• Geophysics and Geophysical Exploration
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• v.12 no.3
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• pp.225-232
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• 2009

As part of seismic experiments investigating crustal velocity structures of the Korean peninsula, permanent (fixed) seismographs of the Korea Meteorological Administration (KMA) network recorded seismic signals from four and eight large explosions in Korean Crustal Research Team (KCRT) profiles shot in 2004 and 2008, respectively. Among the seismograms recorded by 43 velocity sensors and 103 accelerometers at KMA stations distributed throughout the southern Korean Peninsula, 156 records with epicentral distances less than 120 km and high signal-to-noise ratios were analyzed to determine velocity anisotropy of the Pg phase. Relative elevation corrections of -101.6 to 105.3 ms were made using velocity information derived from the 2004 KCRT profile data and differences in elevation between the permanent KMA stations and the temporary stations in the KCRT profiles at the same source-receiver offsets. To remove site effects, receiver-station corrections of -89.6 to 192.2 ms were additionally made to the KMA station data by subtracting the average differences in traveltimes between KMA stations and portable stations at the same offsets for all available shots with different azimuths. With the exception of anomalously fast velocities along trends of the Chugaryeong fault zone and the Okchon fold belt and anomalously slow velocities in the regions of high terrestrial heat near Yeongduk and Ulsan, the analysis of crustal velocity anisotropy using the Pg phase indicates overall isotropy in the southern half of the Korean peninsula.

• The Korean Journal of Petroleum Geology
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• v.13 no.1
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• pp.1-16
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• 2007

The southeastern Korean Peninsula has experienced crustal multi-deformations according to changes of global tectonic setting during the Cenozoic. Characteristic features of the crustal deformations in relation to major Cenozoic tectonic events are summarized as follows. (1) Collision of Indian and Eurasian continents and abrupt change of movement direction of the Pacific plate (50${\sim}$43 Ma): The collision of Indian and Eurasian continents caused the eastward extrusion of East Asia block as a trench-rollback, and then the movement direction of the Pacific plate was abruptly changed from NNW to WNW. As a result, the strong suction-force along the plate boundary produced a tensional stress field trending EW or WNW-ESE in southeastern Korea, which resultantly induced the passive intrusion of NS or NNE trending mafic dike swarm. (2) Opening of the East Sea (25${\sim}$16 Ma): The NS or NNW-SSE trending opening of the East Sea generated a dextral shear stress regime trending NNW-SSE along the eastern coast line of the Korean Peninsula. As a result, pull-apart basins were developed in right bending and overstepping parts along major dextral strike slip faults trending NNW-SSE in southeastern Korea. The basins can be divided into two types on the basis of geometry and kinematics: Parallelogram-shaped basin (rhombochasm) and wedged-shaped basin (sphenochasm), respectively. In those times, the basins and adjacent basement blocks experienced clockwise rotation and northwestward tilting contemporaneously, and the basins often experienced a kind of propagating rifting from NE toward SE. At about 17Ma, the Yonil Tectonic Line, which is the westernmost border fault of the Miocene crustal deformation in southeastern Korea, began to move as a major dextral strike slip fault. (3) Clockwise rotation of southeastern Japan Island (about 15 Ma): The collision of the Izu-Bonin Arc and southeastern Japan Island, as a result of northward movement of the Philippine sea-plate, induced the clockwise rotation of southeastern Japan Island. The event caused the NW-SE compression in the Korea Strait as a tectonic inversion, which resultantly tenninated the basin extension and caused local counterclockwise rotation of blocks in southeastern Korea. (4) E-W compression in the East Asia (after about 5 Ma): Decreasing subduction angle of the Pacific plate and eastward movement of the Amurian plate have constructed the-top-to-west thrusts and become a major cause for earthquakes in southeastern Korea until the present time.

• Korean Journal of School Psychology
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• v.15 no.1
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• pp.69-89
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• 2018

This study first investigated the relationship among elementary school students' perceived academic stress, self-esteem, and aggression. This study further tested the moderating effect of self-esteem on the relationship between academic stress and aggression. In particular, the moderating effect was tested three times for the three dimensions of aggression (i.e., behavioral aggression, hostility, & anger). A total of 758 (woman 52.1%) 5th to 6th grade elementary school students participated in this study by responding to a questionnaire including measures of academic stress, self-esteem and aggression. The main results of the study were as follows. First, academic stress perceived by the elementary school students showed significant, positive correlations with all of the three dimensions of aggression. Second, the students ' self-esteem was negatively associated with the three aggression dimensions. Third, self-esteem was found to be a significant moderator between academic stress and two dimensions of aggression (hostility & anger), respectively, yet forth, the moderating effect of self-esteem was not significant between academic stress and the behavioral aggression dimension. This study suggests that academic stress can be a risk factor to increase elementary school students' aggression, and that their level of self-esteem can be a buffer to lower the risk. This study provides implications for educators to develop a program that can reduce elementary school students' aggression under academic stress by boosting the students' self-esteem.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1509-1521
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• 2013

Social demand for the stability of structures lead to the development of the technology to accomplish it. The non-destructive seismic technique, which is able to assess structural integrity of infrastructures, belongs to this category. Seismic technique is focused on the measurement of seismic velocity propagating through the material, and has to utilize sensors coupled to material surface, which does not allow the testing to be performed on the fly. In this paper, a general vocal microphone, which works as a non-contact sensor, was adopted to facilitate seismic testing with mobility and efficiency improved. The target of using microphones was oriented toward quality assessment of compacted subgrade, stiffness evaluation and health monitoring of concrete structures. Experimental parametric study and field applications were performed to investigate reliability and efficiency of microphones. Finally, the optimal test configuration of microphones was suggested for resonance tests and surface-wave tests.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.107-127
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• 2003

After detailed geological mapping, structural and fracture-density data were collected and analyzed in the vicinity of Cheonseong and Jeongjok Mts., Gyeongsangnam-do. A extensive dextral strike-slip fault (Beopgi Fault) Parallel to Yangsan and Dongrae Faults, a dextral-transtensional-NW fault, and a few intermittent faults have been found in the study area. Based on strike and frequency, fracture system has been divided into three sets such as NNE-trending J1 ($NS-40^{\circ}E$), WNW-trending J2 ($N50^{\circ}-80^{\circ}W$), and ENE-trending J3 ($N60^{\circ}-90^{\circ}E$). According to analysis of fracture density, it is revealed as follows: (a) Jl is the combination of Y-, P-, and R-shear fractures due to the dextral strike-slip of the Beopgi Fault. (b) J2 is the preexisted fracture zone conducting the intrusion of granite. Two tensional fractures dipping to NNE and SSW respectively have been induced by intrusion of granite and followed crustal uplift. (c) J3 is the tensional fracture developed between Yangsan and Dongrae Faults having NNE trend and dextral strike-slip sense. This study aims to reduce environmental impact and insure stability of underground facilities and tunnels.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.236-244
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• 2008

We propose a new building detection and description algorithm for Lidar data and photogrammetric imagery using color segmentation, line segments matching, perceptual grouping. Our algorithm consists of two steps. In the first step, from the initial building regions extracted from Lidar data and the color segmentation results from the photogrammetric imagery, we extract coarse building boundaries based on the Lidar results with split and merge technique from aerial imagery. In the secondstep, we extract precise building boundaries based on coarse building boundaries and edges from aerial imagery using line segments matching and perceptual grouping. The contribution of this algorithm is that color information in photogrammetric imagery is used to complement collapsed building boundaries obtained by Lidar. Moreover, linearity of the edges and construction of closed roof form are used to reflect the characteristic of man-made object. Experimental results on multisensor data demonstrate that the proposed algorithm produces more accurate and reliable results than Lidar sensor.

• Journal of Digital Convergence
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• v.9 no.6
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• pp.217-229
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• 2011

Conventional IT device has been evolving into smart device based on more powerful computing, the adoption of platforms, and next generation networking. There are not many empirical studies with regard to the early adoption stage of smart IT technology devices. This paper aims to investigate intention to use smart device based an extended technology acceptance model (TAM) with flow empirically. We get the results that there are positive influences among multidimensional user characteristics and flow, perceived usefulness and the intention to use. According to this results, companies which want to dominate the market in advance should understand the characteristics of potential consumers in developing marketing strategies and contents.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.1
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• pp.38-48
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• 2018

The purpose of this study is to improve the understanding of visual perception and to extend the landscape evaluation area by comparing eye-tracking evaluation and landscape adjective evaluation methods towards various type of nightscapes. As a result of the study, it showed that 'blink count', 'fixation duration average', and 'saccade duration average' of eye tracking measurements have a significant correlation with 'beautiful', 'interesting', 'accessible', 'satisfying', and 'safe' regarding landscape adjectives. In addition, there was a tendency toward areas of interests (AOIs) depending on 12 different nightscapes, which showed that the gaze was fixated by focusing on certain landscape elements such as 'door' and 'signs'. These results suggest that the eye-tracking method is an effective tool to specify the evaluation of 'landscape elements' rather than the 'whole landscape' and can be used as a basis to support landscape preference theories, which has been presented as conceptual only. In this way, the results of this study demonstrated the possibility of various applications of eye tracking as an objective landscape evaluation technique, and it is possible to suggest specific implications to landscape planning through the accumulation of continuous research results.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.215-226
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• 2014

The 3D technology has been spread slowly and the reason would be attributed to the fact that most commercialized 3D displays require 3D glasses. There have been various researches on human factors of glass type 3D display. In this study we measured and modeled crosstalk as well as 3D visual fatigue induced by mobile glassless 3D display. Crosstalk as well as visual fatigue varied depending on horizontal position of the 3D mobile display. Measured crosstalk was relative low around the center of the display and it increased at the side of the display. Similar results were found in the measurement of 3D visual fatigue and discomfort. These results imply that human factors should be considered in the process of design and evaluation of mobile 3D displays.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.144-146
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• 2011

VTS 항해의 특징은 동적복잡계의 특성을 보인다는 점이다. 자율적인 행위자들인 여러 선박이 서로 영향을 끼치며 상호작용하기 때문에 불확실성이 지배하게 된다. 이러한 불확실성으로 인한 위험을 극복하기 위한 방안으로 본 연구에서는 협력항해(co-navigation)이라는 개념을 중심으로 논의를 전개하였다. 본질적으로 협력항해는 수많은 상황판단과 의사결정들의 집합체이기 때문에 우선 개별 선박들의 상황판단이 어떻게 이루어지는가를 연구하는 것으로부터 출발하여야 한다. 따라서 본고에서는 항해에서 있어서의 상황자각이 어떻게 기능하는지 알아보고, 개인적인 상황판단에서 VTS 전체 차원의 최종 의사결정이 이루어지는 전 과정을 6단계로 세분하여 논의를 전개하였다. 이렇게 세분한 각 단계에서 양질의 인지과업이 이루어지도록 돕고, 이때 저지르게 되는 실수를 수정할 수 있도록 여유시간을 확보할 수 있도록 함으로써 궁극적으로 항해위험을 줄일 수 있다는 것을 이번 연구에서 밝히고자 하였다.