• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.267-272
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• 1998

A new signal processing technique, the directional harmonic wavelet map(dHWM), is presented to characterize the instantaneous planar motion of a measurement point in a structure from its transient complex-valued vibration signal. It is proven that the auto-dHWM essentially tracks the shape and directivity of the instantaneous planar motion, whereas the phase of the cross-dHWM indicates its inclination angle. Finally, the technique is successfully applied to an automobile engine for characterization of its transient motion during crank-on/idline/engine-off.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1383-1384
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• 2011

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.126-130
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• 2009

Arytenoid motion has long been recognized as complex. Misunderstandings about the specifics of arytenoid motion remain prevalent. The resultant misunderstandings have led to erroneous or suboptimal clinical approaches to the treatment of vocal fold immobility. A thorough understanding of the anatomy of the arytenoid and cricoid cartilages, the cricoarytenoid joint, and related ligaments, muscles, and other structures is essential in order to fully understand laryngeal motion disorders. Arytenoid motion occurs in three directions. Movements involving a change anteriorly and posteriorly, as well as vertically, are due to the revolving or pitchlike motion of the arytenoid along the minor axis of the cricoid's elliptically shaped facet. The medial and lateral movements are due to the orientation of the arytenoid which in turn is determined by the forward, lateral, and inferior inclination of the cricoid-arytenoid facet. During adduction it is the outward angulation of the vocal process from the body of the arytenoid that allows the entire length of the vocal proceses to approximate one another and to have this meeting occur at the proper vertical height.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.33-38
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• 2011

A cubic spline trajectory planner with arc-length parameter is formulated with estimation by summing up to the 3rd order in Taylor's expansion. The PVAJT motion planning is presented to reduce trajectory calculation time at every cycle time of servo control loop so that it is able to generate cubic spline trajectory in real time. This method can be used to more complex spline trajectory. Several case studies are executed with different values of cycle time and sampling time, and showed the advantages of the PVAJT motion planner. A DSP-based motion controller is designed to implement the PVAJT motion planning.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.533-538
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• 1991

In the design and operation of robot arms with flexible links, the equations of motion are required to exactly model the interaction between rigid motion and elastic motion and to be formulated efficiently. Thus, the flexible link is represented on the basis of the D-H rigid link representation to measure the elastic deformation. The equations of motion of robot arms, which are configured by the generalized coordinates of elastic and rigid degrees of freedom, are formulated by using F.E.M. to model complex shaped links systematically and by eliminating elastic mode of higher order that does not largely affect motion to reduce the number of elastic degree of freedom. Finally, presented is the result of simulation to flexible robotic arm whose joints are controlled by direct or PD control,

• Journal of computational fluids engineering
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• v.14 no.3
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• pp.63-68
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• 2009

The motion of a rising liquid droplet is different that of a bubble motion. Treatment of liquid drops is more complex because internal motion must be considered. A 3D unstructured CFD code has been developed to solve incompressible N-S equation for the droplet simulation. This front-tracking consideration which the interface is tracked explicitly is very available to apply for not only exact interface topology but also the high schmidt number issue, such as $CO_2$ dissolution. This paper is forced on the zig-zag motion of the liquid droplet. The simulation shows that if the rising droplet is located at the corner of the zig-zag path, the velocity is low and shape of the droplet is more spherical shape, results in the less drag coefficient. Twin horse shoe vortexes behind the rising droplet are presented and the topology of the droplet is compared with an experimental result during one period of the path.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.10
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• pp.1571-1583
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• 2008

The study aimed to investigate the actual condition of working clothes in the Changwon National Industrial Complex and to analyze the industrial workers' satisfaction with and preference to the working clothes in terms of the clothing performance and work motion factors. 1 major companies in machinery, automotive, industrial engineering, shipbuilding and rolling stock industries located in the industrial complex were selected as the subject firms. Approximately 900 workers responded to the questionnaire designed for the research and the results derived from the research were as follows. (1) The subject employees were divided into 4 work groups, i.e. the $1^{st}$ work group: managerial, general affairs, sales, production planning; the $2^{nd}$ group: quality assurance, material planning and distribution, product inspection; the $3^{rd}$ group: electric, facilities, machinery, vehicles; and the $4^{th}$ group: cutting, pressing, rolling, welding and coating. (2) The significant work environmental factors considered by all work groups were air ventilation, noise and dust factors and in particular, the most dissatisfied factors evaluated by manufacture workers were insulation, noise, dust and vibration. (3) According to the employees' work motion evaluation, the work motion diversity and frequency increased in proportion to the degree of work intensity. Besides, manufacture workers more frequently wore the working clothes even during the off-duty hours comparing to the evaluation of the other work groups. (4) The most important clothing performance factors considered by manufacture work groups were perspiration absorption, stretch, air permeability, tactile sense softness, soil proof in order.

• Physical Therapy Korea
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• v.20 no.1
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• pp.55-63
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• 2013

This study investigated the effects of axillary crutch length on trunk muscle activity and lumbo-pelvic-hip complex movements during crutch gait. Eleven healthy men participated in this study. The participants performed a three-point gait with optimal, shorter, and longer crutch lengths. Weight-bearing (WB) side was determined as the dominant leg side. The electromyography (EMG) activity of the bilateral rectus abdominis (RA) and erector spinae (ES) muscles and lumbo-pelvic-hip complex movements were monitored using a three-dimensional motion system with wireless surface EMG. Differences in the EMG activity of RA and ES muscles and range of motion (ROM) of lumbar spine, pelvis, and hip among conditions were analyzed using one-way repeated-measures analysis of variance, and a Bonferroni correction was conducted. There was less RA muscle activity on the WB side under the optimal crutch length condition compared with shorter and longer crutch length conditions (p<.05). The EMG activity of the RA muscle on the non-WB side and ES muscle on the WB side were significantly decreased under the optimal crutch length condition compared with shorter crutch length condition (p<.05). No significant differences in the EMG activity of the ES muscle on the non-WB side and ROM of lumbo-pelvic-hip complex were found among conditions (p>.05). These findings indicate that the optimal crutch length improves the trunk muscle efficiency during crutch gait.

• Journal of Chest Surgery
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• v.49 no.5
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• pp.366-373
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• 2016

Background: The aim of the study was to test the hypothesis that in patients with chronic complex sternum dehiscence, the use of muscle flap repair minimizes the occurrence of paradoxical motion of the chest wall (CWPM) when compared to sternal rewiring, eventually leading to better respiratory function and clinical outcomes during follow-up. Methods: In a propensity score matching analysis, out of 94 patients who underwent sternal reconstruction, 20 patients were selected: 10 patients underwent sternal reconstruction with bilateral pectoralis muscle flaps (group 1) and 10 underwent sternal rewiring (group 2). Eligibility criteria included the presence of hemisternum diastases associated with multiple (${\geq}$3) bone fractures and radiologic evidence of synchronous chest wall motion (CWSM). We compared radiologically assessed (volumetric computed tomography) ventilatory mechanic indices such as single lung and global vital capacity (VC), diaphragm excursion, synchronous and paradoxical chest wall motion. Results: Follow-up was 100% complete (mean $85{\pm}24months$). CWPM was inversely correlated with single lung VC (Spearman R=-0.72, p=0.0003), global VC (R=-0.51, p=0.02) and diaphragm excursion (R=-0.80, p=0.0003), whereas it proved directly correlated with dyspnea grade (Spearman R=0.51, p=0.02) and pain (R=0.59, p=0.005). Mean CWPM and single lung VC were both better in group 1, whereas there was no difference in CWSM, diaphragm excursion and global VC. Conclusion: Our study suggests that in patients with complex chronic sternal dehiscence, pectoralis muscle flap reconstruction guarantees lower CWPM and greater single-lung VC when compared with sternal rewiring and it is associated with better clinical outcomes with less pain and dyspnea.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.1
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• pp.49-61
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• 2022

PURPOSE: This study compared the effects of proprioceptive sensation, subacromial space, and dynamic function according to proprioceptive neuromuscular facilitation (PNF), static stretching (SS), and complex rotational stretching (CRS). METHODS: Thirty students without any musculoskeletal disease who volunteered to participate were included in this study. The following metrics were measured to evaluate the function and stability under the normal conditions, with the PNF, SS, and CRS: special test and flexion, extension, abduction, adduction, internal rotation, external rotation (shoulder range of motion) and reaching distance on the medial (ME), superolateral (SL), inferolateral (IL), and subacromial space and proprioceptive sensation were evaluated. All measures were analyzed using one-way ANOVA and repeated measures of ANOVA. RESULTS: A clear difference in adduction in the range of motion was observed in all groups (p < .05). Significant differences could not be identified in all values in the error test, except for Ab (p < .05). Significant differences in reach were noted in all directions of the SS and PNF in the Me, SL, and IL (p < .05). After the intervention, significant differences in the average values could be identified in all groups except for the SS group after rest (p < .05). After the intervention, there was a significant difference between the CRS and SS and PNF groups (p < .05). CONCLUSION: The application of CRS is as helpful as the existing SS and PNF for improving the joint range of motion improvement, shoulder balance, and subacromial space.