• Molecules and Cells
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• v.45 no.12
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• pp.896-910
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• 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and potentially fatal virus. So far, most comprehensive analyses encompassing clinical and transcriptional manifestation have concentrated on the lungs. Here, we confirmed evident signs of viral infection in the lungs and spleen of SARS-CoV-2-infected K18-hACE2 mice, which replicate the phenotype and infection symptoms in hospitalized humans. Seven days post viral detection in organs, infected mice showed decreased vital signs, leading to death. Bronchopneumonia due to infiltration of leukocytes in the lungs and reduction in the spleen lymphocyte region were observed. Transcriptome profiling implicated the meticulous regulation of distress and recovery from cytokine-mediated immunity by distinct immune cell types in a time-dependent manner. In lungs, the chemokine-driven response to viral invasion was highly elevated at 2 days post infection (dpi). In late infection, diseased lungs, post the innate immune process, showed recovery signs. The spleen established an even more immediate line of defense than the lungs, and the cytokine expression profile dropped at 7 dpi. At 5 dpi, spleen samples diverged into two distinct groups with different transcriptome profile and pathophysiology. Inhibition of consecutive host cell viral entry and massive immunoglobulin production and proteolysis inhibition seemed that one group endeavored to survive, while the other group struggled with developmental regeneration against consistent viral intrusion through the replication cycle. Our results may contribute to improved understanding of the longitudinal response to viral infection and development of potential therapeutics for hospitalized patients affected by SARS-CoV-2.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.257-265
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• 2023

The purpose of this study was to vaccinate every year according to the general characteristics of COVID-19, whether to vaccinate every year according to the vaccination experience, whether to vaccinate every year according to knowledge/attitude about vaccination, and negative responses to the vaccinate every year In order to understand the factors affecting the vaccination physician every year by identifying the factors of Statistical analysis is based on general characteristics, variables based on vaccination experience, and knowledge/attitudes related to vaccination. The doctor calculates the frequency and percentage, A square test (-test) was performed, and if the chi-square test was significant but the expected frequency was less than 5 for 25% or more, a ratio difference test was performed with Fisher's exact test. Through multiple logistic regression analysis using variables that were significant in simple analysis, a predictive model for future vaccination and the effect size of each independent variable were estimated. As statistical analysis software, SAS 9.4 (SAS Institute Inc., Cary, NC, USA) was used, and because the sample size was not large, the significance level was set at 10%, and when the p-value was less than 0.10, it was interpreted as statistically significant. In the simple logistic regression analysis, the reason why they answered that they would not be vaccinated every year was that they answered 'to prevent infection of family and hospital guests' rather than 'to prevent my infection' as the reason for the vaccination. It was 11.0 times higher and 3.67 times higher in the case of 'for the formation of collective immunity of the local community and the country'. The adverse reactions experienced after the 1st and 2nd vaccination were 8.42 times higher in those who did not experience pain at the injection site than those who did not, 4.00 times higher in those who experienced swelling or redness, and 5.69 times higher in those who experienced joint pain. There was a 5.57 times higher rate of absenteeism annually than those who did not. In addition, the more anxious they felt about vaccination, the more likely they were to not get the vaccine every year by 2.94 times.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.15-25
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• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.1-17
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• 2023

With the recent rapid development of ICT(Information and Communication Technology) and the popularization of digital devices, the size of the online market continues to grow. As a result, we live in a flood of information. Thus, customers are facing information overload problems that require a lot of time and money to select products. Therefore, a personalized recommender system has become an essential methodology to address such issues. Collaborative Filtering(CF) is the most widely used recommender system. Traditional recommender systems mainly utilize quantitative data such as rating values, resulting in poor recommendation accuracy. Quantitative data cannot fully reflect the user's preference. To solve such a problem, studies that reflect qualitative data, such as review contents, are being actively conducted these days. To quantify user review contents, text mining was used in this study. The general CF consists of the following three steps: user-item matrix generation, Top-N neighborhood group search, and Top-K recommendation list generation. In this study, we propose a recommendation algorithm that applies an extended similarity measure, which utilize quantified review contents in addition to user rating values. After calculating review similarity by applying TF-IDF, Word2Vec, and Doc2Vec techniques to review content, extended similarity is created by combining user rating similarity and quantified review contents. To verify this, we used user ratings and review data from the e-commerce site Amazon's "Health and Personal Care". The proposed recommendation model using extended similarity measure showed superior performance to the traditional recommendation model using only user rating value-based similarity measure. In addition, among the various text mining techniques, the similarity obtained using the TF-IDF technique showed the best performance when used in the neighbor group search and recommendation list generation step.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.103-114
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• 2011

The present survey was conducted to investigate effects of weaning age on market weights of steers and calf mortality in Hanwoo. Eight hundred and sixty-two Hanwoo cow-calf operations from all nine provinces were surveyed via personal interviews. The number of farms categorized by herd (heifer plus cow) size were 188, 364, 227 and 83 for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. Approximate 40% of farms surveyed weaned calves at three months of age. The percentages of farms weaning calves over three months of age were 53.5%, 37.5%, 43.7% and 39.0% for <20 heads, 20~49 heads, 50~99 heads and >100 heads, respectively. The herd size did not affect market weights of Hanwoo steers. However weaning age was negatively correlated to carcass weight of Hanwoo steers, showing that as weaning age decreased, carcass weights of Hanwoo steers increased. The average calf mortality was 5.6% and the herd size did not affect calf mortality. But weaning age was shown to be positively correlated to calf mortality and the rate of diarrhea that caused calf death, suggesting that as weaning age decreased, calf mortality and the rate of diarrhea decreased. Overall, the results of present study suggest that a decrease of calf weaning age in Hanwoo can increase the profit of Hanwoo cow-calf operations by increasing carcass weight of Hanwoo steers and by decreasing calf mortality.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.37-53
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• 2014

The purpose of this research is to find what difficulties the agricultural successors, the Korea National College of Agriculture and Fisheries (KNCAF) graduates, face with in implementing eco-friendly agriculture in Jeju, and what solutions they can be provided with. This research, a case study on the basis of open-ended survey questions, has 6 cases out of 8 graduates who have or had implemented eco-friendly citrus farming. In Jeju, 24 graduates have involved in citrus farming. According to the case study, only one case was environment-friendly farming method at the pesticide-free level, and the others at organic farming level. All the cases have tried to alter main crops or to diversify management for coping with global climate change and market-opening. On analyzing operating cost to gain product of merchantable quality, it revealed that the environment-friendly farming method needs much more managing efforts than the conventional farming does. But to the contrary, the materials cost in the environment-friendly farming method was lower than in the conventional farming method. In the total production and the price, the environment-friendly farming was 20~50% lower and 10~50% higher than the conventional farming, respectively. Difficulties which the graduates confronted with in implementing the environment-friendly agriculture are as below. Firstly, many of the difficulties have resulted from lack of the environment-friendly farming techniques, and the high cost of farm scale improvement due to high price of land and topographical features of Jeju. Secondly, the agricultural successors, the KNCAF graduates, have trouble in obtaining approval of their parents to changeover from the conventional farming to the environment-friendly farming. Lastly, there is no advisory organizations and experts for environment-friendly farming in the given area. For shift to the environment-friendly farming, followings are needed. Agricultural Technology & Extension center, with cooperation of leading farms in environment-friendly farming, should have a key role in offering education and consults on the environment-friendly farming techniques. Also, this organization should inform rapidly the research results to the farmers, and their feed-back should be involved in the next research. Therefore, it is suggested that the forum called 'Environment-friendly Organic Farming Forum in Jeju' tentatively is organized.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.123-130
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• 2013

The present study was conducted to investigate effects of feeding concentrate on development of intestinal tract and composition of muscle in suckling Hanwoo calves before weaning(60 days of age). Twenty-four Hanwoo calves(12 heifers and 12 bulls) at six days of age were randomly assigned to one of three dietary treatments[hay and two levels(low and high) of concentrate feeding] and given each diet with free access to their dams for suckling until 60 days of age. At 60 days of age, two calves from each treatment were used for post-mortem examination of intestine development and chemical analysis of muscle. Feed intake between 31 and 60 days of age was significantly(P<0.05) higher for the high concentrate treatment(532.4g/d) than for other treatments(78.9 and 108.9g/d for hay and low concentrate treatments, respectively). Although feed intake showed a large difference between the low and high concentrate treatments, body weights at birth and 60 days of age were similar between the treatments, suggesting that calves in the low concentrate feeding were supplied more milk from their dams than those in the high concentrate feeding. The ratio of intestine weight to body weight at 60 days of age was increased in the high concentrate(3.35%), compared with those in the hay(2.93%) and low concentrate(3.03%) treatments. The chemical composition of muscle in sirloin and hind leg was not affected by the treatments. In conclusions, the results of the present study showed that feeding concentrate to Hanwoo calves before weaning might stimulate intestine development relative to feeding hay.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.193-206
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• 2014

The objectives of the project are to increase farmers' income through GAP and to reduce the loss of agricultural produce, for which the Korean partner takes a role of transferring needed technologies to the project site. To accomplish the project plan, it is set to implement the project with six components: construction of buildings, installation of agricultural facilities, establishment of demonstration farms, dispatching experts, conducting training program in Korea and provision of equipments. The Project Management Committee and the Project Implementation Team are consisted of Korean experts and senior officials from Department of Agriculture, Myanmar that managed the project systematically to ensure the success of the project. The process of the project are; the ceremony of laying the foundation and commencing the construction of training center in April, 2012. The Ribbon Cutting Ceremony for the completion of GAP Training Center was successfully held under PMC (MOAI, GAPI/ARDC) arrangement in SAl, Naypyitaw on June 17, 2012. The Chairman of GAPI, Dr. Sang Mu Lee, Director General U Kyaw Win of DOA, officials and staff members from Korea and Myanmar, teachers and students from SAl attended the ceremony. The team carried out an inspection and fixing donors' plates on donated project machineries, agro-equipments, vehicles, computers and printer, furniture, tools and so forth. Demonstration farm for paddy rice, fruits and vegetables was laid out in April, 2012. Twenty nine Korean rice varieties and many Korean vegetable varieties were introduced into GAP Project farm to check the suitability of the varieties under Myanmar growing conditions. Paddy was cultivated three times in DAR and twice in SAl. In June 2012, vinyl houses were started to be constructed for raising seedlings and finished in December 2012. Fruit orchard for mango, longan and dragon fruit was established in June, 2012. Vegetables were grown until successful harvest and the harvested produce was used for panel testing and distribution in January 2013. Machineries for postharvest handling systems were imported in November 2012. Setting the washing line for vegetables were finished and the system as run for testing in June 2013. New water tanks, pine lines, pump house and electricity were set up in October 2013.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.79-94
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• 2009

The research project was conducted to develop a paper bagging machine for grape. This technology was aimed to highly reduce a labor for paper bagging in grape and bakery. In agriculture labor and farm population has rapidly decreased since 1980 in Korea so there was so limit in labor. In particular there is highly population in women and old age at rural area and thus labor cost is so high. Therefore a labor saving technology in agricultural sector might be needed to be replaced these old age with mechanical and labor saving tool in agriculture. The following was summarized of the research results for development of a paper bagging machine for grape. 1. Development of a new paper bagging machine for grape - This machine was designed by CATIA VI2/AUTO CAD2000 programme. - A paper bagging machine was mechanically binded a paper bag of grape which should be light and small size. This machine would be designed for women and old age with convenience during bagging work at the field site. - This machine was manufactured with total weight of less than 350g. - An overage bagging operation was more than 99% at the actual field process. - A paper bagging machine was designed with cartridge type which would be easily operated between rows and grape branches under field condition. - The type of cartridge pin was designed as a C-ring type with the length of 500mm which was good for bagging both grape and bakery. - In particular this machine was developed to easily operated among vines of the grape trees. 2. Field trials of a paper bagging machine in grape - There was high in grape quality as compared to the untreated control at the application of paper bagging machine. - The efficiency of paper bagging machine was 102% which was alternative tool for the conventional. - The roll pin of paper bagging machine was good with 5.3cm in terms of bagging precision. - There was no in grape quality between the paper bagging machine and the conventional method. - Disease infection and grape break was not in difference both treatments.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.118-130
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• 2005

This study was conducted to evaluate the spent composts of selenium-enriched mushrooms as a feed selenium Source. Total selenium (Se) contents and Se profiles in the spent mushroom composts (SMC) were determined. In addtion, we also investigated the metabolism in relation to Se accumulation in the mushroom. Mushrooms used in this study were Flammulina velutipes and Se enriched mushrooms were grown for 60 days by adding 2 mg of inorganic Se (Na₂SeO₃) per kg of mushroom composts (MC) on as-fed basis and it was compared with mushrooms not to add Se to the MC. Total Se contents for Se-treated mushrooms were significantly increased (P<0.0001) by 20-fold (4.51 ㎍/g of dry) compared to Se-untreated (0.23 ㎍/g of dry). On the contrary, organic Se proportion was significantly lower (P<0.0001) in the Se-treated mushroom (72.3%) than Se-untreated (100%, not analytically detected of inorganic Se). Se distribution upon a length in the Se-treated mushrooms was the highest in the bottom part (6.86 ㎍/g of dry) near to MC, and top and middle parts were significantly lower (3.71 and 3.01 ㎍/g of dry, respectively) than the bottom (P<0.001). In the SMC from Se-treated mushrooms, a high concentration of Se (5.04 ㎍/g of dry) was still remained, but that from Se-untreated mushrooms was significantly low (P<0.0001) as 0.08 ㎍/g of dry. Se-treated SMC showed a high rate of organic Se (65.67%), suggesting that most of inorganic Se in the SMC was converted to organic Se by mushroom mycelia, and Se-untreated SMC showed 100% of organic Se, not being detected of inorganic Se. Prior to mycelia inoculation in the mushroom culture, the sterilization of MC brought approximately 18% of Se loss in the MC. This result is in accordance with facts generally known that Se is weak in the high temperature and it is consequently volatilized under that condition. Apparent and net accumulation rates (%) for Se into mushrooms were 14.81 and 10.14%, respectively and their difference (4.67%) is considered that it is due to the volatilization into the air via metabolic process of mushroom itself. From the result of this study, inorganic Se addition to MC for mushroom improved the Se content in the mushroom and SMC from Se-enriched mushrooms contained a high concentration of Se. Mycelium and fruiting body from mushrooms converted inorganic Se in MC to organic Se, indicating a high proportion of organic Se in the mushroom and SMC. Therefore, Se in Se-enriched mushroom and SMC was recognized as Se sources of food for human as well as feed for livestock.