• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.525-535
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• 2018

If the frequency of a particular class is excessively higher than the frequency of other classes in the classification problem, data imbalance problems occur, which make machine learning distorted. Corporate bankruptcy prediction often suffers from data imbalance problems since the ratio of insolvent companies is generally very low, whereas the ratio of solvent companies is very high. To mitigate these problems, it is required to apply a proper sampling technique. Until now, oversampling techniques which adjust the class distribution of a data set by sampling minor class with replacement have popularly been used. However, they are a risk of overfitting. Under this background, this study proposes ROSE(Random Over Sampling Examples) technique which is proposed by Menardi and Torelli in 2014 for the effective corporate bankruptcy prediction. The ROSE technique creates new learning samples by synthesizing the samples for learning, so it leads to better prediction accuracy of the classifiers while avoiding the risk of overfitting. Specifically, our study proposes to combine the ROSE method with SVM(support vector machine), which is known as the best binary classifier. We applied the proposed method to a real-world bankruptcy prediction case of a Korean major bank, and compared its performance with other sampling techniques. Experimental results showed that ROSE contributed to the improvement of the prediction accuracy of SVM in bankruptcy prediction compared to other techniques, with statistical significance. These results shed a light on the fact that ROSE can be a good alternative for resolving data imbalance problems of the prediction problems in social science area other than bankruptcy prediction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2647-2655
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• 2015

This study has the purpose to evaluate the effects of cooperative learning applying Jigsaw model in simulation based infection control education by comparing perception of infection control, intrinsic motive and learning satisfaction, 54 first-year health related students. It is composed of 27 students of the experimental group and 27 students of the control group. In order to evaluate the homogeneity between the two groups, it surveyed in advance perception of infection control, intrinsic motive and learning satisfaction. There was no significant difference between the two groups, The education program composed cooperative learning applying Jigsaw Model, simulation practice and debriefing to the experimental group was performed twice for 2 weeks and lecture and skill training, simulation practice and debriefing were performed to the control group. After two-week education, perception of infection control, intrinsic motive and learning satisfaction of the participants the research were surveyed. As a result of this study, the Jigsow Model indicated the perception of infection control and learning satisfaction experimental group was significantly high in statistic. Based on this research result, I suggests that utilization of cooperative learning applying the Jigsaw Model as a strategy to improve the scholatic achievement and learning satisfaction of students in the variable simulation based education.

• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.29-34
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• 2013

Objective: All patients who have the disc displacement with reduction (DDwR) are always not progressive but some of them with significant catching or locking progress to disc displacement without reduction (DDw/oR). In this study, we suggest opening exercise therapy using Locking-free Appliance (LA) to be helpful to prevent progressive derangement. Methods: Retrospectively, a total 37 patients who received exercise treatment using LA was analyzed from January 2010 to December 2011. Patients had been instructed in proper exercise technique to practise for opening and closing of mouth wearing the appliance 30 times a day in locking-free position. Results: None of the patients took a turn for worse to DDw/oR (37 patients). The 16 patients (43.2%, locking-free group) of them could open their mouth without intermittent condylar locking. Measurement of data was analyzed using and Mann-Whitney test. There was no statistically significant difference for age, gender, presence of palpational pain, locking period, VAS quantitative pain score between locking-free group and locking group. Conclusions: In this study, some patients could open their mouth without intermittent locking and did not take a turn for worse to DDw/oR after opening exercise therapy with LA. Furthermore, LA had advantages which were short wearing time, low costs and minimizing patients' uncomfortable compared to conventional treatment method. This therapy can be more appropriate new treatment to prevent progress to DDw/oR.

• 재활복지
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• v.17 no.4
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• pp.401-420
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• 2013

This study was performed to investigate the impact of the Neurocognitive Rehabilitation Therapy on the upper limb function recovery of patients with stroke and their abilities to perform daily activities and to provide basic data for a long-term treatment. A total of 30 patients with hemiplegia that occurred due to stroke were recruited as subjects of the present study, and 15 patients were randomly assigned to a Neurocognitive Rehabilitation Therapy group and a conventional treatment group, respectively. And, tests were performed over four weeks, five times a week, and 30 minutes a session. Manual Function Test(MFT), Fugl-Meyer Assessment Scale(FMA), and Korean-Modified Bathel Index(K-MBI) were used to measure the degree of the functional recovery before and after the experiment. According to the data of this study, in the upper limb function test, the Neurocognitive Rehabilitation Therapy group showed significant increase of the measurement values of MFT and FMA(p <.05), and when the difference between the two groups were compared, the upper limb function showed a statistically significant difference. In the daily activity performance test, only the Neurocognitive Rehabilitation Therapy group showed a significant improvement of K-MBI value(p <.05). Based on the results of the present study, it was demonstrated that the Neurocognitive Rehabilitation Therapy was effective in enhancing the upper limb functions and daily activity performance of patients with stroke.

• The Journal of Society for e-Business Studies
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• v.24 no.2
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• pp.71-89
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• 2019

In order to come up with satisfying product and improvement, firms use traditional marketing research methods to obtain consumers' opinions and further try to reflect them. Recently, gathering data from consumer communication platforms like internet and SNS has become popular methods. Meanwhile, with the development of information technology, mobile companies are launching new digital products for children to protect them from harmful content and provide them with necessary functions and information. Among these digital products, Kids Phone, which is a wearable device with safe functions that enable parents to learn childern's location. Kids phone is relatively cheaper and simpler than smartphone but it is noted that there are several problems such as some useless functions and frequent breakdowns. This study analyzes the reviews of Kids phones from domestic mobile companies, identifies the characteristics, strengths and weaknesses of the products, proposes improvement methods strategies for devices and services through SNS consumer analysis. In order to do that customer review data from online shopping malls was gathered and was further analyzed through text mining methods such as TF/IDF, Sentiment Analysis, and network analysis. Customer review data was gathered through crawling Online shopping Mall and Naver Blog/$Caf\acute{e}$. Data analysis and visualization was done using 'R', 'Textom', and 'Python'. Such analysis allowed us to figure out main issues and recent trends regarding kids phones and to suggest possible service improvement strategies based on sentiment analysis.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.76-84
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• 2019

This study evaluated the microleakage of three restorative materials and three tricalcium silicate-based pulp capping agents. The restorative materials were composite resin (CR), resin-reinforced glass ionomer cement (RMGI), and traditional glass ionomer cement (GIC) and the pulp capping agents were TheraCal $LC^{(R)}$ (TLC), $Biodentine^{(R)}$ (BD), and $ProRoot^{(R)}$ white MTA (WMTA). Additionally, shear bond strengths between the pulp-capping agents and dentine were compared. Class V cavities were made in bovine incisors and classified into nine groups according to the type of pulp-capping agent and final restoration. After immersion in 0.5% fuchsin solution, each specimen was observed with a stereoscopic microscope to score microleakage level. The crowns of the bovine incisors were implanted into acrylic resin, cut horizontally, and divided into three groups. TLC, BD and WMTA blocks were applied on dentine, and the shear bond strengths were measured using a universal testing machine. The microleakage was lowest in TLC + GIC, TLC + RMGI, TLC + CR, and BD + GIC groups and highest in WMTA + RMGI and WMTA + CR groups. The shear bond strength of BD group was the highest and that of WMTA group was significantly lower than the others.

• The Mathematical Education
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• v.61 no.4
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• pp.597-612
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• 2022

Recently, large-scale mathematics assessments are shifting from traditional paper-based tests to computer-based tests, nationally and internationally. This study explored the mode effect (the difference in student achievement by the change of test mode) according to the types of test items, the technological function reflected in the items, the characteristics of students' computer use, and the computer-based test environment. To this end, we analyzed the results of the 2020 national assessment of educational achievement of high school mathematics conducted on a paper and computer basis. As a result, firstly, the mode effect induced by the mode transition was generally insignificant, but the mode effect was larger in the extended response type than other types. Secondly, there were differences in the mode effect according to the transition to test with computer mode where innovative items were added. Thirdly, the difference between mode effects was statistically significant according to the student's sense of efficacy in computer use. The results of this study suggest that innovative items should be introduced deliberately according to the targeted content and competency in evaluation, and that assessment design and environment preparation need to be carefully developed so that nonessential abilities other than students' mathematical ability or incidental situation do not distort the assessment results.

• Analytical Science and Technology
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• v.33 no.6
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• pp.262-273
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• 2020

A fluorine content analysis method for krill oils, which is a representative oil formulation in foods, was developed in compliance with the Korea Food and Drug Ministry's "Guidelines for Validation of Testing Methods Related to Food". Using this method for krill oils, the presence of impurities was evaluated via combustion-ion chromatography (C-IC). A review of published technical data on fluorine in krill oils showed that while the traditional wet potentiometric method was typically used, it was not reliable. Moreover, there was no food testing/analysis laboratory in Korea to perform a fluorine test analysis on such an oil matrix. Therefore, we identified halogen (fluorine) tests, developed to national and international standards, and developed a test method suitable for krill oils by selecting a C-IC method that is sufficiently applicable to the oil matrix. Based on the characteristics of the oil matrix, the optimal test method was established through various experiments by reviewing the concerns related to loss and interference in the preparation and introduction of samples. The fluorine content test was carried out on 11 krill oil products that were purchased online. Most products (with the exception of only one) were found to contain less than the reporting limit obtained by the test method. Furthermore, after additional testing, a high fluorine content of approximately 2,000 ~ 3,000 mg/kg was detected on the krill surface, although the concentration varied depending on the area of the krill. A comparison with samples from two ISO/IEC 17025 testing laboratories confirmed that there was no significant difference in the statistical analysis results obtained by ANOVA among the three laboratories. A testing guide for fluorine content analysis was completed.

• Journal of the Korean Chemical Society
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• v.43 no.1
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• pp.110-118
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• 1999

In this study, the instructional influences of the conceptual change model based on the cognitive conflict and the conceptual change model emphasizing the social consensus were investigated. The subjects were 109 7th-graders in a boys' middle school in Seoul, and were taught about the changes of states, density, and dissolution for 8 class periods. The hypotheses provided in the instructions were constructed from the results of a pilot test. Prior to the instructions, three tests regarding the perceptions of discussion, the attitudes toward science instructions, and the perceptions of participation were administered. Two types of the conceptual change instructions and the traditional instruction were used in the treatment groups and the control group, respectively. After the instructions, the students' achievement, the conceptions, the perceptions of discussion, the attitudes toward science instructions, and the perceptions of participation were investigated. ANCOVA results revealed that the scores of the treatment groups were significantly higher than those of the control group in the achievement test. Although the score of the treatment group using the conceptual change model emphasizing social consensus were higher than those of other groups in the conceptions test, the differences were not statistically significant. The perceptions of discussion were significantly more positive in the treatment group using the conceptual change model emphasizing social consensus than in the control group. However, there were no significant differences in the scores of the attitudes toward science class and the perceptions of participation among the three groups. Educational implications are discussed.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.363-372
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• 2020

The purpose of this study is to evaluate the effect of nursing process education based on flipped learning on self-directed learning ability and academic achievement of nursing students. A quasi-experimental study employing a nonequivalent control group and pre-post design was conducted. The study group was composed of 135 college students enrolled in the 2nd grade of C nursing college as an experimental group and 103 college students enrolled in the 2nd grade of the D university nursing department as a control group. The experimental group participated in flipped learning with the theme of nursing process once a week for 5 weeks, and the control group applied the traditional teaching method. Data were analyzed using χ²-test and Independent t-test with SPSS 26.0 program. There were significant differences in self-directed learning ability(t=-4.71, p<.001) and academic achievement(t=-4.93, p<.001) of participants between experimental group and control group after completion of 5 sessions flipped learning. The results indicate that flipped learning can be used to improve self-directed learning ability and academic achievement of nursing students. As a result of this study, the basis for using flipped learning will be prepared, and furthermore, it will have a positive effect on the clinical practice and problem solving ability of nursing students.