• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.269-276
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• 2012

The purpose of This study's aim is to examine the difference in the changes of body segment movement, variables for ball quality, and carry at golf driver swing according to the ball quality using comparative analysis. Regarding the impact variables according to the ball quality using the track man and carry, club speed was the fastest at draw shot, ball speed was the fastest at straight shot, and smash factor was the lowest at draw shot. About the vertical launch angle, the fade shot showed the highest launch angle while the max height of the ground and ball was the highest at fade shot. And carry was the longest at draw shot. For the flight time, it was the longest at draw shot. The landing angle was the largest at fade shot. About the club head position change and trajectory, at the overall event point, the fade shot drew a more outer trajectory at the point of the follow through(E6) than the straight or draw shot. Regarding the angular speed of shoulder rotation, at the overall event point, the fade shot showed the greatest angular speed change in the follow through(E6). Also, about the angular speed of pelvic rotation, at the overall event point, the draw shot showed the greatest angular speed change at the point of down swing(E4). Concerning the stance angle change, both straight and fade shots were open as the concept of open stance whereas the draw shot was close as that of close stance. Regarding the previous study, the most important factor of deciding Ball Quality is the club face angle's open and close state at Impact. In short, the Ball Quality and carry were decided by this factor.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.177-186
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• 2024

Purpose : The purpose of this study was to use oral instruction and taping to induce abdominal draw-in in the previous study, but there is a lack of research on the comparison of effects. Therefore, in this study, we would like to study how the effect of oral instruction, taping, and no feedback can affect muscle activity when performing abdominal draw-in pier exercises. Methods : Before the experiment, group A trained piers and applied only draw-in piers, group B applied taping feedback, and group C were divided into three groups per week for six weeks, and three sets of contractions for five seconds per group were performed five times, and a minute break was provided between each exercise. As a measurement tool, a wireless surface electromyography (EMG) was used to measure surface electromyography (Telemyo-DTS, NORAXON, USA) that derives a synthetic unit of muscle using a surface electrode. For statistical processing of data, the analysis is performed using the SPSS/PC Version 25.0 statistical program for Windows, and the statistical significance level is a=.05 Results : First, the duration was somewhat shorter in order to more accurately compare the muscle activity of the core muscles. Therefore, future research needs to be research that can be exercises with precise biofeedback and taping applied over a longer period of time. Secondly, it is believed that there is no significant difference, since the subjects were studied in healthy young adult men and women, not patients. Thirdly, they could not control the daily life of the subjects. Through future research, it is necessary to analyze the correlation between muscle activity and abdominal muscle thickness by adding ultrasound in addition to muscle activity in various age groups. Conclusion : During draw-in bridge exercise according to feedback, the muscle activity of the back muscle increased, and there was no significant difference in the muscle activity of the back muscle according to each feedback. Therefore, both the feedback applied during the draw-in pier exercise and the control group are effective in changing the thickness of the abdominal muscles.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.23-28
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• 2019

Wire breakage in drawing, which is the most critical process in glass fiber manufacturing, is caused by numerous factors such as height, drawing speed, and air flow. The vibrations of the draw tower, however, is the most dominant factor to create the wire breakage. In this study, the structure of a draw tower has been analyzed through experiments and computer simulations to figure out the main reasons of the vibrations. And the design alterations were applied to the machine to identify the effects of those alterations. The result shows that design alterations of the draw tower structure can suppress the 87% of the vibrations, and further can prevent the wire breakage.

• Textile Coloration and Finishing
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• v.20 no.1
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• pp.28-35
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• 2008

Texturing is the process of including a characteristic of a natural fiber in a synthetic fiber. The most common method of it the false twist texturing. Nylon textured yarn is primarily manufactured by the disk type. The major process parameters or the disk type false twist machine ratio, disk/yarn, and heater temperature. This study therefore investigated the effects of false twist texturing, especially speed and draw ratio, on the physical properties of nylon textured yarn. The increase of speed was proportional to the increase of unwinding tension, which could reduce the production efficiency by elevating the tension affecting to fiber during the process. In addition, the increase of speed was inversely proportional to the increase of crimp rigidity of nylon textured yarn. Draw ratio was proportionally increased with the increase of tenacity and the reductions of fineness and elongation, showing the influence or draw ratio to the ultimate physical properties of textured yarn.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.149-154
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• 2010

Intentional draw and fade shots could be good weapons for lowering golf score. But how to make such shots? To investigate deterministic variables generating different projectile paths of shots in square stance was the purpose of this study. Ten right-handed male collegiate athletes, showing 1.3 of averaged handicap, participated in this study. They were asked to intentionally perform three different shots such as the straight shot(control condition), draw shot, and fade shot. Swing path, pelvis rotation angle, thorax rotation angle and left forearm supination angle were determined for dependent variables on impact event at each trial. For statistical analysis one-way repeated measures ANOVA were used. The results showed that swing path was one of main factor making differences among three kind of shots. Straight shot vs. Draw shot, Straight shot vs. Fade shot and Draw shot vs. Fade shot showed differences on swing path. And left forearm supination angle revealed significant difference between draw shot and fade shot, showing a significant larger angle of draw shot than fade shot. No other significant difference was detected for the other variables. We found that the shot characteristics were influenced primarily by swing path and left forearm supination angle.

• Textile Coloration and Finishing
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• v.3 no.1
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• pp.8-16
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• 1991

In order to investigate the fine structure of PET films, PET films were stretchd at various draw ratios (2, 3, 4, 5) below $T_g$ ($72^{\circ}C$) and then annealed at various temperatures (125, 150, 175, $200^{\circ}C$) under free-annealed (FA) and taut-annealed (TA) conditions. Such changes as thermal shrinkage, crystallinity, crystallite size, dynamic viscoelasticity and thermal behaviour were measured in relation to the draw ratio and annealing condition.The following results were obtained. 1. Thermal shirinkage increased with increasing annealing temperature and draw ratio, but decreased in case of draw ratio 4 (draw ratio 3 at $200^{\circ}C$) and above it. 2. The degree of crystallinity of FA samples were higher than those of TA samples. 3. Tan 5 of TA samples were less than those of FA samples, and storage moduli (E') and loss moduli (E") of FA samples were less than those of TA samples; moreover, maximum tan '||'&'||' temperature of FA samples were shifted toward higher temperature than those of TA samples. 4. The melting endotherm ($T_m$) and heat of fusion $(\DeltaH)$ of the PET film increased with the draw ratio and annealing temperature; in addition, premelting endotherm ($T_m$) and heat of fusion $(\DeltaH)$ of the local crystallization in the FA samples were larger than those of TA samples. 5. The X-ray diffraction pattern displayed sharp peaks gradually with the draw ratio and annealing temperature. 6. Crystallite sizes of FA samples were larger than those of TA samples.

• Polymer(Korea)
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• v.26 no.3
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• pp.335-343
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• 2002

Blend resin (PET/PETG 70/30 blend) of poly (ethylene terephthalate) (PET) and poly (ethylene terephthalate glycol) (PETG) of weight percent 70/30 was prepared by a twin-screw extruder. Undrawn films of the blend and pure PETG were made by melt-press in hot press. Drawn films were made by capillary rheometer. Crystallinity, shrinkage, thermal, dynamic mechanical, and mechanical properties of these blends and PETG drawn films were investigated by wide angle X-ray diffractometer, dry oven, DSC thermal analyzer, and tensile tester. The crystallinity and density of these films increased with increasing draw ratio and draw rate but decreased with increasing draw temperature. The crystallinity and density of the blend films were higher than those of PETG films. The tensile strength and tensile modulus of these drawn alms increased with increasing draw ratio and draw rate but decreased with increasing draw temperature. The tensile strength and tensile modulus of blend films were higher than those of PETG films. Shrinkage of PETG md blend films decreased with draw ratio and draw rate. Shrinkage of undrawn blend film was 600% higher than that of pure PET film.

• Journal of Mechanical Science and Technology
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• v.19 no.8
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• pp.1582-1596
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• 2005

Groundwater flow and behavior have to be investigated based on heterogeneous subsurface formation since the homogeneity assumption of this formation is not valid. Over the past twenty years, stochastic approach and Monte Carlo technique have been utilized very efficiently to understand the groundwater flow behavior. However, these techniques require lots of computational and numerical efforts according to the various researchers' comments. Therefore, utilizing new techniques with much less computational efforts such as Artificial Neural Network (ANN) in the prediction of the stochastic behavior for the groundwater based on heterogeneous subsurface formation is highly appreciated. The current paper introduces the ANN technique to investigate and predict the stochastic behavior of a well draw down in a confined aquifer based on subsurface heterogeneous hydraulic conductivity. Several ANN models are developed in this research to predict the unsteady two dimensional well draw down and its stochastic characteristics in a confined aquifer. The results of this study showed that ANN method with less computational efforts was very efficiently capable of simulating and predicting the stochastic behavior of the well draw down resulted from the continuous constant pumping in the middle of a confined aquifer with subsurface heterogeneous hydraulic conductivity.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.62-69
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• 2003

In most shipyards, the measurement of 3-dimensional relative position of pipes should be connected in the block depends on the manual operation. It results a very tedious and inefficient procedure, thus the proper measurement system is needed to improve productivity and accuracy. This paper describes the development of pipe measurement system including system concepts, measuring procedures, system calibration, and its accuracy and productivity. And also, the possibility and things to be improved for application in shipyard are discussed in this paper.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.201-212
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• 1992

The plane strain analysis for simulating the stretch/draw forming operation of arbitrarily-shaped tool profiles and arbitrarily draw-in conditions is introduced. An implicit, incremental, updated Lagrangian formulation is employed, introducing a rigid-viscoplastic constitutive equation. Contact and friction are considered through the mesh-normal, which compatibly describes arbitrary tool surfaces and FEM meshe without depending on the explicit spatial derivatives of tool surfaces. The FEM formulation is tested in the sections automotive inner panel and two-side draw-in. Not only the excellent agreement between measured and computed strains in the stretched section is obtained, but also the numerical stability of current formulation is verified in the two-side draw-in section.