• Korean Journal of Childcare and Education
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• v.18 no.3
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• pp.19-36
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• 2022

Objective: This study aimed to analyze the changes and predictive factors of mothers' parenting competencies during their children's second to third grades in primary school. Methods: We used the data from the Panel study of Korean Parental Educational Involvement. We classified 373 mothers into three groups, 'reduced' parenting competency, 'maintained' parenting competency, and 'increased' parenting competency, and conducted one-way variance analysis and multinomial logistic regression analysis. Results: First, the mothers' parenting competency decreased between their children's 2nd year and 3rd year in primary school. Second, the 'reduced', 'maintained', and 'increased' groups differed from each other in the degree of change in self-system competency, level of understanding of school life, number of counseling sessions with homeroom teachers, and social networking. Third, the degree of change in self-system competency and social networking predicted the increase in mothers' parenting competency. The degree of change in self-system competency and the level of understanding of school life predicted the maintenance of mothers' parenting competency. Conclusion/Implications: This study, for the first time, has revealed the change in mothers' parenting competency and its predictive factors after the second year in primary school. How to support the growth of mothers' parenting competency was also discussed.

• Journal of Korean Society of Rural Planning
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• v.9 no.3 s.20
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• pp.47-52
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• 2003

The purpose of this study is to evaluate the satisfaction level and to analyze the factors in the environment friendly consolidation canals. In this study, the survey consists of four parts, such as the actual status of environment friendly canals, satisfaction level for each items, overall satisfaction level and the personal features of the users. Total 128 samples out of 140 respondents were used for the final analysis. Analysis of the satisfaction level were fulfilled to survey results such as the basic statistics and the correlations of variables, in addition, dispersion analysis for two user groups were carried out. Function of canal, water quality, landscape, and convenience facilities were chosen as independent variables in the model. Residents in Yeoju area were satisfied with water quality, water quantity and the function of canal. And residents of Yeonggwang area were satisfied with the convenience facilities and the function of the newly consolidated canal.

• Journal of Information Display
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• v.2 no.2
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• pp.32-38
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• 2001

PDP(plasma display panel) represents the gray levels by the pulse number modulation technique that results in undesirable dynamic false contours on moving images. This paper proposes a LUT(Look-up table) based error diffusion algorithm for reduction of the dynamic false contours. A quantitative measure of the dynamic false contours is defined first. The measure of the dynamic false contours is calculated through simulation of every gray level combination of two consecutive frames. Based on the calculated measures, a modified gray level for a pair of gray levels of two consecutive frames is chosen to reduce the dynamic false contours. The chosen gray levels serve as contents of a gray level conversion LUT. Given a pair of gray levels of two consecutive frames, the gray level of current frame is modified based on the gray level conversion LUT. The new gray level is displayed on PDP. An error diffusion algorithm is, then, applied to compensate for the differences in the gray levels.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.316-321
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• 2020

PURPOSE. The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS. Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS. The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION. The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

• Journal of Power Electronics
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• v.11 no.5
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• pp.688-696
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• 2011

This paper proposes a simple space vector PWM (SVPWM) scheme including overmodulation operation for 3-level NPC (Neutral Point Clamped) Inverters. The proposed scheme features a simple decision and calculation procedure for determining switching times in the overmodulation range by utilizing the duty calculation method used in 2-level inverters and the minimum phase error projection method widely employed in motor drive systems. The proposed scheme does not need to detect the angle of the reference vector or calculate trigonometric functions to determine the magnitude of the voltage vector. The magnitude of the angle of the new reference voltage vector is decided in advance with the help of the Fourier Series Expansion to extend the linearity of the output voltage of 3-level inverters in the overmodulation region. Experimental results demonstrate the validity of the proposed SVPWM scheme including overmodulation operation for 3-level NPC inverters.

• Journal of Information Processing Systems
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• v.12 no.2
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• pp.322-331
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• 2016

Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bit-level lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.7-21
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• 2019

In order to improve the edge segmentation effect of the level set image segmentation and avoid the influence of the initial contour on the level set method, a saliency level set image segmentation model based on local Renyi entropy is proposed. Firstly, the saliency map of the original image is extracted by using saliency detection algorithm. And the outline of the saliency map can be used to initialize the level set. Secondly, the local energy and edge energy of the image are obtained by using local Renyi entropy and Canny operator respectively. At the same time, new adaptive weight coefficient and boundary indication function are constructed. Finally, the local binary fitting energy model (LBF) as an external energy term is introduced. In this paper, the contrast experiments are implemented in different image database. The robustness of the proposed model for segmentation of images with intensity inhomogeneity and complicated edges is verified.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.149-153
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• 2005

The optical fiber micro-cellular system requires the high linearity that determines the quality and capacity of system. Hence, there is a need for improving the linearity in mobile communication system. In order to compensate dispersion-induced signal distortion, we fabricated the optical feedforward transmitter. The compared 3rd-IMD was enhanced by 38 dB for two-tone case and the Adjacent Channel Power Ratio was enhanced by 20 dB for W-CDMA 1 carrier and by 16 dB for W-CDMA 3 carriers. Also, the induced noise level was reduced.

• The Journal of the Korea Contents Association
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• v.17 no.5
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• pp.243-251
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• 2017

This study aimed to demonstrate 'moderated mediation' effect of self-control on the relationship of neuroticism-smart phone addiction-school adaptation. For this purpose, we carried out a survey targeting middle school students who were vulnerable to smart phone addiction, and 1,400 middle school students responded to questionnaire. The results showed that the moderated mediation effect of self-control was statistically significant. In detail, school satisfaction and school performance, the sub-factors of school adaptation, showed significant results but social relation non-significant. Concerning moderating effect of self-control, results supported significantly moderating effect, demonstrating that high level of self-control showed consistently lower level of smart phone addiction than low level of self-control regardless of level of neuroticism. We can find the meanings of this study in having demonstrated, on the one hand, the causal process of smart phone addiction, and on the other, moderating effect and moderated mediation effect on this causal process through interaction between neuroticism and self-control. Finally, limitations and suggestions for future research were discussed.

• School Mathematics
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• v.14 no.2
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• pp.213-232
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• 2012

The purpose of this study was to examine and analyze the cognitive demand of the mathematical tasks suggested in the middle school textbooks. In particular, it aimed to reveal the overall picture of the level of cognitive demand of the mathematical tasks on function in the textbooks. We adopted the framework for mathematical task analysis suggested by Stein & Smith (1998) and analyzed the mathematical tasks accordingly. The findings from the analysis showed that 95 percent of the mathematical tasks were at low level and the rest at high level in terms of cognitive demand. Most of the mathematical tasks in the textbooks were algorithmic and focused on producing correct answers by using procedures. In particular, the high level tasks were presented at the end of each chapter or unit for wrap up rather than as key resources.