• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.278-286
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• 2022

In this study, a 33-mode Free-Flooded Ring (FFR) transducer was designed to apply piezoelectric single crystal PIN-PMN-PT, which has high piezoelectric constants and electromechanical coupling coefficient. To ensure low-frequency high transmitting sensitivity characteristics with a small size of FFR transducer, the commercial FFR transducer based on piezoelectric ceramics was compared. To develop the FFR transducer with broadband characteristics, a piezoelectric segmented ring structure inserted with inactive elements was applied. The oil-filled structure was applied to minimize the change of acoustic characteristics of the ring transducer. It was verified that the transmitting voltage response, underwater impedance, and beam pattern matched the finite element numerical simulation results well through an acoustic test. The difference in the transmitting voltage response between the measured and the simulated results is about 1.3 dB in cavity mode and about 0.3 dB in radial mode. The fabricated FFR transducer had a higher transmitting voltage response compared to the commercial transducer, but the diameter was reduced by about 17 %. From this study, it was confirmed that the feasibility of a single crystal-applied FFR transducer with compact size and high-power characteristics. The effectiveness of the performance prediction by simulation was also confirmed.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.365-371
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• 2024

The purpose of this study was to investigate the effect of leisure satisfaction according to calligraphy activities of the elderly on self-efficacy and psychological well-being. In order to conduct this study, the researchers surveyed 306 elderly people aged 65-76 or older from late November to early December 2023 in Anyang City and Xinxiang City, Henan Province, China. In order to verify the research hypothesis, the researchers performed frequency analysis, descriptive statistics analysis, and Pearson correlation analysis using IBM SPSS Statistics 25, and then performed independent sample T-test and one-way analysis of variance (One-Way ANOVA). To verify the hypothesis through the measurement concept, related verification was conducted for Hayes PROCESS macro and Bootstrap. As a result of the study, first, there is a gender difference in leisure satisfaction, leisure satisfaction, self-efficacy, and psychological well-being, and leisure satisfaction and psychological well-being differ significantly according to age. Second, it was found that leisure satisfaction had a positive effect on self-efficacy. Third, it was found that leisure satisfaction had a positive effect on psychological well-being. Fourth, leisure satisfaction was found to have a positive effect on psychological well-being. Therefore, in order to increase the leisure satisfaction and psychological well-being of the elderly, it is necessary to carefully develop a calligraphy activity system to increase self-efficacy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.795-803
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• 2020

The purpose of this study is to verify the differences in learning capability according to the demand of learning programs. The participants of this study included 1,738 S University students. The results of the study are as follows. First, in learning capability according to participation in learning programs, we found statistically significant differences in the ability to organize information, resource utilization, self-awareness, self-improvement and sociality. Second, there were no statistically significant differences in the ability to organize information, resource utilization, self-awareness, self-improvement and sociality in participating in learning programs. Third, there were statistically significant differences in the ability to organize information, resource utilization, self-awareness, self-improvement and sociality in not participating in learning programs. Fourth, there were statistically significant differences in the ability to organize information, resource utilization, self-awareness, self-improvement and sociality in experiencing difficulties in learning. Fifth, learning capabilities in specific areas that students wanted to improve had no statistically significant differences in the ability to organize information, resource utilization, self-awareness. However, there were statistically significant differences in self-improvement and sociality.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.793-806
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• 2020

In this study,for YSU (Yonsei University), MYJ(Mellor-Yamada-Janjic), ACM2 (Asymmetric Convective Model), and BouLac (Bougeault-Lacarrere) PBL schemes, numerical experiments were performed for the case period (June 26-30, 2014). The PBLH calculated by using the backscatter signal produced by the mobile vehicle-mounted lidar system (LIVE) and the PBLH calculated by the prediction of each PBL schemes of WRF were compared and analyzed. In general, the experiments using the non-local schemes showed a higher correlation than the local schemes for lidar observation. The standard deviation of the PBLH difference for daylight hours was small in the order of YSU (≈0.39 km), BouLac (≈0.45 km), ACM2 (≈0.47 km), MYJ (≈0.53 km) PBL schemes. In the RMSE comparison for the case period, the YSU PBL scheme was found to have the highest precision. The meteorological lider mounted on the vehicle is expected to provide guidance for the analysis of the planetary boundary layer in a numerical model under various weather conditions.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.89-97
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• 2010

The ship-borne gravity data is essential to construct geoid in Korea surrounding ocean area. The altimeter data was used in previous study, however, the ship-borne gravity data could be used due to more ship-borne data was collected by improvement of instrument, positioning system. Therefore, the study on verification of precision of ship-borne gravity data and practical usage analysis is needed. In this study, free-air anomaly having 16.47mGal and 18.86mGal as mean and standard deviation was obtained after consistent processing such as Eotvos correction, Kalman Filter, Cross-over adjustment etc. The calculated free-air anomaly was compared to DNSC08 altimeter data and the difference was computed having -0.88mGal and 9.46mGal of mean and standard deviation. The reason causing those differences are owing to spatial limits of data acquisition and effects of ocean topography. To use ship-borne gravity data for precision geoid development, the efforts to overcome the limits of data collection and study for data combination should be proceeded.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.79-88
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• 2009

The objective of this study is to develop the new vehicle classification algorithm and minimize classification errors. The existing vehicle classification algorithm collects data from loop and piezo sensors according to the specification("Vehicle classification guide for traffic volume survey" 2006) given by the Ministry of Land, Transport and Maritime Affairs. The new vehicle classification system collects the vehicle length, distance between axles, axle type, wheel-base and tire type to minimize classification error. The main difference of new system is the "Wandering" sensor which is capable of measuring the wheel-base and tire type(single or dual). The wandering sensor obtains the wheel-base and tire type by detecting both left and right tire imprint. Verification tests were completed with the total traffic volume of 762,420 vehicles in a month for the new vehicle classification algorithm. Among them, 47 vehicles(0.006%) were not classified within 12 vehicle types. This results proves very high level of classification accuracy for the new system. Using the new vehicle classification algorithm will improve the accuracy and it can be broadly applicable to the road planning, design, and management. It can also upgrade the level of traffic research for the road and transportation infrastructure.

• Journal of Radiation Protection and Research
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• v.31 no.3
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• pp.155-164
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• 2006

It is judged that there could be certainty in every process of analyzing environmental samples using Liquid Scintillation Counter. Therefore, this study focuses on quantitative evaluation on uncertainty in an effort to analyze comparatively accurately environmental samples. For this, after parameters which can have an effect on uncertainty was derived, the evaluation on each parameter was tamed out. The results of analysis of each parameter showed that the effect according to the weight difference of Teflon vial did not appear, and that standard deviations of SQP(E) averages reached saturation point at $75{\sim}90$ sec at the result of making increases step by step the irradiation time of External standard, and that values measured by repeat method produces good results compared with replicate. Also, conclusion was derived that analysis on sample after it is left in cold and dark room at least above 1,000 minutes have to be carried out, and the result of carrying out verification on results measured as well as equipment itself using radioactivity-error-analysis and chi-square test, resonable result was derived.

• Journal of Korean Home Economics Education Association
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• v.33 no.3
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• pp.129-142
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• 2021

The purpose of this study was to provide educational data on teaching clothing culture by examining the effects of clothing lifestyle on attitudes toward teachers' clothing for 270 secondary school pre-service teachers. For data analysis, factor analysis, Cronbach's α reliability coefficients, t-tests, one-way analysis of variance, Duncan's multiple comparison verification, and multiple regression analysis were performed using SPSS 24.0 program. As a result of the study, first, the clothing lifestyle of secondary school pre-service teachers was classified as fashion trend orientation, clothing importance orientation, attractive appearance orientation, and economic orientation factors. In addition, the attitude toward teacher's clothes was classified into activity, fashionability, and modesty factors. Second, there was a statistically significant difference in the attitudes toward clothing lifestyle and teacher clothing of secondary school pre-service teachers according to gender and year in college, which are demographic variables. Third, it was found that the clothing lifestyle of secondary school pre-service teachers, who are Generation Z, had an effect on the attitude toward teacher clothes. In conclusion, this study proposes that school administrators and teachers should depart from the former stereotypes about teacher clothes and to encourage a culture in which teachers can dress and perform their role of teaching according to individual's changing lifestyles.

• Journal of Korea Water Resources Association
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• v.51 no.12
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• pp.1217-1227
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• 2018

This paper aims to evaluate the applicability of dam inflow prediction model using recurrent neural network theory. To achieve this goal, the Artificial Neural Network (ANN) model and the Elman Recurrent Neural Network(RNN) model were applied to hydro-meteorological data sets for the Soyanggang dam and the Chungju dam basin during dam operation period. For the model training, inflow, rainfall, temperature, sunshine duration, wind speed were used as input data and daily inflow of dam for 10 days were used for output data. The verification was carried out through dam inflow prediction between July, 2016 and June, 2018. The results showed that there was no significant difference in prediction performance between ANN model and the Elman RNN model in the Soyanggang dam basin but the prediction results of the Elman RNN model are comparatively superior to those of the ANN model in the Chungju dam basin. Consequently, the Elman RNN prediction performance is expected to be similar to or better than the ANN model. The prediction performance of Elman RNN was notable during the low dam inflow period. The performance of the multiple hidden layer structure of Elman RNN looks more effective in prediction than that of a single hidden layer structure.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.373-382
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• 2024

This study attempted to identify the relationship between nursing competency, clinical reasoning competence, and empathy ability according to the center of enneagram power for nursing students. The subjects of the study were 218 students enrolled in the department of nursing at two universities located in one region, data collection was conducted from 16 October to 27 October 2023. Data analysis was performed using SPSS/WIN version 26.0 program, descriptive statistics, and difference verification were analyzed by t-test, ANOVA, pearson's correlation coefficient, Results, The enneagram personality type of the subjects of this study was the most common type 9. And in the enneagram center of power, the instinct-centered type had the highest nursing competence, the thought-centered type had the highest clinical reasoning competence, and the emotion-centered type had the highest empathy ability. In addition, nursing competence and clinical reasoning competence showed a significant positive correlation, and clinical reasoning competence and empathy ability were also found to be positively correlated. Therefore, it is important to continue to develop and apply individualized competency building programs that reflect personality type tests to nursing students. In addition, the higher the empathy ability, the higher the clinical reasoning competence, so it is thought that it is necessary to develop a standardized curriculum that can improve nursing competence and clinical reasoning competence and verify its effectiveness.