• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.210-213
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• 1995

In this study,the effect of both process parameters (wheel velocity, friction coefficients between die and billet, etc) and die-shape (abutment height and shape, flash gap, etc.) on the surface defect on forming process is theoretically investigated. For this work, computer simulation was performed by using the DEFORM, a commercial FEM code. Through numerous simulations with different parameters and die shapes, We propose one optimal die shape for CONFORM process which can remove surface defect.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.260-263
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• 1996

THe Purpose of this paper is to match the feature point of man-made structure and to obtain the DEM which are occluded in a image plane. We use the trinocular matching with epipolar lines and planes. If an occlusion appears at one of the trinocular images, the DEM mapping is used to estimate the height of feature points in it.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.90-97
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• 2022

This study was carried out to investigate the effect of side vent heights on temperature and relative humidity inside and outside the single-span plastic greenhouse (W: 7 m, L: 40 m H: 3.9 m) during natural ventilation. Four different heights (120, 100, 80, 60 cm) of the side vent were used as an experimental condition. Variations of temperature and relative humidity inside and outside the greenhouse and the differences between heights were compared by using one-way ANOVA. In the daytime, the difference in temperature between inside and outside the greenhouse was dropped from 14.0℃ to 7.1℃ as the side vent height increased. The temperature difference in the nighttime was less than 0.2℃ regardless of the height. One-way ANOVA on the temperature difference between heights presented that the statistical significance was founded between all of the combinations of height in the daytime. The difference in relative humidity between inside and outside the greenhouse was grown from -13.8% to -22.2% with a decrease in the side vent height. The humidity difference in the nighttime was less than 1% regardless of the height. One-way ANOVA on the humidity difference revealed that most of the side vent heights showed significance in the daytime but between 100 and 80 cm was not significant. It seemed because the external air became cooler during the experiment with a height of 80 cm. Conclusively, this study empirically demonstrated that the higher side vents resulted in the decrease of differences in temperature and relative humidity between inside and outside the greenhouse, and also the effect of side vent height was statistically significant. This study may be helpful for deciding the height of the side vent effective for controlling temperature and relative humidity in a single-span greenhouse during natural ventilation.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.184-195
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• 2017

Baseball is a life sport that gives vitality to people. However, currently available leg guards do not have a variety of sizes and it is very difficult to purchase a leg guard that is suitable for the size of a specific consumer. Therefore, this study investigated the size system of a leg guard sold in the market and suggested a grading deviation suitable for the legs of Korean males. The results of the study were as follows. First, most brands were sold only in three size systems as children's, teenagers, and adults. Adult size systems were not subdivided. Second, Korean male legs were classified into Group 1 (large girth and height and lower body muscle) and Group 2 (small girth and height and low underbody muscle). Third, the size system is based on vertical items such as height and mid-thigh circumference. Each group produced 10 sizes. The smallest height or the largest height was also found to be about 4.5 to 5.0cm smaller or larger than the sample size for each group. The total length of the leg guard was about 2.5cm when the height was increased or decreased by one size. It was confirmed that the deviation of the circumference of the mid-thigh should be about 2.0cm larger or smaller than the sample size even if the height is the same. The deviation of the knee circumference and ankle circumference was smaller than the other circumference. In conclusion, the dimension combinations of the leg guard must be set differently to provide a leg guard with high size suitability according to leg type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.476-482
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• 2017

This study examined the effects of the seat height of a chair on the muscle activity of the erector spinae and rectus abdominis. Thirty healthy subjects were asked to sit on chairs at three different seat heights. The muscle activities of both the erector spinae and rectus abdominis were measured by surface electromyography. The data were analyzed by repeated one way ANOVA and the muscle activity was compared according to the seat height. The alpha level was set to 0.05. The results showed that the muscle activities of the erector spinae were not significantly different among the three seat heights. The muscle activities of the rectus abdominis were significantly different among the three seat heights. Both the rectus abdominis muscle activities were significantly greater in the low seat height than the other seat heights. These results showed that the seat height of the chair affects the muscle activities of the rectus abdominis muscle, leading to musculoskeletal pain, such as low back pain. Therefore, the seat height of a chair with a correct sitting position is important for preventing musculoskeletal pain.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.529-541
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• 1993

The purpose of this study was to investigate not only the variability in the timing and amount of the maximum pubertal spurt in cranial base and mandible, but also its interrelationship with the timing of peak height velocity. This study was carried out by analysing biannual serial lateral cephalometric radiographs of twenty-six males and twenty-one females who were taken from 8.5years to 16.5years old of mean age, according to the established land-marks and linear measurements. The results of this study were summarized as follows. 1. Prevalance of the maximum growth spurt more than 80 percentage was occurred in all measurements of cranial base and mandible, except posterior cranial base length in the female. 2. In all measurements of cranial base and mandible, the maximum spurt was occurred earlier in the female than the male while it was greater in male in all measurements except ramal height. 3. In body height measurement, the peak height velocity was occurred 2 years earlier for the female(11.0 years old) than the male(13.0 years old). 4. The timing of maximum spurt in anterior cranial base length and total mandibular length in both sexes and ramal height in the female were coincided with PHV. The maximum spurt was occurred in both sexes in all measurements 2 years before or after PHV, except mandibular body length and posterior cranial base length the in female. 5. In all ages, there was significant correlation between the total mandibular length and ramal height, and was also correlation between total cranial base length and anterior cranial base length(P<0.05). However, there was no significant correlation between the ramal height and mandibular body length. In addition, there was also no any correlation between the anterior cranial base length and posterior cranial base length in all ages(P>0.05).

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.3
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• pp.443-453
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• 2008

The purpose of this study was to identify the perception between real and ideal body shapes of college students and to investigate the preferred body shape of college students. The research subjects numbered one hundred forty five male and female students, aged 20 to 29, who lived in Gwangju and Chonnam province. The anthropometric data was collected including both direct and indirect measurements. The data was analyzed by mean and standard deviation, t-test, and factor analysis. The results of t-test showed the significant difference($p{\leq}.001$) between real body size and ideal body size. The result showed that male students want to have bigger chest circumference and a taller height than their real body, the research also showed that the female students want to have a narrow bust and hip width along with a taller height than real body. Regarding ideal body shape, male students pursued bigger height and want an inverted-triangle body shape. On the other hand, female students pursued bigger height and slim body shape. This study established the factors(dimension of torso, height, the side shape of torso, and shoulder shape) as the perception between real and ideal body shapes. In terms of real body, the factor analysis shows two contrasting results in which the height is the most important factor for female students, while the torso dimension is the most important factor for male students. In terms of ideal body, the height factor is the most important for both the male and female students.

• Design & Manufacturing
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• v.11 no.3
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• pp.46-50
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• 2017

Press processing is one of the best machining methods capable of mass production, satisfying dimensional, shape and quality among the methods of processing a metal plate. Among them, Fine blanking is a method of obtaining a precise cross-section such as machining of the shear surface shape. In this research, Using SCP-1 and SHP-1 materials. The deformation behaviors of the material flow affecting the die height of the shear section in accordance with the position of the V-ring in the Fine blanking were compared and analyzed. Result of interpretation, It was confirmed that the force acts on the position where the material flow direction accurately forms the die roll that the material of SCP-1 is at a position of 1.5 mm and the material of SHP-1 is at 2.0 mm. As a result, it was confirmed that the state of fo1111ing the shear surface by the V-ring was excellent. Using analysis results, In the experiment, the height of the die roll was considered by applying The position of the V-ring was 1.5 mm in SCP-1 and 2.0 mm in SHP-1. As a result of comparing the height of the die rolls, the height values of the die rolls were different from each other, It has been considered that the tendency of the die rolls to coincide with each other. It is considered that the difference of the die roll height is caused by the pressure input of the V-ring. In this study, the deformation behavior of the material(In addition to the position of the V-ring, the flow direction of the material depends on the shape of the V-ring and the Indentation amount) is considered to be an important factor in determining die roll height.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.15-20
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• 2018

This study aimed to find an effective intervention measure through establishing the correlation between self-regulation (control over life style) and height growth through neuro-feedback training. 40 elementary students in grades two to four with height growth programs (20 experimental group students, 20 control group students) were examined for the changes before and after undergoing neuro-feedback training. The experiment lasted for three months with one 30-minute training session two times a week. After analyzing the differences in self-regulation among the control group with no neuro-feedback training and the experimental group with neuro-feedback training, the differences in height growth were analyzed. First of all, there were positive changes in self-regulation of the experimental group compared with the control group. Secondly, the experimental group showed larger changes in height growth. In conclusion, neuro-feedback training had positive effects upon the self-regulation that adjusts the acquired factors of height growth, which led to positive effects.

• Journal of Drive and Control
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• v.18 no.4
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• pp.19-27
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• 2021

A bunker bed is a type of furniture that efficiently utilizes a narrow indoor space by having a high bed and using the empty space below as a living and storage space. The demand for multi-purpose furniture is increasing due to the recent increase in single-person households and wide-spread shared accommodation. According to the consumer research, one of the major drawbacks of a bunker bed was to get on and off the bed through a ladder or stairs. In order to overcome these problems, it was confirmed that the height adjustment function that can easily adjust the minimum and maximum heights of the bed was necessary. In this study, a height adjustable bunker bed was designed by using a gas spring that generates a repulsive force by the compressed gas inside. The design process consisted of the following three steps: Firstly, the hysteresis characteristics due to a friction and spring constant of a commercial gas spring were confirmed by measuring the repulsive force vs. compressed displacement. Secondly, requirements of the vertical lifting force exerted on the bed against gravity force were derived. Finally, the height-adjustable bed using the four-bar link mechanism was designed with 4 parameters so that the bed weight of 60-70 kgf could be adjusted to 800 mm in height by an affordable initial operation force. The performance was verified through prototype production and the results of vertical displacement and force to move were nearly the same as designed. In addition, an electrically operated height-adjustable bed was also designed with linear actuators and the performance was proved with the prototype.