• Journal of agriculture & life science
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• 제53권2호
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• pp.121-129
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• 2019

This study carried out to determine control factors for the improvement of productivity of laying hens suffering heat stress during hot weather. A total of 48,451 ISA Brown layers were housed in a farm located in Gyeongsangnam-do, Republic of Korea. Five thermo-hydrometer loggers were installed inside the house to collect data of dry-bulb temperature and relative humidity. The experiment continued for 81 days when the summer season begins from 19th June to 7th September, 2018. This study analyzed the correlations among layers' production index and daily average, highest, and lowest temperature; daily average, highest, and lowest relative humidity; and daily average, minimum, and maximum THI. The result indicated that feed consumption, hen-day egg production, egg weight, and FCR decreased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.01). On the other hand, water intake increased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.001). The relative humidity was not considered to have direct correlations to the layers' production index (p>0.05). However, it was noticeable that the mortality did not have significant relations with daily average and highest temperature; THI; or daily average, highest and lowest relative humidity while it was relevant to the daily lowest temperature and THI (p<0.05). In conclusion, to enhance the productivity of laying hens in a hot climate, it is recommended that daily average, highest, and lowest dry-bulb temperature and THI are maintained as low as possible. Especially, the daily lowest temperature is needed to lower to 20℃, which is the lowest critical temperature for layers.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• 제15권6호
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• pp.135-154
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• 2020

This paper analyzes the 5,521 samples of the small and medium-sized businesses(SMBs) obtained from the Korea Credit Guarantee Fund. From January 2014 to September 2019, 85% of the SMBs have 5 or fewer full-time employees. The proportion of SMBs is overwhelmed by the elderly men, and most founders are the CEO. Also, about 87% of the workplace types are rented, while 64% of the CEO's residence types are owner-occupation. 47% of the financial grade score is less than 10 points out of 100 and 80% of SMBs have less than 200 million won of the loan guarantee. In particular, the total guarantee loan amount or the days of net guarantee have significantly positive relations with the working period of the CEO in the same industry, the number of employees, the operation period of SMBs, and the corporate business type. In the case of the financial grading score which has the highest weight in overall credit rating gets higher with the higher number of employees, the longer the operation period, and the corporate business type. However, the quantified non-financial grading score has no significant relationship with other explanatory variables, except for the corporate business type. This implies that a non-financial grade score is measured by other determinants that are not observed by the Korea credit guarantee fund. The pure non-financial grade score has positive relations with the working period of the CEO. Overall, this paper would help Korean SMBs upgrade their credit ratings and expand the money supply when there is no standardized credit rating model or no publicly available evaluation criteria for SMBs. We expect this paper provides important insights for further research and policy-makers for SMBs. In particular, to address the financial needs of thin-filers such as SMBs, technology-based financial services (TechFin) would use alternative data to evaluate the financial capabilities of thin-filers and to develop new financial services.

• The Korean Journal of Nuclear Medicine Technology
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• 제25권1호
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• pp.21-28
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• 2021

Purpose Brown fat, or brown adipose tissue (BAT), is involved in non-shivering thermogenesis and creates heat through glucose metabolism. BAT activation occurs stochastically by internal factors such as age, sex, and body mass index (BMI) and external factors such as temperature and environment. In this study, as a retrospective, electronic medical record (EMR) observation study, statistical analysis is conducted to confirm BAT activation and various factors. Materials and Methods From January 2018 to December 2019, EMR of patients who underwent PET/CT scan at the National Cancer Center for two years were collected, a total of 9155 patients were extracted, and 13442 case data including duplicate scan were targeted. After performing a univariable logistic regression analysis to determine whether BAT activation is affected by the environment (outdoor temperature) and the patient's condition (BMI, cancer type, sex, and age), A multivariable regression model that affects BAT activation was finally analyzed by selecting univariable factors with P<0.1. Results BAT activation occurred in 93 cases (0.7%). According to the results of univariable logistic regression analysis, the likelihood of BAT activation was increased in patients under 50 years old (P<0.001), in females (P<0.001), in lower outdoor temperature below 14.5℃ (P<0.001), in lower BMI (P<0.001) and in patients who had a injection before 12:30 PM (P<0.001). It decreased in higher BMI (P<0.001) and in patients diagnosed with lung cancer (P<0.05) In multivariable results, BAT activation was significantly increased in patients under 50 years (P<0.001), in females (P<0.001) and in lower outdoor temperature below 14.5℃ (P<0.001). It was significantly decreased in higher BMI (P<0.05). Conclusion A retrospective study of factors affecting BAT activation in patients who underwent PET/CT scan for 2 years at the National Cancer Center was conducted. The results confirmed that BAT was significantly activated in normal-weight women under 50 years old who underwent PET/CT scan in weather with an outdoor temperature of less than 14.5℃. Based on this result, the patient applied to the factor can be identified in advance, and it is thought that it will help to reduce BAT activation through several studies in the future.

• Journal of Nutrition and Health
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• 제55권1호
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• pp.101-119
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• 2022

Purpose: This study examined the demographics, health status, dietary habits, energy, nutrient intake, and protein intake based on levels of inclusion of animal food among females in their 20s by using data from the 7th Korea National Health and Nutrition Examination Survey. Methods: The subjects (n = 912) were divided into 4 groups according to the frequency of animal foods consumed which were categorized as meat, seafood, eggs, and dairy products, or other animal-derived foods. Results: The subjects with a lower frequency of animal food intake ate out less frequently. As the frequency of animal food intake decreased, the total energy intake too decreased with higher carbohydrate and lower protein intake ratios. In the low frequency of animal food intake group, a higher proportion of subjects had energy intake below the estimated energy requirement and the intake of protein, vitamin B₁, vitamin B₂, niacin, calcium, phosphorus, and iron were below the estimated average requirements. The average protein intake was more than the recommended 45 g in all four groups. However, the lower the frequency of animal food intake, the higher the proportion of people having lower protein intake compared to the recommended intake of 0.91 g per kg body weight. It became apparent that people who do not consume animal foods at all did not meet the recommended levels of protein intake. Thus, people pursuing a vegan diet may be at risk of low protein intake. Conclusion: This study suggests that economic characteristics, dietary habits, energy, and nutrient intake are affected by the frequency of animal food consumed, or in other words, by the degree of vegetable-centered diet. Thus, this study would help improve the perception of vegetarianism, develop individualized dietary guidance and nutrition education programs for people practicing vegan or vegetarian diets to ensure that they have a balanced diet.

• Journal of the Korean Chemical Society
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• 제65권3호
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• pp.197-202
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• 2021

In this study, activated clay treated with H₂SO₄ (20% by weight) and heat at 90 ℃ for 8 h for acid white soil was used as an adsorbent for the removal of PO₄^3--P in water. Prior to the adsorption experiment, the characteristics of activated clay was examined by X-ray Fluorescence Spectrometry (XRF) and BET surface area analyser. The adsorption of PO₄^3--P on activated clay was steeply increased within 0.25 h and reached equilibrium at 4 h. At 5 mg/L of low PO₄^3--P concentration, roughly 98% of adsorption efficiency was accomplished by activated clay. The adsorption data of PO₄^3--P were introduced to the adsorption isotherm and kinetic models. It was seen that both Freundlich and Langmuir isotherms were applied well to describe the adsorption behavior of PO₄^3--P on activated clay. For adsorption PO₄^3--P on activated clay, the Freundlich and Langmuir isotherm coefficients, K_F and Q, were found to be 8.3 and 20.0 mg/g, respectively. The pseudo-second-order kinetics model was more suitable for adsorption of PO₄^3--P in water/activated clay system owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal than the pseudo-first-order kinetics model. The results of study indicate that activated clay could be used as an efficient adsorbent for the removal of PO₄³-P from water.

• Journal of Korean Society of Forest Science
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• 제111권4호
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• pp.548-556
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• 2022

In this study, basic data were obtained to determine the optimal cultivation method to achieve stable fruiting and yield increase in "Cheonhwang" jujube trees. Accordingly, thefructification, fruit characteristics, and yield according to tree age were analyzed. The mean (and range of) tree height, crown area, stem diameter near the root, clear stem length, number of main branches, and distance between main branches were 235.6 (217.4-253.8) cm, 3.5 (3.1-4.1) m², 5.5 (4.0-7.1) cm, 70.6 (66.2-72.7) cm, 9.7 (8.6-10.5), and 10.4 (7.9-14.2) cm, respectively. Correlationanalysis results indicated that tree age was positively correlated with crown area, stem diameter near the root, and clear stem length but not with the number of main branches. The mean number (and range) of fruit per fruit-bearing mother shoot and tree were 18.3 (16.7-18.3) and 170.7 (157.9-178.3), respectively. Tree age was not significantlycorrelated with fruiting characteristics (i.e., the numbers of fruit-bearing mother shoots per main branch, fruit-bearing shoots per fruit-bearing mother shoot, fruit per fruit-bearing shoot, and fruit per tree). Given that the shape of jujube trees is constantly managed according to the growing area and greenhouse type, the tree growth characteristics were more affected by tree management techniques than by tree age. The mean (and range of) fruit weight, fruit hardness, and soluble solid content were 28.6 (27.7-30.3) g, 29.4 (28.5-30.4) N, and 20.4 (19.3-21.0) °brix, respectively, and these fruit characteristics were not significantly correlated with tree age.The average yield per tree of the 'Cheonhwang' jujube cultivar was 4.9 (4.8-5.0) kg, which was not significantly correlated with tree age.

• Journal of the Korea Organic Resources Recycling Association
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• 제29권4호
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• pp.67-76
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• 2021

Biogasification is a technology that produces environmentally friendly fuel using methane gas generated in the process of stably decomposing and processing organic waste. Biogasification is the most used method for energy conversion of organic waste with high moisture content, and is a useful method for organic waste treatment following the prohibition of direct landfill (2005) and marine dumping (2013). Due to African Swine Fever (ASF), which recently occurred in Korea, recycling of wet feed is prohibited, and consumers such as dry feed and compost are negatively recognized, making it difficult to treat food waste. Accordingly, biogasification is attracting more attention for the treatment and recycling of food waste. Korea's energy consumption amounted to 268.41 106toe, ranking 9th in the world. However, it is an energy-poor country that depends on foreign imports for about 95.8% of its energy supply. Therefore, in Korea, the Renewable Energy Portfolio Standard (RPS) is being introduced. The domestic RPS system sets the weight of the new and renewable energy certificate (REC, Renewable energy certificate) of waste energy lower than that of other renewable energy. Therefore, an additional incentive system is required for the activation of waste-to-energy. In this study, the operation of an anaerobic digester that treats food waste, food waste Leachate and various organic wastes was confirmed. It was intended to be used as basic data for preparing the waste-to-energy incentive system through precise monitoring for a certain period of time. Four sites that produce biogas from organic waste and use them for power generation and heavy gas were selected as target facilities, and field surveys and sampling were conducted. Basic properties analysis was performed on the influent sample of organic waste and the effluent sample according to the treatment process. As a result of the analysis of the properties, the total solids of the digester influent was an average of 12.11%, and the volatile solids of the total solids were confirmed to be 85.86%. BOD and CODcr removal rates were 60.8% and 64.8%. The volatile fatty acids in the influent averaged 55,716 mg/L. It can be confirmed that most of the volatile fatty acids were decomposed and removed with an average reduction rate of 92.3% after anaerobic digestion.

• Korean Journal of Ecology and Environment
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• 제55권2호
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• pp.120-131
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• 2022

Microcystins (MCs) are cyano-toxins mainly produced by cyanobacteria in the genera of Microcystis, Anabaena, and Oscillatoria. The concentrations of MCs in the water bodies and fish tissues taken from the four weirs (Ipo, Gangjeong-goryeong, Baekje, and Juksan) in the four main rivers in Korea, and the health risk of human due to consumption of toxin-detected fish was examined. The maximum values of MCs concentration in the water samples were as follows: Juksan (3.261 ㎍ L^-1), Gangjeong-goryeong (1.014 ㎍ L^-1), Baekje (0.759 ㎍ L^-1), and Ipo (0.266 ㎍ L^-1) weirs. The MC-RR concentration was the highest among the MCs, and MC-YR was not detected. MCs of 0.222~9.808 ㎍ g^-1 dry weight were detected in the liver of 3 out of 215 fishes of 16 species, and below the detection limit in muscle. As a result of comparing the feeding characteristics of the collected fishes and toxin concentrations in water and fish tissue, it was concluded that the biomagnification of MCs through the food chain did not occur. It was judged that there was no health risk due to the consumption of the fish detected the toxin, based on the amount of the fish intake of the Korean people and the allowable daily intake of MCs. However, in order to reduce the health risk due to MCs, further studies should be conducted to analyze the concentration of MCs contained in fish tissues collected at various times in the area dominated by harmful cyanobacteria to obtain data on the exposure of MCs due to fish consumption. In addition, it is necessary to establish the management guidelines for MCs in fish tissues.

• Journal of Nutrition and Health
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• 제56권2호
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• pp.168-183
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• 2023

Purpose: Cardiovascular disease is one of the major causes of death not only in Korea but also worldwide. Atherogenic index of plasma (AIP) has been extensively investigated, but studies on nutritional intake and eating habits are scarce. The purpose of this study was to analyze the general characteristics, dietary habits, and nutritional status of Korean adults based on their AIP values using data from the 2013-2015 Korea National Health and Nutrition Examination Survey. Methods: A total number of 3,040 adults in their 20s and 30s were included as study subjects. They were divided into quintiles according to their AIP values. Comparisons were then made among the general information, eating habits, and nutritional intake statuses of the groups. Results: The averages of AIP were different by age, obese status, education, occupation, alcohol drinking frequency, smoking, and exercise in men. As for women, the averages of AIP were different by age, obese status, education, occupation, alcohol drinking frequency, and smoking status. Except for high-density lipoprotein (HDL)-cholesterol, higher AIP values in men were associated with significant increasing trends in health indicators, including systolic and diastolic blood pressure, fasting blood glucose, insulin, hemoglobin A1c, total cholesterol, triglyceride, and low-density lipoprotein (LDL)-cholesterol. As for women, as AIP increased, systolic and diastolic blood pressure, fasting blood glucose, insulin, total cholesterol, triglyceride, and LDL-cholesterol showed significant increasing trends except HDL-cholesterol. HDL-cholesterol showed a significant decreasing trend as AIP increased in men and women. In the high AIP group of women, the frequency of breakfast was lower, whereas the frequency of alcohol beverage consumption was higher. Conclusion: Among young adults, the risk of arteriosclerosis was higher in obese, smoking, and non-exercise individuals. More frequent alcohol drink consumption in women is associated with a higher risk of arteriosclerosis. Therefore, weight and lifestyle management are necessary for the prevention of atherosclerosis among young adults.

• Journal of Nutrition and Health
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• 제56권1호
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• pp.54-69
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• 2023

Purpose: Proteins are major components of the body and essential nutrients for proper growth and development. However, studies on protein intake in children and adolescents are insufficient. A few previous studies have reported the relationship with growth indicators, but results vary depending on the source of protein. Therefore, the current study investigates the relationship between protein intake and overweight and obesity among children and adolescents in Korea. Methods: Based on the 2014-2019 Korea National Health and Nutrition Examination Survey, 5,567 children and adolescents aged 6-18 years, who participated in a 24-hour dietary recall with information on height and weight, were included in this study. Protein intake was estimated as percentage of total energy (% of energy) and was classified into animal and plant protein according to the food source. Overweight and obesity were defined using the 2017 pediatric and adolescent growth chart. Results: Total protein intake of the subjects was estimated as 14.5% of total energy (animal protein 8.3% and plant protein 6.3%). The group with the highest total protein intake had a higher odds ratio (OR) of overweight/obesity than those with the least protein intake (OR, 1.36, 95% confidence interval (CI), 1.10-1.67, p for trend = 0.003). When classified by food source, the group with the highest animal protein intake had a significantly higher OR of overweight/obesity than subjects with the lowest intake (OR, 1.30, 95% CI, 1.05-1.61, p for trend = 0.016). However, plant protein was not significantly associated with overweight/obesity. Conclusions: These findings suggest that a high intake of animal protein in children and adolescents increases the risk of being overweight and obese. In order to develop normal growth and prevent obesity in the future, it is necessary to determine an appropriate protein intake level through nutrition education programs and prospective studies on balanced protein intake.