• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.73-78
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• 2008

We introduce OBS and sonobuoy systems which are the typical wide-angle reflection/refraction seismic recorders made by KORDI for the investigation of crustal structure and the sediment/basement structure in the coastal area. These recording devices are examined for their usage through the test survey. The normal operation of these devices were proved and good recordings were obatined. The head waves are recognized in the sonobuoy records, which shows the possibility of velocity structure survey by the refraction and/or tomography method.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.64-69
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• 2006

At starting point, 1D velocity models were inverted by using 430 events with P-wave 5147, S-wave 3729 from KIGAM, KMA, KEPRI, and KINS's seismic networks. A minimum 1D model shows that P-wave velocities are around $6.0{\pm}0.5\;km/s$ slowly increasing with depth between surface and 15 km. The velocities are about $6.4{\pm}0.2\;km/s$ below 15km to 35km. The earthquake data number for 3D tomography was 630 adding to previous 430 events with limitation of more than 6 station detection and relocation stability of location. The checkerboard test shows that only upper curst part from surface to 17 km have reliable resolution. The results of upper crust part present that the boundary of Gyeong-sang basin and Youngnam massif is mach well velocity variation pattern. The western part of the basin is shown as lower velocity and south-eastern part as higher. This is because that sedimentary rocks are widely located around western part of the basin and volcanic origin rocks are distributed around south-eastern part.

• Journal of Korea Game Society
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• v.21 no.6
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• pp.41-50
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• 2021

Character identification is illustrated in terms of game players' altered self-perception during gameplay. Research has shown that players' identification with game characters resulted in game players aligning their attitude with game character. This study investigates the relationships among control, ownership, character customization, identification, flow with game charater, and the impact on game players' behavior toward item purchase and play intention. Empirical results showed that character ownership and character customization significantly predicted use-character identification, but the impact of character control was not supported. In addition, the positive relationships between identification and flow was supported.

• CRM연구
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• v.3 no.1
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• pp.49-71
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• 2010

This study set out to shed more specific light onto sales managers' coaching and salespersons'organizational commitment and role perceptions, which have been proven to work as important variables in salespersons' performance. It thus conducted an in-depth investigation into the overall sale management activities of sales managers from five high-sales organizations and five low-sales organizations and analyzed differences between them. The interviews of the ten sales managers were combined and analyzed. As a result, the ones from the high-sales organizations demonstrated the following characteristics: first, the salespersons of the high-sales organizations were strongly committed to the goals and values of their organizations. Second, the salespersons of the high-sales organizations had clear perceptions of their roles and showed relatively fewer role conflicts than those of the low-sales organizations. Third, the sales managers of the high-sales organizations demonstrated coaching behavior strongly. They provided positive feedback and role models for the salespersons to follow, thus earning great respect from them and maintaining trust-based relationships with them. And finally, the sales managers' organizational commitment and role perceptions had positive impacts on the salespersons' organizational commitment and role perceptions. Those research findings indicate that sales managers' organizational commitment and role perceptions can be a positive role model to salespersons and that such a role model can have influences on salespersons' performances as part of the characteristics of coaching behavior.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.644-655
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• 2020

This study focuses on the margin of human error when a navigator is embarrassed by the psychological fear of collision in a close-quarter situation (CQS) and is unable to perform as per the prescribed collision avoidance measures. The purpose of the study is to identify the effects of the navigator's personal characteristics or factors in relation to on-board career (OC), license rating (LR), and age on the perceived collision risk (PCR) in CQSs. In order to obtain quantified data regarding the collision risk perceived by the navigator in four typical CQSs between their own ship and a target ship, this study measured and collated the heart rate variability of 30 navigators on their own ship when two ships approached each other at a speed of 10 knots from 2.5 nautical miles to a collision situation. According to a multiple regression analysis of the measured values, the navigators' OC and LR factors had negative effects on the PCR, while the age factor had no significant effect on PCR. The t-test results showed that the PCR value was significantly higher for navigators with an OC ≤ 4 years than for those with an OC ≥ 5 years, and the LR factor was significantly higher for a class 4~6 group than for a class 2~3. This finding may be applied to the development of collision risk warning systems, particularly for navigators.

• Journal of the Korean Geophysical Society
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• v.10 no.1
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• pp.13-25
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• 2007

We investigated the undulation of Moho depth and the crustal structure of the continental margin in the East Sea along the Korea Peninsula from inversion and modelling using potential data and previous seismic results. Free-air gravity anomalies generally reflect topography effect. Bouguer gravity anomalies increase toward the Ulleung Basin, indicating that Moho depth is shallower under the Ulleung Basin. Positive magnetic anomalies exist along the continental margin and decrease toward the Ulleung Basin. In analytic signal, the small anomaly in the Hupo Bank infers that the Hupo Bank is uplifted by igneous intrusion and the strong anomaly on the continental slope denotes existence of SDR(seaward dipping reflectors), which are in accordance with the location of SDR detected in previous seismic studies. The inversion result of Bouguer gravity anomaly and the 2-dimensional gravity modelling indicate that the undulation of Moho depth shallows from the continental shelf toward the Ulleung Basin. This is in good agreement with the Moho depth calculated by the previous seismic velocity model using ocean bottom seismometer(OBS). The 2-dimensional gravity modelling infers magmatic underplating zone under the lower continental crust on the continental margin of the East Sea, indicating the possible rifiting of the continental margin.

• Geophysics and Geophysical Exploration
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• v.13 no.2
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• pp.137-143
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• 2010

An earthquake with local magnitude $(M_L)$ 3.7 on December 9, 2000 occurred offshore Yeongdeok area, South Korea. In case of applying Chang and Baag (2006) crustal velocity model, the epicenter is $36.4462^{\circ}N\;and\;129.9789^{\circ}E$, which belongs to the inside of the Korean Peninsula Continental Shelf. Although we use the modified model reducing crustal thickness of Chang and Baag (2006) model by 5 km considering the transition from continental crust to oceanic crust in the East Sea, the epicenter was little changed. We carried out the waveform inversion analysis to estimate focal depth and focal mechanism of this event. The focal depth is estimated to be 11 ~ 12 km. The seismic moment is estimated to be $1.0{\times}10^{15}N{\cdot}m$, and this value corresponds to the moment magnitude $(M_W)$ 3.9. The offshore Yeongdeok event including May 29, 2004 offshore Uljin one show typical thrust faulting, and the direction of P-axis is ESE-WNW. The moment magnitude estimated by the spectral analysis is 4.0, which is similar to that by the waveform inversion analysis. Average stress drop is estimated to be 3.4 MPa.

• Journal of Internet Computing and Services
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• v.20 no.2
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• pp.109-118
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• 2019

The purpose of this study is to deliver both market-practical and civil-centric political implication for sharing economy by investigating the nature of consumer-adoption for car-sharing service. With the global interest and market proliferation of the sharing economy, various service models for sharing idle resources have also been released in Korea. Particularly, in case of car sharing service, public - private partnership projects are spreading rapidly in various local governments including Seoul, along with the growing demand for alternative transportation system centering on the urban area. This study conducted an empirical study on the process of accepting the car sharing service by analyzing the data collected from users of the car sharing service "Sharing Car(Nanum Car)" of Seoul Metropolitan Government. A survey was conducted on 281 users in their twenties who are in the age of main use among the experienced users of the "Sharing Car(NaNum)" residing in Seoul. The result of analysis on the relationship between these users' perceived value and intention to use the vehicle sharing service would provide implications for establishing consumer(citizen)-centeric policies as well as market implications.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.143-151
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• 2012

The tsunami disasters and tectonic movements derived from mega-earthquake(M 9.0) which occured in the sea floor of the Pacific side of northeast Japan in March, 2011 were investigated. Landward invasion limit of the tsunami was 4.0km from the present coastline in Sendai coastal plain. It was observed that sandy deposit was dristributed largely in coastward part and muddy deposit was distributed largely in landward part. The ratios of distribution distances of the above two deposits were, respectively, 60~75% and 25~40% of the whole invasion distance of the 2011 tsunami. The ratios of the above distribution distances of tsunami deposits could be used to estimate landward invasion distances of the past maga-tsunamies(e.g. '2,000year B.P. Mega-Tsunami' and 'Jogan Tsunami' etc.) in Sendai coastal plain. The mega-scale tsunami disasters were caused by the low and flat geomorphic condition in the Sendai coastal plain and the increasing effect of tsunami height affected by narrow inlet condition of the so-called Ria's coast in the Sanriku coastal area respectively. Tectonic subsidences caused by the mega-earthquake in march, 2011 were observed in many areas of Ishinomaki, Ogawa, Ogachi and Onagawa coasts in northeast Japan. The displacements of tectonic subsidence were between 0.5 meters and 1.0 meters.

• Knowledge Management Research
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• v.23 no.1
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• pp.47-67
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• 2022

Computer and Internet information technologies(ICTs) have changed the modern service industry and people's life style. In particular, the global spread of COVID-19 has attracted more attention to contact service types such as self-service technology. With the increase in labor costs and the enhancement of consumer self-awareness, more and more companies transfer part of their work to customers through their own service technology. This study seeks to answer the following questions. (1) Do technology difficulty and safety perception affect customer value recognition in the self-service technologies? (2) Does customer value recognition influence the intention to use such technologies continuously? This study conducted an empirical analysis with 327 samples to validate the influence of self-service characteristics(technology difficulty and safety perception) on customer value recognition and continuous utilization intentions. Also, it analyzes the moderating effects of age and frequency of use on the relationship between self-service characteristics and customer value recognition. The study results show that the technology difficulty does not affect the customer's perceived value recognition; and the higher the customer's value recognition, the higher the intention of continuous use.