• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.345-353
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• 2012

Objectives : The author has studied about correlation of gingival exposure upon smiling and oral facial status that reduce facial aesthetic. Methods : The subjects in this study are 91 female vulunteers who were in aged $21.4{\pm}1.89$ in Suwon. Objectives should be normal oral and facial status without the prosthodontic, orthodontic appliance or conqenital missing tooth, and agree to be examined the oral status and impression taking. 1.Measure the length of gingival exposure upon smiling. 2.Measure of the size on central incisor. 3.Measure of Facial. SPSS(SPSS 10.0 for windows, SPSS Inc, Chicago, USA) was utilized for calculating the correlation coefficient between gingival exposure upon smiling and facial status. Regression analysis was calculated in order to predict the R square for gingival exposure upon smiling. Results : 1.Correlation coefficient between the gingival exposure and length of maxillary central incisor was calculated as reversed correlation(r=-.302, p<0.01), and between the gingival exposure and the ratio of the length of central incisor/width of central incisor was revealed as reversed correlation(r=-.250, p<0.05) on smiling. 2.There was correlation between the gingival exposure and the facial height(r=.351, p<0.01), the lower facial height(r=.454, p<0.01) and the upper lip height(r=.274, p<0.01) upon smiling. 3.There was correlation between the gingival exposure and the ratio of the facial height/facial width(r=.358, p<0.05), the ratio of the upper facial height/facial width(r=.214, p<0.05), and the ratio of the lower facial height/facial height(r=.383, p<0.01) upon smiling. 4.The equation of the regression analysis for gingival exposure upon smiling could be estimated as gingival exposure upon smiling=-5.139+.279${\times}$lower facial height-.615${\times}$maxillary central incisal length-.05${\times}$nasolabial angle. Conclusions : Considering these results, it recommended that treatment planning should be designed in consideration of such factors as the length of maxillary central incisor, facial height, upper lip height and lower facial height, in order to promote the easthetic problems of face on smiling.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1582-1584
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• 2001

In ac plasma display(PDP), an image quality mainly depends on the contrast ratio. And the contrast ratio is affected by the driving condition and size of discharge cell. In this study, the electrical and optical characteristics during reset, address and sustain discharge were investigated as the height and width of barrier rib were varied in order to obtain the highest contrast ratio. As a result, the optimum rib height and width were 140${\mu}m$ and 600${\mu}m$, respectively.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.15-20
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• 2011

This study was conducted to evaluate the characteristics of installation dimensions of speed control humps based on the theoretical dynamic analyses. The field surveys of speed control humps were performed first to compare their sizes with those suggested in the installation standard. Then, the displacement response spectra under impact loads were obtained using the single degree of freedom models where the vehicle and human were assumed to combine completely. The analysis results showed that the human perception became larger as the width and height of the humps increased, but the extremely higher uncomfortableness should be avoided. In addition, the ratio between the width and height should be considered when the humps are designed and installed because the ratio governs the vertical acceleration magnitude.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.320-330
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• 2018

Purpose: The aim of this study was to investigate the harvesting performance of a prototype small combine for buckwheat and adlay. Methods: The prototype small combine was designed and constructed. Its ratio of grain loss, ratio of output components in the grain outlet, and field capacity for harvesting buckwheat and adlay were analyzed through field tests. Results: The prototype small combine required a working width of about 0.6 to 0.7 m to harvest buckwheat. The maximum travel speed was about 0.36 m/. The total ratio of grain loss was about 21.6%, which consisted of 8.8% at the header and 12.8% at the dust outlet. The grain and the material other than grain (MOG) ratios at the grain outlet were 94.1% and 5.9% respectively. In the case of adlay harvest, the maximum working width was about 1.2 m, that is, two rows. The range of maximum travel speed was about 0.45 to 0.46 m/s. When adlay was harvested in one row, the total ratio of grain loss ranged from 36.3 to 42.8% according to the cutting height. The cutting height of 30 cm resulted in a higher total ratio of grain loss than 60 cm and 90 cm. When the cutting height was 60 cm, there was no significant change in the total ratio of grain loss according to the number of working rows and the stage of the primary transmission shift. The total ratio of grain loss ranged from 35.2 to 37.7%. The grain and the MOG ratios at the grain outlet ranged from 93.1 to 95.8% and from 4.2 to 6.9%, respectively. No significant difference was observed in relation to cutting height, number of working rows, and the stage of the primary transmission shift. Conclusions: The prototype small combine for harvesting miscellaneous cereal crops showed good potential for the efficient harvesting of buckwheat and adlay. However, to improve the harvesting performance, there seems to be a need to develop new crop varieties suitable for machine-based harvesting and improve the transmissions, reels, separation/cleaning systems.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.1 s.29
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• pp.49-58
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• 1989

A clothing-erogonomics study was performed to investigate the difference of the upper arm skin skin surface and the relationship among the three aspects of upper arm (height of sleeve rap, sleeve width and armhole girth) by changing arm movements. Plaster cast was used for this experimental research. Arm movements consist of 9 types; just carmly standing on ($0^{\circ}$), and each 4 types ($45^{\circ},\;90^{\circ},\;135^{\circ},\;180^{\circ}$) to the vertical direction in front and in side. The results were as follows; 1) As the arm-movement angle increased, the height of sleeve cap decreased and that ratio was largest in the portion A-B3. 2) The steeve width was enlarged with the increment of movement angle in all portions of upper arm except B1-B5. 3) As increasing the movement angle, the whole armhole girth decreased and the ratio o(front armhole girth (F-A) was larger than that of back. 4) In the vertical direction in front, the height o( the sleeve caps was larger, the sleeve widths were smaller than in the vertical direction in side in all movement types, but there was no significant difference in arm-hole girth between the two cases. 5) There were significantly negative relationships between measurements in height of sleeve cap and those in sleeve width, and also between those in height of sleeve cap and in arm-hole girth. And significantly positive relationships were found between neasurements in height of sleeve cap and those in arm-hole girth.

• Geomechanics and Engineering
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• v.1 no.3
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• pp.219-239
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• 2009

Vertical vibration tests were conducted using model footings of different size and mass resting on the surface of finite sand layer with different height to width ratios and underlain by either rigid concrete base or natural red-earth base. A comparative study of the ratio of predicted and observed natural frequency ratio of the finite sand stratum was made using the calculated values of equivalent stiffness suggested by Gazetas (1983) and Baidya and Muralikrishna (2001). Comparison of results between model footings resting on finite sand stratum underlain by the rigid concrete base and the natural red-earth base showed that, the presence of a finite base of higher rigidity increases the resonant frequency significantly. With increase in H/B ratio beyond 2.0, the influence of both the rigid concrete and natural red-earth base decreases. Increase in the contact area of the footing increases the resonant frequency of the model footings resting on finite sand stratum underlain by both the types of finite bases. Both the predicted and the observed resonant frequency ratio decreases with increase in force rating and height to width ratio for a given series of model footing.

• Journal of the Korean Home Economics Association
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• v.12 no.2
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• pp.621-631
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• 1974

The objective of the study was to obtain standard sizes of body of the high school girls for designing clothes and developing pattern grading of clothes. In 1972, 342 students, selected by the stratified cluster random sampling method, at three high schools in Seoul were measured on forty-one items by the R. Martin method. Statistical techniques of mean, standard deviation, coefficient variable, maximum and minimum, range, t-test were utilized to analyze the data. The findings of the study were as follows ; 1. No differences were found among the age groups in the all measured variables. 2. Stature, bust girth, hip girth, acromion width, posterior waist girth/stature ratio of the high school girls were significantly smaller than those sizes of adult women. This result implies that those sizes will be increased as the students grow up. But upper arm girth, upper arm girth/bust girth ratio, and thigh girth/bust girth ratio were bigger than those sizes of adult women. Waist girth, thigh girth, total head height/stature ratio, acromion width/stature ratio, and foot length/stature ratio were nearly similiar to those of adult women. 3. According to the result of t-test, waist breadth, spinailiaca anterior height/stature ratio, thigh girth/bust girth ratio, and thigh/hip girth ratio of the 15 year old group were significantly different from those of the 16 year old group at the level of 0.05. Bust girth, weight, foot breadth, posterior croth length, and cervical height/stature ratio of the 16 year old group were significantly different from those of the 17 year old group at the level of 0.01. Hip girth, upper arm girth, waist breadth/stature ratio, and neck base girth/bust girth ratio of the 16 year old group were significantly different from those of the 17 year old group at the level of 0.05.

• Imaging Science in Dentistry
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• v.37 no.4
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• pp.197-203
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• 2007

Purpose: To provide diagnostic information by evaluation of the positional relationship between the mandibular third molar and the mandibular canal. Materials and Methods: Eighty-nine mandibular third molars were classified as mesioangular, horizontal, vertical, distoangular groups. The distances between the mandibular third molar and the mandibular canal were measured in cone-beam computed tomographs. The height and width ratios of distances from the mandibular third molar and the mandibular canal to the mandibular inferior border and to the lingual cortical plate were calculated. Results: The vertical and buccolingual distances between the mandibular third molar and the mandibular canal were 0.03 mm, 2.96 mm in the mesioangular, 0.37 mm, 3.38 mm in the horizontal, -1.50 mm, 1.38 mm in the vertical, -1.10 mm, 4.20 mm in the distoangular group. There were significant differences in vertical (P < 0.05), but not in buccolingual (P>0.05). The height and width ratios of distances on the mandibular third molar were 47.1 %, 36.1 % in the mesioangular, 47.4%, 34.4% in the horizontal, 37.0%, 46.7% in the vertical, 40.9%, 37.4% in the distoangular group. There were significant differences between the mesioangular and the vertical group, and the horizontal and the vertical group in height ratio (P < 0.05), and also between the mesioangular and the vertical group in width ratio (P < 0.05). The height and width ratios of distances on the mandibular canal showed no significant differences between groups (P > 0.05). Conclusion : The mesioangular group showed the nearest distance between the mandibular third molar and the mandibular canal vertically. The root apex of the mandibular third molar was positioned more buccally in the vertical group than in the mesioangular group.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.955-962
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• 2000

Scanning Probe Microscope (SPM) such as Scanning Tunneling Microscope (STM) and Atomic Force Microscope (AFM) was shown to be the powerful tool for nano-scale characterization of a fracture surface . AFM was used to study cross sectional profiles and dimensions of fatigue striations in 2017-T351 aluminum alloy. Their widths (SW) and heights (SH) were measured from the cross sectional profiles of three-dimension AFM images. The following results that will be helpful to understand the fatigue crack growth mechanism were obtained. (1) Coincidence of the crack growth rate with the striation width was found down to the growth rate of 10-5 mm/cycle. (2) The relation of SH=0.085(SW)1.2 was obtained. (3) The ratio of the striation height to its width SH/SW did not depend on the stress intensity factor range K and the stress ratio R. (4) Not only the SW but also the SH changed linearly with the crack tip opening displacement (CTOD) when plotted in log-log scale. From these results, the applicability of the AFM to nano-fractography is discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1047-1054
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• 2001

Atomic Force Microscope (AFM) was used to study cross sectional profiles and dimensions of fatigue striations in 2017-T351 aluminum alloy. Their widths(SW) and heights (SH, SH(sub)h, SH(sub)ι) were measured from the cross sectional profiles of three-dimension AFM images. The following results that will be helpful to understand the fatigue crack growth mechanism were obtained. (1) The relation of SH=$\alpha$(SW)(sup)1.2 was obtained. (2) The ratio of the striation height to its width SH/SW, SH(sub)h/SW and SH(sub)ι/SW did not depend on the stress intensity factor range ΔK and the stress ratio R( =P(sub)min/P(sub)max = K(sub)min/K(sub)max). (3) Effect of precipitate on the morphology of striation was changed by the relative dimensional difference between the striation width SW and the precipitates. From these results, the applicability of the AFM to nano-fractography is discussed.