• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.80-83
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• 2016

In the present paper, garnet structured $Y_3Al_5O_{12}:Ce^{3+}$ (YAG : Ce) ceramic phosphor plate (CPP) for high power laser diode (LD) was prepared and optical properties were analyzed. We synthesized monodispersed spherical nano-sized YAG : Ce particles by liquid phase method, fabricated phosphor ceramic plate with the addition of $Al_2O_3$. $75{\mu}m$ and $100{\mu}m$ thick YAG : Ce CPPs were compared in terms of the factors of conversion efficacy, thermal quenching, luminance and correlated color temperature (CCT). In conclusion, conversion efficacy decreased by 25 % in both samples and $100{\mu}m$ thick sample provides better optical properties of thermal quenching, maximum light conversion efficacy and maximum luminance value.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.306-315
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• 2018

The purpose of this study was to investigate the effects of football talents program on body composition, fitness, self-control and self-efficacy in elementary school students The subjects were eighty males students volunteers, composed of the lower group (n=40; 1-3th grade) and senior group (n=40; 4-6th grade). The test data were analyzed by paired t-test, independent t-test and two-way repeated measures ANOVA. The alpha level of p<0.05 was set for all tests of significance. The results of the study in the both group were as follows; The muscle mass in the body composition had significantly increased, and there was a significant difference between groups. Body fat mass had significantly decreased. Fitness(cardiorespiratory endurance, muscular strength, flexibility, power and agility) had significantly increased, cardiorespiratory endurance, muscular strength, and power was a significant difference between groups. Self-control and self-efficacy had increased significantly in both groups. Therefore, the football talents program had a positive effects on body composition and physical fitness levels of elementary school students. And it seems to be effective in increasing self-control and self-efficacy.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.185-188
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• 2005

The recent growth in the use of impactive and nonlinear loads, electronic devices sensitive to power quality has caused many power quality problems. Dynamic voltage restorers(DVR) are known as the best effective and economic means to compensate for power quality problems(especially, voltage sag and swell). In this paper, we addresses the detecting algorithms of an voltage sag and phase for operating DVR. Experimental results are included to illustrate the efficacy of the proposed algorithm.

• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.694-703
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• 2013

In electric power system, the line stability indices adopted in most of the instances laid stress on variation of reactive power than real power variation of the transmission line. In this paper, a proposal is made with the formulation of a New Voltage Stability Index (NVSI) which originates from the equation of a two bus network, neglecting the resistance of transmission line, resulting in appreciable variations in both real and reactive loading. The efficacy of the index and fuzzy based load flow are validated with IEEE 30 bus and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India. The results could prove that the identification of weak bus and critical line in both systems is effectively done. The weak area of the practical system and the contingency ranking with overloading either line or generator outages are found by conducting contingency analysis using NVSI.

• Journal of information and communication convergence engineering
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• v.22 no.2
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• pp.159-164
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• 2024

This study aimed to develop an advanced anomaly-detection system tailored for solar power distribution panels using thermal imaging cameras to ensure operational stability. It addresses the imperative shift toward digitalized safety management in electrical facilities, transcending the limitations of conventional empirical methodologies. Our proposed system leverages a faster R-CNN-based artificial intelligence model optimized through meticulous hyperparameter tuning to efficiently detect anomalies in distribution panels. Through comprehensive experimentation, we validated the efficacy of the system in accurately identifying anomalies, thereby propelling safety protocols forward during the fourth industrial revolution. This study signifies a significant stride toward fortifying the integrity and resilience of solar power distribution systems, which is pivotal for adapting to emerging technological paradigms and evolving safety standards in the energy sector. These findings offer valuable insights for enhancing the reliability and efficiency of safety management practices and fostering a safer and more sustainable energy landscape.

• Nonlinear Functional Analysis and Applications
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• v.29 no.2
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• pp.435-450
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• 2024

This study depends on the modified conformable fractional derivative definition to generalize and proves some theorems of the classical power series into the fractional power series. Furthermore, a comprehensive formulation of the generalized Taylor's series is derived within this context. As a result, a new technique is introduced for the fractional power series. The efficacy of this new technique has been substantiated in solving some fractional differential equations.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1080-1088
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• 2014

By combining a wind turbine with an energy storage system (ESS), we are able to attenuate the intermittent wind power characteristic making the power derived from a wind farm dispatchable. This paper evaluates the influence of the phase delay of the low-pass filter in the conventional smoothing power control on the ESS capacity; longer phase delays require a larger ESS capacity. In order to eliminate the effect of the phase delay, we optimize the power dispatch using a zero-phase low-pass filter that results in a non-delayed response in the power dispatch. The proposed power dispatching method significantly minimizes the ESS capacity. In addition, the zero-phase low-pass filter, which is a symmetrical forward-reverse finite impulse response type, is designed simply with a small number of coefficients. Therefore, the proposed dispatching method is not only optimal, but can also be feasibly applied to real wind farms. The efficacy of the proposed dispatching method is verified by integrating a 3 MW wind turbine into the grid using wind data measured on Jeju Island.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.151-160
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• 2020

The purpose of this study was to investigate the moderating mediation effect of resilience, on the relationship between emotional intelligence and self-efficacy in career decision-making of nursing students. The participants were 136 nursing college students in the Jeonbuk region. Data was collected in September 2020 via a structured questionnaire survey. The data was analyzed using the SPSS/23.0 program. The analysis used descriptive statistics, Pearson's correlation coefficient, independent t-test, one-way ANOVA, multiple regression analysis, and Sobel's tests. The results showed that emotional intelligence was a circle activity (F=3.13, p=.047), and motivation to nursing (F=4.16, p=.008). Resilience was a circle activity (F=5.50, p=.005), and nursing major satisfaction (t=2.19, p=.031). Career decision-making self-efficacy showed significant differences in grade (F=3.12, p=.048) and major satisfaction (t=2.36, p=.020). Emotional intelligence and resilience (r=.63, p<.001), emotional intelligence and career decision-making self-efficacy (r=.67, p<.001), resilience and career decision-making self-efficacy (r=.76, p<.001) showed significant static correlation. In emotional intelligence and career decision-making self-efficacy, resilience had a partial mediating effect (Z=6.48, p<.001), and explanatory power was 62.2%. Based on the results of this study, to improve the emotional intelligence and career decision-making self-efficacy of nursing students, it is necessary to develop a personalized and resilience-enhanced education program.

• Journal of Industrial Convergence
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• v.18 no.2
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• pp.37-44
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• 2020

This paper of descriptive-correlative design determined the effects of health perception, need of exercise and self-efficacy on the frequency of exercise among diabetic patients. A total of 86 questionnaires were retrieved from these groups of diabetic patients, who regularly visits endocrinology clinics and accomplished voluntarily the major instrument distributed from two university hospitals in A city, during June to July, 2018. The result was a significant positive relationship that existed between health perception (r=.215, p=.043) and self-efficacy (r=.440, p<.001) with frequency of exercise respectively. Regression analysis revealed that the factor affecting the frequency of exercise is self efficacy (β=.440, p<.001) which illustrated to have a significant effect in the model's explanatory power at 18.4%(F=20.836, p<.001) results. This suggests that diabetic patients with a high positive health perception increase self-efficacy, their self-efficacy will help increase the frequency of exercise if further developed. Therefore, if an intervention program is developed to improve the health perception and self-efficacy education program for diabetics, it will help improve the frequency of exercise, namely diabetes management exercise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.571-579
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• 2019

The purpose of this study was to identify levels of hearing handicap, depression, and self-efficacy, and to determine the effect of hearing handicap on depression and self-efficacy in home-based elderly. Data were collected from August to September 2017. Two hundred and seventy eight elderly living at home in three cities participated in this study. Data were analyzed using the independent t-test, one-way ANOVA, Scheffe's test, Pearson's correlation coefficients, and by multiple regression analysis using SPSS Ver. 20.0 for Windows. Mean levels of hearing handicap, depression, and self-efficacy were 10.91 (${\pm}19.83$), 4.75 (${\pm}3.90$), and 46.87 (${\pm}6.75$) respectively. A statistically significant positive correlation was observed between hearing handicap and depression (r=.228, p<.001), and significant negative correlations were found between hearing handicap and self-efficacy (r=-.284, p<.001) and between depression and self-efficacy (r=-.526, p<.001). Hearing handicap had a negative effect on self-efficacy (${\beta}=-.161$, p=.008) and its explanatory power was 27.2%. The study results suggest that the developments of multidisciplinary interventions and education programs are important to prevent or minimize hearing handicap in the elderly.