• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.49-54
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• 1977

In order to obtain the field efficiency of the power tiller plowing on the various size of and its length-width field tests were performed with 8ps.10ps. power tiller popularly used in the korean rural area, and Satoh 5ps. made in Japan, Land Master 5ps. made in England were tested to compare with the field efficiency of the above power tillers. The results obtained in this tests were as follows ; 1. In considering of the resting time and the refueling time and others, the field efficiency of Satoh was the highest among the power tillers as to be 80%, at the 8ps. power tiller 76.5%, at the 10ps. power tiller 79.3% and the lowest field efficiency was obtained at the Land Master as 75.7%. 2. The field efficiency of the each power tiller increased as the ratio of the length to width of the field was increased. 3. The increasing rate of field efficiency was much bigger in the below the ratio of 5 : 1 but at the upper ratio increased above, the ratio was nearly constant. 4. The field efficiency of the power tiller was higher at the smaller power tiller than the larger, except the Land Master , because of easily operating and turning of the power tiller by virtue of its lighter weight.

• Transactions of Materials Processing
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• v.15 no.4 s.85
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• pp.311-318
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• 2006

One of the most important quality problems in flat plate leveled from hot rolled coils in cut-to-Iength lines is bowing and cambering when they are cut in small width parts. It is verified analytically and experimentally that residual stress remained in plate is th ε source of the problem. In order to produce low residual stress flat plate from hot rolled coils, the proper conditions of leveling are studied and two things are implemented. One is proper plastic deformation area ratio to reduce residual stress within customer requirement by applying suitable plastic deformation and maintain leveling load within structural strength limit of leveler. The other is maintaining uniform plastic deformation along the width of the plate during leveling. Customer requirement for residual stress is met by applying above 70% of plastic deformation area ratio and uniform deformation along width of coil by adjusting back up rolls according to deformation analysis of work roll and back up roll assembly and leveling tests.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.1
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• pp.43-54
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• 1992

The purpose of this study was to obtain the guides of establishing vertical dimension by analyzing the facial and oral landmarks of Korean adults. The following conclusions were obtained from this study. 1. The ratio of bizygomatic width to dental arch width was 3.26 : 1 in male and 3.21 : 1 in female, and the ratio of vertical dimension to dental arch length was 2.49 : 1 in male and 2.39 : 1 in female. 2. It was obtained by analysis of multiple regression that the corelative formula, vertical dimension$=23.37+0.24{\times}bizygomatic$ $width+0.29{\times}dental$ arch length. 3. There was no statistically significant difference between the results of vertical dimension acquired by means of Hayakawa's prediction($68.04{\pm}3.16mm$ in male, $64.38{\pm}3.00mm$ in female) and that of vertical dimension by this study.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1932-1940
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• 2004

Although the previous researches evaluated the fatigue behavior of Al/GFRP laminates using the traditional fracture mechanism, their researches were not sufficient to do it : the damage zone of Al/GFRP laminates was occurred at the delamination zone instead of the crack-metallic damages. Thus, previous researches were not applicable to the fatigue behavior of Al/GFRP laminates. The major purpose of this study was to evaluate delamination behavior using the relationship between crack length (a) and delamination width (b) in Al/GFRP laminate. The details of investigation were as follows: 1) Relationship between the crack length (a) and the delamination width (b), 2) Relationship between the delamination aspect ratio (b/a) and the delamination area rate ((A$\_$D/)/subN// (A$\_$D/)$\_$All/), 3) The effect of delamination aspect ratio (b/a) on the delamination shape factor (f$\_$s/) and the delamination growth rate (dA$\_$D// da). As results, it was known that the delamination aspect ratio (b/a) was decreased and the delamination area rate ((A$\_$D/)$\_$N// (A$\_$D/)$\_$All/) was increased as the normalized crack size (a/W) was increased. And, the delamination shape factors (f$\_$s/) of the ellipse-II(f$\_$s3/) was greater than of the ellipse-I(f$\_$s2/) but that of the triangle (f$\_$s1/) was less than of the ellipse-I(f$\_$s2/).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.357-366
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• 1997

Rice quality is considered to have two general meanings; 1) milling, cooking, and processing quality, which refer to suitability of the grain for a particular end-use; and 2) physical quality, which means cleanliness, soundness, and freedom from foreign materials. Grain type is associated with specific milling, cooking, and processing characteristics. Thus, this experiment was conducted to classify the grain type categories and marketing grades for Korean leading rice varieties. Length: width ratio of brown rice kernel ranged from 1.57 to 2.25 and most of varieties belonged to short grain except Tongil type rice varieties. Mean of length: width ratio of brown rice kernel was 1.77 and coefficient of variance was 4.79％ in short grain type varieties. Grain shape could be further classified into 5 types by length:width ratio of brown rice kernel; 1 type(less than 1.75), 2 type(1.76∼1.80), 3 type(1.81∼1.90), 4 type(1.91∼2.00), and 5 type (greater than 2.00). For 1 and 2 type of varieties, woven wire sieve having 1.7mm openings showed better whole-kernel yields for special marketing grade, and sieve having 2.0mm openings for 3 and 4 type of varieties. Grain type which classified into 5 categories was not associated with physicochemical and cooking characteristics of rice grain, but sensory evaluation of cooked rice showed better score for 1 type varieties in terms of appearance, gloss, flavor, texture, stickiness, and taste.

• Tunnel and Underground Space
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• v.30 no.3
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• pp.226-241
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• 2020

The stability of underground mine cavity is closely related with pillar strength. The vulnerability of pillars can be judged and reinforced if the pillar strength is known. The pillar strength is affected by characteristics of discontinuities and shape of a pillar. The change of pillar strength due to a discontinuity passing through the center of a pillar, width-to-height ratio of a pillar and small joints existing within a pillar was analyzed using PFC 3D. The result showed that the pillar strength is influenced by dip angle of a discontinuity and it increases as width-to-height ratio of a pillar increases. The pillar strength decreases as the number of contained joints increases. The relationship between total trace length observable from the pillar surface and the pillar strength was regressed with exponential function. The correlation coefficient of the regression was high enough so that pillar strength can be predicted using total trace length if a joint set exists in a pillar. Lastly, the method to estimate the strength of a pillar that includes two joint sets was proposed if the joint dip angles are 60°, 30°. The method also need total trace lengths of two joint sets.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.769-776
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• 2010

The relationship between morphological characteristics and sensibility of hands for beautiful hands were investigated for college woman in early twenties. Hand Emotional Quotient (HEQ) which is classified as 10 grades was newly suggested as one of the sensibility evaluation methods for the beautiful hands and was applied to assess the qualitative and quantitative relationships between morphological characteristics and HEQ. The factors influenced on the HEQ were in order as width-length ratio of hands, finger length-hand length and finger width-hand length ratios. Otherwise the influences of hand length-nail length and finger length-nail length ratios on HEQ were insignificant. The longer length of hand, finger, and nail and the narrower width of hand and finger, the higher HEQ hands get. In conclusion, it is found that all morphologic characteristics of hands influenced on the sensitivity synthetically. The data constructed on the hand's sensibility is very useful for various beauty products and service areas related to hands.

• Animal Systematics, Evolution and Diversity
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• v.29 no.1
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• pp.23-30
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• 2013

This study reports the discovery of two oxytrichid ciliates, Cyrtohymena primicirrata (Berger and Foissner, 1987) and Oxytricha granulifera Foissner and Adam, 1983, in Jeju Island, Korea. The morphology of the two species was studied using live observation and protargol impregnation. These species are described as follows: Cyrtohymena primicirrata has a body size in live specimens $90-140{\times}40-60{\mu}m$, length : width ratio 2.3 : 1 on average; elongated and slender obovate in outline of body. Cortical granules are shiny yellow on the ventral and dorsal side. Adoral zone of membranelles (AZM) is covering about 48% of the cell with about 38 adoral membranelles. Arrangement of undulating membranes is ordinary Cyrtohymena pattern. Dorsal kineties is six rows with $5{\mu}m$ long bristles. Oxytricha granulifera has a body size in live specimens $90-115{\times}25-38{\mu}m$, length : width ratio 3.31 on average; elongated ellipsoidal in outline of body. Cortical granules are colorless on the ventral and dorsal side. AZM is covering 28% of the cell length in vivo with about 24 adoral membranelles. Arrangement of undulating membranes is Oxytricha pattern. Dorsal kineties is five rows with about $3{\mu}m$ long dorsal bristles.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.3
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• pp.236-247
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• 2015

In this paper, the experimental equipments for ventilated supercavitation in cavitation tunnel is constructed and the basic data of ventilated supercavitation regard to the entrainment coefficient and Froude number is fulfilled. The experiments are conducted for the disk cavitator with injecting air and the pressure inside cavity and the shape of cavity are measured. As the entrainment coefficient increases while the Froude number is kept constant, the ventilated cavitation number decreases to a minimum value which decreases no more even with increasing the air entrainment. The minimum value of ventilated cavitation number, caused by the blockage effect, decreases according to increasing the diameter ratio of test section to cavitator. The cavity length is rapidly enlarged near the minimum cavitation number. In low Froude numbers, the cavity tail is floating up due to buoyancy and the air inside the cavity is evacuated from its rear end with twin-vortex hollow tubes. However, in high Froude numbers, the buoyancy effect is almost negligible and there is no more twin-vortex tubes so that the cavity shape becomes close to axisymmetric. In order to measure the cavity length and width, the two methods, which are to be based on the cavity shapes and the maximum width of cavity, are applied. As the entrainment coefficient increases after the ventilated cavitation number gets down to the minimum cavitation number, the cavity length still increases gradually. These phenomenon can be confirmed by the measurement using the method based on the cavity shapes. On the other hand, when the method based on the maximum width of cavity is used, the length and width of the cavity agree well with a semi-empirical formular of natural cavity. So the method based on the maximum width of cavity can be a valid method for cavitator design.

• 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.