• Physical Therapy Korea
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• v.17 no.4
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• pp.8-15
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• 2010

This study was designed to investigate the effect of different hand positions on scapulothorcic muscle activities during push-up plus exercises. Fourteen healthy males performed push-up plus exercises under three conditions (neutral, $90^{\circ}$ internally rotated, and $90^{\circ}$ externally rotated hand positions), during which the activities of the serratus anterior, pectoralis major, and upper trapezius muscles were recorded using surface electromyography. The statistical significance at three different hand positions was tested by repeated one-way ANOVA. The mean activities of the serratus anterior increased and the mean activities of the pectoralis major decreased in the order of neutral hand position, internally rotated hand position, and externally rotated hand position. There was a significant difference during push-up plus between neutral and externally rotated hand positions as well as in the serratus anterior/pectoralis major activity ratio (p<.0.5). However, no significant differences were found in the activity of the upper trapezius muscle or the serratus anterior/upper trapezius activity ratio. We suggest that the push-up plus exercise performed in the externally rotated hand position could a beneficial strategy for selective strengthening of the serratus anterior muscle, while minimizing the activity of the pectoralis major muscle.

• Ocean Systems Engineering
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• v.4 no.1
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• pp.63-82
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• 2014

Declutching control is applied to a hemispherical wave energy converter with direct linear electric Power-Take-Off systems oscillating in heave direction in both regular and irregular waves. The direct linear Power-Take-Off system can be simplified as a mechanical spring and damper system. Time domain model is applied to dynamics of the hemispherical wave energy converter in both regular and irregular waves. And state space model is used to replace the convolution term in time domain equation of the heave oscillation of the converter due to its inconvenience in analyzing the controlled motion of the converters. The declutching control strategy is conducted by optimal command theory based on Pontryagin's maximum principle to gain the controlled optimum sequence of Power-Take-Off forces. The results show that the wave energy converter with declutching control captures more energy than that without control and the former's amplitude and velocity is relatively larger. However, the amplification ratio of the absorbed power by declutching control is only slightly larger than 1. This may indicate that declutching control method may be inapplicable for oscillating wave energy converters with direct linear Power-Take-Off systems in real random sea state, considering the error of prediction of the wave excitation force.

• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.449-465
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• 2017

The aim of the present work is to present a computational study of the non-linear aero-elastic behavior of a multi-layered Thermal Protection System (TPS). The severity of atmospheric re-entry conditions is due to the combination of high temperatures, high pressures and high velocities, and thus the aero-elastic behavior of flexible structures can be difficult to assess. In order to validate the specific computational model and the overall strategy for structural and aerodynamics analyses of flexible structures, the simplified TPS sample tested in the 8' High Temperature Tunnel (HTT) at NASA LaRC has been selected as a baseline for the validation of the present work. The von $K{\acute{a}}rm{\acute{a}}n^{\prime}s$ three dimensional large deflection theory for the structure and a hybrid Raleigh-Ritz-Galerkin approach, combined with the first order Piston Theory to describe the aerodynamic flow, have been used to derive the equations of motion. The paper shows that a good description of the physical behavior of the fabric is possible with the proposed approach. The model is further applied to investigate structural and aero-elastic influence of the number of the layers and the stitching pattern.

• Korean Journal of Adult Nursing
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• v.29 no.2
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• pp.143-153
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• 2017

Purpose: Purpose of the study was to identify the effect of the Comprehensive Education Program (CEP) on intra-procedure anxiety, post-procedure uncertainty and athletic performance of back strengthening of patients undergo spinal nerve block (SNB). Methods: The participants (experimental group=33, control group=33) were recruited from a university hospital in G metropolitan city. Data were collected from July to November 2015. The experimental group was individually provided with a booklet/motion picture about the SNB and back strengthening exercise training before the SNB. This group also received a leaflet about back strengthening exercise post SNB. The Anxiety-Visual Analog Scale (A-VAS), the Mishel adapted uncertainty scale and newly created knowledge scale/athletic performance checklist were utilized as our study tools. Results: Intra-procedure anxiety score (F=25.70, p<.001), post-procedure uncertainty score (F=82.56, p<.001), post-procedure knowledge score (F=14.63, p<.001) and athletic performance rate of back strengthening (p=.003) of the experimental group showed statistically significant differences in comparison with the control group. Conclusion: This CEP is a cost and time-effective intervention for patients who undergo spinal injections, so it should be actively utilized as an educational management strategy in outpatient.

• The Research Journal of the Costume Culture
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• v.18 no.6
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• pp.1063-1075
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• 2010

Studying awareness, importance, satisfaction, and wearing behavior of functional textiles for active silver generation related with gender and age is expected to contribute to clothing products development to improve and maintain their health and marketing strategy fit for user characteristics. For empirical research, a survey was developed and the aged 50 and above were 332 respondents. The results of the study are as follows. First, silver generation considered all the clothing comfort sensations important when wearing clothes, such as tactile sensation, clothing pressure sensation, thermal/wet sensation, and motion sensation in human physiological aspect. Also, stretchy fabrics were ranked first in awareness, the number of wearing times, and satisfaction of comfort functional fabrics. More than 30% of silver generation have fifteen items out of 36 functional clothes. Second, in analysis of awareness by gender on functional clothing products, women were more aware of health/safety-oriented fabrics than men were. Otherwise, men had more knowledge about the water-related properties of functional fabrics than women have, such as water/moisture absorptive and water-repellent/vapor permeable fabrics. While women have more indoor casual wear, men had more active sportswear. Also, women expressed a strong preference to the stretchy function of fabrics.

• Journal of Korean Elementary Science Education
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• v.19 no.1
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• pp.101-112
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• 2000

The purpose of this study was to develop the modular multimedia instructional materials emphasizing the particulate nature on the realm of matter in elementary science classes. Features of the material are as follows: 1 To be in focus on particulate model named 'phenomenal magnifying glasses' in order to change the student's belief system of continuous matter into the belief system of particulate matter . The 'phenomenal magnifying glasses' is a new instructional strategy designed to change into the view of particulate matter through facilitating the reflective thinking resulted from the simultaneous consideration of experimental phenomena(macroscopic world) and particulate model(microscopic world). 2. To introduce modular system into the instructional materials, which was consisted of 14 subunits according to the sequential instruction unit of 'molecule and molecular motion'. Each subunit was composed of 5 types of modules(module 1: motivation, module 2: experimental result, module 3: discussion, module 4: phenomenal magnifying glasses, module 5: related experiment) 3. The multimedia program was composed of 36 kinds of experimental animation and 59 kinds of computer animation materials combined with text resources, photographic materials and sounds.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.733-740
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• 2016

To achieve bipedal walking in real human environments, a bipedal robot should be capable of modifiable walking both on uneven terrain with different heights and on flat terrain. In this paper, a novel walking pattern generator based on a 3-D linear inverted pendulum model (LIPM) is proposed to achieve this objective. By adopting a zero moment point (ZMP) variation scheme in real time, it is possible to change the center-of-mass (COM) position and the velocity of the 3-D LIPM throughout the single support phase. Consequently, the proposed method offers the ability to generate a modifiable pattern for walking on uneven terrain without the necessity for any extra footsteps to adjust the COM motion. In addition, a control strategy for bipedal walking on uneven terrain with unknown height is developed. The torques and ground reaction force are measured through force-sensing resisters (FSRs) on each foot and the foot of the robot is modeled as three virtual spring-damper models for the disturbance compensation. The methods for generating the foot and vertical COM of 3-D LIPM trajectories are proposed to achieve modifiable bipedal walking on uneven terrain without any information regarding the height of the terrain. The effectiveness of the proposed method is confirmed through dynamic simulations.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.346-352
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• 2009

The objective of the present work is to improve numerical predictions of unsteady turbulent swirling flows in the draft tubes of hydraulic power plants. We present Large Eddy Simulation (LES) results on a simplified draft tube consisting of a straight conical diffuser. The basis of LES is to solve the large scales of motion, which contain most of the energy, while the small scales are modeled. LES strategy is here preferred to the average equations strategies (RANS models) because it resolves directly the most energetic part of the turbulent flow. LES is now recognized as a powerful tool to simulate real applications in several engineering fields which are more and more frequently found. However, the cost of large-eddy simulations of wall bounded flows is still expensive. Bypass methods are investigated to perform high-Reynolds-number LES at a reasonable cost. In this study, computations at a Reynolds number about 2 $10^5$ are presented. This study presents the result of a new near-wall model for turbulent boundary layer taking into account the streamwise pressure gradient (adverse or favorable). Validations are made based on simple channel flow, without any pressure gradient and on the data base ERCOFTAC. The experiments carried out by Clausen et al. [1] reproduce the essential features of the complex flow and are used to develop and test closure models for such flows.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.394-406
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• 2015

In this work, an efficient aircraft landing simulation strategy is proposed to develop an efficient and reliable hard-landing monitoring procedure. Landing stage is the most dangerous moment during operation cycle of aircraft and it may cause structural damage when hard-landing occurs. Therefore, the occurrence of hard-landing should be reported accurately to guarantee the structural integrity of aircraft. In order to accurately determine whether hard-landing occurs or not from given landing conditions, full nonlinear structural dynamic simulation can be performed, but this approach is highly time-consuming. Thus, a more efficient approach for aircraft landing simulation which uses a hierarchical aircraft landing model and an extended inertia relief technique is proposed. The proposed aircraft landing model is composed of a multi-body dynamics model equipped with landing gear and tire models to extract the impact force and inertia force at touch-down and a linear dynamic structural model with an extended inertia relief method to analyze the structural response subject to the prescribed rigid body motion and the forces extracted from the multi-body dynamics model. The numerical examples show the efficiency and practical advantages of the proposed landing model as an essential component of aircraft hard-landing monitoring procedure.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.41-48
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• 2005

The Rotating transmission is made up of belts, mass disks and gears. This transmission is controlled electro-mechanically by the motor and operation program. The control strategy of the system can be to change belts' stiffness and the masses of mass disk and gear. This system can be modeled as a rigid body, and also finds broad application in such diverse fields as machine tools, the cruise control system In automobiles, and control in the attitude and gimbals of spacecraft. This Transmission proves the necessity and effect of a closed loop control. The study of the Rotating Transmission excited by its base motion is able not only to predict the rotational performance, but to obtain the fundamental data for vibration isolation. In this research, we compared the response characteristics of the two controllers by means of the experiments on PD controller and PID controller added on integral action. Furthermore, we studied the response abilities such as steady state error, overshoot, and ect. and the response velocities such as rising time, settling time, and ect. in the rotating transmission.