• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1967-1974
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• 1991

When the functional electrical stimulation is employed to recover mobility to the plegic, it is very important to understand functions of the selected muscles. I have investigated how a muscle acts to accelerate the body segments, since the body segements are connected by joints so that contraction of a muscle not only rotates the segments to which it is attached but also causes other segments to rotate by creation a reaction force at every joint, which is called the inertial coupling. I found that a single-joint muscle always acts to accelerate the spanned joint in the same direction as the joint torque produced by the muscle. However, a double-joint muscle can act to accelerate the spanned joint in the opposite direction to the joint torque produced by the muscle depending on (1) the body position, (2) the body-segmental parameters, and (3) the type of the movement. Investigating the condition number of the inertia matrix of the body-segmental model gave us some insights into how controllable the body-segmental system is for different values of the factors mentioned above. The results suggested that the upright position is the most undesirable position to independently control the three segments(trunk, thigh and shank) and that the controllability is the most sensitive to variation of the shank length and the trunk mass, which implies that accuracy is required particularly when we estimate these two body-segmental parameters before the paralyzed muscles are innervated by using electrical stimulation.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.5
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• pp.10-18
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• 2019

In this study, flow characteristics and the starting pressure of a center body diffuser (CBD) were analyzed at various center body (CB) positions and cone angles. According to the CB position, the location of oblique shock moved to the front from behind the CB cone with an increase in the flow momentum. Additionally, when a strong oblique shock occurred, the direction of supersonic flow was affected and induced to diffuser wall. As a function of different cone angles for the oblique shock, the starting pressure of the CBD was significantly affected.

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.99-115
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• 1994

This styudy analyzed the main bodies, marginal space, Position of the main bodies of curent textbooks in high schools and "the eriteria of reading system for textbooks" which was sugested the Department of Education and Provided some sugestions for the improvement. The research methods used for the study were both literature review and survey rdsdarch with a questionaire. Inorder to research for the main body of textbook, space of margin, the optimum position fo the main body, sizes of litters, spaces between letters, words, lines length of lines, sizes of main body and margin, and margin, and postitionof main body were checked through a related literature review. For the questionaire experiment, a questionaire based on data drawn from analysis of textbooks, "criteria for reading system of textbook" sugested by the Department of Education, and some suggestions for improvement by the researcher was made and used for the test, targetting 384 body and girl students in high schools.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.1
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• pp.65-74
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• 2004

This study analyzed the main bodies, sizes of litters, spaces between letters, Words, lines, length of lines, sizes of main body and margin, Position of the main bodies of PDF(Portable Document Format) in high schools and "the criteria of reading system for the textbooks" which was suggested by the Department of Education and Provided some suggestions for the improvement. First, it is judged that spaces of the main body of textbooks should be shrunken to make the ratio of 50:50 between the main body and space margin. Second, it is judged that the main body should be placed in the center of text page. Third, the results of the above findings showed that it would be difficult to deal with the task of deciding space and position or the main body and marginal space in a form of single project, because there are many variables involved and psychologically complicated elements which can not be measured objectively.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.139-147
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• 2020

Purpose : Proprioceptive position sense plays a key role in providing joint stability, and multiple factors are related to proprioceptive position sense. Thus, this study aimed to determine the effects of body composition, particularly skeletal muscle mass on proprioceptive position sense following muscle fatigue. Methods : Healthy female subjects agreed to have their body composition analyzed. Only subjects who had 18.5-22.9 kg/㎡ of BMI (body mass index) were included in this study, and the participants were divided into two groups by skeletal muscle mass level. The experimental group had a level of skeletal muscle lower than the standard level (n=9), while the control group showed a standard or high level of skeletal muscle mass (n=11). To determine the change in proprioceptive position sense of the knee joint, the absolute angle error (AAE) was evaluated following muscle fatigue on low extremity. The muscle fatigue was induced by isokinetic resistance exercise program of Biodex system. AAE was measured by the Biodex system and compared the result before and after muscle fatigue. Results : The experimental group showed a significant AAE difference between before (3.16±2.48 °) and after (5.40±2.61 °) muscle fatigue. In addition, there was a AAE difference between the experimental (5.40±2.61 °) and control groups (3.53±1.67 °) after fatigue; however, there was no significance. Those results indicated that low level of skeletal muscle mass might influence the proprioceptive position sense of the knee joint after muscle fatigue. Conclusion : Thus, maintaining the proper level of skeletal muscle mass is pivotal to reduce the risk of injury following muscle fatigue in ADL or sport activities.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.1
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• pp.9-21
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• 2009

Purpose : To know how much weight bearing on left and right leg on 14 different positions. The second is to know how about different the weight bearing ratio on same positions of ages group. Methods : The third is to know how about changes the weight bearing ration between exercise group and non exercise group. The group of age is divided 20s, 30s, 40s, 50s, over the 60 years. The subjects are 93 males(44), females(49). Results : The ordering of ratio of weight bearing on one side leg is as follows: The position of the highest weight bearing ratio is one leg standing with the other leg on chair(right 0.82, left 0.81) and the position of lowest weight bearing ratio is hooklying with natural leg position(both legs 0.08). There are statistically significant difference between right and left leg of weight bearing ratio on the 6 positions among the 14 positions. As for the ages, there are statistically significant difference on 5 different positions of 20 ages body weight bearing ratio between right and left leg. But as for the 50 ages there are no statistically significant difference on all of 14 positions between right and left leg body weight bearing. As for the exercise group there are statistically significant difference on only one position of one leg standing with the other leg on chair between right and left weight bearing ratio. But as for non exercise group there are statistically significant difference on 4 positions between right and left weight bearing ratio. Conclusion : When the therapist exercise with patient's always considerate of patient's position and weight bearing ratio.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.128-133
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• 2021

Recently Recently, the incidence of spinal diseases due to poor posture among students and office workers is increasing, and various studies have been conducted to help maintain correct posture. In previous studies, a membrane sensor or a pressure sensor was placed on the seat cushion to see the weight bias, or a sensor that restrained the user was attached to measure the position change. In our previous study, we developed a sensor device which can be easily attached to the body with an adhesive gel sheet and that measures and outputs the user's posture and body position in real time, but it has a limitation in the accuracy of the sensor value. In this study, a study was conducted to improve the performance of the position conversion sensor device and quantitatively evaluate the accuracy of the angle conversion measurement value, and a high accuracy with 2.53% of error rate was confirmed. In future research, it is considered that additional research targeting actual users is needed by diversifying posture correction training contents with multimedia elements added.

• Journal of Ocean Engineering and Technology
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• v.38 no.2
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• pp.53-63
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• 2024

Submerged breakwaters can be installed underneath floating structures to reduce the external wave loads acting on the structure. The objective of this study was to establish an optimization analysis framework to determine the corresponding shape and position of the submerged breakwater that can minimize or maximize the external forces acting on the floating structure. A two-dimensional frequency-domain boundary element method (FD-BEM) based on the linear potential theory was developed to perform the hydrodynamic analysis. A metaheuristic algorithm, the advanced particle swarm optimization, was newly coupled to the FD-BEM to perform the optimization analysis. The optimization analysis process was performed by calling FD-BEM for each generation, performing a numerical analysis of the design variables of each particle, and updating the design variables using the collected results. The results of the optimization analysis showed that the height of the submerged breakwater has a significant effect on the surface piercing body and that there is a specific area and position with an optimal value. In this study, the optimal values of the shape and position of a single submerged breakwater were determined and analyzed so that the external force acting on a surface piercing body was minimum or maximum.

• Journal of Sensor Science and Technology
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• v.23 no.6
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• pp.402-408
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• 2014

Heart rate is one of the most important signal to monitor the health condition of the patient or exerciser. Various wearable devices have been developed for the continuous monitoring of ECG signal from human body during exercise. Among these, ECG chest belt has been widely used. However wearing chest belt with ECG sensor is uncomfortable in normal life due to the electrode contact between metal electrodes of ECG sensor and skin of the human body. So we develop the royal healthcare backpack that can measure ECG signal without skin contact by using capacitor-type ECG sensor. The position of the measurement point is critical to collect a clear ECG signal in the capacitive ECG measurement from backpack. Various tests were conducted to find the optimal ECG measurement position which has less noise and could get strong and clear ECG signal during exercise, walking, hiking, mountain climbing and cycling.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.555-555
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• 2000

This study is concentrated on the development of hight speed multi-object image processing algorithm, and based on these a1gorithm, vision control scheme is developed for the robot's position control in real time. Recently, the use of vision system is rapidly increasing in robot's position centre. To apply vision system in robot's position control, it is necessary to transform the physical coordinate of object into the image information acquired by CCD camera, which is called image processing. Thus, to control the robot's point position in real time, we have to know the center point of object in image plane. Particularly, in case of rigid body, the center points of multi-object must be calculated in a image plane at the same time. To solve these problems, the algorithm of multi-object for rigid body control is developed.