• Journal of Ocean Engineering and Technology
• /
• v.29 no.2
• /
• pp.175-185
• /
• 2015

Jack-up type WTIV(Wind Turbine Installation Vessel) is used to avoid the effects of waves when installing wind turbines in the Southwest Sea of South Korea. During the preloading procedure, unexpected penetration may cause some risks such as excessive penetration or punch-through failure. To ensure the safety of the WTIV during preloading, the bearing capacities should be evaluated based on the soil data at each borehole. Eight boreholes (OW-1 to -8) have been drilled in the Southwest Sea of South Korea. The bearing capacities of a spudcan designed to be used in this district are calculated using both a conventional analysis and finite element analysis with the soil properties of OW-1 to -8. A finite element analysis is carried out for OW-1, -3, and -4 to gain an in-depth understanding of the soil behavior during the penetration. OW-1, -3, and -4 are representative boreholes for a strong layer overlying a soft layer, a general soft layer, and a soft layer overlying a strong layer, respectively. The resultant bearing capacity curves versus the depth of the numerical analysis are compared with the conventional method. The results show that the conventional analysis is conservative. Case studies for different spudcan areas and shapes are also conducted to seek an appropriate spudcan type for the Southwest Sea of South Korea. Finally, a spudcan with a rectangular shape and a bearing area of $112.8m^2$ is selected.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.72.2-72.2
• /
• 2014

We have made a comparison of three cone models (an asymmetric cone model, an ice-cream cone model, and an elliptical cone model) in terms of space weather application. We found that CME angular widths obtained by three cone models are quite different one another even though their radial velocities are comparable with one another. In this study, we investigate which cone model is proper for halo CME morphology and whether cone model parameters are similar to observations. For this, we look for CMEs which are identified as halo CMEs by one spacecraft and as limb CMEs by the other ones. For this we use SOHO/LASCO and STEREO/SECCHI data during the period from 2010 December to 2011 June when two spacecraft were separated by $90{\pm}10$ degrees. From geometrical parameters of these CMEs such as their front curvature, we classify them into two groups: shallow cone (5 events) and near full-cone (28 events). Noting that the previous cone models are based on flat cone or shallow cone shapes, our results imply that a cone model based on full cone shape should be developed. For further analysis, we are estimating the angular widths of these CMEs near the limb to compare them with those from the cone models. This result shows that the angular widths of the ice-cream cone model are well correlated (CC = 0.81) with those of observations.

• Journal of the Korean Geographical Society
• /
• v.48 no.3
• /
• pp.453-465
• /
• 2013

This paper aims to reveal that 'identity' plays the crucial role of explaining the relation between humans and space. Geography is preoccupied with footprints of humans which are engraved on the ground. It explores why such tokens are left over. It explains the existence of humans through footsteps of them. Men leaves traces of themselves to notify that who I was and who we were. The traces left behind by humans contain narratives of their own. Through those narratives, the very men who left the traces on the ground are to be grasped. A trace engraved by a person expresses its own identity of representing that person, so the narrative contained by one trace is the narrative of that individual. The identify which is composed of its own narrative can be largely divided into two types. The two are 'changing identity' and 'unchanging identity'. 'Changing identity' shapes the identity of oneself by difference. 'Unchanging identity' constructs the identity by identifying itself with sameness. However, as one's figure in everyday life becomes identical or different, identity also varies through processes of generation and repetition. Therefore, identity is currently changing and in progress.

• Journal of the Korean Institute of Gas
• /
• v.8 no.3 s.24
• /
• pp.1-7
• /
• 2004

The polyethylene pipe can use semi-permanent because of the high corrosion resistance with chemical stability. In addition to, there is the merit that is an easy to establish and to maintain. However, as the reason that it is simply degraded when the polyethylene pipe was exposed to the outside, mainly it is used to lay under the ground with low-pressure gas transportation pipe. In this study, the nondestructive evaluation method was used to maintain the integrity of the polyethylene pipe. We simulated the various defects on the polyethylene pipes, and then the AE signal occurred according to the impact test of steel ball was evaluated by the acoustic emission method. From the results, the waveform and dominant frequency could be distinguishing from the defect shapes of polyethylene pipe. Especially, in the case of notch defect, the AE signals occur different by the angle and depth of the notch.

• Progress in Superconductivity and Cryogenics
• /
• v.21 no.4
• /
• pp.9-12
• /
• 2019

We performed Raman spectroscopy on two different over-doped Bi₂Sr₂CaCu₂O_8+x (BSCCO), of which superconducting transition temperatures are 89 K and 77 K. Line-shape analysis of the Raman-spectrum was done, focused on B_1g bond buckling mode which have drawn a lot of attention, since photoemission studies showed an evidence for strong coupling between the mode and electron. The line-shapes show asymmetry and are well fitted by the Fano line-shape formula. Remarkably, we found that the peak line-widths from B_1g bond buckling mode in BSCCO show much broader than those in YBa₂Cu₃O_7-x. The broad line width can be attributed to the superstructure modulation of BSCCO. Our results imply that B_1g bond buckling mode may have close relation to the origin of superconductivity or to boosting the superconducting transition temperature in BSCCO.

• BMB Reports
• /
• v.40 no.1
• /
• pp.119-124
• /
• 2007

Adenoviral vectors are among the most promising vectors available for human gene therapy. However, the use of recombinant adenoviral vectors, including replicationcompetent adenovirus (RCA), raises a variety of safety concerns in relation to the development of new therapies based on gene therapy. To examine how organic compounds change in rat plasma following the injection of adenovirus, $\beta$-galactosidase expressing recombinant adenovirus (designated rAdLacZ) or RCA, we investigated the content of fatty acids (FAs), which are important biochemical indicators in pathological conditions. Pattern recognition analysis on the level of FAs in rat plasma is described for the visual discrimination of adenovirus infection groups from normal controls. Plasma FAs from four control rats (normal group), and from four rats with rAdLacZ infection and six rats with RCA infection (the two abnormal groups), were examined by gas chromatography-mass spectrometry in selected ion monitoring modes as their tert-butyldimethylsilyl derivatives. In total, 20 FAs were positively detected and quantified. The results of the Student's t-test on the normal mean of two abnormal groups, the levels of three FAs (p<0.05) from rAdLacZ group and eleven FAs (p<0.05) from RCA group were significantly different. When star symbol plotting was applied to the group mean values of 20 FAs after normalization to the corresponding normal mean values, the resulting eicosagonal star patterns of the two infected groups were distorted into similar shapes, but were distinguishable from each other. Thus, these approaches will be useful for screening and monitoring of diagnostic markers for the effects of infection following the use of adenoviral vectors in gene therapy.

• Journal of the Korean Society of Costume
• /
• v.60 no.10
• /
• pp.163-179
• /
• 2010

False sleeves are 'the sleeves that are attached to clothes but exist just as a part without any function to put arms in them.' They are different from sleeves to put arms in them and are to follow the trend or a way of wearing clothes. They are mostly found in medieval Europe's decorative sleeves named 'Hanging sleeves', but they are also found in Eastern region, too. They are found in sleeves that attached women's headgear in East and Middle Asia, and also in high-class male caftan in Ottoman Turk in the 16th and 17th century. False sleeves can be divided into two kinds by shapes. The first ones are the decorative sleeves of which trunk-shaped sleeves hang around the whole or part of the arm hole but have no function to put arms in them; this is called as 'sleeve-shaped False sleeves'. These sleeves are found in women's headgear in medieval Europe, Ottoman Turk, and East and Middle Asia. False sleeves in Europe and Ottoman Turk played a role in showing wealth and power while those in East and Middle Asia had a great role in highlighting the costume's decorative effect. The second ones are the sleeves hanging down from the arms by attaching long cloth to the arm hole, in design; these are named as 'cape-shaped False sleeves.' This style is found only in medieval Europe, and presumably, these cape-shaped false sleeves may have played a role in boasting of one's wealth and power.

• Journal of the Korean Society of Costume
• /
• v.61 no.10
• /
• pp.135-150
• /
• 2011

The ranking belts for Joseon dynasty officials that are based on references and relics are studied in this paper in terms of architecture, detailed names, and structural changes according to different time. Officials' uniforms consist of hats, clothes, belts, and shoes. Among these, the belt is an important sign that represents the wearer's ranking. The ranking belts of the Joseon dynasty which were brought from Ming at the late stage of the Koryo dynasty became classified as the following four classes : Seo-dai(a rhinoceros' horn, 犀帶), Gum-dai(gold, 金帶), Eun-dai(silver, 銀帶), and Heug-gag-dai(black horn, 黑角帶). A ranking belt consists of a basic belt body and a plaque that represents the wearer's rank. A plaque consists of 20 plates: three front-center plates that represent the Sam-tai(三台) constellation, six front-side plates that represent the Namduyug constellation(南斗六星), seven back plates that represent the Big Dipper(北斗七星), left side Bo(輔), right side Pil(弼), and a couple of Tamie at both ends. The architecture of the belt body; the basic frame for ranking belts, shows some differences between the former and the latter periods of the Joseon dynasty. In the former period, the belt had a pair of a buckle so that the wearers were able to adjust the belt size. But later, the belt didn't have the buckles to adjust the belt size and consequently it only performed a locking or unlocking function. Therefore, the belts in the latter period were longer than normal and one size fit all. In addition to the functional change of buckles, the shapes of the ranking belts show changes from the round shape to the square shape as time goes on.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2000.11a
• /
• pp.92-97
• /
• 2000

Low-velocity impact damage of a thick pressure vessel by composite materials was studied using the modified Herzian contact radius theory. Impactors of various masses and various tup shapes were dropped freely in the range of 20m to 200mm height. With acceleration gage and strain gage installed on the impactor, impact force and acceleration and Contact radius were measured. After a test, the samples were radiographed to scan the state of damage. Compared with hemispherical tup of 12.7mm diameter, the contact radius of hemispherical tup of 25.4mm diameter was bigger. And the experimental data and the theoretical data was different due to the mechanical properties difference. The acceleration value was changed linearly according to the height.

• Structural Engineering and Mechanics
• /
• v.52 no.5
• /
• pp.889-901
• /
• 2014

Very long life fatigue tests were carried out on 16Mn steel base metal and its welded joint by using the ultrasonic fatigue testing technique. Specimen shapes (round and plate) were considered for both the base metal and welded joint. The results show that the specimens present different S-N curve characteristics in the region of $10^5-10^9$ cycles. The round specimens showed continuously decreasing tendency while plate specimens showed a steep decreasing step and an asymptotic horizontal one. The fatigue strength of round specimen was found higher than plate specimen. The fatigue strength of as-welded joint was 45.0% of the base material for butt joint and 40% for cruciform as-welded joint. It was found that fracture can still occur in butt joint beyond $5{\times}10^6$ cycles. The cruciform joint has a fatigue limit in the very long life fatigue regime ($10^7-10^9$ cycles). Fatigue strength of butt as-welded joint was much higher as compared to cruciform as-welded joint. Improvement in fatigue strength of welded joint was found due to UPT. The observation of fracture surface showed crack mainly initiated from welded toe at fusion areas or geometric discontinuity sites at the surface in butt joint and from welded toe in cruciform joint.