• Journal of Life Science
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• v.20 no.11
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• pp.1704-1710
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• 2010

The purpose of this study was to describe the biomechanical characteristics of stroke patients. These characteristics were obtained during walking on a Zebris system, cinematography system and EMG system. Seven female stroke patients participated in this study. The magnitude of the profiles (joint peak angle, joint peak moments, foot pressure COP, EMG data) correlated with rehabilitation training duration using t-test. The significance level selected for this study was p<0.05, t-test. Joint analysis identified significant differences in hip joint peak angle and hip joint peak moment. Foot pressure verified significant differences in gait line length of COP. The EMG signal proved significant differences in rectus femoris and vastus lateralis.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.235-243
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• 2013

The purpose of this study was to analyse scientific according to period of rehabilitation training of ACL patients. ACL patients seven subjects participated in this study. Gait (1.58 m/sec) analysis was performed by using a 3-D Cinematography, a Zebris system and a electromyograph system. The data were analyzed by paired t-test. The joint angles were recorded from the ankle, knee, hip joints. Peak max dorsi-flexion and peak max plantar-flexion identified significant differences (p<0.05). Another angles were no significant difference. Vertical force (Fz) and max pressure variables improved 6 month RTP better than 3 month RTP. EMG were collected from 4 muscles (rectus femoris, biceps femoris, gastrocnemius, tibialis anterior) with surface electrides in gait system. EMG signals were rectified and smoothed data. EMG signas were no significant difference but they also improved 6 month RTP better than 3 month RTP. More research is necessary to determine exactly what constitutes optimal rehabilitation training period for ACL patients.

• Journal of Auto-vehicle Safety Association
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• v.15 no.4
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• pp.95-101
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• 2023

As the popularization of autonomous vehicles is anticipated, it is expected that the variety of passenger postures will diversify. However, the current vehicle safety system is expected to be inadequate for accommodating these diverse passenger postures, particularly in reclined positions where severe injuries have been reported in frontal collisions. Therefore, it is necessary to investigate the biomechanical responses and tolerances of occupants in reclined postures. In this study, the behavior and injuries of a Hybrid-III dummy model in a reclined position are analyzed through frontal collision sled simulations equipped with the semi-rigid seat provided by the previous study, three-point safety belt with pretensioner and load limiter, and airbag models. The results are evaluated by comparing thouse reponses with post-mortem human surrogate (PMHS) data, and the findings are expected to be applicable to the basic design of a new restraint system suitable for various postures in autonomous vehicles.

• BMB Reports
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• v.39 no.2
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• pp.132-139
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• 2006

Vascular endothelial cadherin (VE-cadherin), which belongs to the classical cadherin family, is localized at adherens junctions exclusively in vascular endothelial cells. Biochemical and biomechanical cues regulate the VE-cadherin adhesive potential by triggering the intracellular signals. VE-cadherin-mediated cell adhesion is required for cell survival and endothelial cell deadhesion is required for vascular development. It is therefore crucial to understand how VE-cadherin-based cell adhesion is controlled. This review summarizes the inter-endothelial cell adhesions and introduces our recent advance in Rap1-regulated VE-cadherin adhesion. A further analysis of the VE-cadherin recycling system will aid the understanding of cell adhesion/deadhesion mechanisms mediated by VE-cadherin in response to extracellular stimuli during development and angiogenesis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.1
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• pp.9-13
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• 2002

The objective of this study was to analyze and make comparison between the physical responses such as oxygen consumption rate, heart rate, and EMG-measurement for lifting tasks. Lifting activities with three different working frequencies(5, 8, 11 lifts/min) and two different weights(10, 20kg) for a lifting range(from floor to 76cm height) were studied. It was found that theme are positive correlations between the oxygen consumption rate and the EMG-measurements on the region of law back. Even though these physical responses were influenced by work weights and work frequency, it was found that the work frequency plays more important role in making muscle fatigue than the work weight. From these finding it is suggested that the work frequency should be considered as a more influencing factor than the work weight as long as the weight belongs to the permissible range based on the viewpoint of the biomechanical criterion for designing a job of manual materials handling tasks.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.10.1-10.1
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• 2011

Energy harvesting technologies converting external sources (such as thermal energy, vibration and mechanical energy from the nature sources of wind, waves or animal movements) into electrical energy is recently a highly demanding issue in the materials science community for making sustainable green environments. In particular, fabrication of usable nanogenerator attract the attention of many researchers because it can scavenge even the biomechanical energy inside the human body (such as heart beat, blood flow, muscle stretching, or eye blinking) by converging harvesting technology with implantable bio-devices. Herein, we describe procedure suitable for generating and printing a lead-free microstructured $BaTiO_3$ thin film nanogenerator on plastic substrates to overcome limitations appeared in conventional flexible ferroelectric devices. Flexible $BaTiO_3$ thin film nanogenerator was fabricated and the piezoelectric properties and mechanically stability of ferroelectric devices were characterized. From the results, we demonstrate the highly efficient and stable performance of $BaTiO_3$ thin film nanogenerator and the integration of bio-eco-compatible ferroelectric materials may enable innovative opportunities for artificial skin and energy harvesting system.

• Journal of Mechanical Science and Technology
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• v.17 no.1
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• pp.32-39
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• 2003

In this study we examined connections between vertebral motion and patterns of muscle activation during voluntary head tracking movements. A Rhesus (Maraca mulatta) monkey was trained to produce sinusoidal tracking movements of the head in the sagittal plane while seated. Radio-opaque markers were placed in the cervical vertebrae, and intramuscular patch electrodes were implanted to record from eight neck muscles. Videofluoroscopic images of cervical vertebral motion, and EMG (electromyographic) responses were simultaneously re-corded. Experimental results demonstrated that head and vertebrae moved synchronously and that motion occurred primarily at skull-C$_1$, C$\_$6/-C$\_$7/ and Csub 7/-C$_1$. Our findings illustrate that although the biomechanical constraints of each species may limit the number of solutions available, it is the task requirements that appear to govern CNS (central nervous system) selection of movement behaviors.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.2
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• pp.87-99
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• 1985

The purpose of this study is to analyze the changes in centers-of-gravity (COG), acceleration and body posture and their associated effects both on EMG and on the maximum capability of weight lifting during Clean & Jerk and Snatch motions. Displacement, velocity, acceleration of joints were obtained from film analysis. Also levels of exertions on 11 major muscle groups were obtained from EMG analysis during a lifting cycle. The EMG data were measured from Telemetry System which is useful in field experiments. Magnitude and direction of force, change in center-of-gravity were extracted from COG data which were measured from force platform. The results of this study can be to be useful both to coaches and to athletes in weight-lifting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1088-1092
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• 2002

The purpose of this investigation was to study the kinematics of joints between foot segments based on computer graphic-based model during the stance phase of walking. In the model, ail joints were assumed to act as monocentric, single degree of freedom hinge joints. The motion of foot was captured by a video collection system using four cameras. The model fitted in an individual subject was simulated with this motion data. The kinematic data of tarsometatarsal joints and metatarso-phalangeal joint were quantitatively similar to the previous data. Therefore, our method using the computer graphic-based model is considered useful.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.333-338
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• 2007

The concept of "Allowable Load Set (ALS)" introduced by the author allows an easy understanding of load and strength characteristics of a structure in relation to its integrity under uncertainties. Two criteria of safety are introduced: A relative safety index denotes the distance to the boundary of the ALS and a normalized safety index is a distance in terms of functional value. They have been utilized in several examples, including multi-body mechanical systems such as a biomechanical system. Both formulations amount to robust designs in the sense that designs most insensitive to uncertainties are obtained in the context of newly defined safety indices, without using any input probability information.