• 한국수학교육학회지시리즈A:수학교육
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• 제51권4호
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• pp.471-484
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• 2012

It is not easy to find the auxiliary line to solve the problem in connection with the circle, where it is the problem finding the central angle or angle at the circumference in a circle. The purpose of the study is to give an aid for this difficulties. The angle at the circumference is closely related to the arc. And so we looked into the problem in connection with the angle at the circumference in point of view of the arc. We have got the following the results. It is not necessary to draw the auxiliary line when solving the problem in connection with the angle at the circumference in point of view of the arc. And we can find the reason to draw the specific auxiliary in point of view of the arc. We hope that the results of research are given aids to a lot of students.

• 한국의류학회지
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• 제48권4호
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• pp.756-773
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• 2024

This study proposes a prototype design method for pants suited to adult women with a difference of 27cm or more between the circumference of their waist and hip. The first pattern was modified around the hem, in the number of darts at the waist and in the slope of the front center. The second pattern was modified in the position of the waist darts and the length of the front and back darts. The third pattern showed side-line wrinkling, so the slope of the side-line and the number of darts were adjusted. Pants patterns for women with large hips can be calculated by inserting the difference between hip and waist circumference in the settings for the center front angle, center back angle, front side line angle, back side line angle, dart length, etc. This enables designers to draft pants patterns suited to the body shape of women with a difference in hip and waist circumference of 27cm or more.

• 한국의류산업학회지
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• 제12권5호
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• pp.633-641
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• 2010

The purpose of this study is to evaluate a new flight suit in bilateral ways; subjectively and objectively in the improvements of comfort and mobility. Seven healthy males at the age of twenties volunteered in this wearing test. They were over 177 cm in height and 92-95 cm in chest circumference, which satisfies the M95 Special' size described in the Korean Military Specifications and Standards. The subjective satisfaction was evaluated according to the criteria of ease of donning and doffing, fitness of wear, mobility, space between cloth and body, convenience in using restroom. Subjective satisfaction evaluation says that the best improvement of movement are neck circumference, chest breadth, armscye circumference, waist back length, crotch length, crotch height and body rise. According to the evaluation, improvements of mobility were conspicuous especially in parts of body like neck, breast, waist, back, and arms. When evaluating objective satisfaction, we measured a angle difference in a prescribed standard-grid on a photograph that picked up while the subject performed each motion in front of 10 cm-interval grid. As a result, the motion that had angle difference above 5 degrees were arm stretching and standing on single leg holding at forward or at his side. Bending necks and waist, crouching also had angle difference of over 5 degrees. The improvements are discussed from the viewpoint that the increased ease in parts of armscye circumference and crotch in new flight suit pattern.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.611-614
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• 2002

Rotating stall in vaneless diffusers of centrifugal compressor occurs in the diffuser wall due to flow separation at large inlet flow angle. For this reason, the critical inlet flow angles are suggested by several researchers. Beyond this critical angle, flow separates in the diffuser, and develops into rotating stall. This paper studied this critical flow angle. Rotating stall is measured through eight fast-response pressure transducers which are equally spaced around the circumference at the inlet and exit of a vaneless diffuser. Experiments are done from 20000rpm to 60000rpm for the diffuser stall. Two-cell structure which rotates at $6{\~}l0{\%}$ of impeller speed is fully developed at $20000{\~}40000rpm$, and three-cell structure which rotates at $7{\~}9{\%}$ of impeller speed is fully developed at $50000{\~}60000rpm$. This paper shows that the critical inlet flow angle is not constant but related with tip speed of impeller. As tip speed increases, so does the critical inlet flow angle.

• 복식문화연구
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• 제8권4호
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• pp.577-586
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• 2000

The objectives of this study were to develope slacks basic block to be used for improving the attactive silhouette and bodily fitness in ready-to-wear and educational patterns. The subjects were from 20 to 24 years old and twenty six body measurements were taken on the National Anthropometric Survey of Korea in 1977. The women in 20's think ideal body shapes are high stature, long legs, slander waist, hip, abdomen, thigh, ankle and light weight. And so it needs to be studied to studied to make slacks pattern which show slander girth and long length. The study was carried out by the following procedures. 1. Through the comparative investigation on the conventional slacks patterns of System M. Muller & Sohn, Secolli, 文化's in Japan, and Won-ja Rim's and the clothing experiment, the characteristics of every four patterns were found. 2. According to the center back slant, reflecting the change of waist circumference, thigh circumference, back crotch length, and the new suitable slacks pattern was achieved. 3. The sensory evaluation for appearance and comfort was applied to evaluate the new slacks pattern by comparing with the conventional slacks pattern. From the result of the sensory evaluation, it was found that the new slacks pattern was more suitable for appearance. 4. The new slacks pattern for women in their 20's were developed as follows ; The waist line came down 2 ㎝, the waist circumference was plus 2㎝ than originally, and the back hip circumference was larger 1 ㎝ than the front hip, the slacks length was created stature/8×4.9, the knee length was stature/8×2.7. The center back crotch length was interspaced 1∼1.5㎝ at the center front, and was at right angle the point which was raised 5㎝ at the side front. This size is not the absolute size but it helps to make the surplus on any other ready-made slacks for women.

• 복식문화연구
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• 제14권3호
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• pp.387-403
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• 2006

The purpose of this study was to develop a new torso pattern for the schoolgirl of a tween generation who had different somatotype from children and teenagers. The subjects in this study were female elementary school students of fifth or sixth grade. Through a sensory evaluation of four existing torso patterns, the first research torso pattern was developed. Drafting methods of each item, which closed to the optimum value three, were selected. The differences between the values of the selected drafting methods and the optimum three were verified through a Wilcoxon's ranked sum test. The final research torso pattern was developed through adjusting the drafting methods according to the deviation from the optimum value three. The schoolgirl of a tween generation is at the time to show the remarkable breast development compared with a waist circumference, so the bust drafting was defined as B/4+ 1.25cm separately front and back. The drafting of a waist circumference was defined as W/4+1cm separately front and back which taken the ease amounts of the somatotype into consideration of the schoolgirl of a tween generation. A princess line was used instead of a waist dart because their hip circumference was more developed than a waist circumference. The crossed amount of a front hemline was 0.3cm and that of a back hemline was 0.7cm. and the princess line of the position was drawn with a straight line at a right angle of the back waistline. The armhole depth was determined B/4-1cm in consideration of the aesthetic and the trend, although the effective movement of upper arm was required.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.24-32
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• 2004

The characteristics of heat transfer from horizontal cylinder immersed in both a riser and downcomer of a circulating fluidized beds were investigated experimentally under different values of solids mass flux, superficial air velocity, particle size diameter, and different bed materials. The test results indicated that local heat transfer coefficients in both riser and downcomer are strongly influenced by angular position, and mass flux, as well as by particle size and bed materials. The local heat transfer coefficients around a circumference of the cylinder inside a riser and downcomer of a CFB exhibited a general tendency to increase with decreasing particle size and increasing solids mass flux and vary with different bed materials. Also the averaged heat transfer coefficient calculated from local heat transfer coefficient exhibited the same trend as a local i.e increase with decrease particle size and increasing solids mass flux and vary with varying bed materials. The general trend for a riser local heat transfer coefficient is decrease with increase angle until ${\Phi}$ = 0.5-0.6 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Also the general trend for a local heat transfer coefficient in downcomer is to increase with increase the angle until ${\Phi}$= ${\theta}/{\Pi}$ = 0.3-0.5 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Comparison the results of the heat transfer in the riser and downcomer of a circulating fluidized beds shows that they have approximately the same trend but the values of heat transfer coefficients in riser is higher than in downcomer.

• 한국의류산업학회지
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• 제20권4호
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• pp.429-438
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• 2018

This study analyzed the fit-zone of the neck for females in their 60s. We considered the standard body types of females in their 60s and the four body types from the sixth Size Korea. The results of the study were as follows. We could not determine a pattern formula for the neck based on the changes in the body type of females in their 60s. However, the position of the lateral neck point generally showed a significant difference from that of females in their 20s. In the case of the shoulder angle, the point of the shoulder was angled slightly towards the back in all body types. It was also found that the curve of the neck circumference for both the collar and the bodice should have been smoother than what was shown on the 3D shape. The larger the height difference between the point of the back of the neck and the lateral neck point in the 3D shape, the smoother the design should be at the curve of the circumference at the front of the neck. A larger curvature in the front radius of the 3D shape increased the difference in the shape of the curve between the collar and the basic pattern of the bodice. Hence, a more careful design is required for these parts of the pattern. In addition, the more the front neck is bent, the smoother the circumference curve should be in the pattern design at the front of the neck and the collar.

• 한국의류산업학회지
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• 제13권6호
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• pp.934-942
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• 2011

This study was intended to analyze conventional grading increments and methods for middle-age men's pants, and to suggest new grading guidelines that will enable to improve satisfaction with size and silhouette as a result of combining the concept of grading, which help maintain the ratio and proportion by sizes as one of ready-made apparel's advantages, with body form oriented and aesthetic approaches. In the apparel industry, the current sizing specifications and methods adopted by relevant companies, as well as the characteristics of body forms of men aged 35 to 55 years were comparatively analyzed to find out problems and ultimately to suggest their solutions or improvements. It was considered that as the conventional grading practices used in the industry were customary on the basis of the past experiences, it was required to take the body forms of target consumers into account and also, to reconsider the conventional grading methods. Analyses of sizing and specifications by brands show that 4 to 19 sizes including 82 or 84 as standard size have been produced. Since men's apparel has a large number of sizes with the large range of sizes, grading is critically important. As silhouettes depend on the distribution of grading rule values at each point of increment pattern in the main regions during grading, it is necessary to consider both size grading and form variations. To maintain an appropriate silhouette with keeping the angle of center back line of a pattern, it is desirable to set the ratio of side line part to center part from the crease line to approximately 3:7. It is required to diversify the values of grading rules according to different sizes and pattern regions in consideration for the body forms of key consumers. In addition, if the natural lines of designs and patterns for the width increments of waist circumference and hip circumference, the increments of hip width in pant's front and back panels, the ratio of grading rule values of the right and left sides of crease line, knee circumference, thigh circumference and so on are taken into account, grading will be satisfactory in the all aspects of size, silhouette and ratio.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.556-561
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• 2000

This paper deals with the control of an active bending actuator fur a catheter. The bending actuator with 40mm in length utilizes three zigzag SMA (shape memory alloy) springs which are equally located in the circumference between inner $({\phi}2.5 mm)$ and outer $({\phi}3.0mm)$ tube. It is purposed on realization of desired bending angle $(90^{\circ})$ and direction $(360^{\circ})$. It is also installed in front of the catheter and used to guide a path at extremely bent or branched blood vessel. The performance-analysis of the bending actuator are investigated fur the purpose of optimizing the control of the bending actuator. The analog joy stick is used to command a bending angle and direction for the fast and accurate response. According to the commands of the joy stick, tensile force of each SMA spring is computed and obtained by controlling the temperature of each SMA spring using PWM (pulse width modulation) of supplied electric power.