• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.282-291
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• 2018

The pristine fluorine-doped $SnO_2$ (abbreviated as FTO) inverse opal (IO) was developed using a 410 nm polystyrene bead template. The nanolayered copper tungsten oxide ($CuWO_4$) was decorated on the FTO IO film using a facile electrochemical deposition, subsequently followed by annealing at $500^{\circ}C$ for 90 min. The morphologies, crystalline structure, optical properties and photoelectrochemical characteristics of the FTO and $CuWO_4$-decorated FTO (briefly denoted as $FTO/CuWO_4$) IO film were investigated by field emission scanning electron microscopy, X-ray diffraction, UV-vis spectroscopy and electrochemical impedance spectroscopy, showing FTO IO in the hexagonally closed-pack arrangement with a pore diameter and wall thickness of about 300 nm and 20 nm, respectively. Above this film, the $CuWO_4$ was electrodeposited by controlling the cycling number in cyclic voltammetry, suggesting that the $CuWO_4$ formed during 4 cycles (abbreviated as $CuWO_4$(4 cycles)) on FTO IO film exhibited partial distribution of $CuWO_4$ nanoparticles. Additional distribution of $CuWO_4$ nanoparticles was observed in the case of $FTO/CuWO_4$(8 cycles) IO film. The $CuWO_4$ layer exhibits triclinic structure with an indirect band gap of approximately 2.5 eV and shows the enhanced visible light absorption. The photoelectrochemical (PEC) behavior was evaluated in the 0.5 M $Na_2SO_4$ solution under solar illumination, suggesting that the $FTO/CuWO_4$(4 cycles) IO films exhibit a photocurrent density ($J_{sc}$) of $0.42mA/cm^2$ at 1.23 V vs. reversible hydrogen electrode (RHE, denoted as $V_{RHE}$), while the FTO IO and $FTO/CuWO_4$(8 cycles) IO films exhibited a $J_{sc}$ of 0.14 and $0.24mA/cm^2$ at $1.23V_{RHE}$, respectively. This difference can be explained by the increased visible light absorption by the $CuWO_4$ layer and the favorable charge separation/transfer event in the cascading band alignment between FTO and $CuWO_4$ layer, enhancing the overall PEC performance.

• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.109-113
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• 2019

The soft rice varieties, Hangaru and Singil, were developed via mutation breeding using N-methyl-N-nitrosourea treatment to obtain dry-milled rice flours. The physicochemical, morphological, and pasting properties of these starches were compared with those of Seolgaeng and Chuchung starches. Singil starch was found to exhibit the highest amylose content and initial pasting temperature, whereas Hangaru starch exhibited the highest water binding capacity and swelling power. Hangaru starch's granule size at $d_{50}$ was the largest among the four different starch types. Some Seolgaeng, Hangaru, and Singil granules were observed to have a round-faced polygon shape. Furthermore, the crystallinity of all four starch types was type A. The peak, trough, and final viscosities of the soft rice starches were also lower than those of normal starches. Notably, Hangaru starch showed the highest breakdown viscosity, but the lowest total setback viscosity among the four starches. From these results, the starch characteristics of the soft rice flours were discovered to be different based on the rice variety.

• Journal of Ginseng Culture
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• v.3
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• pp.119-131
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• 2021

The purpose of this study was to explore the characteristics of and solution to thermogenic reactions to Korean ginseng through bibliographic research. A review of bibliography on the thermogenic reaction induced by ginseng indicated that people who lack fluids, have fever in lungs, a stuffy chest, coughing up sputum, a strong pulse, and constipation due to fever in the stomach may exhibit such a reaction. In the herbal medicine book of the Qing Dynasty, Bon-Cho-Jeong-Ui (本草正義) recorded that wild simulated ginseng is slightly cold and replenishes the body's liquid reserves. The book also describes the field cultivated ginseng is slightly warm and enhancing stamina. Bon-Kyung-Bong-Won (本經逢源), Bon-Cho-Pyon-Dok (本草便讀), and Bon-Cho-Jeong-Ui were published authors in the Qing Dynasty, and they explained that ginseng fine root is bitter, supplements bodily fluids, and can be easily ingested because it is cold. Wol-Ji-In-Sam-Jeon (月池人蔘傳) and Bon-Cho-Bi-Yo (本草備要) described fresh ginseng assweet, bitter, and slightly cold in the Ming and Qing Dynasties, respectively. On the basis of this bibliographic description, the thermogenic reaction induced by Korean ginseng can be overcome by using ginseng fine root, fresh ginseng, or wild simulated ginseng. These ginseng radices are slightly cool, replenish human bodily fluids, and show the physiological effects of easy ingestion properties.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.282-288
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• 2022

Facial masks have become indispensable in daily life to prevent infection and spread through respiratory droplets in the era of the corona pandemic. To understand how effective two different types of masks (i.e., KF-94 mask and dental mask) are in blocking respiratory droplets, i) we preferentially analyze wettability characteristics (e.g., contact angle and contact angle hysteresis) of filters consisting of each mask, and ii) subsequently observe the dynamic behaviors of microdroplets impacting at high velocities on the filter surfaces. Different wetting properties (i.e., hydrophobicity and hydrophilicity) are found to exhibit depending on the constituent materials and pore sizes of each filter. In addition, the pneumatic conditions for stably and uniformly dispensing microdroplets with a certain volume and impacting behaviors associated with the impacting velocity and filter type change are systematically explored. Three distinctive dynamics (i.e., no penetration, capture, and penetration) after droplet impacting are observed depending on the type of filter constituting the masks and droplet impact velocity. The present experimental results not only provide very useful information in designing of face masks for prevention of transmission of infectious respiratory diseases, but also are helpful for academic researches on droplet impacts on various porous surfaces.

• Korean Journal of Environment and Ecology
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• v.36 no.2
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• pp.202-216
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• 2022

Animals exhibit certain behaviors and movement patterns as they react to their internal needs, external stimuli, and surrounding environments. They have a bounded range in which they mostly spend their time, and it is referred to as a home range. Based on the fact that the home range is a critical area for the survival and preservation of species, there has been a growing body of research on developing more precise home range estimation methods to use the estimated ranges as a ground for establishing an effective conservation policy since the early 1940s. Recent rapid advancements in telemetry technology that resulted in the presence of autocorrelation between locations with short time intervals revealed the limitations of the existing estimators. Many novel estimators have been developed to compensate for it by incorporating autocorrelation in calculating home ranges. However, studies on the animal home range are still in their early stage in Korea, and newly developed methodologies have not yet been adopted. Therefore, this study aims to introduce the foreign home range estimation methods and foster domestic research activities on home ranges. Firstly, we compared and contemplated seven estimators by categorizing them into geometrical and statistical methodologies and then divided them into estimators that assume independent observations and those that consider autocorrelation in each category. After that, the home ranges of black-tailed gulls (Larus crassirostris) were calculated using GPS tracking data for the month of June and derived home range estimators by applying the methodology introduced in this study. We analyzed and compared the results to discuss the strengths and weaknesses of each method. Lastly, we proposed a guideline that can help researchers choose an appropriate estimator for home range calculation based on the animal location data characteristics and analysis purpose.

• Smart Media Journal
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• v.10 no.4
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• pp.111-120
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• 2021

This study looked at how the digital cultural heritage, which is being actively built by the government and public institutions, can be utilized in the metaverse service. Through an expert interview, we investigated how the digital cultural heritage of Bulguksa can be serviced with the four elements of the metaverse: augmented reality, mirror world, lifelogging, and virtual world. As a result of the study, it was confirmed that when digital cultural heritage is used in a virtual space called metaverse, interactive and realistic services can be provided to users. In addition, it was found that users can exhibit, experience, and educate online parts that are not available in real life in the same situation as if they were in the field. Through this, it was confirmed that if digital cultural heritage is designed as a metaverse service, it can provide functions and services of a different level than before. In particular, the result was obtained that it is possible to provide services considering the characteristics of each of the four elements of the metaverse. First, it is possible to obtain the convenience of augmenting the senses by using augmented reality, and secondly, it is possible to obtain the scalability and efficiency of reproducing the real space by using it as a mirror world element. Third, by using the lifelogging element, communication can be strengthened through the user's record and connection, and fourthly, through the virtual world element, roles and activities in the virtual world can be given to the user. Therefore, if digital cultural heritage is developed as a metaverse service in consideration of these factors, a more active and open experience environment can be provided to users.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.466-472
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• 2021

This paper aims to guide experts who manage dementia by exploring the various non-drug interventions and analyzing the effective intervention methods applicable according to the functional level of the elderly with dementia. Fourteen studies were analyzed in this study. Meta-analysis was performed using the means, standard deviations, and the number of samples. Subsequent meta-analysis showed that the Holnis program had the largest effect size in cognitive function, the bakery activity program in memory, and the composite intermediation program with ADL was the largest. In addition, client-centric cognitive stimulation interventions showed the most significant effect sizes, while in depression and BPSD, rhythmic movement activities had the most significant effect size. Elderly with dementia exhibit various symptoms depending on their characteristics and the progress of the disease. Therefore, more efficient arbitration could be provided if the effects of each intervention can be applied differently.

• Journal of Korea Entertainment Industry Association
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• v.15 no.6
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• pp.55-70
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• 2021

This study investigates the following important financial questions using entertainment enterprises: 1) how does cash reserve affect a firm's financial value? 2) what factors influence the level of cash retention of a firm? For empirical tests, we use accounting and financial data of entertainment companies listed in the KOSPI and KOSDAQ markets for a long-term time period covering from 2000 to 2018. The main findings of this paper are as follows: First, entertainment companies maintain higher level of cash holdings compared to non-entertainment companies. Second, the cash holdings of entertainment enterprises have positive influence on firms' financial value. Third, among various firm characteristics known for affecting the cash holdings level, leverage and profitability exhibit strong relationships in entertainment enterprises. Entertainment firms with lower leverage and higher profitability tend to reserve more cash inside them. These findings suggest that entertainment companies are highly valued by stock market participants as having prospective opportunities, thus, firms with sufficient cash holdings tend to have higher firm value. In addition, these findings imply that cash in entertainment enterprises functions as a substitute for debts and the cash holdings are less likely driven by agency problems.

• 한국노년학
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• v.40 no.3
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• pp.485-509
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• 2020

This study reviews empirical studies that investigated the impact of marketization of long-term care services on quality of care in Korea, England, Sweden, United States, and Japan. The trend and characteristics of marketization and regulatory system in those countries were compared. Since 2008 when long-term care insurance was introduced in Korea, we selected and reviewed empirical studies which were listed in the National Research Foundation, PubMed and Web of Science and examined the relationship between marketization and quality of care. Seven Korean, three English, two Swedish, seven American studies and one Japan study were identified and there was little evidence supporting that marketization would lead to better quality of care. Specifically, competition had no consistent relationship with quality of care while there was little evidence supporting that for-profit nursing homes tended to exhibit greater quality of care compared to non-for-profit nursing homes. The chains of for-profit nursing homes were revealed to have greater deficiencies. The findings of this review imply that improvement of quality of care may not be achieved by making for-profit nursing homes have chains. Reconstruction of nursing home markets should be needed, and the number and the proportion of public and non-for-profit nursing homes should be increased.

• Journal of Pharmacopuncture
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• v.26 no.1
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• pp.27-37
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• 2023

Objectives: Moroccan Arbutus unedo is an essential medicinal plant; however, little is known about the biological properties of its leaves mentioned in Moroccan traditional medicine. Methods: Various standard experiments were performed to evaluate the phytochemical, antidiabetic, antioxidant, antibacterial, and acute and sub-chronic toxicity characteristics of A. unedo leaves. Results: Phytochemical screening led to the identification of several phytochemical classes, including tannins, flavonoids, terpenoids, and anthraquinones, with high concentrations of polyphenols (31.83 ± 0.29 mg GAEs/g extract) and flavonoids (16.66 ± 1.47 mg REs/g extract). Further, the mineral analysis revealed high levels of calcium and potassium. A. unedo extract demonstrated significant antioxidant and anti-diabetic activities by inhibiting α-amylase (1.350 ± 0.32 g/mL) and α-glucosidase (0.099 ± 1.21 g/mL) compared to the reference drug Acarbose. Also, the methanolic extract of the plant exhibited significantly higher antibacterial activity than the aqueous extract. Precisely, three of the four examined bacterial strains exhibited substantial susceptibility to the methanolic extract . Minimum bactericidal concentration (MBC)/minimum inhibitory concentration (MIC) values indicated that A. unedo harbor abundant bactericidal compounds. For toxicological studies, mice were administered with A. unedo aqueous extract at single doses of 2,000 and 5,000 mg/kg. They did not exhibit significant abnormal behavior, toxic symptoms, or death during the 14-day acute toxicity test and the 90-day sub-chronic toxicity test periods. The general behavior, body weight, and hematological and biochemical status of the rats were assessed, revealing no toxicological symptoms or clinically significant changes in biological markers observed in the mice models, except hypoglycemia, after 90 days of daily dose administration. Conclusion: The study highlighted several biological advantages of A. unedo leaves without toxic effects in short-term application. Our findings suggest that conducting more comprehensive and extensive in vivo investigations is of utmost importance to identify molecules that can be formulated into pharmaceuticals in the future.