• Advances in concrete construction
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• v.6 no.3
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• pp.269-283
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• 2018

This study presents the effects of geometrical dimensions of concrete gravity dams on the seismic response considering different base width/dam height (L/H) ratios. In the study, a concrete gravity dam with the height of 200 m is selected and finite element models of the dam are constituted including five different L/H ratios such as 0.25, 0.5, 0.75, 1.00, 1.25. All dams are modeled in ANSYS software considering dam-reservoir-foundation interaction. 1989 Loma Prieta earthquake records are applied to models in upstream-downstream direction and linear time history analyses are performed. Dynamic equilibrium equations of motions obtained from the finite element models of the coupled systems are solved by using Newmark time integration algorithm. The seismic response of the models is evaluated from analyses presenting natural frequencies, mode shapes, displacements and principal stresses. The results show that the L/H ratios considerably affect the seismic response of gravity dams. Also, the model where L/H ratio is 1.00 has more desirable results and most appropriate representation of the seismic response of gravity dams.

• 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 Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1601-1610
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• 2007

The purpose of this study was to determine whether a pulse analyzer was useful 1) to characterize the variables of pulse wave of diabetes mellitus group, compared with those of healthy subjects, and 2) to determine Sasang Constitution in diabetes mellitus group and healthy subjects. 1. The sum of pulse pressure (energy) and the ratio of systolic period area (As%), called pulse pressure-related variables, were higher in diabetes mellitus group than healthy group, while the height of dicrotic wave (h5) and the ratio of height of dicrotic wave to height of percussion wave (h5/h1), correlated with arterial compliance, were lower in diabetes mellitus group than healthy group. 2. Taeumin of diabetes mellitus group showed higher pressure-related variables than that of healthy group. 3. Soumin of diabetes mellitus group had shorter the time to dicrotic wave (t5) than that of healthy group. 4. Soyangin of diabetes mellitus group showed higher heart rates and lower values in pulse wave time-related variables, including time to dicrotic wave(t5), time to incisura (t4), total time minus time to incisura (t-t4), total time (t), width of percussion wave (w), and the ratio of width of percussion wave to total time (w/t), than that of healthy group. 5. Contact pressure (CP), sum of pulse pressure (energy), height of pre-incisura (h2), height of incisura (h4), width of percussion wave (w), time to incisura (t4), time to percussion wave (t1), variance of total time (Vt), variance of height of percussion wave(Vp) and the ratio of height of incisura to height of percussion wave (h4/h1) were used to develop the rules of Sasang Constitution Classification with about seventy five percents accuracy. These suggested that the pulse analyzer was useful to evaluate the risk degree of diabetes mellitus and to determine Sasang Constitution among either diabetes mellitus group or healthy 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.

• 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.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.627-630
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• 2003

This work presents a numerical procedure to optimize the shape of three-dimensional channel with angled ribs mounted on one of the walls to enhance turbulent heat transfer. The response surface method is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis of flow and heat transfer. SST turbulence model is used as a turbulence closure. The width-to-height ratio of the rib, rib height-to-channel height ratio, pitch-to-rib height ratio and attack angle of the rib are chosen as design variables. The objective function is defined as a linear combination of heat-transfer and friction-loss related terms with weighting factor. D-optimal experimental design method is used to determine the data points. Optimum shapes of the channel have been obtained for the weighting factors in the range from 0.0 to 1.0.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.9
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• pp.1351-1359
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• 2003

This study presents a numerical procedure to optimize shape of streamwise periodic ribs mounted on both of the principal walls to enhance turbulent heat transfer in a rectangular channel flow. The response surface method is used as an optimization technique. The optimization is based on Navier-Stokes analysis of flow and heat transfer with $k-{\varepsilon}$ turbulence model. The width-to-height ratio of a rib, rib height-to-channel height ratio and rib pitch to rib height ratio are chosen as design variables. The object function is defined as a function of heat transfer coefficient and friction drag coefficient with weighting factor. Optimum shapes of the rib have been obtained for the range of 0.02 to 0.1 of weighting factor.

• 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.

• 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.

• 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.