• Journal of the Ergonomics Society of Korea
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• v.7 no.1
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• pp.21-30
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• 1988

The investigation of the surface areas, volumes and sizes (circumference, length, breadth) changes has been performed on women during menstruation, non-menstruation, pregnancy and post-pregnancy periods. (1) During menstruation and non-menstruation periods: The subjects were 30 healthy women from 19 to 24 years of age. The changes of lower leg areas were measured using the paper replacement method, showing an increase of 0.71% in surface during the menstruation period. The changes of lower 1g volumes were measured by the water replacement method, showing an increase of 1,74% in volume during the menstruation period. The correlation between the surface area changes and the volume changes was of r=0.45. The greatest change among the four parts of the leg was found at the ankle in both experiments. We measured also the foot length(1), the ball of foot girth(2), the foot breadth(3), the instep height (4), the instep girth(5), the ankle girth(6), the calf circumference(7) and we found the greatest changes in(4)=3,92% in(5)=0.79% and in (7) =0.84%. (2) During pregnancy and post-pregnancy periods: The subjects were 3 women, two pregnants(both from the 24th to the 36th week of pregnancy during the experiment) and one post-pregnant(from the second week to the eighth week during the expriment). For the first two subjects, we measured only the last 6 items of the preceding experiments(foot length(1),ball of foot girth(2), (3), (5), (6), (7)), Showing the greatest changes in the instep girth(5) and the calf circumference(7). In the case of the post-pregnant subject, these two items (5) and(7) decreased sharply during the second, third and fourth week and remain approximately the same afterwards.

• Geomechanics and Engineering
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• v.33 no.6
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• pp.529-542
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• 2023

Wave propagation with high transverse deflection could affect the stability of the ball in its trajectory. For low stiffness balls similar to soccer and volleyball balls, the waves are more noticeable in comparison to other balls like ping-pong ball. On the other hand, the soccer balls are under heavy impact loads from shoots and contacting different objects in the field. The maximum recorded speed of a soccer ball after kicking is the 211 km/hr and the average maximum speed is around 112 km/hr. Therefore, in such speeds the aerodynamic forces become important which are directly related to geometrical shape of the ball. In this regard, the wave propagation in soccer ball is examined in the current study using large deformation shear deformable formulations. Classical relations of stress-strain components are taken into consideration along with minimum total energy principle. The final derived relations were solved by using harmonic differential quadrature method. The results are generally presented ion term of phase velocity as function of different influencing parameters of the materials, geometry and mass of the ball.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.13-24
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• 2005

The purpose of this study was to compare kinematic data between experts and novices, and identify difference kinematic parameters changing direction to kick in penalty kick of soccer play. Novice subjects were 5 high school students Who has never been experienced a soccer player, and expert subjects were 5 competitive high school soccer players. The 3-d angle was calculated by Euler's Angle by inertial axis and local axis with three-dimensional cinematography. Kinematic parameters in this study consisted of angles of knee joints, hip joints, lower trunk and upper trunk when the support foot was contacted on ground and kicking foot impacted the ball. The difference of angle of knee joints in the flexion/extension was insignificantly showed below $4{\sim}9^{\circ}$ in groups and directions of ball at the time of support and impact. But the difference of angle of hip joint was significant in groups and directions of ball at the time of support and impact. Specially the right hip joint of experts were more flexed about $12^{\circ}$($43.99{\pm}6.17^{\circ}$ at left side, $31.87{\pm}4.49^{\circ}$ at right side), less abducted about $10^{\circ}$ ($-31.27{\pm}4.49^{\circ}$ at left side, $-41.97{\pm}6.67^{\circ}$ at right side) at impact when they kicked a ball to the left side of goalpost. The difference of amplitude angle in the trunk was significantly shown at upper trunk not lower trunk. The upper trunk was external rotated about $30^{\circ}$ (novice' angle was $-16.3{\pm}17.08^{\circ}$, expert's angle was $-43.73{\pm}12.79^{\circ}$) at impact. Therefore the significant difference of kinematic characteristics could be found at the right hip joint and the upper trunk at penalty kick depending on the direction of kicking.

• The Research Journal of the Costume Culture
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• v.25 no.2
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• pp.175-191
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• 2017

The purpose of this study is to analyze the body mass index(BMI) and foot characteristics of senior-generation women and to use those values to develop a standard shoe last for producing shoes that best fit the foot of senior-generation women. In order to develop a standard shoe last that reflects the BMI and foot characteristics of senior-generation women, I analyzed the morphometric characteristics of feet by conducting descriptive statistics for each item. The foot characteristics based on BMI were analyzed by conducting ANOVA and Duncan's tests via the foot's measured values. Subsequently, I developed a standard shoe last reflecting the BMI and the foot characteristics of senior-generation women by applying all those values. Senior-generation women showed significant differences among three groups based on BMI-normal weight, overweight, and obese-in all the items except for medial ball width and toe 5 angle. Through these values, I realized that as the value of the BMI becomes higher, the size of the foot becomes larger. This suggests that as a woman's weight increases or decreases, her shoes need to be replaced as well as her clothes. Deviations in the toe-side parts of the shoe could cause deformation of the foot. If someone keeps wearing shoes produced using a shoe last with a large deviation, she risks developing foot conditions like hallux valgus. This situation points to the need for shoe manufacture that utilizes a standard shoe last that reflects the BMI and foot characteristics of the senior generation.

• Korean Journal of Veterinary Service
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• v.38 no.4
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• pp.211-220
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• 2015

Many chemical disinfectants are using to protect the foot and mouth disease (FMD) and avian influenza (AI) in Korea since 2000. This study was performed to confirm disinfective ability of commercialized chemical disinfectants and to investigate the sterilizing ability of E-ball as alterative to chemical disinfectants. 4 kinds of acidulant, 3 kinds of aldehyde, 1 kind of oxidizer and 300 g of E-ball were used in this study. Dilution rate of disinfective power of all chemical disinfectants were to 200 times. The sterilizing ability of aldehydes were better than the acidulant and oxidizer with Salmonella typhimurium. The sterilizing ability of E-ball treated solution was guessed due to the friction of E-ball deads. In the case of the friction of 2 beads of E-ball, Salmonella typhimurium was sterilizted on $1{\times}10^6/mL$ CFU in the E-ball treated solution. The E-ball treated solution had superior sterizing power compared with the chemical disinfectants in the bacteria of soil for antibacterial examination. E-ball treated solution has a possibility as the substitute of chemical disinfectants to protective the animal diseases contains FMD, AI.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.58-66
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• 2005

Usual human gait can be modeled as continual impact phenomenon that happens due to the topological change of the kinematic structure of the two feet. The human being adapts his own control algorithm to minimize the ill effect due to the collision with the environment. In order to operate a Humanoid robot like the human being, it is necessary to understand the physics of the impact and to derive an analytical model of the impact. In this paper, specially, we focus on impact analysis of the kicking motion in playing soccer. At the instant of impact, the external impulse exerted on the ball by the foot is an important property. Initially, we introduce the complete external impulse model of the lower-extremity of the human body and analyze the external impulses for several kicking postures of the lower-extremity. Secondly, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, will be introduced. The aerodynamic effect such as drag force and lift force is also considered. We carry out numerical simulation and experimentation to verify the effectiveness of the proposed analytical methodology.

• Journal of the Korean housing association
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• v.14 no.5
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• pp.105-116
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• 2003

The purpose of this study is to suggest the method of prevention of staircase accidents, and to make housing environment better through researching the dimension of a housing staircase for Korean. The scope and method of this thesis is to investigate the dimension limits of a staircase (slope, minimum width of tread, maximum height of riser), and to analyze the characteristics of foot condition (jutting rate, foot angle, ball joint, nosing clearance, clearance distance) using the experiment which takes a photograph of foot motion during walking stairs. The results of this thesis are as follows. The slope of a staircase in house is $32.3^{\circ}$$^{\circ}$-$42.1^{\circ}$$^{\circ}$. The riser should be less than 190 mm. The minimum size of tread is 210 mm and proper size is 270 mm.

• Korean Journal of Applied Biomechanics
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• v.13 no.1
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• pp.173-184
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• 2003

The purpose of this study was to investigate the batting characteristics in elite baseball players. Seven skilled collegiate players hit the ball which was thrown by a pitching machine linearly and strongly to the center of the field. Time, velocity, angle and pound reaction force variables were measured by using high-speed video cameras and pound reaction force analyzer. The results were as follows: 1. The elite players finished their stride performance in a short time and they stayed longer in a swing phase. The increases in the range of trunk rotation were associated with the delay of the swing phase. 2. The 'take-back' phenomenon in the trunk was showed after the stride phase. 3. The down swing demonstrated powerful line drives. 4. Equivalent body weights were placed on both feet during the ready phase. 95% of the body weights were moved to the rear foot during the stride phase, whereas the body weights were driven to the front foot during the swing phase. 95% of the body weights were placed on the front foot at impact.

• Journal of Institute of Convergence Technology
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• v.7 no.1
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• pp.7-10
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• 2017

In general, the shoe stretcher is utilized to stretching the leather of shoe upper in the longitudinal direction. In the capstone design class, we tried to make a shoe leather stretcher for the ball of foot. Since a natural cow leather was recovered in length according to relaxation time after stretched, it was difficult to predict the initial amount of set up of stretching. In this paper, tensile and relaxation experiments were conducted in order to predict the amount of initial stretching for appropriate tensile length. Apparatus of leather stretching was designed and strains of leather were measured according to relaxation times of 12, 18, 24 hours after stretching of 24 hours. It was revealed that the ratio of the final relaxed strain and the initial applied strain was about 0.404 with R-square of 0.990 for a shoe cow leather.

• Journal of Veterinary Clinics
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• v.32 no.3
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• pp.268-271
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• 2015

About 2-year old northern goshawk (Accipiter gentilis) which is designated as natural monument (#323-1) in Republic of Korea was rescued by a local farmer and presented with a 2-weeks history of pain, swelling, stiffness and limping. On physical examination, plantar pododermatitis and digit IV weakness were observed. Radiographic findings also showed bone lyses with soft tissue swelling in the foot. A definite diagnosis was made as stage III bumble foot after multidisciplinary approach of the patient. Bacterial culture was performed, and concurrently antibiotic susceptibility testing is determined using wound site exudates specimen. Bacterial isolates were identified as Staphylococcus aureus, known normal skin flora. Treatment was initiated with surgical incision and necrotized tissues removal. Lavage-drainage and ball bandage were applied with topical mupirocin ointment application. Doughnut shaped pad was attached on bottom of the ball bandage to reduce weight bearing. After three weeks of intensive care, the wound site completely healed but digit IV weakness remained permanently. The goshawk returned to nature after eight weeks after treatment.