• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.83-87
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• 1995

Impact-bouncing height of steel balls dropped from 1m height on various floor materials were measured to evaluate impact-bouncing characteristics depending on floor materials and the effect of these properties on walkability and fatigue of humanbody. Stone and tile finished concrete floor showed the highest bouncing height of around 70%, and soil showed the lowest bouncing height of around 3%. The second highest bouncing height was about 40% which corresponded to terazo finished concrete floor and about twice as high as the bouncing height on concrete floor without finishing. The impact-bouncing height could be lowered to 15~20% by using gum tile on concrete floor. Steel showed similar bouncing height to concrete floor, and wood-based materials showed the second lowest bouncing height next to soil. Among wood-based materials, hardwood species having higher specific gravities showed relatively high bouncing height of 8~24%, softwood species having low specific gravities showed relatively lower bouncing height of 5~18%, and wood composites showed bouncing height of 8~18%. Among all the materials used in this study, wood-based floor materials corresponded to the bouncing height of 10~15% which is considered to be best for humanbody. Surface painting on wood-based materials increased the bouncing height, and the number of bouncing of steel balls after dropping from 1m height increased as the bouncing height increased.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.225-230
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• 2001

Morphological characteristics of the asymmetric mandible in 135 adult male patients were investigated. Panoramic X-ray images were recorded. Age, ramus height, antegonial notch height, condylar height, coronoid process height, ramus body height and condylar neck angle were calculated and measured. Statistical analysis of unpaired two-tailed t-test and correlation coefficients was performed to find the morphologic differences between short ramus height side and the other. Condylar height and ramus body height in short ramus height side were smaller than those of the other side. Antegonial notch height, coronoid process height, condylar neck angle showed no differences. Condylar neck height was correlated with condylar neck angle.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.124-133
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• 1995

A field study was conducted to assess the preferred height and the range of discomfort recognition of school desks and chairs for students from elementary school to high school. For this study 43 male subjects and 44 female subjects in Taejon area were surveyed. The result shows that the preferred height of chairs is about 1.7cm higher than the popliteal sitting height, while the preferred height of desks shows no significant difference with the elbow sitting height which is known to be the ergonomically proper desk height. The threshold value between comfort and discomfort recognition of chair height is 1.88cm below the most prefeered height and 1.79cm about it. The threshold value between comfort and discomfort recognition of desk height is 1.76cm below the most prefeered height and 2.62cm about it.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.109-123
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• 1981

The author studied and analyzed statistically 112 adults female ranging in age from 18 to 20 years with normal occlusion, 56 adults female ranging in age from 18 to 24 years with deep overbite and 53 adults female ranging in age from 18 to 28 years with open bite by vertical cephalometric analysis. The results were as follows; 1. In comparing normal occlusion with deep overbite and open bite, skeletal linear measurements were more significant than dentoalveolar linear measurements. SN-MP angle, SN-OP angle, PP-OP angle and Xi angle (ANS-Xi-Pog) were significant in anglular measurements. 2. Upper posterior facial height (SE-PNS), upper anterior alveolar height, lower posterior alveolar height, lower posterior alveolar height/lower anterior alveolar height and SN-PP angle were non significant between deep overbite and open bite. 3 The most significant items between deep overbite and open bite were lower anterior facial height (ANS-ME) and SN-MP angle. 4. Correlation coefficients of angular measurements were higher in deep overbite, while that of linear measurement total anterior facial height (N-ME) was higher in open bite. 5. In the multiple regression equation, significant variables were total anterior facial height (N-ME), lower anterior alveolar height, upper anterior alveolar height, upper posterior alveolar height, Xi angle (ANS-Xi-Pog) and ramus height (AR-Go) in deep overbite, and total anterior facial height (N-Me), lower anterior alveolar height, ramus height (AR-Go), lower posterior alveolar height, PP-MP angle and upper posterior facial height (SE-PNS) in open bite.

• Korean Institute of Interior Design Journal
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• v.15 no.1 s.54
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• pp.88-97
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• 2006

The purpose of this study was to provide a guideline for the bathroom fixtures of the aged by examining current status. The study has been carried out by measuring physical size of 50 aged peoples over 65 years old and their bathroom fixture status. The results were revealed as follows; 1. The height of washstand is $0.46\~0.52$ time of person's height. Adequate height of wash stand is proposed as $74\~80$ cm. The height of current market available wash stand is very close to the proposed size. 2. The height of toilet is $0.23\~0.27$ time of person's height. Adequate height of toilet is proposed as $38\~41$ cm. The height of current market available toilet is also very close to the proposed size. 3. The height of bathtub is $0.26\~0.35$ time of person's height. Adequate height of bath tub is proposed as $45\~49$ cm. The proposed height is higher than that of current bath tub available in the market. However, it should be noted that the proposed height is the sum of bath tub it self and elevation during actual installation. As stated above, it is revealed that the physical dimensions of the bathroom fixtures in the current market are properly sized. However, to draw more practical guideline for the bathroom fixture, more studies including actual experimentation will be required in the future.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.211-217
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• 2019

This study is designed to reduce worker fatigue, improve efficiency and provide a functional working environment based on previous studies that pain occurs in the shoulder area, especially the upper trapezius muscle, when the keyboard height is not appropriate. In this study, the height of the keyboard is four, the height of the elbow and desk is the same height, the height of the desk is 3cm lower than the elbow, the height of the desk is 6cm high, and the height is 9cm high. When working on the keyboard, the wrist and forerunner were organized into four groups of 10 people so that the height was different for each group. When the height of the keyboard is given in various ways compared to the height of the elbow of the subject, it is verified whether there is a difference in the RMS (Root Mean Square) of the upper trapezius muscle. The results of this study showed that the muscle activity of the upper trapezius muscle cap was significant only in the left and right keyboard height -4cm, 0cm, +4cm, +8cm group, but the difference in muscle activity was not significant in the rest group. The first study will require a study of the control of the factors affecting the tension of the subjects, the measurement of muscle activity against various muscles, and whether the length of the shoulder and fingertips of the subject affect muscle activity according to the keyboard type.

• Journal of the Ergonomics Society of Korea
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• v.14 no.2
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• pp.41-50
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• 1995

A field study was conducted to assess the preferred height and the range of discomfort recognition of school desks and chairs for students from elementary school to high school. For this study 43 male subjects and 44 female subjects in Taejon metropolitan area were surveyed. The result showed that the preferred height of chairs were found to be about 1.7cm higher than the popliteal sitting height, while the preferred height of desks showed no significant difference with the elbow sitting height which is known to be the ergonomically proper desk height. The threshold value between comfort and discomfort recognition of chair heigth was 1.88cm below the most preferred height and 1.79cm above it. The threshold value between comfort and discomfort recognition of desk height was 1.76cm below the most preferred height and 2.62cm above it.

• The Journal of Pediatrics of Korean Medicine
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• v.28 no.1
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• pp.43-51
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• 2014

Objectives The purpose of this study is to find out the relationship between mid parental height (MPH), birth weight, current growth condition of children (height, weight, BMI, body fat percentage, bone age) and final height of the future. Methods The study was conducted with 237 children, who were 12 - 14 years old. They were analyzed to find out the relationship between MPH, birth weight, height, current weight, BMI, body fat percentage, bone age and predicted height. Results 1. As MPH was increased, height and predicted height were also increased. As MPHs in girls were increased, 'bone age - chronological age' were decreased. As MPHs in girls were increased, body fat percentages were decreased. 2. As birth weights were increased, height, weight, BMI and body fat percentages were also increased in boys. 3. As body fat percentage was increased, predicted height was decreased. As 'bone age - chronological age' was increased, predicted height was decreased. As BMI was increased, 'bone age - chronological age' was increased. As body fat percentages in boys were increased, heights were decreased. As body fat percentages in girls were increased, 'bone age - chronological age' were increased. Conclusions MPH, birth weight, current growth condition (height, weight, BMI, body fat percentage, bone age) and predicted height are correlated to each other. There are some differences between boys and girls in these relationships.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1218-1224
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• 2000

A half-height waveguide power combiner is designed and analyzed for Ka-band satellite application. The branch line directional coupler is utilized as a power combiner to achieve high port-to-port isolation and low insertion loss. The half height waveguide is adopted to reduce the volume and mass of a power combiner. In this paper a half height waveguide power combiner is designed and analyzed by FDTD and its performance is compared with that of a full-height waveguide power combiner. The designed half-height combiner having optimum order is manufactured and tested. The measurement shows that the designed half-height power combiner satisfies all the performance requirements (insertion loss less than 0.3 dB, reflection loss more than 20dB, port to port isolation more than 20 dB, and port to port phase difference within 5$^{\circ}$) in the satellite communication frequency band of 20.255 GHz to 21.255 GHz.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.27-41
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• 2008

Purpose : The purpose of this study was to supply basic data for the impact on the accuracy of basic CPR according to position and foot-board height of basic CPR provider. Methods : Study design was within - group design. Subjects were 25 EMT-P Students in K city. Interventions was basic CPR performed on a resuscitation manikin placed on a hospital bed, kneeling on the bed adjacent to the manikin. Data was analyzed using descriptive statistics and Friedman test. Results : In case of the basic CPR performed on a resuscitation manikin placed on a hospital bed, ventilation accuracy was the highest in less than 160 cm height, foot-board height : $34.2{\pm}1.48cm$, 91.4% and in 161-165 cm height, foot-board height : $26.0{\pm}2.14cm$, 88.4% and in 171-175 cm height, foot-board height : $23.0{\pm}1.41cm$, 91.3% and in the above 176 cm, kneeling on the bed, 95%. Chest compression accuracy was the highest in less than 160 cm height, foot-board height : $30.2{\pm}1.48cm$, 95.6% and in 161-165 cm height, kneeling on the bed, 97.6% and in 171-175 cm height, kneeling on the bed, 98.5% and in the above 176 cm, kneeling on the bed, 98.7% and foot-board height : $20.5{\pm}1.91cm$, 98.7%. Chest compression error was due to too weak : 2.0-35.4 times. There were ststistically significant differences in 191-195 cm group according to chest compression mean depths($x^2=10.824$, p = .013) and chest compression error (p = .040). Conclusion : In contrast to current guidelines, the position and foot-board height of basic CPR provider are very important to the accuracy of the basic CPR. Furthermore, we recommend that a using real time audiovisual feedaback system significantly improve the quality of chest compression and ventilation during resuscitation.