• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.44-49
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• 2022

The number of single-person households is increasing worldwide, and among them, the proportion of elderly single-person households is increasing. In the case of elderly single-person households, a significant portion of their leisure time is devoted to watching TV. However, if they fall asleep while watching TV without turning it off, it may be difficult to sleep well due to lights and sounds of TV, which can cause health problems such as depression and reduced immunity. Therefore, in this paper, we propose a system that automatically turns off the TV when a person watching TV falls asleep. Images are collected using the camera installed in front of the TV. Since the posture of a person watching TV varies from a sitting posture to a lying posture, the system is designed to determine whether or not to fall asleep regardless of the posture. In addition, since it becomes difficult to judge eye movements as a person moves away from the TV, a method for extending the judgmentable distance is proposed. The system model was implemented and tested using a Raspberry Pi, a monitor, an infrared sensor, and a camera. Eye movements were judged regardless of sitting or lying position, and the distance between a user and a TV was extended by about 200 cm.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.561-568
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• 1994

A man model can be used as an effective tool to design ergonomically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movement was known to be a difficult problem. To solve this redundancy problem, a psychophysical cost function was suggested in this study which defines a cost value for each joint movement angle. The psychophysical cost function developed integrates the psychophysical discomfort of joints and the joint range availability concept which has been used for redundant arm manipulation in robotics to predict the arm reach posture. To properly predict an arm reach posture, an arm reach posture prediction model was then developed in which a posture configuration that provides the minimum total cost is chosen. The predictivity of the psychophysical cost function was compared with that of the biomechanical cost function which is based on the minimization of joint torque. Here, the human body is regarded as a two-dimensional multi-link system which consists of four links ; trunk, upper arm, lower arm and hand. Real reach postures were photographed from the subjects and were compared to the postures predicted by the model. Results showed that the postures predicted by the psychophysical cost function closely simulated human reach postures and the predictivity was more accurate than that by the biomechanical cost function.

• Journal of Biomedical Engineering Research
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• v.39 no.6
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• pp.278-283
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• 2018

Nowdays, many people suffer from the neck pain due to forward head posture(FHP) and text neck(TN). To assess the severity of the FHP and TN the craniovertebral angle(CVA) is used in clinincs. However, it is difficult to monitor the neck posture using the CVA in daily life. We propose a new method using the cervical flexion angle(CFA) obtained from a wearable sensor to monitor neck posture in daily life. 15 participants were requested to pose FHP and TN. The CFA from the wearable sensor was compared with the CVA observed from a 3D motion camera system to analyze their correlation. The determination coefficients between CFA and CVA were 0.80 in TN and 0.57 in FHP, and 0.69 in TN and FHP. From the monitoring the neck posture while using laptop computer for 20 minutes, this wearable sensor can estimate the CVA with the mean squared error of 2.1 degree.

• The Journal of Korean Physical Therapy
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• v.35 no.3
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• pp.83-88
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• 2023

Purpose: This study was to investigate the effect of forward head posture (FHP) and round shoulder posture (RSP) on changes in muscle activities according to shoulder flexion and abduction tasks. Methods: Twenty-two male subjects with no history of neurological, musculoskeletal surgery or injuries, or pain in the spine region within the previous 3-month periods were recruited for this study. Craniovertebral angle (CVA) and Scapula Index were measured before performing 90° abduction and flexion tasks holding a 3kg dumbbell. Muscle activities were measured during the tasks. All measurements except height of the acromion were carried out in a sitting position at the height of the subject's knee angle of 90 degrees, and two tasks were randomly performed with the arm that the subject mainly use to throw the ball. The abduction and flexion angles were checked by the examiner using a goniometer beside the subject. Results: Correlation coefficient analysis between Scapular Index and upper trapezius muscle activity during shoulder abduction task showed significant positive correlation. No significant correlation was observed between CVA, Scapular Index, and other muscle activities. Conclusion: FHP showed increased muscle activation, making it difficult to change muscle activity under lower loads, and RSP was correlated with UT activation in shoulder abduction. Therefore, in the RSP, the loaded shoulder abduction is considered a potential risk factor for increasing shoulder muscle tension. This paper proposes an approach to treating RSP before FHP.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.38-45
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• 1999

The 2-trowel type concrete floor finishing robot can move in any direction by adjusting the posture or trowels without any wheels. Since the quality of the smoothed and polished concrete floor is determined by plastering speed, we need to control the velocity of the robot. However, we cannot use the typical motion control method because it is very difficult to measure the velocity of the robot, in contrast to the mobile robots with wheels. To overcome this difficulty, the following are studied in this paper: we found that the robot dynamics has the disturbance depending on its translational speed, and showed that there exists the saturated velocity of the robot which is set by the posture of the trowels, and obtained the relationship between the saturated velocity and the posture in the translation. The result enables us to control the motion of the robot only by adjusting the posture of trowels without measuring the velocity of the robot. Currently, we built the troweling robot and are experimenting its performance with the proposed motion control method.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.435-448
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• 2008

3D posture recognition is a solution to overcome the limitation of 2D posture recognition. There are many researches carried out for 3D posture recognition using 3D data. The 3D data consist of massive surface points which are rich of information. However, it is difficult to extract the important features for posture recognition purpose. Meanwhile, it also consumes lots of processing time. In this paper, we introduced a dimension reduction method that transform 3D surface points of an object to 2D data representation in order to overcome the issues of feature extraction and time complexity of 3D posture recognition. For a better feature extraction and matching process, a cylindrical boundary is introduced in meshless parameterization, its offer a fast processing speed of dimension reduction process and the output result is applicable for recognition purpose. The proposed approach is applied to hand and human posture recognition in order to verify the efficiency of the feature extraction.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.183-192
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• 2021

Purpose : The purpose of this study was to investigate the impact of postural correction training on pulmonary function on 28 college students suspected of turtle neck syndrome, and the following conclusions were obtained. Methods : Turtle neck syndrome suspicion 28 person were randomly divided into a posture training group (n = 14) and group that does not perform posture training (n = 14). Respiratory function was measured by SPIROVIT SP-1 and respiratory gas analyzer. The posture training group performed balloon blowing and stair climbing after 20 minutes of posture training, and the group without posture training carried out balloon blowing training and stair climbing. Five times a week and for two weeks. Results : 1. The comparison of the FVC before and after experiments caused by balloon blowing showed a higher level of effortful pulmonary function in the control group than in the experimental group. 2. Comparison of PEFs before and after the experiment by balloon blowing showed that the experimental group's peak flow rate was higher than that of the control group. 3. Comparison of the FIVC before and after experiments with balloon blowing showed that the comparison of the FIVC showed a higher level of effortless intake pulmonary function in the control group than in the experimental group. 4. The comparison of the maximum ventilation volume(VE) before and after the experimental gas measurement showed that the maximum ventilation rate of the experimental group was higher than that of the control group. 5. The comparison of pre-test and post-test heart rate(HR) by breath gas measurement showed that the heart rate of the control group was higher than that of the experimental group. Conclusion : the results of this study showed that postural correction training, balloon blowing training, and stair climbing could have a positive impact on improving pulmonary function. However, the two-week experiment conducted five times a week showed an increase in pulmonary function, but it was difficult to see the effect due to the short study period. Therefore, it is hoped that later studies will be conducted more systematically on the effects of breathing exercises on improving pulmonary function after post-postural correction training for patients with pulmonary function problems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.584-590
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• 2009

Since driving include compilcated actions that require a variety of abillity and cause extrme concentration or strain, divers tend to feel tired easiy. However, divers can't recognize fatigue degree by himself and accordingly the methods to measure quantitative fatigue degree exactly is quite difficult to be secured. In this study, the most efficient driving posture was suggested based on the analysis of quantitative muscular strength and fatigue degree according to posture. The driver whom we experimented included 9 commercial bus drivers. We also analyzed quantitative legs' muscular strength according te operating each pedal, left and right then we analyzed muscular strength and muscular fatigue degree according to driving pattern while driving commercial buses. And then we suggested the most efficient driving posture.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.227-233
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• 2020

The purpose of this study is to compare the speed, confidence, and ease of endotracheal intubation in a difficult posture by using the SALT(Supraglottic Airway Laryngopharyngeal Tube), and a direct laryngoscope to improve the ability to implement professional airway management. The subject of the study was an experimental study by a randomized crossover design, targeting 30 first-class emergency medical technicians working in J-do fire station, and the SPSS 20.0 version was used for data analysis. The endotracheal intubation by using SALT showed a significant difference in speed compared to endotracheal intubation by using a direct laryngoscope(p<.001), and also showed a significant difference in confidence and ease(p<.001). If it is difficult to endotracheal intubation by direct laryngoscope, or in the case of trauma patients, if SALT is used, safe and rapid intubation will be possible. In addition, to improve the efficiency of professional airway management, it is believed that the introduction of SALT in domestic sites is necessary.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.450-456
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• 2014

Humanoid robot is the most suitable robot platform for effective human and robot interaction. However, the robot's complicated body structure containing more than twenty joint actuators makes it difficult to generate stable and elaborate postures using the conventional inverse kinematic method. This paper proposes an alternative approach to generate difficult postures of touching an object placed in front of the foot by the left or right hand with its torso bent forward in single support phase using the fast computational optimization method, particle swarm optimization. The simulated postures are also applied to a commercial humanoid robot platform, which validates the feasibility of the proposed approach.