• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.199-204
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• 2021

Objective: The purpose of this study was to present a new idea of methodology to evaluate Poomsae performance using inertial measurement unit (IMU) sensors in terms of signal processing techniques. Method: Ten collegian Taekwondo athletes, consisting of five Poomsae elite athletes (age: 21.4 ± 0.9 years, height: 168.4 ± 11.3 cm, weight: 65.0 ± 10.6 kg, experience: 12 ± 0.7 years) and five breaking demonstration athletes (age: 21.0 ± 0.0 years, height: 168.4 ± 4.7 cm, weight: 63.8 ± 8.2 kg, experience: 13.0 ± 2.1 years), voluntarily participated in this study. They performed three different black belt Poomsae such as Goryeo, Geumgang, and Taebaek Poomsae repeatedly twice. Repeated measured motion data on the wrist and ankle were calculated by the methods of cosine similarity and Euclidean distance. Results: The Poomsse athletes showed superior performance in terms of temporal consistency at Goryeo and Taebaek Poomsae, cosine similarity at Geumgang and Taebaek Poomsae, and Euclidian distance at Geumgang Poomsae. Conclusion: IMU sensor would be a useful tool for monitoring and evaluating within-subject temporal variability of Taekwondo Poomsae motions. As well it distinguished spatiotemporal characteristics among three different Poomsae.

• Safety and Health at Work
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• v.13 no.1
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• pp.99-103
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• 2022

Background: Firefighters may experience high environmental temperatures or carry out intensive physical tasks, or both, which leads to increased core body temperature and risk of fatalities. Hence there is a need to remotely and non-invasively monitor core body temperature. Methods: Estimated (heart rate algorithm) and actual core body temperature (ingested telemetric pill) measures were collected simultaneously for comparison during training exercises on 44 firefighter volunteers. Results: Prediction of core body temperature varied, with no specific identifiable pattern between the algorithm values and directly measured body core temperatures. Group agreement of Lin's Concordance of 0.74 (95% Upper 0.75, lower CI 0.73), was deemed poor. Conclusion: From individual agreement data Lin's Concordance was variable (Min 0.11, CI 0.13-0.01; Max 0.83, CI 0.86-0.80), indicating that the heart rate algorithm approach was not suitable for core body temperature monitoring in this population group, especially at the higher more critical core body temperatures seen.

• Advances in nano research
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• v.15 no.2
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• pp.155-163
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• 2023

Exercise is beneficial to the body in some ways. It is vital for people who have heart problems to perform exercise according to their condition. This paper describes how an Android platform can provide early warnings of fatigue during wushu exercise using Photoplethysmography (PPG) signals. Using the data from a micro-electro-mechanical system (MEMS) gyroscope to detect heart rate, this study contributes an algorithm to determine a user's fatigue during wushu exercise. It sends vibration messages to the user's smartphone device when the heart rate exceeds the limit or is too fast during exercise. The heart rate monitoring system in the app records heart rate data in real-time while exercising. A simple pulse sensor and Android app can be used to monitor heart rate. This plug-in sensor measures heart rate based on photoplethysmography (PPG) signals during exercise. Pulse sensors can be easily inserted into the fingertip of the user. An embedded microcontroller detects the heart rate by connecting a pulse sensor transmitted via Bluetooth to the smartphone. In order to measure the impact of physical activity on heart rate, Wushu System tests are conducted using various factors, such as age, exercise speed, and duration. During testing, the Android app was found to detect heart rate with an accuracy of 95.3% and to warn the user when their heart rate rises to an abnormal level.

• The KIPS Transactions:PartD
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• v.16D no.2
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• pp.249-256
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• 2009

This paper introduces an efficient USN (ubiquitous sensor network) for monitoring blind areas in a skiing resort, developed as a part of u-Sport showcase project of Gangwon Province. Blind areas of a skiing resort are dangerous and/or steep areas located aroud ski slopes, which are rarely traveled and not easily seen by a ski patrol. If an accident occurs in such a blind area, the main control center of the sking resort can hardly recognize the accident and provide first aid and rescue services promptly. The blind area monitoring system proposed in this paper monitors a blind area of a skiing resort using five battery-powered sensor nodes each of which has an image sensor on it and wirelessly transmits images around the blind area to the main control center on a regular basis, therebly allowing real-time monitoring of the blind area and prompt rescue services in case of accidents. Additionally, the monitoring system provides an emergency button which skiers injured in the blind area can push. If the button is pushed, an image around the button and an alarm signal are transmitted to the main control center and therefore the main control center can take prompt actions for rescuing the injured skiers.

• Korean Journal of Applied Biomechanics
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• v.27 no.4
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• pp.247-255
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• 2017

Objective: The purpose of this study was to investigate the maximum core muscle activation angle according to core-strengthening exercises. Method: Twenty-six young female football players (age: $17.84{\pm}0.80years$, height: $163.08{\pm}5.25cm$, weight: $54.96{\pm}7.41kg$) registered in the Korea Football Association from D High School located in Seoul were the subjects of this research. An electromyogram (Noraxon, USA) was used for monitoring the maximum core muscle contraction activity. Results: The angle for the maximum core muscle strength per core exercise and muscle was the smallest for the upper rectus abdominis in the windshield wiper exercise. The angle of the vastus medialis was significantly the largest. The range of angles at which the maximum strength was observed for each core exercise were as follows: 1) abdominal flutter kicks ($11{\sim}40^{\circ}$), 2) leg raises ($21{\sim}34^{\circ}$), 3) scissors ($45{\sim}66^{\circ}$), 4) knee to elbow sit-ups ($42{\sim}64^{\circ}$), 5) reverse crunches ($9{\sim}40^{\circ}$), 6) butt-ups ($24{\sim}32^{\circ}$), 7) V sit-ups ($5{\sim}24^{\circ}$), 8) windshield wipers ($11{\sim}20^{\circ}$), 9) bird dog ($11{\sim}18^{\circ}$), and 10) raised leg plank ($38{\sim}50^{\circ}$). Conclusion: Four kinds of motion could be classified according to the range of angles at which the core muscles were maximally activated. The first group involves the range of motion that gives the maximum muscle strength when the lower extremity and ground angle was between $5^{\circ}$ and $24^{\circ}$, such as the V sit-ups, windshield wipers, and bird dog. The second group comprised the flutter kicks and reverse crunches at an angle between $9^{\circ}$ and $40^{\circ}$. The third group comprised the leg raise and butt-up exercises at an angle between $21^{\circ}$ and $34^{\circ}$. The fourth group included the scissors, knee to elbow sit-ups, and raised leg plank at an angle between $38^{\circ}$ and $66^{\circ}$. These results may be useful as basic data for core movement and core muscle training according to the purpose of exercise.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.27-32
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• 2012

Balance measurement is widely used in fields of physiotherapy, neurology, sport medicine and rehabilitation medicine. This paper presents the development of balance measurement and rehabilitation training system. To this end, we have developed a prototype system using an 3-axis accelerometer sensor attached to the under surface of balance board. As a results, the system is stable and shows a good degree of balance function. Also, the various patterns for rehabilitation training can be added easily. This system can be used for daily balance monitoring and will contribute to increasing the effectiveness of training.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.495-501
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• 2011

The purpose of this study was to develop the inertial sensor module system to detect gait event using single angular rate sensor(gyroscope), and evaluate the accuracy of this system. This sensor module is attached at the heel and gait events such as heel strike, foot flat, heel off, toe off are detected by using proposed automatic event detection algorithm. The developed algorithm detect characteristics of pitch data of the gyroscope to find gait event. To evaluate the accuracy of system, 3D motion capture system was used and synchronized with sensor module system for comparison of gait event timings. In experiment, 6 subjects performed 5 trials level walking with 3 different conditions such as slow, preferred and fast. Results showed that gait event timings by sensor module system are similar to that by kinematic data, because maximum absolute errors were under 37.4msec regardless of gait velocity. Therefore, this system can be used to detect gait events. Although this system has advantages of small, light weight, long-term monitoring and high accuracy, it is necessary to improve the system to get other gait information such as gait velocity, stride length, step width and joint angles.

• Journal of the Korea Convergence Society
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• v.7 no.5
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• pp.247-254
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• 2016

The purpose of this study is to identify the degree of participation sport for how this affects the objectified body consciousness of the Physically Disabled. The subjects were enrolled in the members participating in the sport for the disabled, while 221 people living in the city A. Data processing was carried out frequency analysis, factor analysis using SPSS 21.0 program, the analysis of the specific factors independent t-test and the way analysis of variance and multiple regression analysis was carried out. All statistical significance level was set at .05. First, population, gender (male), age of the sociological characteristics of the handicapped (40, 50), the objectification of the body consciousness level of the disability rating (Level 4) showed that a positive effect. Second, there are life sports participation rate (exercise duration, exercise time, exercise intensity) has positive effects on the body shame of objectification of the body consciousness of the handicapped, the body monitoring Exercise Period, the body shame, the intensity of exercise, control beliefs this exercise showed that each time a positive impact.

• East Asian Journal of Business Economics (EAJBE)
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• v.10 no.4
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• pp.29-38
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• 2022

Purpose - The present research aims to assess the meaningful association between the extension of sports leisure culture and the spread of wearable devices. The research will discuss the current utilization of wearable devices in sports leisure and the present and future application of wearable devices in sports perspectives. Research design, Data, and methodology - We have investigated and conducted the qualitative content analysis (QCA) to obtain the adequate textual dataset in the current literature and conducted an in-depth analysis of the incorporation of cloud computing in the leisure sports industry by focusing on the development of wearable technologies. Result - From the QCA, it is evident that there is a meaningful connection between the extension of sports leisure culture and the spread of wearable devices, figuring out four kinds of associations as follows: (1) Monitoring the Impact of Sporting Activities, (2) Benefits of Sensor Technology, (3) Reducing Sedentary Behaviors, and (4) Measuring Workload done in Sport Leisure. Conclusion - The present research concludes that wearable devices positively influence individuals to participate in sports and leisure activities. Various technologies are very effective in motivating individuals to adopt sports leisure culture mainly because there is a certain degree of satisfaction that individuals gain in seeing the level of physical activities.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.41-48
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• 2022

Vehicle vibration was introduced in the time and frequency domains using fast Fourier transform (FFT) analysis. In particular, a vibration mode analysis and characteristics of the frequency response function (FRF) in a sport utility vehicle (SUV) passing over a bump barrier at different speeds was performed systematically. The response behavior of the theoretical acceleration was obtained using a numerical method applied to the forced vibration model. The amplitude and frequency of the external force on the vehicle cause various power spectra with individual intrinsic system frequencies. In this regard, several modes of power spectra were acquired from the spectra and are discussed in this paper. The proposed technique can be used for monitoring the acceleration in a vehicle passing over a bump barrier. To acquire acceleration signals, various experimental runs were performed using the SUV. These acceleration signals were then used to acquire the FRF and to conduct mode analysis. The vehicle characteristics according to the vehicle condition were analyzed using FRF. In addition, the vehicle structural system and bump passing frequencies were discriminated based on their power spectra and other FRF spectra.