• Structural Engineering and Mechanics
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• v.74 no.4
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• pp.533-545
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• 2020

An optimal design method for a spoke double-layer cable-net structure (SDLC) is proposed in this study. Simplified calculation models of the SDLC are put forward to reveal the static responses under vertical loads and wind loads. Next, based on an energy principle, the relationship among the initial prestress level, cross-sectional areas of the components, rise height, sag height, overall displacement, and relative deformation is proposed. Moreover, a calculation model of the Foshan Center SDLC is built and optimized. Given the limited loading cases, material properties of the components, and variation ranges of the rise height and sag height, the self-weight and initial prestress level of the entire structure can be obtained. Because the self-weight of the cables decreases with increasing of the rise height and sag height, while the self-weight of the inner strut increases, the total weight of the entire structure successively exhibits a sharp reduction, a gradual decrease, a slow increase, and a sharp increase during the optimization process. For the simplified model, the optimal design corresponds to the combination of rise height and sag height that results in an appropriate prestress level of the entire structure with the minimum total weight.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.29-35
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• 2011

This paper examines several articulatory properties of /k/, known as a trigger of place assimilation as well as the object of post-obstruent tensing (/tk/), in comparison to non-assimilating controls (/kk/ and /kt/). Using EMMA, tongue body articulation in the place assimilation context robustly shows greater spatio-temporal articulation and lower jaw position. Results showed several characteristics. Firstly, constriction duration of the tongue body gesture in C2 of the assimilation context (/tk/) was longer than non-assimilating controls (/kk/ and /kt/). Secondly, constriction maxima also demonstrated greater constriction in the /tk/ sequences than in the control /kk/, but similar values with the control /kt/. In particular, results showed a significant relationship between the two variables - the longer the constriction duration, the greater the constriction degree. Lastly, jaw height was lower for the assimilating context /tk/, intermediate for the control /kk/, and higher for the control /kt/. Results suggest that speakers have lexical knowledge of place assimilation, producing a greater tongue body gesture in the spatio-temporal domains with lower jaw height as an indication of anticipating reduction of C1 in /tk/ sequences.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1070-1086
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• 2020

This study analyzed the size of women in their 60s, 70s and 80s in the 2014 Human Body Dimension Survey data among Size Korea's 7th Human Dimension Survey Data in 2015. This study examined the characteristics of changes in female body shape according to aging and the age range. The height item gradually decreased from the 60s and then rapidly decreased to the 80s. In the case of the circumference item, a sharp change occurred in the section from 69 to 70 years old. The reduction in hip height, waist height, and navel level waist height was not significant compared to the decrease in stature. Both width, thickness, and circumference gradually decreased with age. It can be seen that the back bends forward and the legs become thinner than the body due to the aging phenomenon with increasing age. Even for older women, the characteristics of aging differ in their 60s, 70s and 80s, so age segmentation of silver clothing should be considered.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.8-13
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• 2013

Drag reduction of a running vehicle is very important issue for the energy savings and emission reduction of its power train. Especially for a solar powered electric vehicle, the drag reduction and weight lightening are two serious problems to be solved to extend its driving distance under the given energy condition. In this study, the ground effect of an airfoil shaped road vehicle was studied for an optimum body design of an ultra-light solar powered electric vehicle. Clark-Y airfoil type was adopted to the body shape of the model vehicle to reduce aerodynamic drag. From the study, it was found that the drag of the model vehicle was reduced as the height(h) between ground and the lower surface of the model vehicle was decreased. It is due to the reduction of the down-wash decreasing the induced drag of the vehicle. The lift was also decreased as the height decreased. It is due to the turbulent boundary layer developed beneath the vehicle body. The drag is classified into two types; the form and friction drag. The fraction of form drag to friction one is 76 to 24 on the model vehicle. As the height(h) of the model vehicle from the ground surface increases the form drag also increases but the friction drag is in reverse.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.1
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• pp.27-33
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• 1987

This study was carried out to investigate the effect of cultural practices on the nicotine and sugar contents in flue-cured tobacco(NC82), and the relationship between them. Significant reduction I sugar content and ratio of total sugar to nicotine(ratio, S/N) were observed with increased fertilizer, lower topping height, late transplanting and decreased application of male hydrazide(MH). Significant increases were observed in nicotine content with increased fertilizer and lower topping height. A positive correlation was found between total sugar content and plant density. A negative correlation was found between nicotine and total sugar contents for 8-years. An increase of 1.0% nicotine in the cured leaf would result in a 4.8% reduction in total sugar. The most desirable contents were 2.7% for nicotine and 19.0% for total sugar(S/N=7).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.6
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• pp.457-461
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• 2009

In this paper, barrier height between Ni-silicide and source/drain is reduced utilizing Pd stacked structure (Pd/Ni/TiN) for high performance PMOSFET. It is shown that the barrier height is decreased by Pd incorporation and is dependent on the Pd thickness. Therefore, Ni-silicide using the Pd stacked structure is promising for high performance nano-cale PMOSFET.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.122-126
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• 2001

Magnetic hard disk drive is continually being pushed to reduce head-disk spacing for higher recording densities. The current minimum spacing between the air-bearing slider and disk has been reduced to under 15 nm. In this work, it was investigated if flying height could be lowered under the height of laser bumps. With the reduction of the spinning speed, the flying height was decreased under the height of laser bumps. When a head swept between landing zone and data zone, the head-disk impact was monitored using AE and friction signals. It is demonstrated that magnetic hard disk drive could be operated without tribological failures under the height of laser bumps.

• The KSFM Journal of Fluid Machinery
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• v.14 no.1
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• pp.11-17
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• 2011

The numerical study was conducted to investigate the pump performance due to impeller related parameters change in centrifugal pump of very low specific speed by using CFD code. A small centrifugal pump whose specific speed is $N_s=76.2$ was used, and the performance characteristics were discussed for different number of vanes, rotational speed, and the length and height of vane. The numerical results at a very low specific speed show that the increase of the number of vanes has little effect on improvement of output pressure but results in the reduction of pressure fluctuation, and that the head increases with the increase in the rotational speed. The decreasing the length of vane has a considerable reduction of the capacity coefficient in comparison with decreasing the height of vane.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.137-143
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• 1999

The straight spatial distance or geodesic distance on WGS84 ellipsoid measured by GPS should be reduced on geoid to be used in Korean Geodetic System. The factors for this reduction are geoidal height and mean radius of the earth. On this study the effects of these factors on reducing distance were analyzed and the result showed that mean geoidal height should be multiplied by $1.6\times{10}^{-7}$ per unit distance for reducing geodesic distance on reference ellipsoid to that on geoid. Condsidering that the geoidal height on Bessel ellipsoid in Korea is -45 m in northeast and -75 m in middle west. It also showed that the difference of geodesic distance between on reference ellipsoid and on geoid is about 7-12 mm per km.

• Earthquakes and Structures
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• v.23 no.2
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• pp.139-150
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• 2022

In most self-center braces, decreasing residual deformation is possible only by increasing pretension force, which results in lower energy dissipation capacity. On the other hand, increasing energy dissipation capacity means higher values of residual deformation. The goal of this research was to find the best design for a self-centering buckling restrained brace (SC-BRB) system by balancing self-centering capability and energy dissipation. Three, six, and nine-story structures were investigated using OpenSees software and the TCL programming language to achieve this goal. For each height, 62 different SC-BRBs were considered using different values for the pretension force of cables, the area of the buckling restrained brace (BRB) core plate, and the yield stress of the core plate. The residual deformation and dissipated energy of all the models were calculated using nonlinear analyses after cyclic loading was applied. The optimum design for each height was determined among all the models and was compared to the structure equipped with the usual BRB. The residual deformation of the framed buildings was significantly reduced, according to the findings. Also the reduction of the energy dissipation was acceptable. The optimum design of SC-BRB in 6-story building has the most reduction percent in residual deformation, it can reduce residual deformation of building 83% while causing only a 57% of reduction in dissipated energy. The greatest reduction in residual deformation versus dissipated energy reduction was for the optimum SC-BRB design of 9-story building, results indicated that it can reduce residual deformation of building 69% while causing only a 42% of reduction in dissipated energy.