• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.356-363
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• 2022

To investigate the functional activity of different citrus fruit peels, antioxidant compounds in 70% ethanol extracts of mandarin, lemon, orange, and grapefruit peel powders were identified, and antioxidant and antibacterial activities were quantitated. Mandarin peel contained the highest content of total phenolic compounds and total flavonoid substances (21.46±0.12 mg GAE/g and 11.57±0.05 mg RE/g, respectively). The total phenolic compound content of the three other citrus fruits was 14.16±0.18-18.44±0.07, and their total flavonoid content was 5.51±0.10-7.46±0.09 mg RE/g. DPPH radical scavenging activity was the highest in lemon peel (87.64±0.21%), and mandarin peel displayed the best antioxidant activity with respective ABTS radical scavenging activity and FRAP measurements of 43.20±0.61% and 78.82±1.06 mM TE/g. Grapefruit peel antimicrobial activity increased with treatment time, and was the most potent among the four tested citrus species, inhibiting Staphylococcus aureus by about 4.05 log cycle. These findings demonstrate that mandarin and grapefruit peel can be used to prevent oxidation, improve food storage capabilities, and potentially preserve food quality.

• The Korea Journal of Herbology
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• v.29 no.3
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• pp.35-42
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• 2014

Objectives : Since single extract powders was released at 1987, the insurance fee has not been changed, but the price of raw material has been increasing. According to this, Pharmaceutical company couldn't invest on quality of the product, so, the quality of single extracts went down and lost the consumer's trust. We checked the contents of marker ingredients in single extract thereby to recover the reliability of insurance-covered herbal preparations. Methods : we bought total twelve products of eight different single extracts of two main pharmaceutical companies among total 65 kinds of single extract powder stipulated in KHP (The Korean Herbal Pharmacopoeia) monograph III at Jan. 2013. Assays of selected single extract powders are performed by KHP regulation. And we surveyed price fluctuation of relevant herb raw materials from 2005 to 2012. Results : Among twelve products, eight single extract powders were suitable by the KHP regulation. But four products didn't reach the content amount of KHP. Marker contents in the single extracts product of Pueraria Root, Licorice, Peony root and Scutellaria Root of A company were 70%, 1%, 23.7% and 75.1%, respectively. Conclusions : We can acertain whether there's a quality problem in the insurance-covered single extract powders. But, A company is no longer producing these improper single extract powders. As a medicine, single extract powders needs to be strictly quality controlled by the company, and regularly monitored by the KFDA.

• The Korea Journal of Herbology
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• v.33 no.5
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• pp.105-110
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• 2018

Objectives : We tried to observe the fluorescence anisotropy and intensity of ethidium ion in the intercalating binding interaction between DNA and ethidium ions in the presence of berberine, and then tried to explain the effect of berberine on the intercalating interaction of ethidium ion with DNA. Methods : DNA(calf thymus DNA), berberine and ethidium bromide(EtBr) were purchased from Sigma-Aldrich Co. Proper amount of each compound was dissolved in 20 mM sodium phosphate buffer(pH 7.0) containing 100 mM of NaCl to prepare stock solutions. Collections of the fluorescence anisotropy and intensity data were performed on JASCO FP-8300 spectrofluorometer equipped with a polarizer and a Peltier temperature controller. The excitation of ethidium ion was done at 550 nm and the emission data were collected at 600 nm. For Stern-Volmer plot, the fluorescence data were collected at $18^{\circ}C$ and $30^{\circ}C$. Results : According to the results of this research, the weak competitive binding pattern between ethidium ion and berberine appeared in binding with DNA at low ratio of DNA to ethidium ion. But at high ratio of DNA to ethidium ion, this weak competition disappeared. Instead, berberine might bind to DNA by intercalating way. In other words, berberine could de-intercalate ethidium ion from DNA at low concentration of DNA relative to ethidium ion, but could not at high concentration of DNA relative to ethidium ion. In addition, the mechanism of fluorescence quenching of ethidium ion could also proceed differently, depending on the ratio of the amount of DNA to that of ethidium ion. Conclusions : The effect of berberine on the DNA-ethidium ion intercalating interaction could work differently, depending on the relative ratio of the amount of DNA to that of ethidium ion. This study also showed that fluorescence anisotropy analysis is very useful method to obtain detailed information for investigation of the complex binding interactions. In order to fully understand the mechanism of action of the pharmacological effect by berberine, studies on the effect of berberine on the action of proteins such as various enzymes closely related to berberine-induced medicinal effects should be continued.

• Journal of Ginseng Research
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• v.46 no.3
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• pp.396-407
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• 2022

Background: Colorectal cancer (CRC) has a high morbidity and mortality worldwide. 20 (S)-ginsenoside Rh2 (G-Rh2) is a natural compound extracted from ginseng, which exhibits anticancer effects in many cancer types. In this study, we demonstrated the effect and underlying molecular mechanism of G-Rh2 in CRC cells in vitro and in vivo. Methods: Cell proliferation, migration, invasion, apoptosis, cell cycle, and western blot assays were performed to evaluate the effect of G-Rh2 on CRC cells. In vitro pull-down assay was used to verify the interaction between G-Rh2 and Axl. Transfection and infection experiments were used to explore the function of Axl in CRC cells. CRC xenograft models were used to further investigate the effect of Axl knockdown and G-Rh2 on tumor growth in vivo. Results: G-Rh2 significantly inhibited proliferation, migration, and invasion, and induced apoptosis and G₀/G₁ phase cell cycle arrest in CRC cell lines. G-Rh2 directly binds to Axl and inhibits the Axl signaling pathway in CRC cells. Knockdown of Axl suppressed the growth, migration and invasion ability of CRC cells in vitro and xenograft tumor growth in vivo, whereas overexpression of Axl promoted the growth, migration, and invasion ability of CRC cells. Moreover, G-Rh2 significantly suppressed CRC xenograft tumor growth by inhibiting Axl signaling with no obvious toxicity to nude mice. Conclusion: Our results indicate that G-Rh2 exerts anticancer activity in vitro and in vivo by suppressing the Axl signaling pathway. G-Rh2 is a promising candidate for CRC prevention and treatment.

• Journal of Life Science
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• v.32 no.2
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• pp.167-174
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• 2022

In modern society, interest in antioxidants is increasing as the stress caused by oxidants increases. However, the demand for synthetic antioxidants is decreasing because some studies have confirmed that they are harmful when consumed in large quantities; thus, studies on antioxidants derived from natural substances are actively being conducted to replace synthetic antioxidants. Blueberry, known as one of the world's top ten long-lived foods, is a plant of the Vaccinium (Ericaceae) family, and various pharmacological activities of blueberry including antioxidant activity have been studied. Vaccinium oldhamii (VO) is a deciduous broad-leaved shrub in the same genus as blueberries, and in this paper, we summarize the studies on the efficacy analysis of VO extracts and purified products. The content of phenolic compounds in VO fruits was proportional to antioxidant and anti-influenza activity such as the inhibition of NO production, and the total content of polyphenols and anthocyanin was higher than that in blueberries. VO fruit extracts showed anti-inflammatory activity and anti-cancer activity against human acute leukemia; in contrast, VO branch extracts showed anti-inflammatory activity, activity to inhibit osteoclast differentiation and bone resorption due to inflammatory response, and anti-cancer activity against several human cancer cell lines. Compared to blueberries, VO showed higher phenolic compound content, antioxidant activity, and various physiological activities. In addition, VO is considered to have sufficient value as an alternative crop to blueberries, such as it can be grown natively in Korea, with simple mass cultivation and no need to pay royalties for commercialization.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.147-155
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• 2022

In this study, we developed a system to dynamically balance a daily stock portfolio and performed trading simulations using gradient boosting and genetic algorithms. We collected various stock market data from stocks listed on the KOSPI and KOSDAQ markets, including investor-specific transaction data. Subsequently, we indexed the data as a preprocessing step, and used feature engineering to modify and generate variables for training. First, we experimentally compared the performance of three popular gradient boosting algorithms in terms of accuracy, precision, recall, and F1-score, including XGBoost, LightGBM, and CatBoost. Based on the results, in a second experiment, we used a LightGBM model trained on the collected data along with genetic algorithms to predict and select stocks with a high daily probability of profit. We also conducted simulations of trading during the period of the testing data to analyze the performance of the proposed approach compared with the KOSPI and KOSDAQ indices in terms of the CAGR (Compound Annual Growth Rate), MDD (Maximum Draw Down), Sharpe ratio, and volatility. The results showed that the proposed strategies outperformed those employed by the Korean stock market in terms of all performance metrics. Moreover, our proposed LightGBM model with a genetic algorithm exhibited competitive performance in predicting stock price movements.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.12
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• pp.499-508
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• 2022

A lot of research has been carried out on the Hangeul generation model using deep learning, and recently, research is being carried out how to minimize the number of characters input to generate one set of Hangul (Few-Shot Learning). In this paper, we propose a CKFont2 model using only 14 letters by analyzing and improving the CKFont (hereafter CKFont1) model using 28 letters. The CKFont2 model improves the performance of the CKFont1 model as a model that generates all Hangul using only 14 characters including 24 components (14 consonants and 10 vowels), where the CKFont1 model generates all Hangul by extracting 51 Hangul components from 28 characters. It uses the minimum number of characters for currently known models. From the basic consonants/vowels of Hangul, 27 components such as 5 double consonants, 11/11 compound consonants/vowels respectively are learned by deep learning and generated, and the generated 27 components are combined with 24 basic consonants/vowels. All Hangul characters are automatically generated from the combined 51 components. The superiority of the performance was verified by comparative analysis with results of the zi2zi, CKFont1, and MX-Font model. It is an efficient and effective model that has a simple structure and saves time and resources, and can be extended to Chinese, Thai, and Japanese.

• Analytical Science and Technology
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• v.19 no.4
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• pp.290-300
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• 2006

Disinfection by-products(DBPs), such as volatile trihalomethanes and the nonvolatile organochlorine acids, created by chlorination have been extensively studied. However MX which contributes 20-50% of the mutagenic activity in drinking water began to people's attention since 1990. Its chemical name is 3-chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone. According to WHO guidelines its concentration should be controlled, but its value has not been set up. Due to analytical difficulties in measuring this compound at such a low concentrations and lack of information on toxicity to human. Because concentration (ng/L) of MX in drinking water is low traditional testing methods are ineffective. Therefore this study compared LLE and SPE and have chosen SPE to improve preconcentration. MX has been identified in chlorinated drinking water samples in several countries but not in korea Therefore this study analyzed concentration of MX in different water sources and in spring water. This study examined the causes of changing MX content. Chlorine dosage, seasons, water temperature and distance from the source was all discoverd to be relavant. MX was analyzed in various treatment to find optimum disinfection methods. The outcome was that the concentration of MX was minimized when using biological activated carbon-O3 and granular activated carbon.

• Analytical Science and Technology
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• v.20 no.5
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• pp.361-369
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• 2007

Uncomfortable odor emitted from air conditioning system is the main cause of indoor air quality deterioration. To solve evaporator odor problems, odor active compounds, have to be identified then the quality of the product can be improved its quality. Because evaporator odor in exhaust gas has low odor intensity and discontinuity, it is very difficult to collect and analyze sample. In this study through the identification of odor compounds in condensed water, the evaluation of the eraporator was tested. Odor compounds were extracted from water by headspace-solid-phase microextraction (HS-SPME) method. The single odor was separated by GC/FID/Olfactometry (GC/FID/O) and odor active compounds were identified by GC/AED and GC/MS. Compared to air sample, result of sensory evaluation and the single odor compound appeared similarly. It was identified that odor active compounds have functional group containing oxygen such as alcohols and acids. Evaluation method of odor active compounds using condensed water in evaporator appeared effective on the side of simplicity of collection, low expanse and rapid analysis.

• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.353-362
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• 2023

TOC, which can measure more than 90% of organic substances, can be measured quickly and easily,replacing BOD and COD, which were indicators of organic pollutants. According to water quality pollution control standards, when measuring TOC, if the inorganic carbon ratio in the sample is over 50%, the NPOC (Non-Purgeable Organic Carbon) method should be used. If volatile organic compounds (VOCs) are present at a certain concentration, the TC-IC (subtracting inorganic carbon from total carbon) method should be used. To validate the limitations of these analytical conditions, experiments were conducted by varying the ratio of TOC to IC in purified water and measuring the concentration of TOC in test solutions. The results showed no significant difference between the TC-IC method and the NPOC method. When measuring samples with added VOC standard solutions, it was observed that the carbon loss due to purging was not significant when using the NPOC method. Therefore, it is concluded that the choice of analytical method does not lead to significant differences when VOCs are present in the sample. To account for potential variations in results based on water quality pollution control standards and regulations regarding the approval and testing of environmental measurement devices, a comparison of field sample concentration values was made using two widely used types of TOC analyzers in Korea. The results showed variations of 0.02 to 0.83 mg/L between methods depending on the manufacturer, highlighting the need for caution when selecting an instrument.