• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.4
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• pp.241-250
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• 1997

The velocity dispersion of surface acoustical wave(SAW) of Si layer/mesh Au/Si substrate was measured by the frequency analysis technique of backward radiation at liquid/solid interface. The difference of backward radiation patterns depending on used transducers (2, 5, 10MHz) confirmed that the backward radiation phenomenon was caused by the energy radiation from SAW generated in surface region. An ultrasonic goniometer was constructed to measure continuously the angular dependence of backscattered intensity. The angular dependences of backward radiation(5MHz) were measured for Ni layer/Al substrate specimens that were bonded by epoxy involving different content of Cu powder. It was known that the width and pattern of backward radiation had informations such as the velocity dispersion, bonding quality and structure of surface region.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.13-25
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• 2021

Hoseonmu belongs to the genre of a composite of song, music, and dance. At that time, there was no widely known record of Hoseonmu in Baekje, but it is clear that it was popular enough to be invited to Changan by Emperor Yang of Sui. The musical instruments, songs, and dances were analyzed through the research method of literature and the content of the Hoseonmu version was established. The setting of the stage for the performance of Baekje instrumental music reveals its characteristics through sabangak from Gigaku in the neighboring countries. The stage for Hoseonmu was set up utilizing the creation of the imperial performance stage in the Baekje instrumental music. In particular, Hoseonmu has two types: heavenly and earthly. The heavenly Hoseonmu can be found on the wall of the Cave No. 220 formed in the Chodang (618-707) era. They include Dongbang Pharmacopoeia jingbian and Western Paradise jingbian. Hoseonmu would have chosen to be the fast-paced spinning dance. Motions for Hoseonmu could be set up through them. Meanwhile, Mimaji's instrumental dance is presented. Six dancers appear in two turns of the performance. Four dancers in front row and other two in the back are dressed up as hunters, wearing goblin masks, and holding flowering plum tree branches in their right hands. Through this, the movements and costumes of Hoseonmu are reproduced in more detail. Various sectors of education, theater, dance, and tourism in the Hoseonmu contents of Baekje instrumental music contributed to the Korean Wave.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.19-30
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• 2018

The main purposes of this study are to analyze the contents and text network of online tourism information. For this purpose, Jeju Island, one of the representative tourist destinations in South Korea is selected as a study site. And this study collects the contents of both JeJu official tourism website and Sina Weibo's personal blogs which is one of the most popular Social Network Systems in China. In addition, this study analyzes this online text information using ROST Content Mining System, one of the Chinese big data mining systems. The results of the content analysis show that the formal website of Jeju includes the nouns related to natural, geographical and physical resources, verbs related to existence of resources, and adjectives related to the beauty, cleanness and convenience of resources mainly. Meanwhile, personal blogs include the nouns of Korean-wave, food, local products, other destinations and shopping, verbs related to activity and feeling in Jeju, and adjectives related to their experiences and feeling mainly. Finally, the results of text network show that there are some strong centrality and network of online tourism information at formal website, but there are weak relationships in personal blogs. The results of this study may be able to contribute to the development of demand-based marketing strategies of tourists destination.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.6
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• pp.644-653
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• 2013

In this paper, a formulation for obliquely incident electromagnetic wave has been presented for an analysis of highpower electromagnetic pulse penetration into multilayered dispersive media. Based on generalized models of measured dielectric constants and propagation channels reflecting the Earth's general features, the propagation phenomenon of the obliquely incident early-time(E1) high altitude electromagnetic pulse(HEMP) is analyzed. In addition, the polarization and critical angle are also considered. It is found that the total reflection occurs at an incident angle of about 38 degrees at the soil-rock interface, and that the parallel-polarized E1 HEMP penetrates better than the perpendicular-polarized one. The peak level of the penetrating electric field is found to be 5.6 kV/m at normal incidence, regardless of the type of polarization, and E1 HEMP is greatly reduced near the critical angle. Moreover, the penetrating E1 HEMP is analyzed as a variation of moisture content and depth of materials, resulting E1 HEMP could be useful in determining the levels of shielding required for buried facilities.

• Transactions of the KSME C: Technology and Education
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• v.4 no.1
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• pp.63-71
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• 2016

Although mechatronics education in a mechanical engineering curriculum is recently recognized as important, its experimental education has been done generally in the laboratory equipped with all the apparatus and could not be done at home by students. This paper introduces experimental educations on mechatronics, e.g., digital logic circuits, 7-segment LED drive, square wave generation, microcontroller programming using assembly and C languages, timer interrupt, and step motor drive using a small 5 V power supply, a breadboard, various electronic and electric components, a microcontroller and its programmer, a step motor, and a student's PC. In the developed mechatronics course, experimental educations are scheduled in parallel with content's lectures together, and cheap and economic experimental environment is prepared for students in which students can easily practice experimental works in advance or later at home by themselves.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.116-122
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• 2000

The molecular modification of antiepileptic drugs and direct synthesis of new drugs with the predetermined antiepileptic properties are perspective. New neurochemical attacking to solve the problem including prevention and inhibition of seizures seems to be related to ginsenosides and ginseng polypeptides. The main study based on the severity of febrile convulsions of rat pups has been done from the earlier investigations of antiepileptical action of ginsenosides between KGTRI and MSU (Chepurnov, Park et al., 1995) with different kinds of experimental models of epilepsy. From the cultured cell line DAN25 of ginseng root, the extracts of ginsenosides made in "BIOKHIMMASH" were studied by the project of preclinical anticonvulsant screening (Stables, Kupferberg, 1997). The inhibition of severity of convulsions, decrease of seizures threshold, decrease of audiogenic seizures in rats of different strains and normalization of cerebral blood flow (measured by hydrogen test) were demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-different region of the amygdala and demonstrated that the level of sex steroids and content of neurosteroids in amygdaloid tissue can modify the development of seizures. The chemical structures of ginsenosides not only have some principal differences from well-known antiepileptical drugs but the Plant Pharmacology gives us unique possibility to develop new class of antiepileptic drugs and to improve its biological activity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.594-604
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• 2021

To evaluate the causes of beach erosion in Sinji-Myeongsasimni Beach, external forces, such as tides, tidal currents, and waves, were observed seasonally from March 2019 to March 2020, and the surface sediments were analyzed for this period. In addition, the shoreline positions and beach elevations were regularly surveyed with a VRS GPS and fixed-wing drone. From these field data, the speed of the tidal currents was noted to be insufficient, but the waves were observed to af ect the deformation of the beach. As the beach is open to the southern direction, waves of heights over 1 m were received in the S-SE direction during the spring, summer, and fall seasons. Large waves with heights over 2 m were observed during typhoons in summer and fall. Because of the absence of typhoons for the previous two years from July 2018, the beach area over datum level (DL) as of July 2018 was greater by 30,138m² compared with that of March 2019, and the beach area as of March 2020 decreased by 61,210m² compared with that of March 2019 because of four typhoon attacks after July 2018. The beach volume as of March 2019 decreased by 5.4% compared with that of July 2018 owing to two typhoons, and the beach volume as of September 2019 decreased by 7.3% because of two typhoons during the observation year. However, the volume recovered slightly by about 3% during fall and winter, when there were no high waves. According to the sediment transport vectors by GSTA, the sediments were weakly influxed from small streams located at the center of the beach; the movement vectors were not noticeable at the west beach site, but the westward sediment transport under the water and seaward vectors from the foreshore beach were prominently observed at the east beach site. These patterns of westward sediment vectors could be explained by the angle between the annual mean incident wave direction and beach opening direction. This angle was inclined 24° counterclockwise with the west-east direction. Therefore, the westward wave-induced currents developed strongly during the large-wave seasons. Hence, the sand content is high in the west-side beach but the east-side beach has been eroded seriously, where the pebbles are exposed and sand dune has decreased because of the lack of sand sources except for the soiled dunes. Therefore, it is proposed that efforts for creating new sediment sources, such as beach nourishment and reducing wave heights via submerged breakwaters, be undertaken for the eastside of the beach.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.117-127
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• 2008

The volumetric pressure plate extractor (VPPE) was modified for the measurement of shear wave velocity ($V_s$) at various levels of matric suction as well as soil water characteristic curve (SWCC). A non-destructive technique with a pair of bender element (BE) was employed in order to measure the $V_s$ and the corresponding maximum shear modulus ($G_{max}$) of unsaturated soil specimens. Three types of soil were collected from different road construction sites in Korea. For all test soils, the variations in $G_{max}$ with the various levels of water content and matric suction were investigated using the developed apparatus. Compared with the preceding results from the suction-controlled torsional shear (TS) testing system and in-situ seismic tests, the feasibility fur evaluating modulus characteristics of unsaturated compacted soils with the developed VPPE-BE system was assessed. It was confirmed that the newly developed system would be potentially helpful in modeling seasonal variation of modulus.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.268-276
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• 2010

Earthquake Hazard Mitigation Law was activated into force on March 2009. By the law, the obligation to monitor the effect of earthquake on the facilities was extended to many organizations such as gas company and local governments. Based on the estimation of National Emergency Management Agency (NEMA), the number of free-surface acceleration stations would be expanded to more than 400. The advent of internet protocol and the more simplified operation have allowed the quick and easy installation of seismic stations. In addition, the dynamic range of seismic instruments has been continuously improved enough to evaluate damage intensity and to alert alarm directly for earthquake hazard mitigation. For direct visualization of damage intensity and area, Real Time Intensity COlor Mapping (RTICOM) is explained in detail. RTICOM would be used to retrieve the essential information for damage evaluation, Peak Ground Acceleration (PGA). Destructive earthquake damage is usually due to surface waves which just follow S wave. The peak amplitude of surface wave would be pre-estimated from the amplitude and frequency content of first arrival P wave. Earthquake Early Warning (EEW) system is conventionally defined to estimate local magnitude from P wave. The status of EEW is reviewed and the application of EEW to Odesan earthquake is exampled with ShakeMap in order to make clear its appearance. In the sense of rapidity, the earthquake announcement of Korea Meteorological Agency (KMA) might be dramatically improved by the adaption of EEW. In order to realize hazard mitigation, EEW should be applied to the local crucial facilities such as nuclear power plants and fragile semi-conduct plant. The distributed EEW is introduced with the application example of Uljin earthquake. Not only Nation-wide but also locally distributed EEW applications, all relevant information is needed to be shared in real time. The plan of extension of Korea Integrated Seismic System (KISS) is briefly explained in order to future cooperation of data sharing and utilization.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.174-179
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• 2000

Objectives : Cognitive psychological models propose that auditory hallucinations arise from a problem with monitoring one's auditory verbal imagery. Most auditory hallucinations are derogatory in content and accompany negative emotions. If auditory verbal imagery plays an critical role in the pathogenesis of auditory hallucination, it must be influenced by negative emotions. This study was aimed at understanding the influence of negative emotions on the development of hallucinations by investigating the way by which negative emotions have influence on cortical activity induced by auditory verbal imagery. Methods : For both normal subjects and patients with schizophrenia, quantitative electroencephalography(Q-EEG) was applied during the auditory verbal imagery tasks using a two word list. The one word list accompanied negative emotion and the other accompanied neutral emotions. The difference of EEG activity between two tasks was compared by paired t-test. We also compare the difference of the influence of negative emotions between normal subjects and patients with schizophrenia Results : In normal subjects, amplitude of beta wave was increased in temporal area such as TCP1, and, the amplitude of theta frequency wave was decreased in right hemisphere such as FP2, F4, C4, CP2, P4. But, in the schizophrenia group, there were no significant differences. Conclusion : These results may suggest that auditory verbal imagery with negative emotion requires more activation in left temporal area, but, appropriate activation may not achieved in schizophrenia patients. So, the possibility that the resultant disturbance of verbal self monitoring may be related to auditory hallucination is suggested in this study.