• Journal of Technology Innovation
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• v.29 no.3
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• pp.33-62
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• 2021

This study compares and analyzes the efficiency of R&D activities of technology-innovative small and medium-sized enterprises(SMEs) between industries and proposes ways to improve efficiency. The research samples are 6,708 technology-innovative SMEs, which have received a guarantee by the KIBO from 2008 to 2011. Input variables are the level of R&D personnel, R&D investment, and output variables are patent applications, prototype. Efficiency is measured by the DEA model, and indirect comparisons that are individually measured by industry are performed. As a result of the analysis, the CCR for determining the optimal returns to scale is 0.19, the BCC for determining the optimal input distribution is 0.70, and the SE for determining the optimal output is 0.30. By industry type, the medium and low-tech industries have high CCR and BCC, while the high-end and high-tech industries have high SE. R&D activities need to be operated on an optimal scale through managing R&D performance because there is the inefficiency of scale across the industry. The contribution of the study is to analyze the R&D efficiency of each industry of technology-innovative SMEs by the technology evaluation data of the KIBO.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.189-201
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• 2021

The art of dynamic images has experienced three development stages, including experimental films, recording art, and new media image. By introducing all kinds of new materials, new media to the art, and the art of dynamic images has created more freedom for art creation. With the development of digital information technology, dynamic image works have put forward an increasingly high requirement of visual art. The combination of dynamic images and visual illusion can give rise to different forms and expression methods, thus endowing artworks with more vigor. This paper provides an overview by sorting out the lineage and development of dynamic images in the background, as well as understanding the application and performance of contrasted visual illusion. Based on the understanding of the characteristics of visual illusion, we discuss the new characteristics of applying the theory of visual illusion to new media dynamic images in relation to the technical approach of dynamic images. Through the analysis of specific works of Telematic Vision, we search for its reasonable combination and find the appropriate technical means of implementation. We discuss how to use digital multimedia technology and spatial optical illusion to make the design more novel and impactful, and consider how the combination of digital dynamic image technology and visual illusion should be interpreted and applied.

• Smart Media Journal
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• v.10 no.3
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• pp.31-38
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• 2021

It is hard to predict when and where a fall accident will happen. Also, if rapid follow-up measures on it are not performed, a fall accident leads to a threat of life, so studies that can automatically detect a fall accident have become necessary. Among automatic fall-accident detection techniques, a fall detection scheme using an IMU (inertial measurement unit) sensor attached to a wrist is difficult to detect a fall accident due to its movement, but it is recognized as a technique that is easy to wear and has excellent accessibility. To overcome the difficulty in obtaining fall data, this study proposes an algorithm that efficiently learns less data through machine learning such as KNN (k-nearest neighbors) and SVM (support vector machine). In addition, to improve the performance of these mathematical classifiers, this study utilized feature data aquired in the frequency space. The proposed algorithm analyzed the effect by diversifying the parameters of the model and the parameters of the frequency feature extractor through experiments using standard datasets. The proposed algorithm could adequately cope with a realistic problem that fall data are difficult to obtain. Because it is lighter than other classifiers, this algorithm was also easy to implement in small embedded systems where SIMD (single instruction multiple data) processing devices were difficult to mount.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.667-680
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• 2021

We investigated changes in frost days and frost-free periods and to comparatively assess frost event prediction models developed using logistic regression (LR), random forest (RF), and long short-term memory (LSTM) networks. The meteorological variables for the model development were collected from the Suwon, Cheongju, and Gwangju stations for the period of 1973-2019 for spring (March - May) and fall (September - November). The developed models were then evaluated by Precision, Recall, and f-1 score and graphical evaluation methods such as AUC and reliability diagram. The results showed that significant decreases (significance level of 0.01) in the frequencies of frost days were at the three stations in both spring and fall. Overall, the evaluation metrics showed that the performance of RF was highest, while that of LSTM was lowest. Despite higher AUC values (above 0.9) were found at the three stations, reliability diagrams showed inconsistent reliability. A further study is suggested on the improvement of the predictability of both frost events and the first and last frost days by the frost event prediction models and reliability of the models. It would be beneficial to replicate this study at more stations in other regions.

• Journal of Korean Home Economics Education Association
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• v.33 no.1
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• pp.151-167
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• 2021

This study reports on the development of a dietary education program for Korean young adults in single-person households. The 7th National Health and Nutrition Survey (2016-2018) was used to compare and analyze the dietary behavior of single-person households and multi-person households, and an online survey was conducted on 350 young adults (age 19-39 years) living in Seoul. According to the analysis, single-person households had higher rates of breakfast and eating out than multi-person households, and significantly lower average intake of energy and nutrients (p<0.05). In particular, in the case of single-person households, the lower the frequency of cooking at home, the higher the rate of breakfast and the higher the frequency of eating out and delivery food (p<0.05). Based on the survey, a dietary education program for young adults single-person households was developed by applying the DESIGN six-step procedure and social cognitive theory as a conceptual model. The first session consisted of the health and economic benefits of home-cooked meals, the second session of the importance of the breakfast and the effect of exercise in life, the third session of the importance of balanced nutrition and the principles of a healthy diet, the fourth session of food safety and storage, and the fifth session of social dining. Each session was composed of a combination of theoretical lectures to motivate 'more making and eating healthy home-cooked meals' and cooking practice for improving behavioral performance.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.610-621
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• 2021

The soil creep, primarily caused by earthquakes and torrential rainfall events, has widely occurred across the country. The Korea Forest Service attempted to quantify the soil creep susceptible areas using a discriminant value table to prevent or mitigate casualties and/or property damages in advance. With the advent of advanced computer technologies, machine learning-based classification models have been employed for managing mountainous disasters, such as landslides and debris flows. This study aims to quantify the soil creep susceptibility using several classifiers, namely the k-Nearest Neighbor (k-NN), Naive Bayes (NB), Random Forest (RF), and Support Vector Machine (SVM) models. To develop the classification models, we downscaled 292 data from 4,618 field survey data. About 70% of the selected data were used for training, with the remaining 30% used for model testing. The developed models have the classification accuracy of 0.727 for k-NN, 0.750 for NB, 0.807 for RF, and 0.750 for SVM against test datasets representing 30% of the total data. Furthermore, we estimated Cohen's Kappa index as 0.534, 0.580, 0.673, and 0.585, with AUC values of 0.872, 0.912, 0.943, and 0.834, respectively. The machine learning-based classifications for soil creep susceptibility were RF, NB, SVM, and k-NN in that order. Our findings indicate that the machine learning classifiers can provide valuable information in establishing and implementing natural disaster management plans in mountainous areas.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.649-660
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• 2021

Through analytical method based on S-76 model, the level of rotor hub vibration reduction was analyzed according to higher harmonic actuating by individual blade control. The higher harmonic actuating method for individual blades was divided into a method of generating an additional actuating force from the pitch-link in the rotating part and generating actuating force through the active trailing edge flap control of the blade. In the 100kts forward flight conditions, the hub load analysis was performed by changing the phase angle of 15 degree for the 2P/3P/4P/5P harmonic actuation for individual blades. Through the harmonic actuation results, the sensitivity of the rotor system according to the actuating conditions was analyzed, and the T-matrix representing the characteristics of the rotor system was derived based on this analysis result. And through this T-matrix, optimal higher harmonic actuating condition was derived to minimize hub vibration level for flight condition. In addition, the effect on the performance of the rotor system and the pitch-link load under minimum hub vibration condition, as well as the noise influence through the noise analysis were confirmed.

• Korean Journal of Comparative Education
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• v.28 no.4
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• pp.221-248
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• 2018

The purpose of this study was to analyze the performance of the Daegu Happiness Competency Education Program. It was confirmed that students, parents, teachers, and education professions are aware of the middle and higher level of education for happiness in Daegu in terms of the formation and operation of the curriculum. There is no significant difference between students and parents in terms of average value, and teachers' perception level is relatively high, which is understandable in that teachers are the subjects of the curriculum organization and operation. In addition, there was no statistically significant difference between the parents and the school level, but there were significant differences between students and teachers. In particular, students' and teachers' perceptions were lowered as the number of schools increased, unlike the predictions. They showed the lowest results in the special schools, autonomous schools and special schools. The reason for this is that Daegu Happiness Competency Education was implemented in 2014, and it was because there was little room to recognize and accept the new curriculum due to the burden of college entrance examination or employment. In the future, it will naturally improve as the education process is settled, but here we can find suggestions for the establishment of Daegu Happiness Competency Education.

• Food Engineering Progress
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• v.15 no.1
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• pp.75-79
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• 2011

Analytical methods for food antioxidants including ascorbic acid, erythorbic acid, ascorbyl palmitate (AP), and ascorbyl stearate (AS), were validated using high performance liquid chromatography. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), and recovery were tested using lard and cider as food model systems. Linearity of ascorbic acid and erythorbic acid were both higher than ($R^2$> 0.99), LOD of these compounds were 0.46 and 0.48 ${\mu}g/mL$, respectively and LOQ were 1.39 and 1.45 ${\mu}g/mL$, respectively. The recovery rates of these compounds were 86.35-94.78% and 84.76-95.02%, respectively. However, the concentration of AP and AS decreased in methanol stock solution. Four other solvents including ethanol, acetonitrile, mixture of methanol and acetonitrile, and mixture of ethanol and acetonitrile were tested to increase the stability of AP and AS under room temperature and refrigerated temperature. Ethanol provided better stability of AP and AS under both room and refrigerated temperature. This study can help to accurately analyze the content of ascorbic acid and its derivatives in processed foods.

• Food Engineering Progress
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• v.15 no.4
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• pp.376-381
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• 2011

The baking performance of Cudrania tricuspidata leaf powder as a value-added food ingredient was investigated in a model system of sponge cakes. Cudrania tricuspidata leaf powder was incorporated into cake batter at 5 levels (0, 5, 10, 15, and 20%, w/w) by adding equivalent amount based on total weight of wheat flour. The specific volume, height, moisture content, volume index, and symmetry index of sponge cakes decreased significantly with the increase in Cudrania tricuspidata leaf powder content (p < 0.05). Sponge cakes became darker and firmer with increase in Cudrania tricuspidata leaf powder content (p < 0.05), as indicated by decrease in the $L^*$ and increase in the firmness measured by the texture measuring instrument. Total polyphenol content also increased gradually as the Cudrania tricuspidata leaf powder content increased. Finally, the consumer acceptance test indicated that addition of Cudrania tricuspidata leaf powder up to 10% in the formulation of sponge cakes did not significantly influence the consumers' acceptability with respect to taste and flavor. In addition, the overall acceptability was not different from each other for control and 5% sample (p > 0.05).