• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1739-1744
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• 2010

The calculation method using the numerical model developed is currently one of the mose required method to predict sediment transport and bed changes in the rivers. Specially, it is real condition that is applying as it is a single sediment transport equation and sediment transport mode mostly without verification process with field data. The sensitivity analysis and calibration process considering the different sediment transport equations and sediment transport modes should be performed for the accurate bed change prediction of the specified study reach using the a model. Through its process, the optimum sediment transport equation and mode for the study reach should be defined. In this study, bed changes for the actual river are computed using the CCHE2D model allowed to select various sediment transport equations and modes. The bed change sensitivity analysis with different ranges of river flow discharge through its process, the optimum sediment transport equation and mode for the study reach should be defined. The bed change simulation with the actual hydraulic condition and the modeling results are compared with the field survey results.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.31-40
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• 2011

In this study, the methods of sedimentation reduction for the estuary barrage were analyzed using the CCHE2D bed change model. Especially, the effectiveness of sediment dredging currently applied in the field was evaluated quantitatively and also the channel contraction method which is a substitute method was analyzed for the Nakdong River Estuary Barrage (NREB). The numerical model was calibrated and validated for the sediment transport equations and transport modes. In the NREB case, the Ackers and White formula and bed load type was the most similar to the field condition. As a results of the dredging simulation, there was the sedimentation reduction effect of 0.2 m in the bed changes. Furthermore, the analysis result of the channel contraction method represented that the sedimentation reduction effects of the average 0.4 m and the maximum 2.0 m were produced.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.587-594
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• 2019

This study experimentally investigated the effects of high and low densities of vegetation patches on the flow characteristics in a stream-scale outdoor experimental channel with rooted willows. Stream-scale experiments on vegetated flows were carried out for an emergent condition of vegetation. Vegetation patches were arranged by alternate bar formation and the flows in vegetated and non-vegetated sections were compared. Three-dimensional flow structure was measured by ADV (Acoustic Doppler Velocimeter) and the vertical distributions of longitudinal velocity were mainly analyzed from the measurements at various points. Flow velocities show different patterns depending on the density of vegetation patches. The difference in flow velocity between in the vegetated and non-vegetated sections appear to large in the dense patches and the flow becomes complicated at the downstream edge of the patch. Despite the upstream flow disturbed by the first patch, the flows over the second patch show the similar pattern.

• Food Science and Industry
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• v.51 no.3
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• pp.245-258
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• 2018

Natural and synthetic antibacterial materials are used in foods to avoid bacterial contamination-induced food poison and deterioration. Due to the human and environmental safety, natural products including plant extracts have been extensively added into foods as antibacterial materials. Since some of core molecules comprised in those plant extracts are hardly dissolved in aqueous phases or food matrixes, nanotechnological approaches have been suggested to overcome such obstacles. Here we report domestic and international various types of plant- or non-plant-origin antibacterial materials that have been commercialized and used for the food industry. To improve solubility and stability of such antibacterial materials, nano-encapsulation or nano-complexation methods are also investigated focusing on the utilization of dextrins and proteins as coating materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.284-293
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• 2022

In this study, we aimed to optimize the blending conditions of sunflower oil (A), water (B), and oriental sauce (C) for canned smoked oysters Crassostrea gigas in oriental sauce (SOO). Using response surface methodology (RSM), we found that the optimal independent variables [X₁, A/(B+C); X₂, B/C] based on the salinity (Y₁) amino acid nitrogen content (Y₂), and overall acceptance (Y₃) of high-quality SOO were 48.7% (w/w) for sunflower oil, 25.5% (w/w) for water, and 25.8% (w/w) for oriental sauce. Under optimal conditions, the experimental values of Y₁, Y₂, and Y₃ were 1.68±0.4 g/100 g, 155.4±2.4 mg/100 g, 6.2±0.23 score, respectively, which were not significantly different from the predicted values (P<0.05). The SOO prepared under optimal conditions had a higher overall acceptance than commercial canned smoked oysters. These results suggest that developing canned smoked oysters in oriental sauce can be industrialized, and the product is predicted to be competitive in the global market.

• Journal of Biomedical Engineering Research
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• v.41 no.2
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• pp.107-119
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• 2020

The deep neural networks (DNN) that can replicate the behavior of the human expert who recognizes the characteristics of ECG waveform have been developed and studied to analyze ECG. However, although the existing DNNs can not provide the explanations for their decisions, those trials have attempted to determine whether patients have certain diseases or not and those decisions could not be accepted because of the absence of relating theoretical basis. In addition, these DNNs required a lot of training data to obtain sufficient accuracy in spite of the difficulty in the acquisition of relating clinical data. In this study, a small-sized continuous data processing DNN (C-DNN) was suggested to determine the simple characteristics of ECG wave that were not required additional explanations about its decisions and the C-DNN can be easily trained with small training data. Although it can analyze small input data that was selected in narrow region on whole ECG, it can continuously scan all ECG data and find important points such as start and end points of P, QRS and T waves within a short time. The star and end points of ECG waves determined by the C-DNNs were compared with the results performed by human experts to estimate the accuracies of the C-DNNs. The C-DNN has 150 inputs, 51 outputs, two hidden layers and one output layer. To find the start and end points, two C-DNNs were trained through deep learning technology and applied to a parameter acquisition algorithms. 12 lead ECG data measured in four patients and obtained through PhysioNet was processed to make training data by human experts. The accuracy of the C-DNNs were evaluated with extra data that were not used at deep learning by comparing the results between C-DNNs and human experts. The averages of the time differences between the C-DNNs and experts were 0.1 msec and 13.5 msec respectively and those standard deviations were 17.6 msec and 15.7 msec. The final step combining the results of C-DNN through the waveforms of 12 leads was successfully determined all 33 waves without error that the time differences of human experts decision were over 20 msec. The reliable decision of the ECG wave's start and end points benefits the acquisition of accurate ECG parameters such as the wave lengths, amplitudes and intervals of P, QRS and T waves.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.443-454
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• 2020

The purpose of this study is to propose a structural theoretical model that can explain the learning flow of online distance education participants and to clarify the structural causal relationship among related variables that affect the learning flow of cyber university learners. Study results found a modified final model with a statistically significant fit based on the structural research model proposed in this study explained the learning flow of cyber university learners. Second, as a result of verifying the relationship between learning motivation and learning flow of cyber university learners, it was found that intrinsic motivation had a significant positive effect on learning flow. Third, as a result of the empirical verification on the relationship between academic self-efficacy and learning flow of cyber university learners, it was found that academic self-efficacy had a significant effect on learning flow. Fourth, as a result of empirical verification on the relationship between self-directed learning and the learning flow of cyber university learners, it was found that the learner's self-directed learning ability had a significant effect on learning flow. Such research results can be used to suggest a strategic direction for successful settlement and diffusion of a new paradigm of online non-face-to-face distance education, which has recently attracted attention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.55-63
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• 2018

This study was intended to identify path structures through pathway analysis with an emphasis on the cognitive elements that influence the acculturative stress of marriage-based immigrant women. The results of the study were designed to establish a foundation for practical measures and policies to support marriage-based immigrant women to adjust their lives in the culture. This study has established research model on the path structure according to the psychological stress theory as to how social support, coping strategy, and acculturative attitude recognized as a cognitive element of marriage-based immigrant women on the acculturative stress and implement practical verification. In addition, control variables for the use of ages, education level, period of marriage, and income level of socio-demographic variables were analyzed. To obtain data for the study, convenience sampling and snowball sampling of marriage-based immigrant women that resided in the area of C and J were conducted simultaneously through surveys and applied to the analysis of 204 cases. Analysis of the path structure of influence of social support, coping strategies, and acculturative attitudes that were perceived as a cognitive element of marriage-based immigrant women influencing acculturative stress revealed that these factors were specifically weighted towards acculturative. Moreover, comprehensive acculturative attitude was identified as a crucial variable reducing the effects of acculturative stress during the acculturative procedures of marriage-based immigrant women. This assumes that establishing and performing policies supporting co-existence of homeland cultures of marriage-based immigrant women and Korean cultures might be an efficient action for dealing with acculturative stress rather than forcing them to adjust to Korean culture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.270-278
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• 2018

In this study, the Pedagogical Content Knowledge for childhood's music education and Teacher's Efficacy empirically examined the relationship between teachers' attitudes through structural equation model analysis. Data were collected for 132 infant teachers working for early childhood educational institutions for this study. Structural equation model analysis was performed using SPSS and AMOS. In this research, conformity to the research model was appropriate. Pedagogical content knowledge for childhood's music education clearly confirmed the relationship between the teacher's efficacy, the attitude variables of the teacher. The Pedagogical Content Knowledge for childhood's music education proved to have a meaningful influence on the attitude of the teacher for music education. The Pedagogical Content Knowledge for childhood's music education proved to have a meaningful influence on Teacher's Efficacy for music education. The Pedagogical Content Knowledge for childhood's music education has been found to influence the attitude of the teacher indirectly with the intermediation of Teacher's Efficacy. The effect of the parameter was the effect of the partial parameters. The results of this study can be used as basic material important for strengthening the expertise of young children's teachers for music development of young children. In particular, it was confirmed that the knowledge variable of the content of the music professor of an infant teacher is a very important variable in early childhood music education.

• Journal of Oral Medicine and Pain
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• v.36 no.4
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• pp.245-252
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• 2011

The aim of this study is to clinically evaluate the effect of a mouthwash containing cetylpyridinium and zinc chloride on reduction of morning oral malodor in healthy subjects measured by organoleptic measurement and a portable sulfide monitor. A total of 8 healthy non-smoking male volunteers were enrolled in this study of crossover design consisting of two experimental phases. The subjects were instructed to rinse the mouth with 10 mL of the experimental mouthwash containing cetylpyridinium and zinc chloride for 30 seconds at the first phase. At the second phase after a one-week washout period, each subject rinsed with distilled water as a control. All experiments were conducted at around 8:30 a.m. and oral malodor was measured using organoleptic measurement and a portable sulfide monitor just before rinsing with the experimental mouthwash or control (baseline), 1 hr, 2 hrs, and 3 hrs after rinsing. The mouthwash containing cetylpyridinium and zinc chloride reduced morning oral malodor up to 3 hrs after rinsing. Organoleptic score and concentrations of volatile sulfur compounds after use of the experimental mouthwash significantly decreased with time, and the decreases were significantly different between the mouthwash and control. In conclusion, the mouthwash containing cetylpyridinium and zinc chloride is significantly effective on reduction of morning oral malodor in healthy subjects by 3 hrs.