• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.225-232
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• 1988

To improve the storage method for Kimchi, optimal ripening Kimchi was irradiated with doses of 1,3,5 kGy Co-GO gamma radiation, followed by the microbiological, physicochemical and sensory evaluations during storage at $5^{\circ}C$. 1. Total aerobic count increased in the beginning of storage and then decreased slowly as the number of total lactobacilli (anaerobe) increased. The above total aerobic and lactobacilli were reduced by 1 to 3 log cycles with irradiation and at the 90th day after storage the number of total lactobacilli remained $1.30{\times}10^{8}\;per\;ml$ in3 kGy irradiated group. Irradiation treatment at 3 kGy sterilized coli forms and molds contaminating the sample as the level of $2.0{\times}10^{4}\;per\;ml\;and\;5.4{\times}10^{2}\;per\;ml$, respectively and no apparent growth was observed in both control and 1 kGy irradiated groups after 20 days of storage. The population.of yeast, $3.5{\times}10^{3}\;per\;ml$ initially, in, creased steadily during Kimchi storage and at 90 days of storage the number was shown to be $5.6{\times}10^{4}\;per\;ml\;and\;6.5{\times}10^{2}\;per\;ml$ in control and 3 kGy irradiated groups, respectively. 2. In the physicochemical changes during Kimchi storage, pH, acidity and volatile acid of non-irradiated control at the 45th day after storage were 4.0,0.7% and 0.066%, while those of 3 kGy irradiated group were 4.2, 0.59 and 0.06% at the 90th day of storage, respectively. The reducing sugar content of all stored samples changed inversely total acidity content, indicating irradiation delayed the changes of them. The amount of aseorbic acid decreased gradually with the storage time and irradiation dose increase. Textural parameters of 3 kGy irradiated group were superior to those of other groups at the latter stage of storage. 3. Sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend tite shelf-life of Kimchi more than two months as compared to control.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.325-331
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• 2015

Skin is exposed to sunlight or artificial indoor light on a daily. The reached solar light on the earth surface consist of 50% visible light and 45% infrared (IR) except for ultra violet (UV). The negative effects of UV including UVB and UVA have been steadily investigated within the last decades. However, little is known about the effects of visible or IR light. In this study, we irradiated human dermal fibroblasts using light emitting diode (LED) to investigate the optimal parameter for enhancing cell growth and collagen synthesis. We found that red of 630 nm and green of 520 nm enhance the cell proliferation, but irradiation with purple and blue light exerts toxic effects. To examine the response of irradiation time and light intensity on the fibroblasts, cells were exposed to red or green light with intensities from 0.05 to $0.75mW/cm^2$. Procollagen secretion was increased of 1.4 fold by 10 min irradiation, while 30 min treatment decreased the collagen synthesis of dermal fibroblasts. Treatment with red of $0.3mW/cm^2$ and green of 0.15 and $0.3mW/cm^2$ resulted in enhancement of collagen mRNA. Lastly, we investigated the combinatorial effect of red and green light on dermal fibroblasts. The sequential irradiation of red and green light is an efficient way for the purpose of the increase in the number of fibroblasts than single light treatment. On the other hand, the exposure of red light alone was more effective method for enhancing of collagen secretion. Our study showed that specific light parameters accelerated cell proliferation, gene expression and collagen secretion on human dermal fibroblasts. In conclusion, we demonstrate that light exposure with specific parameter has beneficial effects on the function of dermal fibroblasts, and suggests the possibility of its cosmetically and clinical application.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.262-273
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• 2020

Amending biopolymers such as β-glucan (BG) and Xanthan gum (XG) generally enhances soil strength by ionic and hydrogen bonds between soil particles. Thus, biopolymers have been studied as eco-friendly construction materials in levees. However, physiological responses of plants grown on soil amended with biopolymers are not fully understood. This study focuses on the effects of biopolymers on the growth of Camelina sativa L. (Camelina) under excess zinc (Zn) stress. The optimal concentrations of BG and XG were confirmed to have a 0.5% ratio in soil depending on the physiological parameters of Camelina under excess Zn stress. The Zn binding capacity of biopolymers was investigated using 1,5-diphenylthiocarbazone (DTZ). The reduction of Zn damage in Camelina was evaluated by analyzing the Zn content and expression of heavy metal ATPase (HMA) genes under excess Zn stress. Amendments of BG and XG improved Camelina growth under excess Zn stress. In DTZ staining and ICP-OES analysis, Camelina grown on BG and XG soil showed less Zn uptake than normal soil under excess Zn stress. The Zn-inducible CsHMA3 gene was not stimulated by either BG or XG amendment under excess Zn stress. Moreover, both BG and XG amendments in soil exhibit Zn-stress mitigation similar to that of Zn-tolerant CsHMA3 overexpres sed Camelina. These results indicate that biopolymer-amended soils may influence the prevention of Zn absorption in Camelina under excess Zn stress. Thus, BG and XG are proven to be suitable materials for levee construction and can protect plants from soil contamination by Zn.

• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.65-75
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• 2021

Coin cell is a basic testing platform for battery research, discovering new materials and concepts, and contributing to fundamental research on next-generation batteries. Li metal batteries (LMBs) are promising since a high energy density (~500 Wh kg^-1) is deliverable far beyond Li-ion. However, Li dendrite-triggered volume fluctuation and high surface cause severe deterioration of performance. Given that such drawbacks are strongly dependent on the cell parameters and structure, such as the amount of electrolyte, Li thickness, and internal pressure, reliable Li metal coin cell testing is challenging. For the LMB-specialized coin cell testing platform, this study suggests the optimal coin cell structure that secures performance and reproducibility of LMBs under stringent conditions, such as lean electrolyte, high mass loading of NMC cathode, and thinner Li use. By controlling the cathode/anode (C/A) area ratio closer to 1.0, the inactive space was minimized, mitigating the cell degradation. The quantification and imaging of inner cell pressure elucidated that the uniformity of the pressure is a crucial matter to improving performance reliability. The LMB coin cells exhibit better cycling retention and reproducibility under higher (0.6 MPa → 2.13 MPa) and uniform (standard deviation: 0.43 → 0.16) stack pressure through the changes in internal parts and introducing a flexible polymer (PDMS) film.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.343-355
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• 2021

Eelgrass, Zostera marina L., was widely distributed around Sinyangseopji Beach in Bangdu Bay, on the eastern coast of Jeju Island, until breakwater construction in the late 1990s resulted in its complete loss. Six experimental sites were identified for restoration of the Z. marina bed in Bangdu Bay. Using the staple method, 500 Z. marina shoots were transplanted at each site in January 2019 and 2020. The transplants, along with environmental parameters, were monitored for 10 months following transplantation. There were significant differences in underwater irradiance, water temperature, and salinity among the sites, but all were suitable for Z. marina growth. The Ulva species, an opportunistic alga, appeared in spring and accumulated during summer at all sites; however, there was no significant effect of Ulva species on the survival and growth of the eelgrass transplants. Most of the transplanted Z. marina survived, and after 3 months, the density increased by 112.5-300% due to vegetative propagation, with a rapid rate of increase observed during spring and early summer at all sites. For 1-2 months after transplanting, the Z. marina shoots showed signs of transplant shock, after which the shoot density increased at all sites, confirming that all transplants adapted well to the new environment. However, in both 2019 and 2020, during late summer to early fall, the sites experienced heavy damage from typoons (twice in 2019 and three times in 2020) that hit Bangdu Bay. The transplants at two sites located in the center of Bangdu Bay were completely destroyed, but those at three sites located to the west of the bay showed a 192-312% increase in density. Thus, we confirmed that the Bangdu Bay Z. marina bed can be restored, with the highest probability of success for Z. marina restoration on the western side of Bangdu Bay, which is protected from typhoons.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.55-64
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• 2022

The potassium cream soap with fatty acid called cleaning foam has a crystal gel structure, and unlike an emulsion system, it is weak to shear stress and shows characteristics that are easily separated under high temperature storage conditions. The crystal gel structure of cleansing foams is significantly influenced by the nature and proportion of fatty acids, degree of neutralization, and the nature and proportion of polyols. In order to investigate the effect of these parameters on the crystal gel structure, a ternary system consisting of water/KOH/fatty acid was investigated in this study. The investigation of differential scanning calorimeter (DSC) revealed that the eutectic point was found at the ratio of myristic acid (MA) : stearic acid (SA) = 3 : 1 and ternary systems were the most stable at the eutectic point. However, the increase in fatty acid content had little effect on stability. On the basis of viscosity and polarized optical microscopy (POM) measurements, the optimum degree of neutralization was found to be about 75%. The system was stable when the melting point (T_m) of the ternary system was higher than the storage temperature and the crystal phase was transferred to lamellar gel phase, but the increase in fatty acid content had little effect on stability. The addition of polyols to the ternary system played an important role in changing the T_m and causing phase transition. The structure of the cleansing foams were confirmed through cryogenic scanning electron microscope (Cryo-SEM), small and wide angle X-ray scattering (SAXS and WAXS) analysis. Since butylene glycol (BG), propylene glycol (PG), and dipropylene glycol (DPG) lowered the T_m and hindered the lamellar gel formation, they were unsuitable for the formation of stable cleansing foam. In contrast, glycerin, PEG-400, and sorbitol increased the T_m, and facilitated the formation of lamellar gel phase, which led to a stable ternary system. Glycerin was found to be the most optimal agent to prepare a cleansing foam with enhanced stability.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.2
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• pp.80-98
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• 2023

This study explores the effectiveness of various data preprocessing algorithms for improving subseasonal to seasonal (S2S) climate predictions from six climate forecast models and their Multi-Model Ensemble (MME) using a deep learning-based postprocessing model. A pipeline of data transformation algorithms was constructed to convert raw S2S prediction data into the training data processed with several statistical distribution. A dimensionality reduction algorithm for selecting features through rankings of correlation coefficients between the observed and the input data. The training model in the study was designed with TimeDistributed wrapper applied to all convolutional layers of U-Net: The TimeDistributed wrapper allows a U-Net convolutional layer to be directly applied to 5-dimensional time series data while maintaining the time axis of data, but every input should be at least 3D in U-Net. We found that Robust and Standard transformation algorithms are most suitable for improving S2S predictions. The dimensionality reduction based on feature selections did not significantly improve predictions of daily precipitation for six climate models and even worsened predictions of daily maximum and minimum temperatures. While deep learning-based postprocessing was also improved MME S2S precipitation predictions, it did not have a significant effect on temperature predictions, particularly for the lead time of weeks 1 and 2. Further research is needed to develop an optimal deep learning model for improving S2S temperature predictions by testing various models and parameters.

• Journal of the Korean Society for Library and Information Science
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• v.58 no.1
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• pp.5-30
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• 2024

The purpose of this study is to extract topics from experimental data using the topic modeling methods(LDA, Top2Vec, and BERTopic) and compare the characteristics and differences between these models. The experimental data consist of 55,442 papers published in 85 academic journals in the field of library and information science, which are indexed in the Web of Science(WoS). The experimental process was as follows: The first topic modeling results were obtained using the default parameters for each model, and the second topic modeling results were obtained by setting the same optimal number of topics for each model. In the first stage of topic modeling, LDA, Top2Vec, and BERTopic models generated significantly different numbers of topics(100, 350, and 550, respectively). Top2Vec and BERTopic models seemed to divide the topics approximately three to five times more finely than the LDA model. There were substantial differences among the models in terms of the average and standard deviation of documents per topic. The LDA model assigned many documents to a relatively small number of topics, while the BERTopic model showed the opposite trend. In the second stage of topic modeling, generating the same 25 topics for all models, the Top2Vec model tended to assign more documents on average per topic and showed small deviations between topics, resulting in even distribution of the 25 topics. When comparing the creation of similar topics between models, LDA and Top2Vec models generated 18 similar topics(72%) out of 25. This high percentage suggests that the Top2Vec model is more similar to the LDA model. For a more comprehensive comparison analysis, expert evaluation is necessary to determine whether the documents assigned to each topic in the topic modeling results are thematically accurate.