• International Journal of Ocean System Engineering
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• v.3 no.4
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• pp.188-208
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• 2013

The motion response of floating structures should be adequately low to permit the operation of rigid risers along with dry well heads. Though Spar platforms have low heave responses under lower sea state, could become unacceptable in near resonance region of wave periods. Hence the hydrodynamic response, heave in particular, must be examined to ensure that it is minimized. To reduce heave motions, external damping devices are introduced and one such effective damping device is heave plate. Addition of heave plate can provide additional viscous damping and additional added mass in the heave direction which influence the heave motion. The present study focuses on the influence of heave plate on the hydrodynamic responses of Classic Spar in regular waves. The experimental investigation has been carried out on a 1:100 scale model of Spar with single and double heave plates in regular waves. Numerical investigation has been carried out to derive the hydrodynamic responses using ANSYS AQWA. The experimental results were compared with those obtained from numerical simulation and found to be in good agreement. The influence of disk diameter ratio, wave steepness, pretension in the mooring line and relative spacing between the plates on the hydrodynamic responses of Spar are evaluated and presented.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.62.2-62.2
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• 2017

We have made an investigation on the radial and azimuthal wave modes of full halo coronal mass ejections (HCMEs). For this, we consider 24 HCMEs which are simultaneously observed by SOHO and STEREO A & B from August 2010 to August 2012 when they were roughly in quadrature. Using the SOHO/LASCO C3 and STEREO COR2 A & B running difference images, we estimate the instantaneous apparent speeds of the HCMEs at 24 different position angles. Major results from this study are as follows. First, there are quasi-periodic variations of the instantaneous radial velocity with the periods ranging from 24 to 48 mins. Second, the amplitudes of instant speed variations are about a third of the projected speeds. Third, the amplitudes are found to have a weak anti-correlation with period. Our preliminary identification from SOHO observations shows that there are several distinct radial and azimuthal wave modes: m=0 (radial) for five events, m=1 for eleven events, m=2 for three events, and unclear for the other events. In addition, we are making a statistical investigation on the oscillation of 733 CMEs to understand their physical origins.

• Journal of Ocean Engineering and Technology
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• v.30 no.6
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• pp.440-450
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• 2016

The capsizing and consequent sinking of a coastal car ferry was recently reported, with numerous human casualties. The primary cause was determined to be a sudden turn with improperly stowed and secured cargo. Part I of this study introduces how long term acceleration components are determined from seakeeping analyses. A carferry with a displacement of 1,633 tonf was selected as the target vessel. Sea data that included the significant wave heights and periods were collected at four observation buoys, some of which were far away from two main voyage routes: Incheon-Jeju and Pusan-Jeju. Frequency response analyses were performed to obtain the linearized radiation force coefficients, hydrostatic stiffnesses, and wave excitation forces. Time response analyses were sequentially performed to produce the motion-induced acceleration processes. The probabilistic distributions of the acceleration components were determined using a peak and valley counting method. Long term extreme acceleration components were proposed as a final result.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.1
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• pp.45-53
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• 1998

Video monitoring techniques and their applications to beaches were reviewed. The recent development of video hardware and image process made it possible to measure shoreline changes, sandbar morphology, wave runup, swash motion, and so on using video camaras. Especially, quantitative information from the video image can be obtained by digitization of image, rectification procedure, and image process. Using video monitoring techniques, measurements can be made at much lower cost and for long periods of time compared to the traditional measurement techniques, although these techniques are of lower accuracy and provide only indirect information on the land and water surface.

• International journal of advanced smart convergence
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• v.8 no.1
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• pp.204-213
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• 2019

Perhaps nothing more vividly illustrates the many different ways in which traditions can be interpreted than a study of the life of Confucius in modern times. In China and Korea, Confucian values and culture are dismissed and scorned during some periods and held up as facilitators of cultural prosperity in others. This changing perception of and attitude toward the Confucian tradition in modern society embodies the long life of the Confucian tradition and its continually evolving trajectory, as well as its versatility within shifting sociopolitical milieux spanning distance and time. In this paper, I investigate the (re)emergence of Confucius in modern Korea and China with a comparative and critical gaze. I demonstrate how different modern interpretations of Confucius, both negative and positive, in these two countries bring new life to the Confucian tradition within their own complex social realities. By focusing on the recent revival of Confucius in China-Anti-tradition of Korean dramas, the Restoration of Confucian Culture in China and Korean Wave, the modernity of China in Confucius are examined, and finally, in terms of the means of realization of the Chinese dream-I illuminate how the image of Confucius serves the (re-)invention of contemporary China, with her pervasive desire to romanticize and materialize China's past as well as her future.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.183-195
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• 2022

Under the effects of the near-field earthquakes, the incident angle of the incoming wave could be different. In this study, the influences of some parameters such as incident angle, basin edge, peak ground acceleration level of the bedrock motion as well as different clay types with different consistency on the amplification behavior of the shallow basins are investigated. To attain this goal, the numerical analyses of the basins filled with three different clay types are performed using a fully nonlinear method. The two dimensional models of the basins are subjected to a set of strong ground motions with different peak ground acceleration levels and three different incident angles of 30◦, 45◦ and 90◦ with respect to the horizontal axes. The results show the dominant effect of the obliquely subjected waves at most cases. The higher effect of the 45◦ incident angle on the basin response was concluded. In the other part of this study, the spectral amplification curves of the surface points were compared. It was seen that the maximum spectral amplification of different surface points occurs at different periods. Also, it is affected by the increase in the peak acceleration level of the incoming motions.

• Pediatric Infection and Vaccine
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• v.29 no.3
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• pp.131-140
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• 2022

Purpose: Since the coronavirus disease 2019 (COVID-19) pandemic began, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged, and distinct epidemic waves of COVID-19 have occurred for an extended period. This study aimed to analyze the clinical and epidemiological characteristics of children with COVID-19 from the third wave to the middle of the fourth epidemic wave in Korea. Methods: We retrospectively reviewed the medical records of hospitalized patients aged ≤18 years with laboratory-confirmed COVID-19. The study periods were divided into the third wave (from November 13, 2020 to July 6, 2021) and the fourth wave (from July 7 to October 31, 2021). Results: Ninety-three patients were included in the analysis (33 in the third and 60 in the fourth waves). Compared with the third wave, the median age of patients was significantly older during the fourth wave (6.7 vs. 2.8 years, P=0.014). Household contacts was reported in 60.2% of total patients, similar in both periods (69.7 vs. 55.0%, P=0.190). Eighty-one (87.1%) had symptomatic SARS-CoV-2 infection. Among these, 10 (12.3%) had no respiratory symptoms. Anosmia or ageusia were more commonly observed in the fourth epidemic wave (10.7 vs. 34.0%, P=0.032). Most respiratory illness were upper respiratory tract infections (94.4%, 67/71), 4 had pneumonia. The median cycle threshold values (detection threshold, 40) for RNA-dependent RNA polymerase (RdRp) and envelope (E) genes of SARS-CoV-2 were 21.3 and 19.3, respectively. There was no significant difference in viral load during 2 epidemic waves. Conclusions: There were different characteristics during the two epidemic waves of COVID-19.

• Journal of Life Science
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• v.26 no.3
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• pp.346-352
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• 2016

Aroma inhalation therapy has traditionally been used not only in alternative medicinal treatment but also in psychotherapy. In the first stage of the study, the in silico molecular binding affinity of the major ingredients of Smart-Wave (SW) on the active site of the odorant-binding protein (OBP) was compared with that of citrate anions. The binding affinity of the chemical mixture formula of the major ingredients of SW on the OBP was relatively higher than that of citrate anions. In addition, nasal inhalation of SW had a positive effect upon changes in brain waves. Eighteen healthy volunteers participated in the experiment. The study consisted of measurements of the brain’s meditation level recordings in the pre- and post-SW inhalation periods as compared with negative (EV) and positive (HB) control groups. After SW inhalation, all the subjects stated that they felt “fresher” and that the SW trial group had significantly changed the brain’s meditation in a positive way. SW inhalation also converted EV-induced unstable brain meditation wave patterns into more stable patterns. Collectively, the results of this empirical study strongly suggest that the SW mixture activates the OBP and controls the mental state by regulating brain waves. The results provide scientific evidence that the SW formula has potential as an effective mental-stress controller.

• Journal of Korean Elementary Science Education
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• v.32 no.4
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• pp.567-580
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• 2013

This study is to activate gifted students' brains for creativity ability and also an integrated science and art teaching program. The learning programs integrating science and art, which have 30 periods and 10 topics on art and the knowledge of science, were developed dependant on five steps - observing, having interests and curiosity, experimental designing and performing, internalizing, and expressing in an arts-based manner. This programs were applied to 20 senior gifted students in Y Elementary School in Gyeonggi province, by one group pretest-posttest design. The results from these integrated programs of science and art are as follows: First, in the performance of science tasks, prefrontal lobe(F7, FT7) of left brain increase the relative power of theta wave, whereas in the performance of drawing tasks increase the relative power of beta wave in prefrontal lobe(FP1) of left brain, bilateral frontal(F7, F3, Fz, F4, F8, FT7, FC3, FCz), bilateral temporal(T7, TP7, TP8, P7), parietal lobe of left brain(CP3, CPz, P3, Pz), bilateral occipital(O1, Oz, O2). Second, in the performance of science tasks, the relative power of beta wave activity in the left temporal lobe(T7) of the brains of talented students in science significantly decreased whereas it was greatly activated in another part, the left frontal lobe(F3) of the brain (p<.05). Third, in the performance of drawing tasks, the relative power of theta wave activity in five areas of the brain, namely the left temporal lobe(T7), the left frontal lobe(F3), the right frontal lobe(F4), and the left and right parietal lobes of gifted students in science who took the course of the integrated programs, was considerably increased statistically(p<.05). On top of that, these programs were especially effective in balancing the symmetrical development of both cerebral hemispheres by multiplying theta wave activity in the frontal lobes(F3, F4) and the parietal lobes(CP3, P3, P4), which are particularly related to creative thinking. According to the results of this study of brain-based teaching strategies combining science and art, it is an effective program to develop overall activate gifted students' brains for creativity ability. This is expected to be utilized to activate the brain areas for creativity of gifted students in science.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.187-197
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• 2007

Experimental study for a submerged structure was conducted to protect coastal structures and shorelines. The rectangular submerged structure known as the most efficient shape among various submerged structures in the literature was fabricated at the nose of a rubble mound breakwater. The reflection coefficients and the run-up heights along the slope of a breakwater were measured for different significant wave heights and periods. It is found in this study that the reflection coefficient is affected more relatively by the significant wave period than the significant wave height and the run-up heights are reduced approximately 28% in terms of ${^{RU}}_{2%}$ and 26% in terms of ${^{RU}}_{33%}$, respectively, by the installation of a submerged structure inducing the interception and breaking of waves.