• Title/Summary/Keyword: Height Difference

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Measurement of Infinitesimal Delaminaton Thickness by Echo Amplitude of Ultrasonic Wave (초음파의 에코 높이를 이용한 미소(微小) 박리(剝離) 두께 측정에 관한 연구)

  • Han, E.K.;Jang, K.Y.;Hwang, B.I.;Lee, B.S.;Park, I.G.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.13 no.1
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    • pp.21-28
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    • 1993
  • If the infinitesimal delamination exists and the two waves can hardly be distinguished from each other on account of being much closer, we cannot measure the thickness of delamination by the time difference method. On this study, we calculated the thickness of infinitesimal delamination model by means of measuring echo height due to the deflection of material particles and utilized Newton Ring for optical measurement as a delamination model. From the result of Newton Ring expressed in the delamination model, we can calculate the infinitesimal delamination thickness up to $0.2{\sim}0.3{\mu}m$ due to the difference of acoustic impedance by the ratio of the echo height to the total reflection.

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THE STUDY FOR THE PROFILES OF MIXED DENTITION (한국인 아동의 측모에 관한 연구)

  • Park T. W.
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.8 no.1
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    • pp.17-21
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    • 1978
  • The study was to analyze on the hard and soft tissue profiles in mixed dentition. The subject consisted of 100 males and 100 females from 9 to 12 years of age and with a normal occlusion and acceptable profiles. On the basis of SnH line and SnV line, the author traced all the cephalograms and calculated the mean value and standard deviation in each measuring category and evaluated the sexual difference, the proper limit of development. The obtained results were as follows; 1. Individual variations of the lower facial part were larger the upper facial part in depth and height. 2. Sexual difference of lower facial part was significant in depth and height. 3. All the measured values to the SnH and SnV line were larger in male than in female but revealed resemblance in the profilogram. 4. The measured values of the region of nose, upper lip and point A showed stable tendency.

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Optimum Design of Suspension on Impulse to AGV (AGV가 받는 충격량에 대한 현가장치의 최적설계)

  • 김재헌;최환도;김중완;전언찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.361-365
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    • 2002
  • This research is presented for optimizing the coefficients of spring and damper by impulse which is applied to AGV when the two containers are loaded on AGV. The suspension is estimated to the condition that two containers, initial velocity of container, initial height of container and maximum of suspension stroke. The coefficients of spring and damper are calculated numerically through Newmark method uses finite difference expansions. The procedure of calculation is applied by one DOFs of mass-spring-damper system. The coefficients of spring and damper have large value as increase of height or decrease of stroke. The result of calculation is shown in graph and the investigation is used AGV design.

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Effect of Fertilizer Level of Organic Matter on Growth and Yield in Perilla (유기물의 시비량 차이가 잎들깨의 생장특성 및 수량 생산효과)

  • 하상영
    • Journal of Life Science
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    • v.9 no.4
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    • pp.481-488
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    • 1999
  • This study was conducted to survey some characteristics in growth of perilla by fertilization level organic matter. Corn stalk, acorn and chestnut were used as organic fertilizer in this study. In the height of perilla, chestnut fertilizer with 880kg/10a that R2 is 0.9996 showed the height level, and followed by acorn and corn stalk in order. Number of the harvested leaves was the highest in acorn among the three organic fertilizer by chestnut and corn stalk in order. However, number of the harvested leaves continuously was the highest in chestnut. Weight of a leaf was more effective at three kinds of organic fertilizer than control. There were no difference in the rate of dried leaf weight according to kinds of organic fertilizer. On the other hand, the rate of dried leaf weight by growth period was different. It was found that the rate of dried leaf in 30days or 110days. Diameter of perilla stem at 30cm above the ground according to kinds and fertilizer level of organic fertilizer was surveyed. However, the difference was not detected in this study.

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A Performance Comparison of Positioning Methods Considering Measurement Noise (측정 잡음을 고려한 위치 결정 기법의 성능비교)

  • Park, Chan-Sik;Yim, Jae-Geol
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.12
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    • pp.1176-1181
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    • 2010
  • This paper proposes three positioning algorithms using TOA measurements: 1) The well-known linearization method using Taylor series, 2) a modified Savarese method considering measurement noise, which does not need linearization, and 3) a modified Bancroft method where TOA measurements instead of pseudorange measurements are considered. Furthermore, through an error analysis, for Savarese method, divergence of altitude is anticipated if the transmitters are located at the same height. To prevent height divergence, the Savarese method is modified again for receivers which assumed moving on the even plane. Error analysis also shows the relationship between Bancroft and Savarese method. From the analysis it is expected that the performance of Savarese method is worse than Bancroft method because of error amplification during difference operation. Experiments using real TOA measurement from the time difference of ultra sound and RF validate the proposed methods and show that analysis is correct.

Optimum Design of Suspension in Loading Container on Trailer (컨테이너 상차 시 트레일러 현가장치의 최적설계)

  • Kim, Jae-Heon;Hong, Do-Kwan;Kim, Joong-Wan;Jeon, Un-Chan;Ahn, Chan-Woo
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.710-715
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    • 2001
  • This research is presented for optimizing the coefficients of spring and damper by impact load which is applied to a trailer when the containers are loaded up trailer. The procedure utilize the condition that two containers, initial velocity of container, initial height of container and maximum of suspension stroke. The coefficients of spring and damper are calculated numerically through Newmark method uses finite difference expansions. The procedure of calculation is applied by one DOFs of mass-spring-damper system. The coefficients of spring and damper have large value as increase of height or decrease of stroke. The result of calculation is investigated and is used AGV design.

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Theoretical Performance Analysis of a Modified Rectangular Fin (변형된 사각 핀의 이론적 성능해석)

  • 강형석;김영준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.8
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    • pp.683-690
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    • 2004
  • A modified rectangular fin is analyzed by two-dimensional analytic method and finite difference method. Relative error of heat loss from the modified rectangular fin between analytic method and finite difference method is presented. Comparisons of fin effectiveness and heat loss between a modified rectangular fin and a plane rectangular fin are made as a function of the non-dimensional fin length and wing height for different positions of wings by using analytic method. The ratio of the incremental rate of heat loss to that of the area of a modified rectangular fin is shown as a function of the wing height. One of the results shows that performance of a modified fin is more improved as the wing approaches the fin root.

A Study on the Changes of Vertical height in Teeth and Alveolar Bone with Age (증령에 따른 치아 및 치조골의 고경 변화에 관한 연구)

  • Se-Sook Kang;Kyung-Soo Han
    • Journal of Oral Medicine and Pain
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    • v.13 no.1
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    • pp.13-21
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    • 1988
  • The author studied the vertical height of tooth crown and the amounts of alveolar bone resorption with age. All 84 subjects(44 male, 40female) who visited Dental hospital of Wonkwang University with no history of sever periodontal disease and no experience of periodontal surgery. 84 subject were divided into 3 groups by age, that is, group I(28-32yrs), group II(38-42yrs), and group III(48-52yrs). Informal radiogram with bite wing film(horizontal angulation : $0^{\circ}$, vertical angulation : $+5^{\circ}~+10^{\circ}$) were taken on premolar and molar area. The distances from cusp tip to cementoenamel junction (vertical height of tooth crown) and from cementoenamel junction alveolar crest(amount of alveolar bone resorption) were measured, and then recorded data from 946 teeth were statistically analysed. This study was undertaken to obtain the data for age estimation by the changes of tooth crown height and alveolar bone resorption in the point of forensic odontology. The obtained results were as follows : 1. The average crown height of mandibular right 1st. molar was 7.1mm in group I, 6.7mm in group II, and 6.6mm group III, and the average amount of alveolar bone resorption on mandibular right 1st. molar were 1.8mm in group I, 2.5mm in group II, and 3.0mm in group III. Ratio of tooth crown height to amount of alveolar bone resorption was 4.0:1 in groupI, 2.7:1 in group II, and 2.2:1 in group III, the ratio was decreased with age. 2. In comparison with upper teeth and lower teeth in ipsilateral side, the average value of tooth crown height and amount of alveolar bone resorption were slightly higher in upper arch than those in lower arch, but there was not a statistically significant difference. 3. The ratio of height of tooth crown to amount of alveolar bone resorption was decreased with age, and which depended mainly upon the change of amount of alveolar bone resorption rather than the change of tooth crown height.

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Analysis of Factors Enhancing Growth Effect of Boyangsungjang-Tang (보양성장탕 (補陽成長湯) 투여의 성장효과를 높이는 요인 분석)

  • Hong, Hyo-Shin;Lee, Jin-Yong;Kim, Deog-Gon
    • The Journal of Pediatrics of Korean Medicine
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    • v.26 no.2
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    • pp.62-71
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    • 2012
  • Objectives The purpose of this study is to analyze factors that enhance growth effect after the administration of Boyangsungjang-Tang (補陽成長湯) to children and adolescents. Methods This clinical study has been carried out with 112 children and adolescents, who visited one University Oriental Medicine Hospital Pediatric department, from January 2009 to December 2010. They were treated on height-growth with Boyangsungjang-Tang (補陽成長湯). We used modified-intend to treat analysis to examine children who had their height and weight records six months after the treatment. We use PASW Statistics 18.0 to analyze what factors (Height percentile, Weight percentile, Age, Birth weight, Frequency of taking Medicine, Period of Treatment) enhanced the growth by using t-test, one-way ANOVA, Pearson's correlation analysis. Results The mean value of the height percentile were significantly increased, $2.83{\pm}10.04$ ($36.61{\pm}27.02$ to $39.44{\pm}26.89$, P=0.004). The height percentile difference has significantly correlated with weight percentile (P<0.001) and height percentile (P<0.05). Weight less than 50 percentile (P<0.05), and treatment period more than 15 months (P<0.05) had significant impact on the height percentile differences. Conclusions If we have treated more than 15 months of Boyangsungjang-Tang (補陽成長湯) to children and adolescents whose weight are less than 50 percentile, we would have expected their height percentile to increase as $5.72{\pm}10.64$.

Effects of Ramp Slope and Height on Usability and Physiology during Wheelchair Driving (경사로의 기울기와 높이에 따른 휠체어 사용자의 사용성 및 생리적 특성 분석)

  • Kim, Chung-Sik;Lee, Dong-Hun;Lee, Jee-Hea;Kwon, Sung-Hyuk;Chung, Min-K.
    • Journal of the Ergonomics Society of Korea
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    • v.29 no.4
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    • pp.681-686
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    • 2010
  • Although the height of a ramp is an important design element, it has not been considered in prior studies. Therefore, in this study, the ramp slope and height are considered as independent variables. To analyze the effects of the slope and height, five levels of slope (1:6, 1:8, 1:10, 1:12 and 1:14) and three levels of height (15cm, 30cm and 45cm) are considered. For the dependent variables, the total time, velocity and perceived discomfort were considered as usability measures, pulse rate changes and EMG signals of four related muscles (extensor carpi radialis, triceps brachii, anterior deltoid and posterior deltoid) were considered as physiology measures. As a result, differences among usability and physiological characteristic for the five slopes increased as the height increased. Additionally, slope effects were minor when the height was low (15cm). Almost domestic/international regulations and guidelines related to ramp recommended 1:12 slope for the ramp design, however, there was no significant difference between 1:10 and 1:12 according to result of this study. In addition, slope effects were minor at a low height; thus, a slope of 1:8 can be recommended if the installation space for a gentler ramp is not sufficient.