• Journal of Digital Convergence
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• 제14권7호
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• pp.299-307
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• 2016

The purpose of this study was to understand self-esteem, sexual communication for parents, sexual assertiveness, and safer sexual behavior and. to examine the mediating effects of the sexual assertiveness on the safer sexual behavior of early adults. A structured questionnaire was completed by 291 university students from March 1 to April 31, 2016. Data were analyzed to calculate the direct and indirect effects of factors affecting safer sexual behavior using SPSS WIN 21.0 and AMOS 18.0 programs. Final model fit indices were RMSEA .05, GFI .98, AGFI .94, NFI .96, and self-esteem, sexual communication for parents showed a direct effect on sexual assertiveness and safer sexual behavior of university students. Sexual assertiveness mediated the relationships among self-esteem, sexual communication for parents, and safer sexual behavior. Furthermore, it is shown that the sexual assertiveness significantly mediates the relation between the positive self-esteem, sexual open communication for parents and safer sexual behavior of early adults.

• Journal of Digital Contents Society
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• 제9권3호
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• pp.379-388
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• 2008

This paper is to redefine the concept of Cyber Career Counseling Activation(=C-C-C-A) and verify the effects of the factors affecting the C-C-C-A at Korean academic high school level in Kyunggi Province. In this research, we hypothesize that the three independent variables increase the effects of Cyber Career Counseling Activation.. To discuss the hypothesis, we analyzed survey data of 322 students who had taken Cyber Career Counseling in December 2007 based on Structural Equation Model. The results are as follows: First, the three crucial factors(Expanding C-C-C Opportunities, Improving C-C-C Service, Establishing C-C-C Service System) increase the C-C-C-A effectiveness. Second, as a result of Confirmatory Factor Analysis(CFA), the goodness of fit indices(GFI, AGFI, CFI, RMSEA) demonstrate statistical significance and fitness of the C-C-C-A Model. Therefore, the outcomes show that the three factors are the significant ones of Cyber Career Counseling Activation Model.

• Proceedings of the KIEE Conference
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• 대한전기학회 2006년도 학술대회 논문집 전문대학교육위원
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• pp.185-190
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• 2006

Frequency and phasor are the most important quantities in power system operation because they can reflect the whole power system situation. Frequency reflects the dynamic energy balance between load and generating power, while operators use phasor to constitute the state of system and, moreover, phasor based line relays are currently used in most power systems. So frequency and phasor are regarded as indices for the operating power systems in practice. The proposed technique is suitable for estimation near-nominal, nomina), and off-nominal frequencies. It is useful in designing microprocessor-based relays and meters that need to measure power system frequency. Performance test results, using signals from EMTP source and Excel program, indicate that the proposed technique can provide accurate estimates within 16ms. Maximum estimation errors observed during testing are of the order of 0.006Hz for nominal, near-nominal, and off-nominal frequencies. The proposed technique provides accurate estimates in presence of noise and harmonics and in case ground fault. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

• 한국지형공간정보학회:학술대회논문집
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• 한국지형공간정보학회 1993년도 학술발표회 개요집
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• pp.141-145
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• 1993

A new digital change detection algorithm, Euclidean Distance Analysis, was developed in an attempt to utilize the multi-band information in a selected band-comination, as an alternative to the conventional single-band analysis methods. To evaluate the relative performance of this new method, image differencing was applied. The better performance in change detection between the two algorithms investigated was provided by the Euclidean distance analysis. The new technique of Euclidean distance analysis holds promise for change detection, since it summarizes the multiple-band information on the cover-type changes and reduces the data dimensionality. It is suggested to further evaluate this new method, quantitatively, in the different environments. The use of different accuracy indices was also examined in the determining the optimal threshold level for each change image. As the standard measure for classification accuracy, the Kappa coefficient of agreement was used for evaluation.

• Proceedings of the KIEE Conference
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.1009-1012
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• 1999

Recently, there is a strong need of DVD (Digital Versatile Disk) system of high density. high speed, and high accuracy System performances mostly depend on not only optical system, but also servo technology to drive it. Therefore, we investigate main technology concerned with optical pick-up unit based on 4.7GB DVD-RAM and analyzes technology of optical and servo systems that are required for high density high speed and high accuracy from the viewpoint of control. And then, we design a linear controller based on specification of 4.7GB DVD-RAM that is commercially available now. We analyze the dynamic characteristics of optical system that is coupled with control system and verify effect on performance indices of servo due to Parameter variation of pick-up by simulation. Finally, we will propose controller design specifications and provide direction of technical development for servo system and problems coupled with high capacity for 15GB level in the future.

• Smart Structures and Systems
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• 제30권4호
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• pp.397-410
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• 2022

It is essential to monitor the working conditions of bolt-connected joints, which are widely used in various kinds of steel structures. The looseness of bolts may directly affect the stability and safety of the entire structure. In this study, a guided wave-based method for bolt looseness detection and localization is presented for a joint structure with multiple bolts. SH waves generated and received by a small number (two pairs) of magnetostrictive transducers were used. The bolt looseness index was proposed based on the changes in the reconstructed responses excited by the time reversal signals of the measured unit impulse responses. The damage locations and local damage severities were estimated using the damage indices from several wave propagation paths. The back propagation neural network (BPNN) technique was employed to identify the local damages. Numerical and experimental studies were conducted on a lap joint with eight bolts. The results show that the total damage severity can be successfully detected under the effect of external force and measurement noise. The local damage severity can be estimated reasonably for the experimental data using the BPNN constructed by the training patterns generated from the finite element simulations.

• Korea Trade Review
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• 제46권2호
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• pp.141-160
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• 2021

The scale of global FDI has been decreasing since 2016 due to the ongoing US-China trade dispute, the strengthening of FDI inflow screening regulations with concern over strategic technology leaks, and the spread of reshoring trends due to the reinforcement of national preferences. Eventually, the competition to attract FDI between countries is expected to become more intense. Therefore, in order to attract high-quality FDI for Korea that will contribute to the development of the national economy, it is pressing to evaluate and improve the domestic FDI attraction environment. This study aims to analyze which areas of Korea's economic and non-economic environments need improvement for gaining advantage amid the fierce competition to attract FDI between countries, by the relative comparison between Korea and the U.S., and based on the ranking indicated in key FDI attractiveness indices. As a result, improvement is needed in the following areas. First, according to IMD's "World Competitiveness Ranking 2020," Korea was inferior to the US in terms of business efficiency, productivity, finance and business legislation in terms of government efficiency. Second, according to INSEAD's "Global Talent Competitiveness Index 2020," Korea was inferior to the US in terms of internal openness, external openness, employability, lifelong learning, access to growth opportunity, and business and labor landscapes. Third, according to WEF's "Global Competitiveness Index 2019", Korea was inferior to the US in terms of product market, labor market, business dynamism and workforce skills.

• Journal of the Korean Association of Geographic Information Studies
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• 제24권2호
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• pp.52-63
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• 2021

In previous research, the coastal wetlands were detected by using the vegetation indices or land cover classification maps derived from the multispectral bands of the satellite or aerial imagery, and this approach caused the various limitations for detecting the coastal wetlands with high accuracy due to the difficulty of acquiring both land cover and topographic information by using the single remote sensing data. This research suggested the efficient methodology for detecting the coastal wetlands using the sentinel-2 satellite image and SRTM(Shuttle Radar Topography Mission) DEM (Digital Elevation Model) acquired in Gomsoman Bay, west coasts of South Korea through the following steps. First, the NDWI(Normalized Difference Water Index) image was generated using the green and near-infrared bands of the given Sentinel-2 satellite image. Then, the binary image that separating lands and waters was generated from the NDWI image based on the pixel intensity value 0.2 as the threshold and the other binary image that separating the upper sea level areas and the under sea level areas was generated from the SRTM DEM based on the pixel intensity value 0 as the threshold. Finally, the coastal wetland map was generated by overlaying analysis of these binary images. The generated coastal wetland map had the 94% overall accuracy. In addition, the other types of wetlands such as inland wetlands or mountain wetlands were not detected in the generated coastal wetland map, which means that the generated coastal wetland map can be used for the coastal wetland management tasks.

• Journal of Biosystems Engineering
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• 제41권2호
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• pp.126-137
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• 2016

Purpose: The overall objective of this study was to evaluate the vegetation fraction of soybeans, grown under different cropping conditions using an unmanned aerial vehicle (UAV) equipped with a red, green, and blue (RGB) camera. Methods: Test plots were prepared based on different cropping treatments, i.e., soybean single-cropping, with and without herbicide application and soybean and barley-cover cropping, with and without herbicide application. The UAV flights were manually controlled using a remote flight controller on the ground, with 2.4 GHz radio frequency communication. For image pre-processing, the acquired images were pre-treated and georeferenced using a fisheye distortion removal function, and ground control points were collected using Google Maps. Tarpaulin panels of different colors were used to calibrate the multi-temporal images by converting the RGB digital number values into the RGB reflectance spectrum, utilizing a linear regression method. Excess Green (ExG) vegetation indices for each of the test plots were compared with the M-statistic method in order to quantitatively evaluate the greenness of soybean fields under different cropping systems. Results: The reflectance calibration methods used in the study showed high coefficients of determination, ranging from 0.8 to 0.9, indicating the feasibility of a linear regression fitting method for monitoring multi-temporal RGB images of soybean fields. As expected, the ExG vegetation indices changed according to different soybean growth stages, showing clear differences among the test plots with different cropping treatments in the early season of < 60 days after sowing (DAS). With the M-statistic method, the test plots under different treatments could be discriminated in the early seasons of <41 DAS, showing a value of M > 1. Conclusion: Therefore, multi-temporal images obtained with an UAV and a RGB camera could be applied for quantifying overall vegetation fractions and crop growth status, and this information could contribute to determine proper treatments for the vegetation fraction.

• Journal of Korean Ophthalmic Optics Society
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• 제13권1호
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• pp.59-63
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• 2008

Purpose: Ti thin films were deposited on slide glass and CR-39 lenses using small magnetron sputtering apparatus to of Ti thin films. Methods: The thickness of Ti thin films were measured by cross section SEM, the transmittance and reflectance of them were obtained using spectrophotometer, the refractive index and extinction of them were obtained from VASE data. Results: The transmittances of Ti thin films with 60 nm, 120 nm, 140 nm thickness were a little change within the visual region from 400 nm to 750 nm, but were increased a little amount at near 400 nm. The transmittance of 60 nm, 120 nm, 140 nm Ti thickness in d-line was 30%, 25%, 20%, respectively. Also, it was shown that the refractive indices and extinction coefficients of the Ti thin films obtained from VASE were similar to those of Ti thin film offered macleod program. Conclusions: Ti films on CR-39 with these transmittances were available for sunglass lens. It was indicated that the refractive indices and extinction coefficients of the Ti thin films were decreased with the thickness of Ti thin film, for the thickness of Ti thin films was due to very thin.