• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2365-2370
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• 2017

In this paper, we propose a motion and position recognition technique considering an experiential VR environment. Motion recognition attaches a plurality of AHRS devices to a body part and defines a coordinate system based on this. Based on the 9 axis motion information measured from each AHRS device, the user's motion is recognized and the motion angle is corrected by extracting the joint angle between the body segments. The location recognition extracts the walking information from the inertial sensor of the AHRS device, recognizes the relative position, and corrects the cumulative error using the BLE fingerprint. To realize the proposed motion and position recognition technique, AHRS-based position recognition and joint angle extraction test were performed. The average error of the position recognition test was 0.25m and the average error of the joint angle extraction test was $3.2^{\circ}$.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.2
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• pp.95-105
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• 2007

The purpose of this study is to define the effect of taping and icing on muscle fatigue at knee joint of ordinary adult. The 30 adults meeting research standard were chosen to be observed. The period of the research was 9 days and N-K table was used as equipment to measure position sense of knee joint. Heart rate monitor was also used to measure heart beat during both when in comfortable state and in exercises. For the method of this study, error in position sense of knee joint was measured right before fatigue occurs. Then volunteers were to be exercised for 10 minutes in treadmill aiming to raise the heart beat to 90%. If muscle fatigue occurs after the exercise, let the comparative group rest for 20 minutes while applying taping for group 1 and icing for group 2. For the icing, it was applied for 3 minutes followed by 1 minute rest. 5 sets of icing were applied on thighs and calf each, Then error of position sense of knee joint was measured same way it was done before muscle fatigue. As the result, there were similar differences among comparative group(p<.05), group 1 and group 2 before the muscle fatigue and after the muscle fatigue. There were similar differences in comparative group with muscle fatigue, group 1 and group 2 as the result of one-way ANOVA and with further examination, similar differences were only found in between comparative group and group 2(p<.05). With the result, we can see there wasn't clear effect of rest, icing or taping, however, group 2 with icing showed better condition compared to comparative group who have rested without any application.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.2
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• pp.184-191
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• 2003

A parallel manipulator has high stiffness and all the joint errors on the device are not accumulated at the end -effector unlike a serial manipulator. These are the reasons why the parallel manipulator has been widely used in many fields of industry. In the parallel manipulator, it is very important to predict the exact pose of the end-effector when we want to control the end-effector motion. Installation errors have to be determined in order to predict and control the actual position and pose of the end-effector. This paper presents an algorithm to find the whole 36 joint error components with joint clearance errors and measurement errors considered, when a link length measurement sensor is used and data more than 36 times are acquired for 36 different configurations. A simulation test using this algorithm is performed with a Matlab program which uses the Levenberg-Marquardt method that is known to be efficient for non-linear optimization.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2345-2353
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• 2021

Background: This study evaluated the effectiveness of upper thoracic manipulation (UTM) and proprioceptive training versus proprioceptive training alone on forward head posture (FHP) and cervicocephalic joint position sense (CJPS) in asymptomatic university students during a short interval of time. Objectives: To evaluate whether the suggested combination would provide greater benefit, and be superior to proprioceptive training alone in improving proprioceptive acuity and head posture. Design: A single-blind randomized controlled trial. Methods: Thirty-three university student volunteers with asymptomatic FHP were recruited. Subjects were randomly assigned to a manipulation group (n=16) receiving UTM combined with proprioceptive training or a proprioception group (n=17) receiving proprioceptive training only. The intervention period lasted 5 weeks in total, and consisted of one 15 to 20-minute session per week. FHP and CJPS were assessed before and after the intervention. Results: A significant pre- to post-intervention decrease in FHP and joint position error was identified in both groups (P<.05). Subjects in the manipulation group demonstrated greater improvements in CJPS and head posture compared to the proprioception group (P<.05). Conclusion: These findings support employing either intervention for treating asymptomatic students with FHP. However, the addition of UTM to proprioceptive training was more effective than proprioceptive training alone in reducing joint position errors and improving head posture.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.7-11
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• 1991

The adaptive control of flexible joint manipulator is the focus of this paper. The full order flexible joint manipulator dynamic system does not allow the determination of a feedback linearization control as for rigid manipulators. This drawback is overcome by a model order reduction based on a singular perturbation strategy. The full order flexible joint manipulator dynamic model is adopted for derivation of the adaptive control law to damp out the elastic oscillations at the joints. It is shown that the joint position error will converge to zero asymptotically and that other signals remain bounded without precise knowledge of parameters of the manipulator and its joint flexibility.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.763-766
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• 1991

The moving of each axis in the robot manipulator can be represented with the motion of cartesian space. This paper shows the robot manipulator of the straight line trajectory planning algorithms in the cartesian space. The relation formulas between cartesian space and joint space are induced to accomplish a desired trajectory in the cartesian space and the velocity vector of sampling time in the cartesian space is transformed into the velocity vector of joint by the interpolation method. The error of trajectory in moving is removed by obtaining the real position for the present joint position and the desired distance is made by comparing the real position and the next position. Through the simple tests for suggested algorithms are confirmed the validity of algorithms.

• The Journal of Korean Physical Therapy
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• v.30 no.2
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• pp.54-57
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• 2018

Purpose: Most studies have reported pain in the head-neck and upper-limbs according to smartphone usage, which is related to the proprioception sense in the head and neck, but there have been few studies. Therefore, the aim of this study was identify the adverse effects of the proprioceptive sense in the head-neck according to smartphone usage. Methods: Twenty-seven young adults (male: 9, female: 18) were enrolled in this study. The proprioceptive sense was measured through the joint reposition sense error and neural positon error in the head-neck during smartphone usage for 0, 5, and 20 minutes. The Noraxon MyoMotion system was used to record the joint position angle and neutral positon in the head-neck. One-way repeated ANOVA was used to identify the differences between the three smartphone use durations and the least-squares difference was used as a post hoc test. The data were analyzed using SPSS 18.0 software. Results: The joint reposition sense error and neural positon error in the head-neck were significantly different among the 0, 5, and 20 minutes of smartphone usage (p<0.05). In the post hoc test, the joint reposition sense error and neural positon error showed a significant difference between smartphone use for 0 minute and 5 minute, and between smartphone use for 0 minute and 20 minutes. Conclusion: This study suggests that smartphone use within 5 minutes can have adverse effects on the proprioceptive sense. Therefore, it is necessary to consider the appropriate use time and break time when using smart phones.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3703-3716
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• 2022

Target alignment technology is one of the most critical technologies in laser fusion experiments and is an important technology related to the success of laser fusion experiments. In this study, by combining the open-loop and closed-loop errors of the target alignment, the Kalman state observer is used to estimate the position of the target, which improves the observation precision of the target alignment. Then the optimized result is used to guide the alignment of the target. This method can greatly optimize the target alignment error and reduce uncertainty. With the improvement of the target alignment precision, it will greatly improve the reliability and repeatability of the experiments' results, thereby improving the success rate of the experiments.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.10-19
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• 1996

This paper presents a finger-shaped multisensor system which can measure the tyep and position of a target surface by contactl. The multi-sensor system consists of a sphere-shpaed optical tactile sensor located at the finger tip and a force/torque sensor located at the joint of a finger. The optial tactile sensor determines the type and position of the target surface using the shape and position of the CCD image of the touching area generated by a contact between the sensor and the taget surface. The force/torque sensor also determines the position and surface normal vector by applying the distributionof forces and torques t the contact point to the equations of finger shape. The measurements on the position and surface normal vector at a contact point obtined by two individual sensors are fused using a statistical method. The integrated sensor system has 0.8mm error in position measurement and 1.31$^{\circ}$ error in normal vector measurement. The developed sensor system has many applications, such as autonomous compliance control, automatic grasping and recognition, etc.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.685-688
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• 1989

This paper presents two methods for reducing the position error of the robot hand. The first method change the parameters of the D-H transformation using real position error. The other one calibrates the joint angle by using the datas from the known teaching points. SCARA type robot is used for verifing the validity of the proposed methods.