• 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).

• Journal of Animal Science and Technology
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• v.61 no.2
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• pp.55-60
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• 2019

Colibacillosis is one of the major health problems in young piglets resulting in poor health and death caused by Escherichia coli producing F18 pili and Shiga toxin 2e. It is pivotal to reduce colibacillosis in weaned piglets to enhance production performance. In this study, we evaluated synbiotics as the gut health improvement agents in the mouse model challenged with Shiga toxin-producing E. coli (STEC) isolated from piglets. Prebiotic lactulose was formulated with each $5.0{\times}10^6CFU/mL$ of Pediococcus acidilactici GB-U15, Lactobacillus plantarum GB-U17, and Lactobacillus plantarum GB 1-3 to produce 3 combinations of synbiotics. A total of 40 three weeks old BALB/c mice were randomly assigned to 4 groups (n = 10): a control group and 3 synbiotics treated groups. Each treatment groups were daily administrated with $5.0{\times}10^6CFU/mL$ of one synbiotics for the first week, and every 3 days during the second week. All the mice were challenged with $8.0{\times}10^8CFU/mL$ of STEC 5 days after animals began to receive synbiotics. Mice treated with synbiotics based on Pediococcus acidilactici GB-U15 and Lactobacillus plantarum GB-U17 significantly improved daily weight gain compared to mice in other groups. While mice treated with GB-U15 showed better fecal index, no significant differences were observed among groups. Gross lesion and histopathological evaluations showed that mice treated with GB-U15 moderately improved recovery from STEC infection. In conclusion, our results suggest that the synbiotics formulated with lactulose and Pediococcus acidilactici GB-U15 have potential benefits to prevent and improve colibacillosis in weaned piglets.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.163-176
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• 2019

The purpose of this study is to examine the impact of PM consultant leadership competence on consulting repurchase intention and the impact of SME CEO participation on consulting repurchase intention. The validity of the measurement model was secured through CFA (Confirmative Factor Analysis) for the questionnaire data, and consistency was secured through the same method convenience, and significant results were obtained. In other words, not only the ability of PM consultant in repurchase of consulting is important, but also confirms that repurchase intention differs according to the participation of manager. Therefore, the performance that manager feels depends on the degree of manager's interest in repurchase and plays an important role in repurchase. As a result, it is important for PM to report to manager and / or make the manager participate in consulting process so that manager can be interested. In this study, it is difficult to generalize the relationship between PM's leadership role and manager's involvement in the repurchase intention. However, it is meaningful that PM's competence as well as management's participation are very important, and that this study figured out which drection PM's leadership should focus on. The purpose of this study is to investigate the effect of the variables on the repurchase intention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.23-28
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• 2019

The structural integrity of a surface metal coating was evaluated through numerical results to improve the efficiency and reduce the damage caused by cavitation in ships and marine plants. The goal was to ensure structural strength and performance, even if the thickness of the wing is reduced to reduce the weight of the material and surface coating. Analytical methods were used for four models: a non-coating model, one with the same thickness after coating, one with a thickness reduction of 3% after coating, and one with thickness reduction of 5% after coating. With a thickness reduction of 5% after coating, the stress was increased to 12%, and the safety factor was 0.99%, so the structural integrity was insufficient. However, a better material or a thicker coating could allow a sufficient safety factor to be secured. The structural integrity was improved by the coating, and even when the weight was reduced up to 5%, the structural integrity could be sufficiently secured due to the coating effect.

• Journal of The Korean Association For Science Education
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• v.39 no.3
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• pp.321-335
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• 2019

This study aims to explore the influencing factors and the process of enhancing science self-efficacy (SSE) and to lay the foundation in understanding science self-efficacy of students. The ten categories related to the science self-efficacy were derived through the coding of the interview data based on the grounded theory and paradigm analysis to develop a process model of science self-efficacy improvement. Through the process analysis, four cyclical phases were found in the process of enhancing SSE: 'Entering into learning science' phase, 'enhancing SSE' phase, 'adjustment' phase, and 'result' phase. More specifically, the phase of 'entering into learning science' is where students choose science track and stimulated to construct SSE. The phase of 'enhancing SSE' is where students taking a science track actively learn science and perform science activities. In the phase of 'adjustment', students come to have successful performance about learning science and performing science activities by using diverse strategies. Finally, 'result' phase indicates different appearances of students depending on SSE levels. The phases were non-linear and periodically repeat depending on situation. The core category in the selective coding was indicated to be 'enhancing science self-efficacy.' Students' SSE form by learning science and performing science activities. These finding may help better understand the behavior of students who are taking a science track by facilitating effective science learning through the increase of their SSE levels.

• The Journal of Korean Academy of Sensory Integration
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• v.17 no.1
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• pp.43-53
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• 2019

Objective : This study was designed to find the latest intervention trends in treatment of children with attention deficit hyperactivity disorder (ADHD) in South Korea. Methods : Studies on ADHD published in Korean journals from January 2004 to December 2018 were reviewed. The databases used were DBpia, Google Scholar, RISS, and KISS. The search terms were "attention deficit hyperactivity," "child," and "intervention." A total of 14 studies were selected. The results of this study were as follows: Patient, Intervention, Comparison, Outcome. Results : The level of evidence was the highest in the single subject study of level IV, and the methodological quality was the most common study. The interventional metronome (IM) intervention was the most frequently used, and the evaluation tools used in the measurement were the Long Form Assessment of the Interactive Metronome and the Korean Behavior Child Checklist. The Korean ADHD interventions showed statistically significant improvement in concentration, hyperactivity, task performance, excessive language use, and timing. Conclusions : Various types of interventions were provided for children with ADHD in South Korea. The interventions showed positive effects, and provided basic data for evidence-based implementation in clinical practice. In the future, a model study should be conducted, to establish an effective service delivery system, as well as ongoing research on children with ADHD.

• Journal of the Korean Geotechnical Society
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• v.35 no.6
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• pp.17-26
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• 2019

In this study, the statistical characteristics of the resistance bias factors were analyzed using a high-quality field load test database, and the total resistance bias factors were estimated considering the soil uncertainty and construction errors for the application of the limit state design of aggregate pier foundation. The MLR model by Bong and Kim (2017), which has a higher prediction performance than the previous models was used for estimating the resistance bias factors, and its suitability was evaluated. The chi-square goodness of fit test was performed to estimate the probability distribution of the resistance bias factors, and the normal distribution was found to be most suitable. The total variability in the nominal resistance was estimated including the uncertainty of undrained shear strength and construction errors that can occur during the aggregate pier construction. Finally, the probability distribution of the total resistance bias factors is shown to follow a log-normal distribution. The parameters of the probability distribution according to the coefficient of variation of total resistance bias factors were estimated by Monte Carlo simulation, and their regression equations were proposed for simple application.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.1-14
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• 2019

A full scale hydrodynamic simulation that requires an accurate reproduction of shock-induced detonation was conducted for design of an energetic component system. A detailed hydrodynamic analysis SW was developed to validate the reactive flow model for predicting the shock propagation in a train configuration and to quantify the shock sensitivity of the energetic materials. The pyrotechnic device is composed of four main components, namely a donor unit (HNS+HMX), a bulkhead (STS), an acceptor explosive (RDX), and a propellant (BPN) for gas generation. The pressurized gases generated from the burning propellant were purged into a 10 cc release chamber for study of the inherent oscillatory flow induced by the interferences between shock and rarefaction waves. The pressure fluctuations measured from experiment and calculation were investigated to further validate the peculiar peak at specific characteristic frequency (${\omega}_c=8.3kHz$). In this paper, a step-by-step numerical description of detonation of high explosive components, deflagration of propellant component, and deformation of metal component is given in order to facilitate the proper implementation of the outlined formulation into a shock physics code for a full scale hydrodynamic simulation of the energetic component system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.491-501
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• 2019

In side-channel analysis, which exploit physical leakage from a cryptographic device, deep learning based attack has been significantly interested in recent years. However, most of the state-of-the-art methods have been focused on classifying side-channel information in a profiled scenario where attackers can obtain label of training data. In this paper, we propose a new method based on deep learning to improve non-profiling side-channel attack such as Differential Power Analysis and Correlation Power Analysis. The proposed method is a signal preprocessing technique that reduces the noise in a trace by modifying Auto-Encoder framework to the context of side-channel analysis. Previous work on Denoising Auto-Encoder was trained through randomly added noise by an attacker. In this paper, the proposed model trains Auto-Encoder through the noise from real data using the noise-reduced-label. Also, the proposed method permits to perform non-profiled attack by training only a single neural network. We validate the performance of the noise reduction of the proposed method on real traces collected from ChipWhisperer board. We demonstrate that the proposed method outperforms classic preprocessing methods such as Principal Component Analysis and Linear Discriminant Analysis.