• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.585-590
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• 2022

Objective: The purpose of this study was to investigate the effects of neuromuscular training of ballet dancers with chronic ankle instability on ankle stability and posture controlability. Design: A randomized controlled trial. Methods: A total of Thirty-twoyoung female ballet dancers with chronic ankle instability have voluntarily participated in the study. The participants were randomized to the neuromuscular training group(n₁=11), elastic resistance squat group(n₂=11), and control group(n₃=10). The intervention was applied to a total of 18 exercises per six weeks and conducted in each group for one hour a day, three times a week. All subjects were evaluated for Cumberland ankle instability tool(CAIT), static balance at before-after intervention. Results: In the comparison of the effects within the groups, the effect of the intervention on CAIT and posture control was significantly increased in the neuromuscular training group and elastic resistance squat group (p <0.05). In the comparison of the effects between the groups, the neuromuscular training group, and elastic resistance squat group were found to significantly increase more than the control group (p <0.05). The effect of ankle stability is similar in neuromuscular training and elastic resistance squat training, neuromuscular training is more effective in improving posture control rather than elastic resistance squat training. Conclusions: When planning a rehabilitation training program for a ballet dancer with chronic ankle instability, neuromuscular training can be applied as an intervention method to improve ankle stability and posture control ability.

• ETRI Journal
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• 제29권4호
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• pp.507-515
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• 2007

Skeleton transform of which the medial axis transform is the most popular has been proposed as a useful shape abstraction tool for the representation and modeling of human posture. This paper explains this proposition with a description of the areas in which skeletons could serve to enable the representation of shapes. We present algorithms for two-dimensional posture modeling using the developed simplified shock graph (SSG). The efficacy of SSG extracted feature vectors as shape descriptors are also evaluated using three different classifiers, namely, decision tree, multilayer perceptron, and support vector machine. The paper concludes with a discussion of the issues involved in using shock graphs to model and classify human postures.

• 센서학회지
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• 제27권2호
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• pp.86-92
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• 2018

In recent times, motion capture technology using inertial measurement unit (IMU) sensors has been actively used in sports. In this study, we developed a canoe paddle, installed with an IMU and a water level sensor, as a system tool for training and calibration purposes in water sports. The hardware was fabricated to control an attitude heading reference system (AHRS) module, a water level sensor, a communication module, and a wireless charging circuit. We also developed an application program for the mobile device that processes paddling motion data from the paddling operation and also visualizes it. An AHRS module with acceleration, gyro, and geomagnetic sensors each having three axes, and a resistive water level sensor that senses the immersion depth in the water of the paddle represented the paddle motion. The motion data transmitted from the paddle device is internally decoded and classified by the application program in the mobile device to perform visualization and to operate functions of the mobile training/correction system. To conclude, we tried to provide mobile knowledge service through paddle sport data using this technique. The developed system works reasonably well to be used as a basic training and posture correction tool for paddle sports; the transmission delay time of the sensor system is measured within 90 ms, and it shows that there is no complication in its practical usage.

• 한국기계가공학회지
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• 제10권2호
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• pp.1-8
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• 2011

5-axis NC machining has a good advantage of the accessibility of tool motion by adding two rotary axes. It offers numerous advantages such as expanding machining fields in parts of turbo machineries like impeller, propeller, turbine blade and rotor, reasonable tool employment and great reduction of the set-up process. However, as adding two rotary axes, it is difficult to choose suitable machining conditions in terms of cutter path and cutter posture at a cutter contact point. Therefore in this paper, it is proposed to decide suitable machining condition through an experimental method such as adopting various cutter paths, cutter postures types. Also, in order to increase the efficiency of 5-axis machining, it is necessary to minimize the cutter posture changes and create a continuous cutter path while avoiding interference. This study, by using an MC-space algorithm for interference avoidance and an MB-spline algorithm for continuous control, is intended to create a 5-axis machining cutter path with excellent surface quality and economic feasibility. finally, this study will verify the effectiveness of the suggested method through verification processing.

• 대한산업공학회지
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• 제28권2호
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• pp.216-222
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• 2002

The ergonomic human model can be considered as a tool for the evaluation of ergonomic factors in vehicle design process. The proper anthropometric data on driver's postures are needed in order to apply a human model to vehicle design. Although studies on driver's posture have been carried out for the last few decades, there are still some problems for the posture data to be applied directly to the human model due to the lack of fitness because such studies were not carried out under the conditions for the human model application. In the traditional researches, the joint angles were evaluated by the categorized data, which are not appropriate for the human model application because it is so extensive that it can not explain the posture evaluation data in detail. And the human models require whole-body posture evaluation data rather than joint evaluation data. In this study a postural evaluation function was developed not by category data but by the concept of the loss function in quality engineering. The loss was defined as the discomfort in driver's posture and measured by the magnitude estimation technique in the experiment using a seating buck. Four loss functions for the each joint - knee, hip, shoulder, and elbow were developed and a whole-body postural evaluation function was constructed by the regression analysis using these loss functions as independent factors. The developed postural evaluation function shows a good prediction power for the driver's posture discomfort in validation test. It is expected that the driver's postural evaluation function based on the loss function can be used in the human model application to the vehicle design process.

• 융합신호처리학회논문지
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• 제24권1호
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• pp.15-20
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• 2023

일반적으로 잘못된 앉은 자세를 장시간 유지하는 것은 척추에 나쁜 영향을 미치는 것으로 널리 알려져 있다. 최근 여러 연구자들이 잘못된 앉은 자세와 척추질환의 인과관계에 관심을 두고 있으며, 척추질환 예방을 위해 앉거나 서는 자세의 변화를 정밀하게 측정할 수 있는 방법을 연구해왔다. 우리는 과거 연구에서 실시간 체위 변환 측정이 가능한 센서 디바이스를 개발하고 운동량 계산 알고리즘을 적용하여 실시간 자세 전환 측정 정확도를 향상시켰으며, 체위 변환 측정 센서의 정확도를 검증하였다. 본 연구에서는 좌압 측정을 통해 체중심의 변화를 고려한 자세 측정 및 분석 장치를 개발하였으며, 개발된 센서는 사용자의 시각적 피드백을 개선하여 자세 교정 훈련 정확도를 높이는 보조 도구로의 활용 가능성을 확인하였다.

• 대한인간공학회지
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• 제30권5호
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• pp.637-644
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• 2011

Objective & Background: When applying various evaluation tools that analyze work posture risk through observation, accurate measurement of body flexion angle is very important. Method: This study investigated differences and appropriateness of 5 different existing reference points commonly used in the analysis of the work posture. Twenty five ergonomist and trained professionals were participated in this study. A Same flexion angle was utilized for the evaluation of risk assessment of musculoskeletal disorders using five different reference points to investigate the degree of difference between them. To investigate how different the observers' preferred flexion angle measuring methods were compared to the ISO 11226 Reference Posture, a virtual body model was constructed using the Poser 6.0 program. Six types of body flexion postures were constructed, and since neck flexion differs according to body angle, five types of neck flexion postures were constructed with the trunk bending $20^{\circ}$ forward, making up a total of 30 virtual flexion postures. Results: Results showed that the observers used personally preferred reference points instead of reference points recommend in the evaluation tools. Also the results revealed the their seems to be 6 types of flexion angle for the trunk and 11 types of measurement methods for the neck flexion angle in the form of personally preferred reference points. The results showed that a mean difference of $14^{\circ}$($4{\sim}23^{\circ}$) occurred in the trunk, and a mean difference of $20^{\circ}$($-8{\sim}51^{\circ}$) occurred in the neck. To increase accuracy when using the 5 evaluation tools in combination, the ISO 11226 standards, observers' preferred flexion posture standards, and common flexion posture standards of the evaluation tools were compared with the reference points of the 5 evaluation tools. Results showed considerable variance in angle difference for each evaluation tool. Conclusion: According to the results of this study, considering the angle difference between the flexion angle reference points of the evaluation tool and the reference points selected by the observers, it is concluded that instead of personally preferred reference points, the standardized reference points to enhance the accuracy and the objectivity. Application: The result of this study can be used as reference guide to develop the standardized reference point in the future.

• 대한인간공학회지
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• 제30권3호
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• pp.427-435
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• 2011

Objective: The objective of this study was to evaluate a work of building cleaners using the ergonomic methods. Background: Previous studies about cleaning worker describe typical physical demands of this work. They found that the most significant risk factors associated with the physical work of cleaners are static loads and repetitive movements and high output of force. Method: A head of ergonomics estimation was work analysis(define of combined task, work tool, work time and frequency of combined task) and posture analysis of worker. Results: The results showed that combined task of building cleaners was classification sweeping, mopping(wet), mopping(oil), moving barrels/carts, dumping trash bags, scrubbing, arrangement of cleaning tool, arrangement of circumferential, moving of cleaning tool, and waiting. The work time of combined task such as mopping(wet) and scrubbing indicated high ratio. The posture analysis of building cleaners indicated high value in bending of the head, lower arm, and hands. Conclusion: The findings appear to indicate that building cleaner were related to high risk of work-related musculoskeletal disorders. So, building cleaner would be required an interventional strategy, improvement of cleaning tools and working environment. Application: If ergonomics rule can be integrated into existing cleaning tools and work environments, the risk of occupational injuries will be reduced.

• 한국컴퓨터정보학회논문지
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• 제18권5호
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• pp.53-60
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• 2013

본 논문에서는 키넥트 센서에 의해 획득한 스켈레톤 정보를 이용하여 스노보드 동작을 시각화 할 수 있는 도구를 제안한다. 스노보드 동작에서 가장 기본이 되는 동작은 BBP(Balanced Body Position)자세로서 안정된 턴 동작을 위한 기본 기술이다. 본 논문에서는 BBP자세를 분석하여 가장 이상적인 동작을 실현할 수 있는 시각화 도구를 구현한다. 키넥트 센서로 부터 획득한 좌표정보를 이용하여 발목, 무릎, 엉덩이 관절의 각도와 몸의 중심축을 추적하여 표준 자세와 비교분석한다. 분석결과는 OpenGL 라이브러리를 통하여 최종 결과 화면을 구성하였다. 본 연구결과는 스노보드 턴 동작을 분석하는 기초자료로 활용될 수 있을 것이다.

• 대한물리치료과학회지
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• 제29권4호
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• pp.1-16
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• 2022

Background: This study was conducted to examine the correlation of VDT, posture and shoulder function among each group divided by according to the neck pain disorder index (NDI) scores for female patients with neck pain. Design: Cross-sectional study. Methods: Fifty adult women with neck pain voluntarily participated in this study and the neck pain disorder index questionnaire, VDT syndrome assessment tool questionnaire, craniovertebral angle, thoracic kyphosis angle, round shoulder posture, pectoralis minor length, shoulder joint hypermobility, and serratus anterior strength tests were conducted respectively. Subjects were divided into two groups where 21 subjects were allocated to the mild pain group whom have rated below 14 points on the NDI scores, and 29 subjects were in the severe pain group, whom have rated above 15 on the NDI score. Results: The study found that in the mean difference between variables in each group, VDT syndrome showed a higher mean score in the severe pain group than the mild pain group (p<0.05). In the group correlation and regression analysis, the mild pain group showed a significant negative correlation between the craniovertebral angle and round shoulder posture (r=-0.467, p<0.05), and the round shoulder posture for craniovertebral angle was shown to have significant positive influence (B=10.162, p<0.05). The severe pain group showed that the NDI and the VDT syndrome had a significant amount of correlation (r=0.520, p<0.01), the VDT syndrome showed significant positive influence (B=0.330, p<0.05), and the craniovertebral angle showed significant negative influence (B=-0.809, p<0.05). It was also shown that shoulder joint hypermobility had a significant negative correlation with the serratus anterior strength (r=-0.437, p<0.01), and that serratus anterior strength had a significant negative influence on shoulder joint hypermobility (B=-4.175, p<0.05). Conclusion: This study is of clinical significance in that it presented variables that should be considered depending on the degree of neck pain in treating patients with neck pain and that it presented patients with not only posture but also the function of the shoulder joint as factors to consider.