• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2C
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• pp.61-68
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• 2012

In general, verticality error necessarily occurs in marine pile foundation due to construction error or marine environmental effects. In marine structure, design by vertical load rather than horizontal load is dominant, but in the offshore wind turbine foundation, horizontal load is dominant. As the structure type that has dynamic movement by blade rotation, verticality error may have structurally significant effects. In this study, structural response feature of foundation and ground were analyzed according to verticality error of monopile foundation of 5MW offshore wind turbine. Marine environmental load was calculated per ISO standard and the margin of verticality error was calculated to be $L/{\infty}$(=0), L/300, L/200 and L/100. As a result of analysis, it was found that the maximum value of member force of the foundation with L/100 error increased about 7.2% compared to the monopile without verticality error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.870-877
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• 2020

A suction bucket foundation, especially useful at depths of more than 20m, is a method of construction. The method first places an empty upturned bucket at the target site. Then, the bucket is installed by sucking water or air into it to create negative pressure. For stability, it is crucial to secure the verticality of the bucket. However, inclination by the bucket may occur due to sea-bottom conditions. In general, a repeated intrusion-pulling method is used for securing verticality. However, it takes a long time to complete the job. In this paper, we propose a real-time suction bucket verticality monitoring system. Specifically, the system consists of a sensor unit that collects raw verticality data, a controller that processes the data and wirelessly transmits the information, and a display unit that shows verticality information of a circular steel pipe. The system is implemented using an inclination sensor and an embedded controller. Experimental results show that the proposed system can efficiently measure roll/pitch information with a 0.028% margin of error. Furthermore, we show that the system properly operates in a suction bucket-based model experiment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.772-778
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• 2009

By rising the interests of the railroad, It has been required the research about railroad structure. And since 2000, the study about railway bridges caused by steel box railway bridges has been only 0.2%. So I was hard to find out about steel box railway bridges. In this study, I evaluate and analyze 4 types(KTX, Saemaeul, Mugunghwa, Freight) of dynamic caused by train loading, natural frequency and damping ratio, verticality deflection and verticality acceleration, end slope deflection, impact factor for dynamic characteristics analysis. natural frequency was measured 2.45Hz~3.34Hz and damping ratio revealed for 1.26~2.84%. Maximum verticality deflection(4.86mm) was sufficiently satisfied the design criteria(30.1mm), but in the case of verticality acceleration's respond, design criteria BRDM(Bridge Design Manual) & CTRL presentation derive rail limit value 0.35g be more than value 6 time recorded, maximum was measured 0.49g in 3 kinds of train(KTX, Saemaeul, Mugunghwa), except for Freight. Survey impact factor of Experiment bridge was 0.20 which is measured when the KTX(15:04) was driving. impact factor is enough contended with design criteria 0.29 which is presented in domestic railway design criteria and thoroughly guarantee the dynamic stability.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1306-1314
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• 2009

By rising the interests of the railroad, It has been required the research about railroad structure. And since 2000, the study about railway bridges caused by steel box railway bridges has been only 0.2 %. So I was hard to find out about steel box railway bridges. In this study, I evaluate and analyze 4 types(KTX, Saemaeul, Mugunghwa, Freight) of dynamic caused by train loading, natural frequency and damping ratio, verticality deflection and verticality acceleration, end slope deflection, impact factor for dynamic characteristics analysis. natural frequency was measured 2.45 Hz~3.34 Hz and damping ratio revealed for 1.26~2.84 %. Maximum verticality deflection(4.86 mm) was sufficiently satisfied the design criteria(30.1 mm), but in the case of verticality acceleration's respond, design criteria BRDM(bridge design manual) & CTRL presentation derive rail limit value 0.35 g be more than value 6 time recorded, maximum was measured 0.49 g in 3 kinds of train(KTX, Saemaeul, Mugunghwa), except for Freight. Survey impact factor of Experiment bridge was 0.20 which is measured when the KTX(15:04) was driving. impact factor is enough contended with design criteria 0.29 which is presented in domestic railway design criteria and thoroughly guarantee the dynamic stability.

• Journal of the Korean Vacuum Society
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• v.7 no.2
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• pp.161-168
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• 1998

Reactive ion etching process for InGaAs/InP using the CH4/H2 high density inductively coupled plasma was investigated. The experimental design method proposed by Taguchi was utilized to cover the whole parameter range while maintaining reasonable number of actual experiments. Results showed that the ICP power mainly affects surface roughness and verticality of the sidewall, bias power does etch rate and verticality, CH4 gas concentraion does the verticality and etch rate, and the distance between the induction coil and specimen mostly affects the surface roughness. It was also observed that the chamber pressure is the dominant parameter for the etch rate and verticality of the sidewall. The optimum condition was ICP power 700W, bias power 150 W, 15% $CH_4$, 7.5 mTorr, and 14 cm distance, resulting in about 3 $\mu\textrm{m}$/hr etch rate with smooth surfaces and vertical mesa sidewalls.

• Korea Journal of Geothermal Energy
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• v.9 no.2
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• pp.22-27
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• 2013

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.59-66
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• 2015

The production of high value-added products requires efficient processing and this constant demand for complex shape processing has led to the need for hybrid processing. In this study, the surface characteristics of hybrid machining, which combines wire-cut E.D.M and vibration, are examined. The selected experimental parameters are verticality, waveform, amplitude, peak current and frequency. The experimental results provide a guideline for selecting reasonable machining parameters. Surface roughness was improved by increasing the amplitude of the vibration.

• Journal of the Korea Fashion and Costume Design Association
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• v.12 no.1
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• pp.77-88
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• 2010

The purpose of this study is to evaluate the differences of visual effects by variations in the width of pleats and the length of the accordion pleats skirt. The stimuli are 21 samples: 7 variations of the width of pleats and 3 variations of the length of skirt. The data has been obtained from 43 fashion design majors. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: The visual effects by the number of pleats and the length of skirt are composed of 2 factors: verticality and thickness of lower body, shape of abdomen. In these factors, verticality and thickness of lower body factor is estimated by the most important factor. The accordion pleats skirt makes the lower body look longer when the width of the pleats is wider, and helps the calf and leg look thinner. Also, the waist looks more slender and thin. As the skirt gets longer, one looks taller, and legs look longer and thinner. The shape of abdomen is no difference according to the width of pleats. As the skirt gets longer, the waist looks more slender and thinner. The interaction of visual effect according to the changes in width of pleats and skirt length of accordion pleats skirt is not shown, and the skirt length has more effect than the width of pleats does in verticality and width of lower body factor. The width of pleats has more effect than the skirt length does in shape of abdomen factor.

• Journal of Fashion Business
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• v.10 no.4
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• pp.55-69
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• 2006

The purpose of this study is to evaluate the differences of visual effects by variations in the location and width of the waist band of one-piece dress. The stimuli are 24 samples: 8 variations of the location of the waist band and 3 variations of the width of the waist band. The data has been obtained from 50 fashion design majors. The data has analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: According to the result of factor analysis of the visual effects based on the changes in the location and width of waist bands for one-piece dress, four factors were identified - verticality of whole-body, horizontality of upper-body, curves of lower-body and shape of breast. Whole-body verticality and upper-body horizontality were found to be the most important factor among them. In all of the four factors of the visual effects, significant differences were observed according to the location of the waist bands for one-piece dress. The visual effects were evaluated positively when the waist bands were positioned above the natural waist line and negatively when the waist bands were positioned below the natural waist line. In addition, significant differences were observed in the visual effects according to the width of waist bands when the waist bands were positioned above the natural waist line, and visual effects were better when the band width was 3.5cm and 4.5cm than the others. The interaction of the visual effect showed significant differences in horizontality of upper-body, curves of lower-body and shape of breast.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.55-68
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• 2009

A new borehole roughness and verticality measurement system (BKS-LRPS) for rock socketed drilled shafts were developed and verified its field application. The stability of BKS-LRPS was verified for several field conditions, which included the effect of measuring unit shaking, the application of water/air calibration factors, and the resistance of high water pressure inside piles. Also, effective measurement distances for various conditions of turbidity were defined in the field by measuring borehole roughness and vertical alignment for 6 drilled shafts. Vertical alignments for all drilled shafts could be measured by BKS-LRPS. However, borehole roughness was not able to be measured due to high turbidity caused by RCD drilling processing. Based on the BKS-LRPS field verification, BKS-LRPS is the first borehole roughness and verticality measurement system applying both in the water and air.