• Geophysics and Geophysical Exploration
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• v.21 no.1
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• pp.33-40
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• 2018

We investigate the crustal and uppermost mantle SV- and SH-wave velocity structure and radial anisotropy beneath East Asia including Korea, China and Japan. Rayleigh waves and Love waves were extracted from the seismic data recorded at broadband seismic stations in East Asia. Using the MFT (Multiple Filter Technique), we obtained group velocity dispersion curves of Rayleigh and Love waves with a period range of 3 to 200 s. We obtained 62466 Rayleigh-waves dispersion-curve measurements in vertical components and 54141 Love-waves dispersion-curve measurements in transverse components, respectively. The inverted models using these data sets provide SV- and SH-wave velocity structure of crust and uppermost mantle down to 100 km depth. In both cases of the S-wave velocity structures, strong high-velocity anomalies are observed down to 30 km depth beneath the East Sea, and deeper than 30 km depth, strong low-velocity anomalies are found beneath the Tibetan plateau. In the case of the SH-wave velocity structure, strong low-velocity anomalies are observed beneath the East Sea deeper than 30 km depth, leading to negative anisotropy. On the other hand, positive anisotropy is usually observed beneath the Tibetan plateau.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.242-248
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• 2000

본 연구에서는 가상현실에서 simulator factor [FOV (field of view)와 운행속도, frame rate의 fluctuation]를 변화시키면서 사용자들의 시지각 과제수행도, 생리신호의 변화를 관찰하였고, 가상현실 경험 전·후에 실시한 설문지 조사를 통해 심리적 영향도 알아보았다. 1) 가상현실 운행시 눈깜박임이감소하고 Pz, O1, O2 영역의 알파파가 줄어들며 텔타파가 늘어나는 생리적 변화가 나타났다. 2) 특히 가상현실에서 멀미를 보고했을때 심박률, 피부전도도가 증가하고 피부온도가 감소하는 것으로 나타났다. 멀미 보고시 나타난 변화는 교감신경계의 활동성이 증가하는 방향과 일치하였다. 3) 빠른 운행속도가 느린 운행속도보다 높은 말초혈류량 최대-최소차이값을 나타냈고, 넓은 FOV가 좁은 FOV보다 높은 심박률을 나타냈다. 좁은 화면 보다 넓은 화면 조건에서 Cz, Pz 영역의 알파파는 더 낮게 나타났고 텔타파는 더 높게 나타났다. frame rate의 fluctuation이 없을 때에 비해 있을때 더 높은 피부전도도를 보여주었다. 4) 가상현실 평가설문지 분석결과 신체적 불편감은 좁은 FOV·느린 운행속도 조건에서 가장 적은 불편감을 나타냈다. 과제수행 곤란도는 느린 운행속도에서 가장 적게 나타났고 과제수행 적중률은 느린 운행속도에서 가장 높게 나타났다. 생리신호, 과제수행 적중률, 설문지 분석결과는 좁은 FOV·느린 운행속도의 가상환경이 가장 멀미에 덜 민감하고 과제수행하기에 가장 용이한 것으로 나타났다.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.236-247
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• 2016

Considering the prevalent use of mobile devices and the mobile Internet in Korea, there should be open doors for retailers to a different type of distribution if they could find out what makes consumers satisfied with m-commerce sites as well as what makes consumers purchase from m-commerce sites. Therefore, we explored: 1) the antecedents of satisfaction with m-commerce sites and 2) the determinants of purchasers vs. browsers of m-commerce. As possible antecedents of the two dependent variables, the following were utilized in the current study: the Technology Acceptance Model (TAM), perceived shopping values, and interactivity. According to the results of this study, these variables related to the performance of mobile commerce sites (Perceived ease of use, Perceived usefulness, Synchronicity, Richness of content, and Contextual services) significantly affected satisfaction with m-commerce sites. On the other hand, the most important discriminator of an m-commerce purchaser vs. a browser was human-oriented interactivity, especially interpersonal communication among users. With the help of information technology.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.41-50
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• 2006

The crustal structure of Korean Peninsula have been investigated by analyzing group velocity dispersion data of surface wave. Cross.correlation of seismic background motions (Campillo and Paul, 2003; Shapiro et al., 2005) has been applied to estimate the short.period Rayleigh. and Love.wave group velocity dispersion characteristics of the region. Standard processing procedures were applied to the cross.correlation, except that signal whitening was used in place of one.bit sampling equalize power in signals from different times. Multiple.filter analysis was used to extract the group velocities from the estimate Green's functions, which were then use to image the spatially varying dispersion at periods between 0.5 and 20 seconds. The tomographic inversion technique used inverted all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.

• The Journal of the Korea Contents Association
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• v.6 no.11
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• pp.110-117
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• 2006

With the New media of present age we are living at, strongly entice consumers through various sensible technology and give influences on our life. They are visually formed but make us feel them as if formed tactile. The masses of today are meeting media through all the senses in daily life according to the spread of on-line media and in such course they want momentary and tactile share. Since appearance of mass society and cinema following such current, art has appealed to dispersive and tactile perception, and such public way of perception makes it possible to experience 'visual tactility' in daily life in accordance with the development of on-line game culture among others. The shock effects, given by editing of game animations which are produced for epic experience of on-line game, arouse tactility in addition to visibility. Under this assumption and on the basis of visual tactility theory as well as montage theory of image by Walter Benjamin, the research intends to explain that public tactile shock does not result from simple graphic effect but from montage effect and dispersive acceptance.

• Korean Journal of Ecology and Environment
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• v.45 no.3
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• pp.340-346
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• 2012

The relationships between environmental factors and the dynamics of the microcrustacean community, including planktonic or epiphytic cladocerans and copepods, were studied at Upo Wetlands from 2001 to 2010. Among 10 identified cladoceran taxon, epiphytic cladocerans (Alona, Camptocercus, Simocephalus, Diaphanosoma, Sida) and planktonic cladocerans (Bosmina, Ceriodaphnia, Daphnia, Moina, Scapholeberis) showed distinctive patterns in appearance throughout the year. Overall, epiphytic cladocerans were more abundant during the aquatic plant development season (May to Nov.), planktonic cladocerans were similarly distributed throughout the seasons, but showed a lower density than epiphytic cladocerans. The seasonal changes in copepods abundance showed a similar seasonal pattern when compared to epiphytic cladocerans. Planktonic cladocerans showed no significant relationship to rainfall and physico-chemical factors, while epiphytic cladocerans exhibited a distinct relationship with rainfall and water temperature (n=120, p<0.01), and a negative relationship with pH and conductivity (n=120, p<0.05). Among the epiphytic cladocerans, the Alona and Diaphanosoma showed a distinctive correlation with environmental factors, and their density was affected by rainfall and water temperature (n=120, p<0.01). Copepods had a positive relationship with rainfall (n=120, p<0.01) and water temperature (n=120, p<0.05). In conclusion, changes in rainfall and water temperature can affect the seasonal changes of microcrustacean community and abundance in Upo Wetlands.

• The Journal of Engineering Geology
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• v.13 no.3
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• pp.293-308
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• 2003

New results about the crustal structure down to a depth of 60 km beneath North Korea were obtained using the seismic tomography method. About 1013 P- and S-wave travel times from local earthquakes recorded by the Korean stations and the vicinity were used in the research. All earthquakes were relocated on the basis of an algorithm proposed in this study. Parameterization of the velocity structure is realized with a set of nodes distributed in the study volume according to the ray density. 120 nodes located at four depth levels were used to obtain the resulting P- and S-wave velocity structures. As a result, it is found that P- and S-wave velocity anomalies of the Rangnim Massif at depth of 8 km are high and low, respectively, whereas those of the Pyongnam Basin are low up to 24 km. It indicates that the Rangnim Massif contains Archean-early Lower Proterozoic Massif foldings with many faults and fractures which may be saturated with underground water and/or hot springs. On the other hand, the Pyongyang-Sariwon in the Pyongnam Basin is an intraplatform depression which was filled with sediments for the motion of the Upper Proterozoic, Silurian and Upper Paleozoic, and Lower Mesozoic origin. In particular, the high P- and S-wave velocity anomalies are observed at depth of 8, 16, and 24 km beneath Mt. Backdu, indicating that they may be the shallow conduits of the solidified magma bodies, while the low P-and S-wave velocity anomalies at depth of 38 km must be related with the magma chamber of low velocity bodies with partial melting. We also found the Moho discontinuities beneath the Origin Basin including Sari won to be about 55 km deep, whereas those of Mt. Backdu is found to be about 38 km. The high ratio of P-wave velocity/S-wave velocity at Moho suggests that there must be a partial melting body near the boundary of the crust and mantle. Consequently we may well consider Mt. Backdu as a dormant volcano which is holding the intermediate magma chamber near the Moho discontinuity. This study also brought interesting and important findings that there exist some materials with very high P- and S-wave velocity annomoalies at depth of about 40 km near Mt. Myohyang area at the edge of the Rangnim Massif shield.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.399-417
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• 2015

The purpose of this research is to investigate the effects of brand extension on original brand in mobile market. TAM (Technology Acceptance Model) was used in current research to verify the 'intention to use of mobile service', and 'perceived usefulness', 'perceived ease of use', and the effect of 'extended brand's intention to use' on continuous 'intention to use in original brand' are verified in the process. According to the results, TAM was found to be appropriate to verify the intention to use of mobile service. Also by verifying the effect of decision factor, it is found that perceived ease of use have positive(+) influence on continuous intention to use of original brand. According th this finding, marketers will be able to understand better in performing strategies in mobile service environment.

• Korean Business Review
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• v.17 no.2
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• pp.131-159
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• 2004

The purpose of this paper is to propose and test a conceptual framework that investigates the effects of perceived service quality on customer satisfaction, attitude toward brand(Ab) and customer loyalty. To test the framework, structural equation modeling are applied to data collected from 210 samples in mobile phone service industry. The results of this research indicated that interaction quality and outcome quality of perceived service quality are positively on customer satisfaction, but the outcome quality is stronger influence than interaction quality. The findings also show that outcome quality effect on directly Ab and then interaction quality effect on indirectly Ab through customer satisfaction. But There are no effect outcome quality, interaction quality and Ab on customer loyalty without customer satisfaction effect. These results include implications that mobile phone service company should have customer satisfaction to retain customer and customer loyalty.

• Korean Journal of Culture and Social Issue
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• v.14 no.1
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• pp.19-45
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• 2008

The present study investigated the relationship between the perceptions of social change and subjective well-being, and the effectiveness of coping resources in such a relationship by comparing the structural equation models of the samples obtained in two countries (Korea and the United States). Participants in two countries reported their perceived pace of social change, evaluation of social change, subjective well-being, personal resources(self-esteem and self-efficacy), and social resources. Based on the survey data, a structural equation models was developed and compared across two samples to examine the moderation effects of coping resources by culture and nations. As a result, it was revealed that the perceived pace of social change affected subjective well-being through the mediation of the evaluations of social change and that there were differences in the effectiveness of coping resources: social resources had stronger effects for the Korean sample whereas personal resources had stronger effects for the U.S. sample. Discussions on the psychological impact of a new type of social stress, social change, is included.