• Geophysics and Geophysical Exploration
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• v.6 no.4
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• pp.199-206
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• 2003

Characteristics of the static shift are discussed by comparing the three-dimensional MT inversion with/without static shift parameterization. The galvanic distortion by small-scale shallow feature often leads severe distortion in inverted resistivity structures. The new inversion algorithm is applied to four numerical data sets contaminated by different amount of static shift. In real field data interpretations, we generally do not have any a-priori information about how much the data contains the static shift. In this study, we developed an algorithm for finding both Lagrangian multiplier for smoothness and the trade-off parameter for static shift, simultaneously in 3-D MT inversion. Applications of this inversion routine for the numerical data sets showed quite reasonable estimation of static shift parameters without any a-priori information. The inversion scheme is successfully applied to all the four data sets, even when the static shift does not obey the Gaussian distribution. Allowing the static shift parameters have non-zero degree of freedom to the inversion, we could get more accurate block resistivities as well as static shifts in the data. When inversion does not consider the static shift as inversion parameters (conventional MT inversion), the block resistivities on the surface are modified considerably to match possible static shift. The inhomogeneous blocks on the surface can generate the static shift at low frequencies. By those mechanisms, the conventional 3-D MT inversion can reconstruct the resistivity structures to some extent in the deeper parts even when moderate static shifts are in the data. As frequency increased, however, the galvanic distortion is not frequency independent any more, and thus the conventional inversion failed to fit the apparent resistivity and phase, especially when strong static shift is added. Even in such case, however, reasonable estimation of block resistivity as well as static shift parameters were obtained by 3-D MT inversion with static shift parameterization.

• Geophysics and Geophysical Exploration
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• v.27 no.2
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• pp.129-143
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• 2024

In magnetotelluric (MT) surveys, small inhomogeneities near the surface cause a static shift in which apparent resistivities shift regardless of frequency. As the static shift in MT data leads to errors in subsurface structure interpretation, many studies have been conducted over the past few decades to mitigate or remove the distortions it caused. The most representative method involves removing static shifts from the data before inversion. Conversely, static shifts can be corrected during inversion or included in the inversion process. In addition, other geophysical data can be used to remove static shifts. However, the correction methods are limited to one-dimensional (1D) static responses, and limitations remain in two- or three-dimensional (2D or 3D) interpretation of distorted MT data owing to static shifts. This study provides a foundation for future studies on static shift by analyzing several previously published methods.

• Geophysics and Geophysical Exploration
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• v.17 no.2
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• pp.95-103
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• 2014

This paper presents a practical inversion method for recovering a three-dimensional (3D) resistivity model and static shifts simultaneously. Although this method is based on a Gauss-Newton approach that requires a sensitivity matrix, the computer time can be greatly reduced by implementing a simple and effective procedure for updating the sensitivity matrix using the Broyden's algorithm. In this research, we examine the approximate inversion procedure and the weighting factor ${\beta}$ for static shifts through inversion experiments using synthetic MT data. In methods using the full sensitivity matrix constructed only once in the iteration process, a procedure using the full sensitivity in the earlier stage is useful to produce the smallest rms data misfit. The choice of ${\beta}$ is not critical below some threshold value. Synthetic examples demonstrate that the method proposed in this paper is effective in reconstructing a 3D resistivity structure from static-shifted MT data.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.324-336
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• 2022

The purpose of this study was to investigate the moderating effect of interpersonal contact anxiety due to COVID-19 on the relationship between eating-out motivations of Korean and Chinese consumers, dining out, and delivery-takeout. As a result of examining the moderating effect of Korean consumers' interpersonal contact anxiety, it was found that interpersonal contact anxiety had a moderating effect to weaken the positive influence of rational motivation on dining out. As a result of examining the moderating effect of Chinese consumers' interpersonal contact anxiety, it was found that interpersonal contact anxiety had a moderating effect to weaken the positive influence of rational motivation on dining out. But the positive influence of emotional motivation on dining out was increased. Also, it was found that interpersonal contact anxiety had a moderating effect that strengthened the positive influence of rational motivation on delivery, and it also had the effect of weakening the positive effect of emotional motivation on delivery. It was found that interpersonal contact anxiety had a moderating effect to strengthen the positive influence of emotional motivation on takeout.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.2
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• pp.33-47
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• 2001

성능에 기초한 내진설계에서는 구조물이 보유하고 있는 능력을 효과적으로 파악하기 위해서 비선형 정적 해석이 적용되고 있다. 그러나 비선형 정적해석은 고차모드에 대한 효과를 고려하지 못함으로써 고층구조물이나 비정형 구조물과 같은 경우에는 정확한 비선형 지진응답의 산정과 내진성능을 평가하는데 문제점을 가지고 있다. 본 연구에서는 건축구조물의 선형 및 비선형 지진응답 평가를 위하여 응답 스펙트럼해석을 통하여 얻어지는 층전단력으로부터 층하중을 산정하는 유사동적해석법이 적용되었다. 제안된 방법을 비선형 정적 해석에 적용하여 구조물의 비선형 자동응답을 비선형 시간이력해석의 결과와 비교하였다. 기존의 층분포하중에 의한 비선형 지진응답과 비교하였으며, 제안된 방법에 의한 지진 응답이 구조물의 비선형 거동특성을 가장 정확하게 표현하였다. 그러므로 본 연구에서 제안된 방법을 사용하여 비선형 정적 해석을 수행한다면 비교적 명확한 건축물의 비선형 거동특성과 내진성능을 평가할 수 있을 것으로 판단된다.

• Informatization Policy
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• v.24 no.1
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• pp.48-78
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• 2017

In this study, to reveal determinant factors for degree of open data it conduct empirical analysis for ODB(Open Data Barometer) and OUR Index(Open, Useful, Reusable Government Data Index) that are global open data index among 26 countries. As a result of multiple regression analysis, First focus is on ODB. In the Model 1 with independent variables, e-Government, SW Market size and government efficacy are significantly positive effect for ODB. In the Model 2 with independent variables and moderating variable, e-Government, SW market size and social capital are significantly positive effect for ODB. In the Model 3 with independent variables, moderating variable and interaction term, e-Government and social capital are significantly positive effect for ODB. Second focus is on OUR Index. In the Model 1 and the Model 2 e-Government is significantly positive effect for OUR Index. In the Model, e-Government and SW market size ${\times}$ social capital(interaction term) are significantly positive effect for OUR Index. And in path analysis, only ODB alternative model show Government efficacy with social capital has full mediation effect. In OUR Index alternative model there is no mediation effect with social capital.

• Journal of Agricultural Extension & Community Development
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• v.20 no.3
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• pp.729-753
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• 2013

The purpose of this study was to analyze effectiveness of 4-H Seoul Field-Experiential Learning Program(4-H SFELP). The effectiveness scale of youth accredited activity was applied to analyze the effectiveness and satisfaction of the program. After screening the data, 155 responses were used to analyze the data for this study. The major findings of this study were as follows. First, 4-H SFELP has positive effects on the level of global leadership, initiative in exchange, and understanding other cultures which are related with effectiveness of youth exchange activity. Second, 4-H SFELP has positive effects on the level of confidence, challenge spirit, achievement motivation, and collective leadership which are related with effectiveness of youth adventure and challenge activity. Third, 4-H SFELP has positive effects on the level of problem-solving skills, morality, other-respect, and self-respect which are related with effectiveness of youth self-improvement activity. Fourth, 4-H SFELP has positive effects on the level of self-efficacy and autonomy but has not effects on the level of inquiring mind of participants. All these findings were discussed for youth workers and researchers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04b
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• pp.449-453
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• 1994

공작기계의 가공정밀도는 공구와 공작물간의 상대변위 크기로서 평가되는데, 이 상대변위는 가공중에 발생 하는 절삭력이 공구-척-주축-기계구조물-안내면-가공테이블-공작물로 이어지는 하중전달 폐곡선을 흐르면서 경로상의 정적, 동적 취약부의 주된 영향을 받아 생기거나 각 요소부품의 변형이 누적되어 생겨난다. 본 연구에서는 주축의 취약부를 규명하기 위하여 정적으로는 정적 처짐곡선을 이용하고, 동적으로는 진동모우드의 굽힘곡선을 이용하여 주축선단의 처짐에 가장 영향을 많이주는 부위를 파악하였다. 취약부의 개선방법으로는 주축지름을 변화시켜 주축선단 근처에서 굽힘이 집중되지 않도록 유도하였다. 그리고 구조개선의 효과를 확인 하기 위해서 기존 주축시스템과 개선 주축시스템의 정적, 동적 특성변화를 비교하였다.

• Journal of Korean Medical classics
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• v.20 no.4
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• pp.319-324
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• 2007

대우연구배합호기종약재치료질병적방제(대于硏究配合好기종葯材治료疾病的方제), 이유흔장일단시간료(已有흔長一段시間了). 단시아문잉연무법양세설명정적조합원리(但是我們仍然无法洋細설明定的組合原理). 병차야몰유일정적근거래판단매개인대방제적설명방식(幷且也沒有一定的根据래判단每개人대方劑的說明方式), 시부정확무오(是不正確无오). 이차대방제적설명(而且대方劑的說明), 대다수시채용정적주치증상래해설정적효과(大多수是采用定的主治症상래解說定的效果). 소이약몰유상세적주치화증상적자료시아문취난이유효과래조합방제(所以若沒有효細的主治和症상的자料시我們就難以由效果래組合方劑). 근거상환소설적곤란(根据上환所說的困란), 아문인위수요연구설법이조성적약재래설명방제효과(我們인위需要硏究設法以組成的約材래說明方劑效果). 병차장타전환위계통화(幷且장타전換위系統化). 아문이진행료연구(我們已진行了硏究), 재차상세보고기연구효과(在此상細보告其硏究效果).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.7
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• pp.575-580
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• 2007

During the conceptual design phase of a canard type high maneuverable aircraft, the low speed small scale wind tunnel test was conducted to investigate the high angle-of-attack static stability of the aircraft. In this study, 1/50th scale generic canard-body-wing model was used for the small scale wind tunnel test. For the analysis of static stability including high angle-of-attack nonlinear characteristics, the vertical tail effects were studied due to canard deflections. In addition, the nose chine effects were studied at high angle-of-attack. Based on the results obtained from the experimental study, the configuration change effects for canard type aircraft on high angle-of-attack static stability have been able to analyze.