variation according to the coordinate of feature points. Visual path follow first teaches driving path by selecting milestone images then follows the route by comparing the milestone image and current image. We follow the visual path following algorithm of Chen and Birchfield [8]. In [8], they use fixed translational and rotational velocity. We propose an algorithm that uses different translational velocity according to the driving condition. Translational velocity is adjusted according to the variation of the coordinate of feature points on image. Experimental results including diverse indoor cases show the feasibility of the proposed algorithm.